Soil formation in Central Spitsbergen – Framework for process interaction
Lomonosovfonna Icesheet
"One cannot adequately use soils for any purpose without understanding the processes and factors that control their formation." Birkeland (1974)
Draft Research thesis, MSc Earth and Environment Christian de Kleijn
1
Soil formation in Central Spitsbergen – Framework for process interaction
Research Thesis
Master ‘Earth and Environment’
With the Soil geography and landscape chairgroup
Wageningen University and Research
Author: Christian M.F.J.J. de Kleijn, BSc
WUR (900905-442060)
Supervision: Dr. Arnaud J.A.M. Temme
Examiner: Prof. dr. Jakob Wallinga
Field collegue: W. Marijn van der Meij, Msc
Version 8 – April 2016
Cover photos Figure 1: Research area (Petuniabukta and Ebba glacier) (AeroPhoto_1990_UTM33N_WGS84). Figure 2: Polar Station Adam Mickiewicz University (Poznań), built in 2011 on the eastern coast of Petuniabukta (Petuniabukta, Billefjorden in Spitsbergen: Czech−Polish long term ecological and geographical research).
2
Abstract Soil formation in Central Spitsbergen – Framework for process interaction
Aim is to identify, characterize and quantify Arctic soil forming processes and their spatial and temporal variation. The coasts of Spitsbergen mainly consist of glaciers and raised marine beaches, developed under the isostatic rebound after the Last Glacial Maximum. A chronosequence of beaches was studied to determine the spatial and temporal variation of soil forming processes in Arctic regions. The soils at 30 random and 14 judgmental locations were described and sampled. Fieldwork was performed on gravelly marine beaches and their surroundings in the Ebba valley, central Spitsbergen, with known ages ranging from 3.000 up to 15.000 years. The dependence of soil forming processes on variables such as time, morphology and vegetation cover was assessed. These processes include aeolian deposition, development of organic rich horizons, dissolution of calcaric material and the formation of calcaric pendants and silt caps. Fluvisols, gleysols, chernozems, kastanozems, phaeozems and calcisols were found besides cryosols. The relative importance of processes per landform is illustrated together with a preliminary temporal quantification. The interaction between soil moisture, vegetation, organic matter, bacterial crusts and aeolian deposition is clarified for A-horizons. For B-horizons the interaction between water, physical and chemical weathering, calcaric nodules and precipitation is described. Silt illuviation in the soil is described in a new method that uses the depth of maximum illuviation instead of horizon thickness. The distance to the river is not important for soil development and the only clay in the area originates in colluvial material. River and colluvial soils are diverse and discussed individually, but a decision tree for soil formation could be developed for marine terrace soils. The main conditions for divergent soil development are morphology, hydrology and age. The goal of quantifying weathering rates without the use of models, proved often impossible due to the large variation and influence of variables.
3
Note to the Reader Every region, every landscape, every soil has a story to tell. It truly was a pleasure to try and discover the story of the Ebba valley. The landscape is very diverse, the nature barely surviving but relatively unspoiled. The glaciers can be unforgiving, the winds were predictable but a true force to be reckoned with, and the sea, or as we called it ‘shower’, could be as intense as it seemed calm. The magnificence of waking up, because a polar bear was knocking on your window, was surreal. The combination of many of these factors created the soils, and the soils sustain complex life.
This work, my first MSc degree Thesis (36ECTS), has a broad methodology, integrational approach of many topics and summary of process interactions in the field. The feedbacks sometimes proved to be difficult to quantify or prove, but in many cases I could determine whether the egg, or the chicken, got there first. This research purposely focused on the processes that formed the valley and has a geomorphological and pedogenic view. For a modeling approach and extra information about the area, I suggest to read Marijn’s thesis (van der Meij, 2015). For geology, glaciology, meteorology and other geomorphological aspects, I suggest to find studies by the Adam Mickiewicz University.
What made this thesis difficult for me, is that pretty much every sub-topic could be researched even further, but time would not allow, for I have already spent too much on this work. Unfortunately I still tried on too many occasions. For example I now know tremendous amounts about ‘the effects of cyanobacterial communities on water processes in soil crusts in semi-arid areas’, which is not necessarily a popular topic at parties… Secondary, by far my biggest struggle, is writing in a scientific way instead of the proza that I was used to. Passion told me to write everything I know, supervisors asked me ‘Please, keep it short, please’ and ‘This is NOT a book!’. Well, I did my best... Enjoy! Word of Appreciation I would like to thank Marijn and Arnaud for helping to create this opportunity. Marijn for his very valuable help on this topic, and for becoming a friend, partially via many, many games of chess (breaks). Arnaud for very good supervision, promoting my insights and helping to form ideas. I rarely enjoyed such a stimulating collaboration. Thanks to those who survived my distractions during their work in the SGL Thesis room for their advice and humor and games of twister (breaks). Of course I want to thank the Polish team (Grzegorz Rachlewicz, Krzysztof Rymer, Jakub Małecki, Michał Rychlik, Alfred Stach and Tomasz Kurczaba), for their hospitality and knowledge but also beautiful trips and experiences and humor combined with whiskey (breaks). And thanks to my dad for his insights and passion in geology that I inherited, and for Belgium beers (breaks) to stimulate writing capabilities.
4
Contents Abstract ...... 3 Note to the Reader ...... 4 Word of Appreciation ...... 4 List of Figures ...... 7 List of Tables ...... 8 1. Introduction ...... 9 1.1 Soil research in the arctic ...... 9 1.2 Problem statement...... 10 1.3 Research objective and questions ...... 11 2. Spitsbergen ...... 12 2.1 Geology ...... 13 2.2 Climate...... 14 2.3 Soils ...... 15 2.4 Soil forming processes ...... 16 2.5 Plant life on Spitsbergen ...... 18 2.6 Influence of humans ...... 18 3. Materials and methods ...... 20 3.1 Choice of locations ...... 20 3.2 Sampling ...... 22 3.3 Laboratory analysis ...... 22 3.4 Statistics ...... 22 3.5 Time scales of soil alteration ...... 23 4. Results ...... 25 4.1 Landform characteristics ...... 25 4.2 Processes ...... 30 4.3 Terrace soil formation ...... 30
4.3.1 Unaltered parent material (C, R, I) ...... 31
4.3.2 Slightly altered parent material (BC) ...... 31
4.3.3 B-horizon (Bk, Bl, Blk) ...... 32
4.3.4 Marine A-horizon ...... 34
4.3.5 Aeolian A-Horizon ...... 36 4.4 Interactions in soils ...... 37 4.5 Other soil formation ...... 41
5
4.5.1 River soils ...... 41
4.5.2 Colluvial soils ...... 43 4.6 Soil classification (FAO) ...... 44 5. Discussion ...... 47 5.1 Wet-organism-framework ...... 47
5.1.1 Water availability ...... 47
5.1.2 The effects of soil moisture and vegetation ...... 48
5.1.3 Accumulation and preservation of organic matter ...... 49
5.1.4 Bacterial soil crusts altering the water balance ...... 49
5.1.5 Aeolian deposition dynamics ...... 50 5.2 Carbonate-dissolution-framework ...... 52
5.2.1. Water as a driving force ...... 53
5.2.2. Physical weathering and fine fraction effects ...... 53
5.2.3 Chemical weathering...... 54
5.2.4. Calcaric nodules ...... 55
5.2.5 Calcaric precipitation ...... 55 5.3 Silt redistribution ...... 55 5.4 Soil formation in marine terraces...... 56 5.5 River soils ...... 57 5.6 Colluvial soils ...... 57 6. Conclusions ...... 58 Recommendations ...... 59 Acknowledgement...... 59 References ...... 60 Appendix A – Spitsbergen soils ...... 66 Appendix B – Soil description form ...... 69 Appendix C – Background information Ebbadalen ...... 71
6
List of Figures Figure 1: Research area (Petuniabukta and Ebba glacier) (AeroPhoto_1990_UTM33N_WGS84)...... 2 Figure 2: Polar Station Adam Mickiewicz University (Poznań), built in 2011 on the eastern coast of Petuniabukta ...... 2 Figure 3: Spitsbergen during early spring. (Green and Sisson, 2016) ...... 9 Figure 4: Spitsbergen (NASA Visible Earth, 2015), Petuniabukta and surroundings, the Ebba valley (yellow)(NASA, 2009)...... 11 Figure 5: Geomorphological map of the Petuniabukta area (Karczewski et al., 1990)...... 12 Figure 6: 3D model of the Ebbadalen area by use of satellite data from 12 July 2002 by UAM (Rachlewicz, 2007b) ...... 13 Figure 7: Topview of part of the Ebbadalen. Terrace ridges without vegetation are clearly visible. ... 14 Figure 8: Relative freq. wind direction, mean wind speed, and direction at Petuniabukta (July 09-June 10) (Láska et al., 2012)...... 14 Figure 9: Calcaric nodules (yellow-white specs)(J02). Nodule intensity is level 2...... 16 Figure 10: Cryogenic processes in the topsoil. Mud boil, patterned ground with frost cracks and solifluction lobes...... 17 Figure 11: Topographical map of Petuniabukta, adjusted with largest manmade structures present during 2014. Measurement equipment such as meteorological stations were not taken into account in this map...... 19 Figure 12: Illustrations of the large impact of small topographic differences...... 21 Figure 13: Plot of OSL and C-14 datings on the terrace sequence in the Ebba valley. Error bars indicate the 95% confidence interval (2sigma). (van der Meij et al., 2015) ...... 23 Figure 14: Sample locations of soil profiles, terrace stages and theodolite...... 24 Figure 15: Catena across a marine terrace. Lowest layer is assumption based upon extrapolations. . 28 Figure 16: Three ‘typical’ soil profiles per marine terrace landform...... 28 Figure 17: A typical trough soil (R03), a typical slope soil (R22) and a typical ridge soil (R16) that are visual depictions of the summary in Table 5...... 29 Figure 18: The three types of bottom sediments. From left to right: Bed rock [R] (J5), unaltered marine sediments [C] (R23), frozen parent material [IC] (R28)...... 31 Figure 19: Slightly altered parent material BC (R11)...... 31 Figure 20: On the left the Bk-horizon (R27) where siltation can be seen without a matrix structure. On the right is a picture of the highest level (IIb) of calcaric pendants...... 32 Figure 21: Bl (R12) and Blk-horizons (R16) with silt-matrix level 6 on the left and 5 on the right...... 33 Figure 22: Thickness of Bl- and Blk-horizons of terrace landforms as a function of age...... 34 Figure 23: Presence of calcaric nodules (intensity) and the age of the soil in which they are found. .. 34 Figure 24: Two ridge soils (left R02, right R01) with their A-horizons on top of Blk-horizons...... 35 Figure 25: Gravel fraction in the marine A-horizon as function of age and landform...... 35 Figure 26: Aeolian induced armoring on a ridge...... 36 Figure 27: The vegetation cover as a function of the water availability in the top horizon, differentiated per landform...... 38 Figure 28: Aeolian A-horizon thickness as function of the vegetation cover...... 38 Figure 29: Thickness of the aeolian horizon as function of the soil moisture content...... 39 Figure 30: Aeolian A-horizon plotted against vegetation cover ...... 39 Figure 31: Aeolian A-horizon soil moisture content plotted against the organic matter content...... 40 Figure 32: Relation between silt and soil moisture content in the A-horizon...... 40 Figure 33: The relation of the silt fraction as function of the age in the B-horizon...... 41 Figure 34: Depth of maximum silt concentration as function of time for trough positions...... 41 Figure 35: Salt precipitation on top of a fluvial soil...... 42
7
Figure 36: Vegetation humps in the river area...... 42 Figure 37: Mud boil due to cryoturbation with a sharp distinction between the top and the clay rich subsoil...... 43 Figure 38: Left is a photo of typical frost cracks on a trough soil (R15). Right is a frost boil/mound on a colluvium soil (J12)...... 44 Figure 39: Left is a photo of the Blk-horizon of a very clear example of a strong calcic horizon (R01). Right is a photo of the soil profile of vegetation, two A-horizons and the Bl (R06)...... 45 Figure 40: Framework of the influence of different processes and states in the moisture-organism interactions...... 47 Figure 41: Integrational interpretation of groundwater and aeolian processes with terrace topography ...... 48 Figure 42: Bacterial crusts with vegetation patches in between. Surface cracks, lichens and some bare soil are also visible...... 50 Figure 43: Aeolian sands bury the birch-like vascular vegetation (Salix Polaris) leading to progradation of vegetation in the strongest wind direction...... 51 Figure 44: Framework of the influence of different processes and states in the calcaric weathering. 52 Figure 45: Moisture-weathering-fines feedback in terrace soils...... 54 Figure 46: Edited for Ebbadalen relevance from original (Dallmann, 2004)...... 71 Figure 47: Aerial photograph of the Ebba valley showing the location of the marine terraces and erosion gullies. The aerial photograph is from 2009 edited by Van der Meij (van der Meij, 2015). .... 72 Figure 48: Time series of daily means of global solar radiation, albedo, ground surface temperature, 2m air T., and relative humidity at Petuniabukta in the period 2008–10 (Láska et al., 2012)...... 73
List of Tables Table 1: Division of samples over the terrace strata (van der Meij, 2015)...... 20 Table 2: Soil profile distribution per landform type...... 25 Table 3: Landform characteristics of marine terrace soils...... 26 Table 4: Soil characteristics of non-terrace soils...... 26 Table 5: The diversity of soil horizons per landform...... 27 Table 6: Summarized soil forming processes, loosely based on Table 1 of van der Meij (2015)...... 30 Table 7: Distinctive B-horizons and their characteristics...... 33 Table 8: Summary of soils with an aeolian horizon per landform...... 36 Table 9: Soil type differentiation...... 56 Table 10: Soil science Spitsbergen - Literature summary ...... 66 Table 11: Soil classification (FAO) of all 44 sampled Petuniabukta soils...... 68
8
1. Introduction 1.1 Soil research in the arctic Most people rarely realize that there are developed soils in the arctic area. Pictures of vast snow covered lands, such as in Figure 3, are their first impression. Slowly that view is changing. Growing awareness of global warming and global pollution has greatly increased the general interest concerning the Polar Regions during the last decade. There is much attention in the media for the (endangered) arctic ecology, geology (fossil fuels) but also carbon storage (permafrost). The vulnerability of the region to change is highlighted more often. My interest in this topic is mostly in the field of soil research because of the following five reasons.
Figure 3: Spitsbergen during early spring. (Green and Sisson, 2016)
First, many ecosystem services a soil provides form the core of most life in the area. Most (larger) plant species need soils to grow in. In the arctic there is a clear distinction between where (vascular) plants can and cannot grow, largely depending on the soil underneath (Prach and Rachlewicz, 2012). How and when these soils develop(ed) is important to sustain the local flora and fauna and can help predict their future (Burga et al., 2010).
Second, arctic soil research is also relevant in the light of global climate change and carbon sequestration. Many arctic soils have a relatively high carbon content and especially tundra soils are globally recognized as important carbon containing areas (van der Wal et al., 2007). Arctic tundra soils, which cover a relatively small area of land, are estimated to contain about 13% of all stored soil carbon (Michaelson et al., 1996). The rates at which carbon is stored or released are valuable for climate prediction scenarios (Hitz et al., 2001, Piepjohn and Jochmann, Yoshitake et al., 2011).
Third, Arctic soil formation is more rapid than generally thought, both in soil depth (Forman and Miller, 1984, Pereverzev and Litvinova, 2010) and soil forming processes (Bockheim and Ugolini, 1990, Fischer, 1990, Mann et al., 1986, Melke and Chodorowski, 2006, Pereverzev and Litvinova, 2012) and especially for young soils (Kabala and Zapart, 2009, Kabala and Zapart, 2012). This rapid soil formation has also been noticed in mountainous environments such as in the Alps (Egli et al., 2008, Egli et al., 2014, Temme et al., 2014).
Fourth, the human influence on the arctic is a topic of great uncertainty. Pollution has a big impact in the arctic (Gulińska et al., 2003, Strzelecki, 2011). Human presence mostly has negative effects on soils and the fragile ecology in the arctic regions, as apparent in locations such as Iceland (Arnalds et
9 al., 2001), Alaska (Jorgenson et al., 2006) and parts of Russia (Olech et al., 2011, Worsley, 1986). It is valuable to monitor these changes (Tomczyk and Ewertowski, 2010).
However, human influence also has positive impacts on arctic soil development; due to the strongly increased melting rates of glaciers (Rachlewicz, 2007b) large parts of land come available for soil formation. Although on other locations the warming leads to melting permafrost, which results in strong soil degradation (Jorgenson et al., 2006). Predicting this behavior and modeling its future development require more knowledge on the local soil forming processes.
Finally, water purification is an important aspect of soils worldwide. Also in the polar climates there can be groundwater flow and thus a change in the elements in the water. Some plant species and other organisms cannot live without this groundwater flow (Dolnicki et al., 2013). A clear positive effect of the groundwater and seepage water on vegetation is found. The soil-water(-vegetation) interactions are important to study.
A very accessible region to gain better understanding of pedogenesis and soil development in the arctic region, is the Spitsbergen Archipelago. In the scope of all earlier mentioned relevant research topics, the importance of these studies are even bigger because the Spitsbergen area has a diverse geology and ecology, resulting in many topics being researched. Findings in research at Spitsbergen can be extrapolated to the rest of the Archipelago and perhaps even for other Arctic regions such as parts of Alaska, North Siberia and Greenland (Strzelecki, 2011). The research location of choice is the Ebba valley in Spitsbergen (Figure 4). 1.2 Problem statement Soil research has been performed before, mainly by Polish scientists, and a summary of the soils that have been found in Spitsbergen is included in this report (Appendix A – Spitsbergen soils). However, "Although the Svalbard archipelago was a site of early polar soil studies, the landcape remains among the least understood pedologically. Field studies have primarily examined soils in imperfectly drained sites and concluded that soils are constantly churned by cryoturbation, which inhibits the differentiation of soil horizons.” (Forman and Miller, 1984) It is traditionally assumed that one soil profile is descriptive (enough) for a whole geological unit of a certain climate, age or parent material, depending on the scale (Jenny, 1994, Scalenghe and Certini, 2007). However Klimowicz (1996a) and Klimowicz and Uziak (1996b) state that the local relief and vegetation also are important causes of local variation in between arctic soils. According to them, another interesting parameter for variation is the distance to the river.
Most soil research in the arctic region focuses on variation in time (chronosequence, e.g. terraces), large scale topography (e.g. from sea level to mountain), large scale parent material (different geomorphological units), but scarcely on the presence of vegetation (unless tundra) and other influences (Tedrow et al., 1958). While some research indeed focused on the types of soils and their age (Forman and Miller, 1984, Kabala and Zapart, 2012), others were about soil forming processes (Pereverzev, 2012, Pereverzev and Litvinova, 2012) or focused mainly on parent materials (Kabala and Zapart, 2012) and grain size distributions (Uziak et al., 1999). Most of the projects typically involved small amounts of soil pits and few were conducted near the Petuniabukta area.
Besides these more classical topics, microtopography is also suspected to play an important role in the area. Small differences in location can lead to significant differences in variables such as slope and aspect, which in turn potentially lead to large variation in soil development (Harlaar, 2015, Klimowicz, 1996a, Price, 1971, Temme et al., 2014), which has never been researched in Spitsbergen before. The spatial heterogeneity of the aeolian distribution drew my interest. Understanding the processes responsible for the aeolian horizon formation needs extra attention.
10
Especially the time scales in different processes in these annually frozen soils are apparently unknown or unlike what most would expect for example due to the lack of soil macrofauna. The various processes and process rates are rarely known and quantified for the arctic regions. According to classic theory the most distinguishing factor in our area, and so within the same polar climate, for soil types and development, would be parent material. Then topography and thus hydrology, followed by time and local differences by vegetation (Jenny, 1994). During initial soil formation varying rates in soil formation make a large difference in soil depth and soil type. The influence of organic acids, a wetter moisture regime or inflow of sediments among others, make big differences at small spatial scales.
Therefore this thesis aims to clarify soil forming processes and their spatial and temporal variation to get a better understanding of arctic soils. 1.3 Research objective and questions The research objective is “To identify, characterize and quantify soil forming processes in the arctic”. To fulfill the research objective, certain key questions are answered. They are made specific for marine terrace soils in Spitsbergen and nearby other soils are used for comparison and extrapolation.
What are the soil forming processes? At what spatial scale does each process operate? What are typical time scales for these processes?
Figure 4: Spitsbergen (NASA Visible Earth, 2015), Petuniabukta and surroundings, the Ebba valley (yellow)(NASA, 2009).
11
2. Spitsbergen The island of West-Spitsbergen is about the size of Switzerland and part of the Spitsbergen Archipelago, about 600km north of Norway to which it belongs.
For this research the field location in the Ebba valley at Petuniabukta, also known as Petunia Bay was chosen. Earlier soil research has been performed in this area. Its location is in the center of the West- Spitsbergen island, at the end of the Billefjorden (Figure 4).
The research station of the Adam Mickiewicz University lies near the sea, in the Ebbadalen (valley) which was formed by the Ebbabreen (glacier). All research was done in and around this valley at the marine terraces and surroundings. The Ebbadalen is enclosed by the glacier in the east, the mountain ridge Hult Berget (797masl) in the north and the Wordiekammen (805masl) in the south. The soil parent material is formed by marine deposits near the coast, proglacial deposits inwards in the valley up to the glacier, colluvial material near the mountains and river deposits near the Ebba (Figure 5).
Figure 5: Geomorphological map of the Petuniabukta area ( Karczewski et al., 1990 ) . The green represent the marine terraces and the pro-glacial and fluvial zones are in yellow.
12
2.1 Geology The Spitsbergen archipelago is renowned for to its huge variety in sedimentary rock units and even igneous rocks (Guterch et al., 1990, Harland et al., 1997, Holland, 1961, Kłysz, 1985, Worsley, 1986). The Petuniabukta dates from Holocene sediments to the early Carboniferous and even the Precambrian Proterozoic age. The Ebbadalen is composed of Holocene slope and marine deposits and (glacio)fluvial deposits from the Pleistocene and Holocene. The mountain ridges are mostly composed of “gypsum/anhydrite, limestone” and “multicoloured sandstone, shale, dolomite and conglomerate” from the Carboniferous (Harland et al., 1997, Ingólfsson, Kłysz, 1985, Holland, 1961). A more detailed geological description is given in Appendix C – Background information Ebbadalen.
Figure 6: 3D model of the Ebbadalen area by use of satellite data from 12 July 2002 by UAM (Rachlewicz, 2007b)
The focus of this research is mainly on the marine terraces, although some samples have been taken in nearby materials (only in purple areas, Figure 6). These terraces are comprised of gravel and coarse sand mostly of a limestone origin, but sand and gravel from shales, sandstones or even mafic intrusions can also be found. The beach sediments contain all nearby parent materials because of the (mainly glacial) erosion in the area. The sediment may contain marine fossils and because of sea induced attrition, they are generally well rounded.
There are height differences between troughs and ridges within the same terrace due to differences in abrasion and accumulation (Anderson et al., 1999). This is very clearly visible in figure 5, where on the left the normal sequence is visible. Differences between marine terraces are emphasized due to storm ridges (Karczewski et al., 1981b). The Ebbadalen terraces can be subdivided into six main terrace levels of which the age has been discussed (Bondevik et al., 1995).
The oldest marine terrace soils in the Ebba valley date from the end of the last glacial period Weichselian/Vistulian (Last Glacial Maximum - LGM). The Ebba glacier has been retreating since the LGM, leaving a pro-glacial zone of about 4km (Figure 4)(Rachlewicz et al., 2007, Zwoliński et al., 2013a). Determining the age of younger terraces has become more accurate in the last decade (Forman, 1999, Long et al., 2012) using C14-dating techniques.
13
Figure 7: Topview of part of the Ebbadalen. Terrace ridges without vegetation are clearly visible. 2.2 Climate The climate of the interior of Spitsbergen is referred to as an ‘Arctic Desert’ or (Polar) Tundra Climate (Köppen, 1931). Spitsbergen has a unique climate due to the effect of the Atlantic ocean currents (the conveyer belt) that carries relatively warm and saline Atlantic water towards the south and west coast and cold less saline polar water towards the north and east coast (Strzelecki, 2012). There are strong local deviations in local weather due to the glaciers, mountains and distance to the ocean (Láska et al., 2012, Przybylak et al., 2014, Sjöblom, 2015, Zwoliński et al., 2013a, Zwoliński et al., 2013b).
The average temperatures at the center of Spitsbergen are around -5°C annually with 5°C in July and -15°C in January. For other areas with similar latitudes such as Canada and Russia, the average temperature is at least 20°C colder during winter (Sjöblom, 2015, Zwoliński et al., 2013b). Due to its location in the high north, the area is subject to 24h of sunlight during summer and complete darkness during winter, resulting in a short growth season. Therefore the aspect of a slope might be of lesser importance than in other mountainous regions (Egli et al., 2008, Egli et al., 2014).
Due to wind tunneling the general wind directions are from the south west or north east, the direction of the valley (Figure 6, Figure 8). January is the windiest month, whilst the summer is calmest (Sjöblom, 2015, Zwoliński et al., 2013b). The wind direction changes during the day because of land/sea breeze and strong katabatic winds occur on a regular basis because of the large glacier plateaus (Lomonosovfonna)(Láska et al., 2012, Long et al., 2012, Sjöblom, 2015).
Figure 8: Relative freq. wind direction, mean wind speed, and direction at Petuniabukta (July 09-June 10) (Láska et al., 2012).
14
Annually an average 150-200mm of precipitation reaches the center of Spitsbergen, the majority falls as snow. This is an estimate because year round measurements cannot be performed due to the high energy requirement of precipitation measurements at long term temperatures down to -35°C (Láska et al., 2012). The humidity depends on the wind direction and temperature whilst mountain winds regularly raise the humidity to over a 100%, resulting in low clouds and fog. 2.3 Soils Developed soils are found on the marine terraces, tundra, flat mountain tops and some proglacial areas. By definition, nearly all soils in the arctic region are cryosols (FAO, 2006, WRB, 2014), due to the annually persisting freezing temperatures during winter and an average yearly temperature below 0°C. Arctic soil types consist of a variety of soils instead of only Cryosols (Appendix A).
In general the basic soil properties in Spitsbergen according to literature are; shallow profile with poorly differentiated genetic horizons, particle size of sand or loam, considerable silt content and considerable soil organic carbon content (Melke and Chodorowski, 2006). However there are exceptions, some marine terraces contain paleosols. Mass movements and erosion make it difficult to distinguish between recent soil formation and ancient soil formation in some areas (Kabala and Zapart, 2012, van Vliet-Lanoë, 1998). Terrace and plateau soils would be relatively deep and well developed compared to other regional soils such as the proglacial soils.
For the proglacial areas in Spitsbergen, little soil formation was predicted. There is large uncertainty and discussion about whether or not Spitsbergen was fully glaciated during the LGM (Baranowski, 1997, Birks et al., 1994, Ingólfsson and Landvik, 2013, Karczewski, 1995, Lambeck, 1995, Lambeck, 1996, Lambeck et al., 2006, Lambeck et al., 2010, Landvik et al., 1998, Mangerud et al., 1992, Mangerud and Svendsen, 1992, Musiał, 1985). Plant remains dating back to the LGM have been found (Bernardová and Košnar, 2012) and supposedly at least all of the proglacial zones were glaciated during the LGM (Rachlewicz et al., 2007). Not only this young age but also the nature of the proglacial zones often impede soil formation, its parent material consists mostly of large rocks or boulders. Yearly snow-melt peaks and debris flows or rock slides from surrounding mountains form an unstable environment (Szpikowski et al., 2014). Some soil formation can be found on flat peaks, because they are not disturbed by melt water or scree input.
Based on literature the predicted soil formation is as follows: Terrace soils in the Ebba valley are expected to mainly be affected by silt and carbonate dynamics (Forman and Miller, 1984). Cryic processes alter the soils (Kabala and Zapart, 2012) and cryoturbation will make horizon development difficult (Bockheim, 2015, van Vliet-Lanoë, 1998). Topography has strong effects on the vegetation and moisture regime (Burga et al., 2010). Also the distance to the river, the bedrock and the mountain slopes have effects on the hydrological regime of the soils (Klimowicz and Uziak, 1996b). The topsoil is prone to strong erosion due to wind, snow melt peaks, gullies and lack of vegetation (Price, 1971, Szpikowski et al., 2014).
Marine terraces often have a A,B,C horizon profile already from a young age (Kabala and Zapart, 2009). A ‘marine A-horizon’ is formed directly in the marine parent material whilst the ‘aeolian A- horizon’ formed in the aeolian deposits transported from elsewhere. They consist of windblown sediments, likely from the pro-glacial sandr, and therefore have other properties than the ‘original’ A-horizon. The B horizon according to Forman and Miller (1984) often are Bl, Bk, or Blk horizons. The l is assigned when the matrix of the (gravelly) sediments is strongly affected by the illuviating silt. The k is assigned when the calcaric pendants, that form due to precipitation of dissolved calcaric materials, are continuously covering the bottom of the gravelly sediments. The carbonate class for normal B- or BC-horizons ranges from none to Ic per definition and the silt class from none to 4 per definition. The carbonate and silt suffixes were assigned to the B-horizon when they were IIa, IIb or
15
5-6 respectively. According to Forman and Miller (1984) alteration of the parent material (C -> BC) can occur up to 3m deep.
The marine horizons can contain calcaric nodules as visible in Figure 9. The nodules have been found in all landforms except for colluvial soils, and in all horizons although compared to B- and BC-horizons rarely in A-horizons. Spitsbergen nodules are light porous calcaric precipitates with a high surface area. What I call calcaric nodules, are also known as ‘nodular secondary pedogenic carbonates’ or ‘disseminated detrital carbonates’ (Ugolini, 1986), ‘disorthic carbonate nodules’ (Reinhardt and Sigleo, 1988) or ‘calcium carbonate concretions’ (Friend and Moody-Stuart, 1970) among others.
Figure 9: Calcaric nodules (yellow-white specs)(J02). Nodule intensity is level 2.
Calcaric nodules have also been detected on the surface of river sediments. In our field survey they were ranked in 3 levels; lacking (0), present (1) or abundant (2).
The organisms that are present in the research area in the Ebba valley that affect the soils, comprise several groups. Incidental disturbances such as whale bones, deer skeletons and fox skulls found in the soils are not taken into account. Due to the remote location of the archipelago, extreme temperatures as low as -46°C and ice ages, no large soil fauna such as earthworms are present. The other ‘soil’-organisms can be divided in several categories (Wojtuń et al., 2013); fossils such as the marine shells of A. Borealis (Long et al., 2012), (cyano)bacteria and algae (Schostag et al., 2015), lichens (Øvstedal et al., 2009, Prach et al., 2012), mosses and vascular vegetation (Prach et al., 2012). 2.4 Soil forming processes The following soil forming processes are active in Spitsbergen.
Erosion and deposition are caused by the wind, run-off and the sea. Large areas are without vegetation cover and the increasingly growing pro-glacial sandr (Rachlewicz, 2007b) and steep mountain slopes are subject to weathering and produce easily transportable fines. The strong winds redistribute sands in the valley. The Ebba, a glacial melt water river, transports many fine sediments with a very diverse lithology into the study area. The terraces contain erosion gullies fed by the mountains that are most active during the snow melting season. The mountainous water partially has to pass the marine terraces to reach the river or the sea, creating incisions, mostly on the edge of ridge-slopes and troughs. Some top soils are not very permeable, especially when frozen, and in
16 combination with the local slopes this can turn rain events into run-off. Earlier research also pointed out the significant influence of snow(fall) on the capture of aeolian sands (Rachlewicz, 2010).
Cryopedological processes all are processes that occur due to the freezing of the soil water, which happens annually in the arctic (Jones et al., 2010). Spitsbergen has permafrost which is a permanently frozen subsoil that can have an active (unfrozen) topsoil during parts of the year. The freeze-cycle can result in cryoturbation (frost churning) that can lead to mixing of soil material and horizons. This mixing is often caused by frost heaving, an upward swelling of soil material due to the expansion of water. The cryoturbation effects are different for various materials and particle sizes which can result in sorting such as with mud boils or patterned ground, both illustrated in Figure 10. Clear surface cracks are visible which are caused by shrinking due to temperature variations. When the cracks fill up with water and freeze, ice wedges form (Bockheim, 2015, Tedrow et al., 1958). On hills the cryogenic effects such as creep and solifluction can lead to soil transport and increased erosion rates.
Figure 10: Cryogenic processes in the topsoil. Mud boil, patterned ground with frost cracks and solifluction lobes.
Weathering in the area can occur in a variety of ways. The most dominant is frost weathering, the phenomenon that occurs when water inside cracks of particles, freezes and expands (Forman and Miller, 1984). This occurs most with fluctuating temperatures around the freezing point (Ford and Williams, 1989). The contribution of hydrolysis and hydration weathering in the arctic are disputed from very little to most dominant weathering process (Mann et al., 1986). Hydration chemically binds minerals to water, altering its structure (such as anhydrite, CaSO4 that becomes gypsum, CaSO4.H2O). - + Hydrolysis is a chemical reaction with the base (OH ) and acid (H3O ) from the dissociation of water.
For carbonation this reaction is with different forms of carbondioxide (such as CaCO3+CO2+H2O ->
17
- Ca2++2HCO3 ) and oxidation with oxygen whilst reduction (gley) removes the oxygen. These processes often change the pH. Dissolution removes particles by surrounding and associating them by solvent (water) and kinetic pressure brings the particles in the flow. Finally there is the biological component of weathering. Organic matter accumulation and organisms tend to store water, increasing water related processes (such as lichens on rocks). Roots can create physical pressure on the rocks and root excreted acids and chelating compounds together with oxygenation increase chemical weathering. The bacterial communities and fungi in the area contribute to the nutrient availability by increasing the weathering rates.
The vertical transport in the soils mainly consists of silt translocation and carbonate leaching and precipitation. Peak infiltration events migrate the small silt particles through the course gravel until the flow rate decreases below suspension level. Higher carbonate pressures and water availability increase the leaching of carbonates such as nodules and the marine parent material. When the solution flows down in the soil, the carbonate concentration can be lower, the water can evaporate, freeze or adhere, which all lead to supersaturation and subsequent precipitation.
Any other processes like podsolization or certain clay dynamics do not occur because the requirements aren’t met. 2.5 Plant life on Spitsbergen The cold and dry Tundra climate lead to arctic species. A recent survey found 53 vascular plants species, 71 bryophytes and 83 lichens in Spitsbergen (Jónsdóttir et al., 2006). Smaller species with little environmental demands for survival occupy several niches in Spitsbergen and the diverse geology results in an equally diverse variation of habitats typical for the area. Vascular plants (such as Salix Polaris) and grasses need a moist environment and longer growth season due to more energy intensive investments. Bryophytes (mosses) are found more on the wettest areas. The lichens and microbial crusts inhabit the most extreme niches and can be found on most locations, if not outcompeted. Sharp distinction between surface cover is visible in aerial photos and satellite pictures. Spitsbergen has a remarkably high amount of asexual plant reproduction systems and no tree growth (Jónsdóttir et al., 2006). 2.6 Influence of humans In Spitsbergen, besides four villages, there are numerous research outposts that are used in specific seasons. Due to the historical role of hunters in the area, there are many hunter-huts around, many are still in use. Tourism and research are growing industries, which results into more boat traffic. In the area of Petuniabukta the human influences were mostly visible around the 6 constructed areas (Figure 11). Both are strictly monitored by the Sysselmannen and the Governor of Svalbard to minimize the impact on the environment (Sysselmannen på Svalbard, 2015).
Car tracks from 50 years ago are still clearly visible in the tundra. Besides the current settlements, there is plenty of evidence of historical human activity because even the smallest marks remain in the vegetated areas. The beaches are littered with debris of which drilling/mining equipment, plastic garbage and most of all, the large amount of driftwood are the most prominent features. Our research pursued minimal disturbance to the natural landscape. The influence of human presence on the vegetation is noticeable and depending on the plant species and locations, possibly severe. The influence of human presence on wildlife such as polar bears, because of tourism, hunting, fishing, research and habitation, is a recurring theme for discussion in the northern countries, due to the long persistence time of disturbances.
18
Figure 11: Topographical map of Petuniabukta, adjusted with largest manmade structures present during 2014. Measurement equipment such as meteorological stations were not taken into account in this map.
19
3. Materials and methods To characterize and quantify soil forming processes in the arctic, new field- and labwork was essential. Detailed soil descriptions were made and soil samples were taken at predetermined locations. Lab and data analysis of these soils and soil profiles were performed. In August 2014 fieldwork was conducted in and around the Ebba valley, near Petuniabukta, Spitsbergen. The labwork was performed in the Netherlands Centre for luminescence dating at Wageningen UR. 3.1 Choice of locations The choice for both random stratified and judgmental sampling designs was made.
The random stratified sampling scheme was designed to sample the marine terraces. The goal of the sampling design was threefold. It should be representative for area fraction, randomly distributed and sample all main terrace levels to guarantee a variety of landforms and ages. To determine the locations of the sampling points, randomly generated data points were created over the area. In the field the terraces were distinguished with GPS and grouped in 3 strata of equal size. Vegetation strata within the terrace strata were made, separating ridges (scarcely vegetated) and troughs (highly vegetated) based on an aerial photograph from 2009. 30 Samples, equally divided per terrace strata and representatively selected per vegetation strata, were randomly selected. This division, made by Marijn van der Meij, resulted in the distribution noted in Table 1.
Although ridges generally have a low vegetation coverage, this is not always the case. Lower terraces have more vegetation and this was adjusted in the sampling scheme to increase representativeness.
Table 1: Division of samples over the terrace strata (van der Meij, 2015).
vegetated non-vegetated total stratum 1 Cells in raster (fraction) 644029 (0.933) 46218 (0.067) 690247 Division of locations 8 2 stratum 2 Cells in raster (fraction) 570381 (0.824) 121467 (0.176) 691848 Division of locations 8 2 stratum 3 Cells in raster (fraction) 323835 (0.496) 329701 (0.504) 653536
Division of locations 5 5
For the judgmental sampling design the goal was to discover the full extent of soil variation in the (nearby) area by creating as many catenas as possible, to assess the range of variables by adding extremes. Besides marine terraces, there are colluvial, alluvial and river(bed) soils. Pits were chosen at very stable (flat), moist (pits) and dry (tops) locations. The aspect and the distance to older/newer terraces was evaluated. There are no maps available in such detail (DEM has 10x10m grid), so pits were chosen in the field.
The five different landforms or morphological features that have been distinguished in this report are based upon location and parent material. The marine beaches contain ridges (elevated positions) and troughs (lower locations) within one sequence (Figure 7a and 7b). The transition in between the two features is gentle (Figure 7c) and therefore a class in between is distinguished; the slope (Figure 7d). There are very clear differences in between ridges and troughs of which vegetation density is probably the easiest determining factor (Figure 7b). The river bed and mountain slopes have also been sampled. The difference between colluvial and alluvial mountain deposits has not been thoroughly investigated and are therefore combined.
20
A B
A
Figure 12: Illustrations of the large impact of small topographic differences. A: Illustration of typical terrace sequence (light stony ridge, dark vegetated trough) B: Distinction between all three morphologies is very clear due to vegetation. Left the bare ridge, middle the typical slope vegetation/crust pattern and right the trough vegetation.
C: Mere decimeters of height differences can strongly determine the hydrological regime. D: A clear illustration of mostly aeolian accumulation Moist trough in front, the dry ridge (grey) in between and a swamp-like gulley in the hinterland. on a slope due to the wind shading. C D
21
3.2 Sampling The FAO-guidelines (FAO, 2006, WRB, 2014) were used for the soil profile analysis (field description form in Appendix B). The following characteristics have been assessed for this research: Landform, altitude, slope, profile and plan curvature, surface and horizon rocks, environmental location, vegetation type and cover, rooting depth, crusts and hydrology.
The soil depth was determined by the depth of the R, C, I or BC layer. When the BC or C layer was reached, another 10 to 20cm has been dug for a larger sample representativeness. On average about 4 samples were taken per soil, resulting in 182 samples.
Another 8 sediment samples were taken to distinguish sedimentation history by origin based upon differences in size, shape and parent material of the grains. Microscopic investigation showed that the samples had mixed origins and therefore this method proved too inaccurate.
Some samples have been taken for dating purposes, which will be discussed in §3.5. The soil samples that were taken, were used to determine the SOM content, soil moisture content and grain size distribution in the soil lab in Wageningen. 3.3 Laboratory analysis The soil moisture content, SOM content and grain size distribution were analyzed in several steps. In between every step the samples were weighed first. The samples were dried for 24 hours at 105 degrees Celsius. The weight difference with the original samples resulted in the water content (%).
The carbon content of the soil was measured by loss on ignition (Heiri et al., 2001). The OM content, is a function of the weight loss due to ashing and part of only the fine fraction (sand, silt, clay) and has therefor been corrected for the soil moisture and gravel content and consequently bulk density.
Grain size distribution was determined by dry sieving. The largest section was larger than 2mm (gravel), the middle section (sand) was larger than 65µm and the smallest section comprised both silt and clay. This research makes no differentiation between silt and clay for marine terraces. The amounts of clay in the parent material and after weathering are insignificant compared to the silt content for terrace soils younger than 20ka (Zwoliński et al., 2013a, Zwoliński et al., 2013b). In this document all particles finer than 65µm will be called silt in marine terraces. Soils that formed in colluvium contain more clay and are discussed separately. 3.4 Statistics The data have been analyzed categorically in order to better be able to find trends or relations for specific processes. The groups are categorized per landform, with assessments per horizon and/or age. Most relations were tested with one-way ANOVA for significance (P<0.05). Three main types of data distribution in the results can be distinguished; in some cases the variables were strongly different from each other, as if linearly distributed. In many cases there was a skewed distribution. In many more cases there was an expected relation but it was not strong enough to be statistically significant, or not present at all. Some results were manipulated to test significance accordingly (Webster, 2001).
The variance of the data is also tested by performing the Leven F-test of homogeneity of variances. This value logically depends on the variable used to group the data. If the significance was smaller than 0.05, the data was not of equal variance and thus not suited for proper ANOVA analysis.
The sample sizes were also not equally distributed. A choice was made to extract chosen outliers (most of the J-samples) in some of the tests. The amount of data points in the colluvial, alluvial and
22 river area were too small to test for significance. This leaves just the three main groups (trough, slope and ridge) for testing, these are 36 samples (19, 5, 12 respectively). 3.5 Time scales of soil alteration With a theodolite most altitudes were established and the points that were not visible through the theodolite, were measured using a manual GPS device. Long et al. (2012) found a strong linear relation between the altitude and the age. We used the C-14 dating of shells from Long et al. (2012) and combined this with five of our own OSL-samples. For details on the methodology of dating, see van der Meij et al. (2015). The two sources coincide, form a reliable and linear relation between age and height (Figure 13). Statistically extrapolation up to the highest terraces fits within the same period of uplift, extrapolation up until the colluvium (80m) is disputable due to mixing and unknown uplift rates during the LGM. The first 3000y are missing because the recent sea level rise is stronger than the tectonic uplift in the area (Long et al., 2012). There seems to be no structural difference between troughs and ridges that were supposedly formed together (Anderson et al., 1999).
Equation 1: Age-height relation used for calculation
푎푔푒[푦] = 218 ∗ height[m] + 3500 for 0masl < height < 60masl
Figure 13: Plot of OSL and C-14 datings on the terrace sequence in the Ebba valley. Error bars indicate the 95% confidence interval (2sigma). (van der Meij et al., 2015)
In general the soil ages in Spitsbergen vary in between 3000 years, 4000 years (youngest terrace) and 290 ka at 80masl (Anderson et al., 1999, Forman and Miller, 1984, Karczewski et al., 1981a). In very well preserved Spitsbergen-regions the highest terraces are found up to 275m, dating back to the Pleistocene (Karczewski et al., 1981b). In our area the highest terraces were about 15ka old and highest samples taken around 70masl. The above relation (Equation 1) was chosen as a good average fit of both OSL and C-14 dating and used for calculations throughout.
23
24 Figure 14: Sample locations of soil profiles, terrace stages and theodolite. All judgmental samples are in red, all random samples are black and all sediment samples and theodolite are in green. The lines signify the three sampling strata. The sediment samples (green) were chosen to distinguish origins based upon size, shape and parent material. 4. Results A summary of the visual terrain assessment and vegetation analysis, horizon distribution and other measured characteristics, follows. Hereafter the various soil horizons are described for terrace soils, river and colluvial soils. These, combined with the pit analysis, will result in the distribution of soil types (FAO) over the area. 30 stratified random and 14 judgmental locations were sampled. This resulted in 44 soils that can be split into five main landforms (Table 2).
Terraces in the Ebbadalen are not older than 12 ka and lie below 44masl, except for some colluvial buried terraces at the Wordiekammen, which are ranging up to 14 ka. The terraces can be up to 0.5m thick below 10masl (Figure 12b) and more than 5m thick above 30masl (Figure 12a), with soils of respectively only centimeters thick, up to about 105cm for the oldest terraces. The deepest marine terrace soils found in the Ebba valley, were an old trough soil of 110 cm deep (R15), and a slope soil that was about 115cm deep (R30).
Table 2: Soil profile distribution per landform type.
Landform Random Judgmental Judgmental locations
Ridge 8 4 Shoreline[J2], river [J4], opposite aspect [J9], saddle position [J10])
Slope 5 -
Trough 17 2 Streambed on trough (peaty [J5], swamp [J3])
River(bed) - 3 Fluvial valley (dry [J6], ‘average’ [J7], wet [J8])
Colluvium - 5 Alluvium [J12], debris (on terrace [J11][J13], fresh debris [J1], flat [J14])
Judgmental sampling resulted in 12 soil profiles and 2 small trenches. The last two were made to better understand small scale differences: In the river bed this was dug through a sediment hump, in the oldest terrace this was through a mud boil.
The area contains incised young terraces (J2, J4), small tundra patches (J3, J5), river beds (J6, J7, J8), colluvium (J11, J12) and buried terraces (J1, J13, J14). One point was taken with an opposite aspect (J9) and one point at a saddle position of a small terrace (J10). The three points (J1, J11, J13) lying at the slope of the mountain, where classified as the oldest found terrace soils. However there was clearly a large influence of slope materials and therefore they are categorized as colluvial soils instead of marine terraces. These groups are chosen because the landform is the most dominant distinguishing factor between various soils. The landform summarizes differences between relative height, curvature and parent material. Due to these circumstances, different processes act on different horizons and when the processes are known, the time scales can be estimated. 4.1 Landform characteristics Soils formed very divergently due to variation in parent material and topography that characterize the area’s landforms. The summary in Table 3 and Table 4 is based on this classification. It includes the range of all found data points, except for a possible clear outlier. For example in the marine terrace ridges, all sampled points had an aspect in between 200° and 20°, except for one judgmental outlier (purposed extreme) with an opposite aspect (100°). Note that these characteristics are only of
25 sampled soils; e.g. marine terrace slopes occur also at higher elevations than 20m, but those have not been sampled.
Table 3: Landform characteristics of marine terrace soils.
Terrace Characteristics Landform Marine Terrace Trough Marine Terrace Slope Marine Terrace Ridge Altitude 4-48masl 10-20masl 2-46masl Slope 0°-6° 4°-7° (2°-10° small scale) 1°-11° Aspect 235°-340° 230-250° 200°-20° * Profile Curvature Straight, Convex, Flat Concave, Straight, Convex Straight, Convex, Flat Plan Curvature Straight, Convex, Flat Concave, Straight, Convex Straight, Convex, Flat Surface Rocks None (0-1%) * None (0-5%) 0-90% gravel, 0-35% stones Environment Deposition area Deposition or transport Erosion or transport Vegetation Type Shrubberies, Mosses, Shrubberies, Mosses, Shrubs, Mosses, Grasses, some Grasses Grasses Flowers or no Vegetation Vegetation Cover 40-100% * 20-90% 0-40% Rooting Depth 30-50cm 40-60cm 10-60cm Crusts Microbiotic crusts * Microbiotic crusts Often Microbiotic crusts, None Hydrology Moist-wet Dry-moist (Very) dry Smell 5 pits petrochemical 1 pit petrochemical 4 pits petrochemical Most common soil Cryosol Calcisol Calcisol *In these cases one strong outlier has been removed for clarity.
For the first three landforms, all situated in marine terraces, it seems that the slopes resemble the troughs the most. It should be noted that the slopes are generally short and therefore the averaged slope (10m) is even less than in the case of ridges, that as a landform, have a convex profile. This explains the difference in slopes in between the latter two landforms. Hydrophilic species were found in wet trough positions. Vascular species were found on deep(er) soils. The soils and conditions that occur in river and colluvial sediments are summarized per horizon in Table 4.
Table 4: Soil characteristics of non-terrace soils.
Landform Characteristics Landform River Bed Colluvium Altitude 1.9-2.1masl 50-71masl Slope 0°-1° 4°-16° (2°-32° small scale) Aspect 40° 270°-300° Profile Curvature Flat, Straight Convex, Concave (Convex, Straight small scale) Plan Curvature Flat, Straight Convex, Concave (Convex, Straight small scale) Surface Rocks None (0-2%) 0-5% gravel, 0-5% stones Environment All Deposition or transport Vegetation Type Shrubberies, Mosses, Grasses Shrubberies, Mosses, Grasses Vegetation Cover 20-90% 40-95% Rooting Depth 4-25cm 5-50cm Crusts Microbiotic, Salt, None Microbiotic, None Hydrology Moist-wet Moist-wet Smell 1 pit reduction 1 pit petrochemical Most common soil Fluvisol Cryosol
26
In Table 5 the occurrence and distribution of the different types of soil horizons is illustrated. All the data points in river beds and colluvium were chosen to be the extremes or unique that could be found. This table contains values of only the marine terrace soils because only these soils had a realistic spread and numerous data points collected for generalization and extrapolation purposes. These create a generalized image of some of the differences in soil formation. A visual representation of Table 5 is created as Figure 15, as a catena in Figure 16 and exemplified in Figure 17.
Table 5: The diversity of soil horizons per landform.
Horizon Trough Thickness Horizon Slope Thickness Horizon Ridge Thickness (19 soils) (cm) (5 soils) (cm) (12 soils) (cm) V (50%) 2-3 V (60%) 1-2 1Ah (50%) 3-10 1A (80%) or 7-20 1Ak (40%) or 6-15 or 1Ah (20%) 32 1A (60%) ** 5-12 1A (90%) 5-35 2A (20%) 20 2A (50%) 9-36 2Bl (50%) or 15-65 or 2B (40%)* or 20-26 or 1Blk (90%) 11-66 2Blk (25%) 12-55 2Bl (60%) or 8-85 or 2Blk (20%) 10 1Bl (25%) or 8-25 or 1Bk (40%) 23-40 2BC (100%) >15 2BC (80%) or >27 or 1BC (100%) >15 2IC (20%) > 3C / 3R (15%) > * In one case (20%) a B-horizon was overlying a Bl-horizon so both occurred. ** Two ridge soils had aeolian deposits, 1A (10cm) overlying 2B and 1A (5+10cm) overlying 2A (25cm). Not every horizon is present in every profile, therefore the percentage of occurrence has been added. When this does not add up to 100% it means that the horizon is missing in the rest of the cases. Percentages are rounded of to the nearest 5%.
27
Figure 16: Three ‘typical’ soil profiles per marine terrace landform. Figure 15: Catena across a marine terrace. Lowest layer is assumption based upon extrapolations. Between the red lines is a transition zone (slope). Height to length ratio is exaggerated.
28
Figure 17: A typical trough soil (R03), a typical slope soil (R22) and a typical ridge soil (R16) that are visual depictions of the summary in Table 5. 29
4.2 Processes Most described soil forming processes rely heavily on the presence of water. The water availability is highest in river soils, then colluvial, troughs and slopes and lowest in ridge positions. River soils however don’t show many effects of cryogenic alteration. The soil forming processes or indicators thereof that were found are indicated per landform where they are found (Table 6)
Table 6: Summarized soil forming processes, loosely based on Table 1 of van der Meij (2015).
Type of process Landform Intensity * Erosion and deposition Strongest in: - Aeolian erosion Ridges Top positions - Aeolian deposition Slopes, Troughs, River Slopes, then Troughs - Fluvial erosion and deposition All River soils, then Troughs (includes run-off, snow melt) - Marine erosion and deposition Not colluvial Young terrace (currently only sea level rise) - Creep Colluvial, Slopes, Ridges Colluvial Cryogenic processes - Cryoturbation Not Rivers Wet positions - Frost heaving Troughs, Slopes, Colluvial Colluvial - Surface cracking All Colluvial, then Slopes - Forming of ice wedges Slopes, Troughs, Colluvial Colluvial - Patterned ground forming Slopes, Troughs, Colluvial Colluvial - Mass movement (solifluction) Not Rivers Colluvial Physical weathering - Hydration All Wet positions - Frost All Moist positions, less in Rivers Chemical processes - Oxidation and reduction Rivers, Troughs, Colluvial Rivers - Dissolution All Wet positions - Hydrolysis All Unknown - Changing pH (dissolution of carbonates) All Wet positions - Biological All Wet positions - Organic matter accumulation All Wet positions Vertical transport - Silt translocation Terraces Wet positions - Carbonate leaching and precipitation All Terraces * The intensity column describes of a process in which landform it is most prominently present (normal) or in which positions within the landforms it occurs strongest (italic). The marine erosion and deposition are not active in the area anymore except for the slow decrease of the youngest terraces due to continuous sea level rise. The effects of hydration and hydrolysis were not investigated into detail but rock weathering patterns suggested their presence. 4.3 Terrace soil formation The terrace soils comprise the largest part of the research area and are also the main subject of focus. The terrace soils have processes that can be distinguished per horizon. This chapter on soil formation has a bottom up approach.
30
4.3.1 Unaltered parent material (C, R, I) A base upon the hard rock (R) upon which marine sediments (C) had been deposited was found in one soil. Marine sediments form the parent material for all soils, excluding some colluvial soils. In at least one case the marine sediments are permanently frozen (I). Variation in the C-horizon consists mainly of various gravel sizes. The R-horizon consists of calcaric conglomerate bedrock, likely from the Cambelryggen or Billefjorden group (geo units 19, 20 in Appendix C – Background information Ebbadalen).
Figure 18: The three types of bottom sediments. From left to right: Bed rock [R] (J5), unaltered marine sediments [C] (R23), frozen parent material [IC] (R28).
4.3.2 Slightly altered parent material (BC) The thickness of the BC-horizons are unknown because in general it was the depth at which we stopped digging. The BC was not found in every terrace profile because of the large depth of soil development or when digging was inhibited by a high groundwater table. It is usually characterized by the colour (10YR, 3/4, 2). Due to a lack of fine material, no mottles can be found, the structure is absent and except for very wet soils, there is a strong to extreme reaction to hydrochloric acid. Nodules can be found in the younger soils (<20m, <8000y). The BC-horizons contained between 30% and 95% gravel as well as 1% to 12% silt the rest is sand. The organic matter in the horizon is generally low and between 0.1% and 2.1%. With the fraction of fines and OM this low, the water content is also low and between 0.3% and 7.2% (avg=6%).
Figure 19 : Slightly altered parent material BC (R11). It generally contains rounded pebbles, gravels and sands. On some places silt illuviation can be clearly distinguished, usually these accumulations are strongest on top of (bigger) clasts.
31
4.3.3 B-horizon (Bk, Bl, Blk) 40 Soils contained a B-horizon. Some of the river and colluvial soils were too disturbed for B- formation. Silt accumulation and carbonate precipitation are the most important soil forming processes leading to a B-horizon. Four different B-horizons were distinguished with suffixes; Bk, Bl, Blk and BC. No other soil forming processes were dominant enough to form other types of B- horizonation in terrace soils. The BC horizon is the marine parent material, and is slightly influenced by soil formation. When the soil development progresses to a high silt illuviation (class 5 or 6), the horizon becomes a siltified B-horizon (Bl) or to a high carbonate precipitation class (IIA or IIB), the horizon becomes a carbonated B-horizon (Bk). When both processes happened in the soil, the horizon can become a Blk-horizon. The Bk horizon is overlying the Blk-horizon half of the cases, whilst the Bl-horizons are generally found in a profile without a Blk-horizon. The BC-horizon is distinguished from the unchanged parent material (C-horizon) most often due to both processes. It can occur that only one of the processes alters the C-horizon but the dug soil profiles were not deep enough in general to determine which process affected the parent material the deepest. Only two terrace soils contained a C-horizon without an overlying BC. Both were trough soils with a dense, strongly developed Bl-horizon.
B becomes Bk when it is not wet enough to transport enough silt to form a silt matrix but calcaric dissolution does occur. Bk-horizons form below other B-horizons such as the Blk. Differentiation appears to occur based on stone sizes, although this has not been objectively quantified. Carbonates precipitate best on all types of stones and when the fine fraction is low, whilst silt stagnates best when rocks are bigger and flat on top. In the field there was no clarification about why this distinction exists.
Figure 20: On the left the Bk-horizon (R27) where siltation can be seen without a matrix structure. On the right is a picture of the highest level (IIb) of calcaric pendants. On the lower part of rocks a thick calcaric layer has formed (IIa) and even some flower like structures (IIb, orange coloured, dominantly aragonite) developed.
The major part of the silt in the soils does not come from the parent material (<1%) or wind deposition (mostly sand), but from weathering of the parent material (van der Meij, 2015). Dissolution and chemical processes contribute to the silt-production in situ but frost and hydration shattering produce the most silt (Forman and Miller, 1984, Dredge, 1992). When these processes occur for more than 100ka even clay will be produced, from <3% in younger soils up to 17% after 290.000 years (Forman and Miller, 1984). In the study area clay was only discovered in strongly cryoturbic or fluviatile influenced soils that contained colluvium.
32
Figure 21: Bl (R12) and Blk-horizons (R16) with silt-matrix level 6 on the left and 5 on the right.
When the B-horizon both has a silt-matrix and is strongly calcified, it becomes a Blk-horizon. These horizons have many similarities with the earlier horizons.
Table 7: Distinctive B-horizons and their characteristics.
Horizon Characteristics BC Bk Bl Blk Cases observed 31 9 18 20 Average Thickness (cm) Unknown 24 26 34 Range of Thickness (cm) 20-150 10-40 8-38 10-66 Colour 10YR, 3/4, 2 10YR, 3/4, 2 7.5/10YR, 3/4, 2 10YR, 3/4, 2 (Hue, Chroma, Value) Mottles None None None None Structure Absent Absent Massive (p.d.) Massive (p.d.) HCl Strong/Extreme Extreme (p.d.) Moderate-Extreme Extreme (p.d.) Nodules Yes, if age<8000y Yes, if age<5700y Yes, if age<7000y Yes, if age<7000y Carbonate Class 0-Ic (per definition) IIa-IIb (p.d.) 0-Ic (p.d.) IIa-IIb (p.d.) Silt Class 0-4 (per definition) 0-4 (p.d.) 5-6 (p.d.) 5-6 (p.d.) Gravel+Silt / Sand 30-95% / 1-12% 51-98% / 1-8% 40-80% / 3-20% 55-91% / 3-14% Organic Matter 0.1-2.1% 0.1-2.1% 0.3-3.6% 0.1-1.2% Average Water Content 6% 4% 10% 3.5% Range Water Content 0.3-7.2% 0.2-8.5% 3-20% 1.5-5.5%
Initially it was expected that there would be a clear distinction for the formation of the B-horizon with respect to silt displacement and calcification grade over the depth. However the processes involved in creating a B-horizon of certain stage and thickness were much more complex (Figure 22).
33
Age (yr) 3000 5000 7000 9000 11000 13000 15000 0
10
20 Bl-horizon Trough Blk-Horizon Trough
horizon(cm) 30 - Bl-Horizon Ridge 40 Blk-Horizon Ridge
Thickness Thickness B 50
60
70
Figure 22: Thickness of Bl- and Blk-horizons of terrace landforms as a function of age.
Nodules occurred most commonly in ridge soils (6), then slope soils (3), river soils (2) and seldom in valley soils (3). They have been found up to 8000y old soils in the BC-layer or C-horizon and 7000y old soils in the Blk-horizon (Figure 23). In a 6500y old soil nodules were present in the Bl-horizon and in a Bk of 5700 as well. In one valley soil (4900y) and one ridge soil (7000y) they were present in the A- horizon.
Figure 23: Presence of calcaric nodules (intensity) and the age of the soil in which they are found.
4.3.4 Marine A-horizon The marine A-horizon rarely exceeds a thickness of 25cm. The horizon is usually characterized by the colour (mostly 7.5/10YR, 3,2 (trough) or 7.5YR, 4,2 (ridge)), contains no or very little mottles (max. 20% OM) and has a weak structure (granular, medium to fine grained). All HCl classes can be found and there is a strong link between the HCl class and the gravel fraction. The marine A-horizon nearly always contains some gravel (trough gravel 1-30%, ridge gravel 25-75%) due to the gravelly marine
34 parent material, even when it was strongly weathered, with exception of fluviatile influenced soils. Calcaric pendants were only found when the horizon contains rocks. In three cases a high silt class was identified and only one soil contained nodules in the A-horizon. When the marine A-horizon underlies an aeolian horizon, it contains significantly more silt than the aeolian deposits. The marine terrace horizon is found only twice in concave and just once in flat positions.
Figure 24: Two ridge soils (left R02, right R01) with their A-horizons on top of Blk-horizons.
On the left (Figure 24) is the well-developed A-horizon of R02 with an aeolian horizon on top of an marine horizon, with low gravel content. Part of the underlying Blk is also visible. On the right is the less weathered marine A-horizon of R01 on top of the Blk displayed. The gravel in the marine A- horizon seems to weather in variable rates according to the landform in which it is situated, but also differs within the landform itself, especially for ridges (Figure 25).
80 Gravel fraction 70 [% of mass]
60
50 Ridge 40 Slope 30 Trough
20
10
0 3000 5000 7000 9000 11000 13000 15000 Age [years]
Figure 25: Gravel fraction in the marine A-horizon as function of age and landform.
35
4.3.5 Aeolian A-Horizon In the Ebba valley aeolian transport can be seen on windy days. The sediments come from the colluvial and glacial parts of the more inland Ebba valley. At the end of the pro-glacial area, meters before the hills of the beach terraces, relatively large aeolian deposits accumulated (Figure 12D). On the lee side of every ridge these wind transported sediments are visible as A-horizons in soils, in erosion gullies, and as small heaps under larger plants (Figure 26), especially grasses.
Figure 26: Aeolian induced armoring on a ridge.
Every soil that has been examined, contained an A-horizon, 2/3rd of terrace soils contained two (Table 8). The aeolian A-horizon mostly has the colours 10YR, 3/4, 1/2, contains mottles of organic matter and generally has the same structure as the marine A-horizon. The HCl class is either moderate or high and it always has a less strong reaction than the underlying layer. Stoniness on surface and in horizon is very little to no rocks. Calcaric pendants can’t form without rocks, so they weren’t found. The aeolian layer had a coarser, sandier, texture than the underlying horizon during field observations. It was always a silt loam, loam or sandy loam. According to the lab results in all cases where both the 1A and 2A horizon were sampled, the marine A-horizon had a much higher silt/clay content, except for R10. The marine contained at least 40% more silt/clay and sometimes even three times as much as the aeolian horizon. The aeolian layer often appeared wetter in the field than the underlying marine terrace horizon, but according to the lab results the aeolian sediment was dryer in absolute moisture content.
Table 8: Summary of soils with an aeolian horizon per landform.
Aeolian horizons Nr. Random Nr. Judgmental per landform (out of total) (out of total)
Ridge 2 (8) 0 (4)
Slope 4 (5) -
Trough 16 (17) 1 (2)
River(bed) - 3 (3)
Colluvium - 1 (5)
36
4.4 Interactions in soils The soil moisture content in the A-horizon is relevant for the vegetation and other organisms living from the soil. Topography and relative height differences are found as the main cause of differentiation in water availability. Landforms are strongly interlinked with topographical differences. A summary of the soil moisture findings, from wet to drier soils:
- River soils, at about 2masl and close to the glacial river, have a high groundwater table. The fine sediments often show signs of gley, have a high soil moisture content but do not store much carbon. There is a strong dominance (90%) of bacterial crusts close to the river, contrary to the dominance of larger plants at greater distance from the river.
- Colluvial soils, tens of meters above sea level, away from the river, have a medium groundwater level. The steep slopes create a steady groundwater flow and strong meteorological differentiation such as large temperature fluctuations. Here is the highest influence of cryic processes and weathering. Colluvial soils have a large fine fraction and at stable locations the parent material weathered to heavy clays. Vegetation is either dominant or in cryogenic patches surrounded by bacterial crusts, mosses and lichens. Together with troughs, the highest carbon storage is found here.
- Trough soils are, within the terrace soils, closest to the groundwater and presumably the bedrock. Their relative low position supplies them with run-off and groundwater from a larger catchment area. The A-horizons are strongly weathered, contain nearly no stones and often have had an aeolian input. The fine fraction is very large here, as is the soil moisture content. Vegetation is dominant and carbon storage is highest in the wettest places. Swamp like conditions can occur and even small amounts of peat have been found where gullies are located in the troughs.
- Slope soils can either be similar to the somewhat higher ridges, or the lower lying troughs. Their water availability is in the middle as well. The amount of gravel in these soils is low (<1% in aeolian, ≈15% in marine) in the A-horizon. Actual permafrost was only detected in slope soils and no other landforms. Vegetation and bacterial crusts live next to each other. The organic matter accumulation is in the order of average trough soils.
- Ridge soils are the driest sampled areas in the terrain. Relatively high above slopes and valleys their convex, armored surface is inhabited by scarce vegetation and mainly bacterial crusts and lichens. The thin A-horizon with mostly a small fine fraction and low organic matter content barely withholds soil moisture.
An illustration of these findings, such as how vegetation cover increases with a higher soil moisture content in the A-horizon, are plotted (Figure 27). The lines that have been added are assessed in the Discussion.
37
100 90 80
70 Ridge 60 Slope 50 Trough 40 River Bed
Vegetation cover [%] 30 Colluvium 20 10 0 0 5 10 15 20 25 30 35 40 45 50 Soil Moisture [% of mass] Figure 27: The vegetation cover as a function of the water availability in the top horizon, differentiated per landform.
Vegetation catches aeolian sediments, thus the thickness of the aeolian horizon logically would depend on the intensity of the vegetation cover (Figure 28). This relation is less straight forward (Klimowicz and Banaś, 1995).
100 90 80
70 Ridge 60 Slope 50 Trough 40 Thickness Thickness [cm] River Bed 30 Colluvium 20 10 0 0 10 20 30 40 50 60 70 80 90 100 Vegetation Cover [%] Figure 28: Aeolian A-horizon thickness as function of the vegetation cover.
Other factors that might contribute to the formation of an aeolian horizon, are topography and soil moisture. If the surface is concave, such as troughs, more sediments will be deposited (Rymer, 2014). If the top horizon is moist, the soil is expected to stabilize the aeolian sediments better (Figure 29). The wilting point of the soils in the area are estimated about 5-6% based on the grain size distribution, excluding the gravel fraction (Van Genuchten, 1980).
38
100
90
80
70 Ridge
60 horizon[cm] - Slope 50 Trough 40 Θwp River Bed 30 Colluvium
20 Thickness Thickness aeolian A
10
0 Horizon detection limit [5cm] 0 5 10 15 20 25 30 35 Soil Water Content [%Mass] Figure 29: Thickness of the aeolian horizon as function of the soil moisture content. The yellow line symbolizes the detection limit for aeolian horizons (5cm). The blue line signifies the lower moisture content limit for A-horizons around 6% (Van Genuchten, 1980). The black lines will be explained in Discussion. Unsurprisingly, organic matter comes from vegetation, and thus there is a relation between both. This correlation can be found and is positive for all marine terraces (Figure 30). However the relation is on all aspects stronger for soil moisture (Figure 31).
30
25
20 Ridge
15 Slope Trough River Bed 10
Colluvium Organic Matter [% by mass] 5
0 0 10 20 30 40 50 60 70 80 90 100 Vegetation Cover [%] Figure 30: Aeolian A-horizon plotted against vegetation cover
39
50
45
40
35
30 Ridge
25 Slope Trough 20
River Bed Soil moisture moisture Soil [%] 15 Colluvium 10
5
0 0 5 10 15 20 25 30 Organic Matter [% by mass]
Figure 31: Aeolian A-horizon soil moisture content plotted against the organic matter content.
Logically when a horizon contains a high fraction of fines such as silt, the soil moisture content is higher. The cryogenic processes are stronger and the parent material weathers into silt faster with high water availability. The relation between silt and water can be better illustrated by division per landform (Figure 32).
50
45
40
35
30 Ridge
25 Slope Trough 20 River Bed 15 Colluvium
Soil Moisture Moisture Soil [% bymass] 10
5
0 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 Silt [%] Figure 32: Relation between silt and soil moisture content in the A-horizon.
If Forman and Miller (1984) is correct, the silt fraction in the B-horizon increases with age (Figure 33). For the silt fraction in the B-horizon there were no soils in the river area that met the requirements.
40
0.3 Silt Fraction [% of mass] 0.25
0.2 Ridge 0.15 Slope Valley 0.1 Colluvium 0.05
0 3000 5000 7000 9000 11000 13000 15000 17000 Age [years] Figure 33: The relation of the silt fraction as function of the age in the B-horizon.
Because directly measuring or estimating the silt transport as a function of fraction or horizon thickness over age proved insufficient, other relations were assessed as well (Figure 34).
Figure 34: Depth of maximum silt concentration as function of time for trough positions.
When the silt fraction and average depth of occurrence are calculated for various horizons and the point of highest silt intensity is estimated and plotted against the age, a straight silt illuviation curve can arise. This has been performed for trough positions with an aeolian horizon that were not disturbed by cryic processes like solifluction (Figure 34). 4.5 Other soil formation For comparison and extrapolation of terrace soil formation soils have been sampled in the three main different river areas and three most distinguishing colluvial influenced areas.
4.5.1 River soils During the fieldwork three judgmental soil pits have been dug in the floodplains of the glacial river Ebba at 1.8-2.0masl. These soils were significantly different from each other but show river soil formation rather well and are therefore described individually. All soils were dug until the groundwater made progress impossible.
The first soil pit (J06) was taken closest to the river. In the aerial photograph it is visible as a similar surface as the surface of a terrace ridge, which is not the case. However the whiteness is caused by a
41 thick layer of salts that consist of both calcaric and sea salts and there is little vegetation (30%). It had a BC-horizon that consists of marine deposits with 64% gravel and 34% sand and contained nodules. The overlying A-horizon (10cm) was formed in river sediments that were mixed with aeolian sediments and contained 79% sand and 21% silt and was slightly decalcified (strong HCl). The top layer contained some (1.9%) organic matter and showed drying cracks at 8.3% water content.
Figure 35 : Salt precipitation on top of a fluvial soil . The whitest and ‘fluffiest’ salts are largely NaCl. The largest part consists of Calcium and Magnesium salts.
The second soil (J07) was also taken on the river terrace. The surface seems strongly vegetated but the shrubs only take up about 20% of the vegetation cover. Most of it is covered by mosses and microbial crusts. The soil is considered less than 4000y old and has an Ah- (10cm) and A-horizon (15cm) that was leached. The lower A-horizon only moderately reacts to HCl, the Ah strong and the BC, with level II Forman calcification, reacts extreme. The A-horizons contain about 23% of silt and no gravels, whilst the BC-horizon contains less than 2.6% silt. The wet A-horizons (23% soil moisture content) contain some mottles of both organic matter (2.5%) and gley (reduction and mostly oxidation).
Figure 36: Vegetation humps in the river area.
The last river soil (J08) was taken in an old meander bend. The surface showed vegetation humps that were also found in the trough-gullies. To better understand these processes a trench was dug across such a hump (Figure 36) that is comprised of fluvioglacial sediments. Height differences with the surrounding area could become up to about 15cm. The soil contained two A-horizons which were distinguished because of differences in mottles (A1 OM and rust, A2 gley and rust) and the presence
42 of stones (A1 1%, A2 20% rocks [>5cm]). Although this soil was located furthest away from the river, it contained the most moisture, which was visible through large patches of gley. This soil contained between 21-27% silt in the A-horizons and had at least 3% organic matter content.
4.5.2 Colluvial soils The colluvial soils can be divided into three groups: Purely colluvial material, colluvial on top of terrace and mixed alluvial/colluvial material. The colluvial material is mostly limestone and dolomite that weathers into clay and silt. Every colluvial area had solifluction and frost wedges. Only one pit (J14) represents purely colluvial soils, which is characterized by very high organic matter (≈19%) and silt/clay (≈29%) fractions in the top horizon. With high soil moisture (>43%) and low gravel fraction (<8%) its A-horizon is in strong contrast with the B-horizon (<11% water, >70% gravel). The 10cm thick horizon is strongly weathered and also leached (HCl moderate). Although there are very strong signs of cryic processes such as large mud boils and compaction, it has an unusual thick and developed rooting system. Three soils (J01, J11, J13) were dug upon the suspected oldest terraces. Close to the debris slope moss is the main vegetation cover whilst further down slope shrubs become dominant. The change of hydraulic conductivity between pure colluvium and developed soil horizons leads to seepage that induces some alluvial transport. Patterned ground was the most typical cryic feature. They are again characterized by high silt (15-17%) in the A-horizon but much lower organic matter (3-5%). J13 contained more organic matter in the B-horizon than in the top (10%). J11 was a very unique soil because at the edge of the colluvium/ridge it had accumulated large amounts of fine sediments (A- horizon was 95cm) both from aeolian and fluvial sources on top of the Blk. It was strongly leached and contained many bands of organic matter accumulation. The other soils only had 20-30cm A- horizon, on top of the well-developed Blk-horizon.
Figure 37: Mud boil due to cryoturbation with a sharp distinction between the top and the clay rich subsoil.
The stronger alluvial influence in the area of J12 distinguished it from other colluvial soils because it led to a dominance of grasses and polygonal features. Cryoturbation led to mud boils which are like nearby soils but lack an A-horizon (Figure 37). Organic matter bands showed that the A-horizon was normally not affected by cryoturbation. The soil was strongly leached and the B-horizon contained more clay/silt (27%) than the A-horizon (18%) whilst the organic matter content was the same (5%).
43
4.6 Soil classification (FAO) All soils that have been found are usually defined as cryosols due to the annually freezing conditions. The definition of a cryic horizon states “a Cryic horizon has: continuously for 2 consecutive years one of the following: massive ice, cementation by ice or readily visible ice crystals; or a soil temperature of ≤0 °C and insufficient water to form readily visible ice crystals; and a thickness of 5 cm.” and “Cryic horizons occur in areas with permafrost and show evidence of perennial ice segregation, often associated with evidence of cryogenic processes (mixed soil material, disrupted soil horizons, involutions, organic intrusions, frost heave, separation of coarse from fine soil materials, cracks) above the cryic horizon and/or patterned surface features (earth hummocks, frost mounds, stone circles, stripes, nets and polygons).” Directly from WRB (2014). It is known that the soils are frozen during most of the year but were not frozen during the end of August. Soils have been found with permafrost, however it cannot be said with certainty that especially the dry soils meet the cryic criterion. When discarding this criteria and only defining a soil as a cryosol when there are actual disturbed horizons due to cryoturbation (turbic qualifier) or cryic surface characteristics (Figure 38), many other soil types can be found. Fluvisols (river only), gleysols (river only), chernozems, kastanozems, phaeozems and calcisols were found in the area besides cryosols.
Figure 38: Left is a photo of typical frost cracks on a trough soil (R15). Right is a frost boil/mound on a colluvium soil (J12).
For these soils, the calcic and mollic horizons are important distinctive qualifiers. “The calcic horizon is a horizon in which secondary calcium carbonate has accumulated in a diffuse form or as discontinuous concentrations, in the parent material, subsurface horizons or even in the surface horizon.”, short summary of WRB (2014). It has a calcium carbonate equivalent of at least 15% in the fine earth; and 5% or more (by volume) secondary carbonates higher than the underlying horizon and a thickness of at least 15cm. The 15% equivalent is tested with 1M HCl and is assumed present when a (thick) foam appears (strong or extreme in the data). This was the case in nearly all B and BC horizons and in 1/3rd of the A-horizons. Of these soils, all of the ridges had a calcic horizon whilst some trough and colluvium soils were just below the threshold. “The mollic horizon is a thick, well-structured, dark-coloured surface horizon with a high base saturation and a moderate to high content of organic matter.” (short summary of WRB (2014)) It has a sufficiently strong soil structure with a munsell chroma and value of 3 or less, an organic carbon content of 0.6% or more, a high base saturation and a thickness of at least 20cm. Because nearly all soils had a colour dark enough, a weak but sufficient structure and organic carbon content and base saturation high enough, the thickness was the most important determining factor. About half of the
44 soils had a mollic or rendzic horizon, the most important distinguishing factor for becoming a chernozem, kastanozem or phaeozem. Note that even the unaltered parent material had a colour that was sufficiently dark in most cases to be classified as mollic.
The soil classifications are divided as follows; 17 Cryosols (trough, slope, ridge, colluvium) 2 Fluvisols (river) 1 Gleysol (river) 5 Chernozems (trough, slope, colluvium) 1 Kastanozem (trough) 2 Phaeozems (trough) 16 Calcisols (trough, slope, ridge, colluvium) If the cryosols would not be taken into account, all 17 cryosols would be classified into five different soil types. There would be 7 chernozems (trough, ridge), 6 phaeozems (trough, slope, colluvium), 2 calcisols (trough, ridge), 1 gleysol (trough) and 1 cambisol (colluvium).
Figure 39: Left is a photo of the Blk-horizon of a very clear example of a strong calcic horizon (R01). Right is a photo of the soil profile of vegetation, two A-horizons and the Bl (R06) . The BC can not be seen due to the rising groundwater. R06 has a very dark mollic horizon overlying a B-horizon with a class 2 calcaric pendants (Forman and Miller, 1984), thus forming a calcic horizon. This cryosol therefore has the rendzic qualifier.
Most soils were (endo-, epi-)skeletic, calcic and/or calcaric. About half of the soils had a rendzic or mollic and/or abruptic [silt] qualifier. Nine soils had turbic properties and four soils had the densic, gleyic or gelic qualifier.
There are some additional remarks for the usage of qualifiers. Every single soil that was found contained calcaric parent material or it was present in the neighborhood. Although in some soils a very wet hydrological regime has dissolved much of the original material, there was still enough for every soil to have a eutric qualifier (high base saturation). Therefore this has not been added
45 specifically. This is also true for the calcaric qualifier that cannot be added to the cryosol officially. Logically the qualifiers of calcic/calcaric and mollic/rendzic are not added to chernozems, kastanozems and phaeozems either.
Due to the importance of the soil forming process of silt accumulation described in Forman and Miller (1984), the qualifier abruptic has been modified. The original definition states “Abruptic; an abrupt textural change requires 8% or more clay in the underlying layer and a doubling of the clay content within 7.5cm if the overlying layer has less than 20%.” (all marine terraces and thus all relevant cases had less than 20% clay) The performed sieving in the lab did not make distinction between clay and silt. To distinguish the silt illuviation in certain soils the definition has been modified from ‘clay’ to ‘silt’, therefore many soils have gained the qualifier ‘Abruptic [silt]’.
The full soil survey according to FAO standards (FAO, 2006) is included in Appendix A – Spitsbergen soils.
46
5. Discussion In the Ebba valley I noticed some recurring phenomena that appear to be important characteristic processes for different soil formation. Of these processes the effect and/or relevance are described as I think they interact. This resulted in frameworks that aim to explain which soil forming processes are important at certain time and spatial ranges. The first one is the wet-plant-framework, followed by the carbonate-dissolution- framework and the silt redistribution theory. In the end a tree diagram for soil formation on terraces will be presented and river bed soil formation will be discussed as well. When possible the time range to reach certain development stages and also the limitations in the spatial domain are mentioned. For age calculation Equation 1 is used continuously, but variation in uplift rate (spread in data), might be influenced not only by tectonics but also by climate such as storm intensity and eustatic sea level change as well as sediment dynamics. However these uncertainty ranges are small compared to the time scales of most pedogenic processes.
5.1 Wet-organism-framework This theory describes how soil moisture influences the vegetation and the effects thereof. Because of the many feedbacks within the system, a visual representation describing the processes is included (Figure 40). Each process will be discussed individually.
Figure 40: Framework of the influence of different processes and states in the moisture-organism interactions.
5.1.1 Water availability Water is the driving force behind the processes and depends mainly on topography, height above bedrock, fine fraction and organic matter content but not on distance to the river as Klimowicz and Uziak (1996b) suggested. Theoretically the distance to the river has a large effect on the pedogenic processes due to water availability and temperature buffering (Klimowicz and Uziak, 1996b, Dolnicki et al., 2013). In practice the only influence of the river that has been found was on the soils inside the river area and never on any terraces. The effect of gullies was clearly noticeable and a soil within a gulley outflow bares close resemblance to a river soil in the meander bend. This is especially true for the topsoil and vegetation characteristics. The soil moisture content determines the organisms that can live in a specific location. A high and stable soil moisture content is more favorable for larger species such as vascular plants and mosses than for lichens and bacterial crusts.
47
There is no linear relation between soil moisture and altitude. This can be explained by the effect of terraces, which create relative height differences that affect the soil moisture regime. The effect of the distance to the groundwater influences the soil moisture content of the topsoil according to Figure 41. This effect is strengthened by the supposed presence of shallow (<1-2m) or impenetrable bedrock or permafrost which creates a strong (visibly flowing) horizontal groundwater flow which has been observed in at least two soil pits. However a weakness in this theorem, is that in most of these soils, there was no continuous silt-matrix (Bl) throughout the B-horizon until the groundwater and the B-horizon on average contained 70% gravel. In soil physics such a layer is called a capillary barrier (Sarsby, 2001). The lack of fines in the layer prevents free vertical drainage because the capillary forces can be neglected in the middle layer, which results in gravity being the only downward force. Besides the higher storage capacity itself, this would explain the always higher soil moisture in the A-horizon compared to the B-horizon (Ityel et al., 2011, Kämpf, 1998).
Figure 41: Integrational interpretation of groundwater and aeolian processes with terrace topography
5.1.2 The effects of soil moisture and vegetation Plants were good indicators of hydrological and soil characteristics because clear distinction can be made between wetter and dryer areas based on topography and vegetation cover. A strong link between the (maximum) vegetation cover and soil moisture exists. This relation seems obvious because plants need water to survive, however the quantification might result in surprising data (Figure 27). Because Spitsbergen only has about 150mm precipitation per year, surviving plants can be expected to be drought resistant, even with the low sun-angle and therefore low transpiration. In the figure a band (in between black) covers nearly all soil pits, although some additions are suggested. When soil moisture hits a certain (unknown) value, such as 22%, plant growth is no longer inhibited by water availability but by other processes. The rare occurrence of 100% cover suggests competition might be one of these limitations. On ridges only very scarce vegetation grows, although the ridge’s vegetation cover does increase with distance from the ridge top, which corresponds to a lower relative altitude and presumably more soil moisture. There are multiple other reasons that inhibit plant growth on terrace ridges such as wind effects, but these will not be discussed in further detail. The negative effects of drought are clear, but it is unknown whether the plant species present at location, suffer from long term soil moisture saturation due to oxygen stress or stronger cryic processes (Melke and Uziak, 1989) as well. Evidence of these processes (gley, peat) were only found in two river soils and two valley soils, of which the latter two had high vegetation cover. However the valley soil (26; 50%) outside of the relation-band was characterized by a very high groundwater level (inhibited digging below 70cm) and might therefore signal detrimental effects of high soil moisture. Besides (close-by-)ridge positions and unstable areas, the vegetation cover is at least 40-50%. The vegetation cover on slopes is expected to be in the middle of the drier ridges and wetter valleys,
48 which is consistent with the data. The river beds that have a low vegetation cover were characterized by their locations in or very close to the meander bend of the river. This area is known to flood at least once a year (snow melt peak). The colluvium’s often low vegetation cover would probably be explained by still occurring slope processes such as creep at the rather steep angle. The vegetation band was significant and is also confirmed by soil pits of which only field measurements of soil moisture were taken. The effect of plants on the soil moisture is positive as well. The low transpiration rates in the arctic are much smaller than the insolating effects of vegetation cover. The soil moisture content fluctuates less and is generally highest in moss vegetation and then shrubs. Under lichens and bacterial crusts it fluctuates greatly and depletes quicker (Migała et al., 2014). The presence of vegetation strengthens itself strongly by buffering the water capacity that is needed for plant growth.
5.1.3 Accumulation and preservation of organic matter There is a rather strong relation between the organic matter content and the soil moisture within the aeolian horizon. This relation is assumed to be twofold; “Increased OM generally produces a soil with increased water holding capacity and conductivity, largely as a result of its influence on soil aggregation and associated pore space distribution” (Hudson, 1994, Saxton and Rawls, 2006); when there is more moisture available the vegetation can be more productive (Lambers et al., 1998), as concluded earlier; when there is more moisture available it also preserves the organic matter in the soil better (Tarnocai et al., 2009, Migała et al., 2014), such as in histosols and illustrated by Figure 31. Organic matter can accumulate the quickest near streams or swamps due to the low and steady temperature and high buffer capacities of these areas, consistent with Migała et al. (2014).
5.1.4 Bacterial soil crusts altering the water balance There are plentiful communities of bacteria, lichens and algae in and on the active soil layer above the permafrost in Spitsbergen. They are good bio-indicators of pollution. For example the increasing accumulation of heavy metals over the last decades was most clearly visible in the Bacterial Soil Crust layer (BSC), compared to all locally present organisms (Wojtuń et al., 2013). Although likely present (Bergero et al., 1999), the effect of fungi on the system hasn’t been studied in detail. The effect in northern areas might be important (Clemmensen et al., 2013) but no research into this matter was performed by us.
The effects of the BSC on the soil water content is problematically complex. First there is the development stage, which has not been taken into account during our survey. Only their surface area can be estimated from photos (such as Figure 42), illustrating that in trough and slope soils the surface area not covered by vegetation, was covered mainly by bacterial crusts. Only in ridge, river and colluvial soils, patches of bare soil occurred. Their important role for the local carbon cycle should not be underestimated (Yoshitake et al., 2010) as well as the illustrated importance for the topsoil of the high amount (average 24% of BSC) of nitrogen fixing species (Schostag et al., 2015). Still the lack of proper distinction of various BSC development stages and communities is common practice among geomorphologists (Pushkareva et al., 2015, Chamizo de la Piedra et al., 2012). Secondary the species forming the BSC, as we defined it, were varying greatly from cyanobacterial nitrogen fixers to algae and even lichens. The occurrence of species depends on the stage of development, water content, pH and total organic carbon of the topsoil (Pushkareva et al., 2015). Many of these have different effects on the behavior of the BSC and the variation of BSC in turn affects the soil moisture content differently. Thirdly there is little arctic research on the effect of the BSC on the water content (Chamizo de la Piedra et al., 2012), although there is some data on the higher occurrence of more developed BSCs at wetter locations (Pushkareva et al., 2015). Generally arctic conditions are judged as semi-arid and
49 therefore the BSC’s are compared to other semi-arid bacterial communities (Bär et al., 2002, Karnieli and Tsoar, 1995, Zaady et al., 2014, Zaady et al., 1998, Gile et al., 1981).
“Through their influence on roughness, albedo, porosity and cracking, BSCs also play a key role on water processes, such as infiltration and runoff, evaporation and soil moisture. BSCs exert a strong influence on the emergence, establishment and survival of vascular plants, either through competition for cover and biomass, or through changes in soil properties. However, interactions between BSCs and vascular plant species are complex and studies have reported that BSCs can either promote or retard plant colonization.” (Chamizo de la Piedra et al., 2012). The cyanobacterial communities often have a spongy structure that can withhold water that is used for photosynthesis. Due to the generally low rain intensities, large parts of the summer ‘precipitation’ are drizzle, fog or rain/snow (Hanssen-Bauer, 2003), these small short term retentions add up. The large dependency of the bacterial communities on the water content, results to cracks in the surface crust and infiltration is enhanced when the BSC has dried out (Schostag et al., 2015). The presence of BSC instead of vegetation also means a lower buffering capacity of the topsoil as illustrated earlier in the vegetation cover. When the BSC and lichens are developed, they greatly lower the available water for vegetation (Chamizo de la Piedra et al., 2012). There is no clear outcome from literature whether and how the BSC affect infiltration and run-off of soils in the arctic. There are about equal amounts of research for positive, negative and no effects because all can occur in different settings (Chamizo de la Piedra et al., 2012). Bacterial occur in between vegetation when the soil moisture content is average, and with lichens and bare soil when the soil moisture is low.
Figure 42: Bacterial crusts with vegetation patches in between. Surface cracks, lichens and some bare soil are also visible.
5.1.5 Aeolian deposition dynamics The sand from the aeolian deposits is delivered mainly from the pro-glacial zone, but also from the valley itself. The oldest ridges, closest to the glacier, experience the strongest influences of wind erosion. The aeolian deposits can be found at three typical locations. 1) lower lying areas, ‘under the hill’, on both sides of the general wind direction due to wind shielding/blocking; 2) moist and wet locations, where the sediment is immobilized; 3) larger plants and grasses.
50
Because the soil moisture content and topography have an indistinguishable correlation in the data, their respective effects were combined in the analysis. Although vegetation and moisture also have a strong correlation, they could be seperated more distinctively. Especially the small spatial differentiation of the effects of plants can be seen very clearly on site. Figure 43 shows the progradation of the trapping of aeolian fines by plants, away from the general wind direction (plants grow towards the lee-side, which is towards the sea in this case). The origin of the sediments and location and redistribution for aeolian deposition in the Ebba valley has been measured by Krzysztof Rymer (Rymer, 2014) and confirmed the findings above. A large part of the sediments is even caught by snow and never even reaches the topsoil because it is transported away during the snow melt peak (Rachlewicz, 2007a).
Figure 43: Aeolian sands bury the birch-like vascular vegetation (Salix Polaris) leading to progradation of vegetation in the strongest wind direction.
There is a minimum vegetation cover needed for trapping sediments. The deposition border is about 40% coverage. With the exception of very wet river beds and one trough data point (R17), which was at the exact border of a ridge (typically <10% vegetation) and trough (>50% vegetation) system, this is true. It is uncommon to find an aeolian horizon when there is less than 40% vegetation, and except for one (R23) all terrace soils with more than 50% vegetation cover have it. The thickness of the aeolian horizon itself cannot be predicted by the vegetation cover. Statistically speaking the trend would even be negative; high vegetation cover has lesser thick aeolian deposits. Possible reasons are unclear but might be due to the burying of the plants (as illustrated before in Figure 43) or failing to immobilize the aeolian deposits, due to lack of sufficient soil moisture throughout the year. The organic matter in the aeolian horizon has formed horizontal layers in some cases. This is evidence of accumulation and later the burial of vegetation (Zwoliński et al., 2013a). Also patches of high vegetation cover are in the lee of the wind and surrounded by less vegetated areas that capture the majority of the sands before it reaches the denser areas.
The effects of soil moisture on aeolian sedimentation aren’t straightforward. The soil moisture content in the top-horizon both traps and binds the particles to a location. When the soil in a favorable location is wetter, the aeolian horizon is expected to be thicker, but Figure 29 illustrates
51 that there is a maximum to this effect. - without soil moisture (<10%), little or no aeolian deposits are trapped; - with moderately high soil moisture (10-25%), the horizon is usually well developed; - with high soil moisture (>25%), the thickness of the horizon is thin;
The soil moisture content is only high when a soil is either in the river bed, or very close to, or in a gulley. The erosion caused by these water movements remove the freshly deposited and easily transportable sediments. Erosion of fines, leading to armoring (Figure 26 right), can be distinguished at all ridges. It leaves the gravelly parent material as pedestals on the surface, but this transport is affected by run-off (snow melt events) as well. Although ridge erosion covers the largest surface area, the armoring protects against extreme events. Slope soils erode a lot because of their angle, but troughs erode as well, because actual run-off channels, rills, are formed. Estimating the exact quantities is both part of ongoing research by Rymer (2014) and has been done by van der Meij et al. (2015) which resulted in an estimate of the troughs eroding more, most severe at the border with the slopes.
Possibly the aeolian influence was not discovered in all cases. OM-content was not a suitable distinction criteria because in about 2/3rd of the cases the marine horizon contained more OM, whilst in the other 1/3rd the aeolian contained the highest OM-content. Using the HCl, stoniness, texture and colour as determining factors should make differentiation between the two types of horizons possible. However the intercept between the marine and the aeolian layer was often mixed (f.e. due to cryic processes), sometimes even leading to occurrence of rocks in the aeolian horizon. The horizon was in some cases very thin (much less than 5cm) and in some older soils the marine horizon showed many similar characteristics (such as lack of rocks) due to weathering. 5.2 Carbonate-dissolution-framework The second framework aims to explain the formation of calcaric pendants at the B-horizon such as illustrated in Figure 20. As can be seen from the youngest soils, the calcium- and magnesium-carbonates precipitate over time and are not present from the formation onwards. A quick process is the dissolution of calcaric nodules, which are generally dissolved away after several thousands of years. Plants create organic matter and produce acids from their roots, causing increasing dissolution. Plants and water capture aeolian deposits, which is largely comprised of calcaric fines and dissolve easily. The cryic weathering create a larger fraction of sands and smaller particles, which itself holds more water and dissolves easier.
Figure 44: Framework of the influence of different processes and states in the calcaric weathering.
52
5.2.1. Water as a driving force Water dissolves the carbonate rocks and parent material in Spitsbergen (Melke, 2007, Stankowska, 1989, Dragon et al., 2015). The effect of water on plants, aeolian deposition and the accumulation of organic matter will not be illustrated again, only emphasized here and discussed later. The amount of percolating water depends largely on the season, frozen soil surface is impermeable, snow melt results mostly in direct run-off, and the evapotranspiration is estimated less than half of the precipitation. The water balance of the Ebba valley is difficult to determine and fluctuates strongly per year, because of the large influence of temperature on the permafrost and glacier (Dragon et al., 2015). “Groundwater contributed between 1.0% and even 27.4% of the total runoff, with higher values when total runoff was low.”(Marciniak et al., 2014) The groundwater contains dominantly calcium (carbonate) and sulphate concentrations that are close to the maximum concentrations. Gypsum, anhydrites and dolomites are suggested as the dissolving rocks but the low Magnesium in the water suggests possible other contributions (Dragon et al., 2015).
Because of the importance of water on the dissolution, a clear link between profile and plan curvature what could be expected. Both small distance (2m) and large distance (>10m) curvatures were assessed and multiple relations were tested but none of them revealed a significant (P<10%) link between the intensity of the precipitation and the curvature. However concave profiled soils had the thinnest Bk-horizon whilst straight plan curvature resulted in the thickest Bk-horizons
5.2.2. Physical weathering and fine fraction effects A clear distinction could be made in the field for areas prone to cryic effects such as patterned ground and frost cracks, on the basis of water availability (visible through vegetation cover). Physical cryic processes such as frost weathering are considered by many (Dredge, 1992, Gorniak and Piroznikow, 1992, Melke and Chodorowski, 2006, Strzelecki, 2011, Zwoliński et al., 2013a) to be the main driver for soil formation in the arctic region. The frost increases the surface area and roughness of the carbonate rocks and therefore increases the speed of dissolution, consistent with Ford and Williams (2013). The dissolution of carbonates is most efficient when there is a large range of forms and sizes of the grains and rocks (Ford and Williams, 2013, Ford and Williams, 1989) but this was not evident in the field. According to Ford and Williams (1989) when dissolution has smoothed of the grains and the size variation is low and limited to a smaller grain size, the dissolution is low as well. This was difficult to assess because carbonate dating of many layers of precipitation needs to be performed to verify this for the region. However the effect of a larger fine fraction on the vegetation and water holding capacities would suggest the opposite. Rock weathering due to physical processes is strongly increased when the fine fraction is larger, as can be seen from the young soils with an A-horizon that contains very few rocks. The weathering increases the fine fraction in the soil, which holds the moisture necessary for the cryic processes in the soil (Melke et al., 2013). The lack of cryoturbation as described by Pereverzev and Litvinova (2012) was evident throughout most of the area. Many frost related processes occurred commonly but horizon disturbing cryoturbation was only evident in clay rich colluvial soils. The marine A-horizon contained finer material than the overlying aeolian horizon (40-300% more silt fraction). The in situ fraction of the marine silt and the sandy particles coming from the pro-glacial zone are different, but this is also an indication of the local weathering. Either the weathering takes a long time to produce silts, or the sands mostly don’t weather into silt but dissolve instead. The aeolian horizon in the field appeared to contain more moisture than the marine A-horizon, but the opposite was true according to lab results.
J5 is the most extreme illustration, where there are no rocks left in the 25cm thick marine A-horizon of this soil pit, situated near a gulley. As seen in Figure 25, after 8.000y less than 2% of the mass in the A-horizon is present as rocks for trough-soils (except when there is colluvial or cryic input of new
53 rocks (R6, R17)). The least developed marine A-horizon is only 15cm thick and contains half (30%) the amount of rocks of the underlying layer (60%) after about 4.300y of soil formation. Ridge soils also have rock weathering, but not only is the weathering much slower due to the lack of soil moisture, also a significant part of the fines erode away. This statement is confirmed by the curvature. The two ridge soils containing the least gravel (R2, R5) are coinciding with the most stable, sheltered flat ridge positions, whilst the rockiest points such as R1, R4 and R16 are at unstable positions. These latter three have no deviant slope (1-4°) or curvature (straight). They do however have in common that they have no upwind shielding and are among the oldest terraces and thus the highest point in the upwind direction. This wind erosion theory is strengthened by the field observations where the amount of armoring became stronger with exposure, besides age.
Figure 45: Moisture-weathering-fines feedback in terrace soils.
Slopes have a larger weathering rate than ridges, due to the moisture availability, but are expected to also get some rock input from the elevated ridge positions, placing them in the middle of the graph (Figure 25).
5.2.3 Chemical weathering The presence of aragonite besides calcite in the precipitated pendants reveals strongly oversaturated conditions for calcium carbonates and/or biogenic influences (Monger et al., 1991). The low temperatures in the area are beneficial for the dissolution rate of the parent material.
Hydrolysis is normally not a large contributor to carbonate weathering, but in combination with frost weathering it can be. Hydrolysis on fresh cracks is a very rapid process (hourly timescale) that can even occur without soil moisture but by air humidity (Stipp, 1998).
Organic matter can supply the necessary CO2 for carbonate dissolution. The effect of organic acids excreted by plants and other organisms, as well as the decomposition of organic matter will not lead to acidification. The buffer capacity of the largely calcaric parent material (>80%) is too strong. At least 40% of biogenic CO2 production will directly lead to dissolution of the carbonates nonetheless (Pulina et al., 2003, Ford and Williams, 1989).
The fresh input of aeolian sediments from the pro-glacial zone brings fine sands that contain carbonates. These are considered easily soluble due to the large, irregular surface area as observed under the microscope. Fresh deposits have a high to extreme reaction to HCl, whilst older aeolian deposits have a less strong response, indicating carbonate leaching. These findings have been done earlier by Kabala and Zapart (2009) in the nearby pro-glacial zone. When modelling the carbonate dynamics, dissolution was not taken into account, and therefore difficult to quantify (van der Meij et al., 2015).
54
Some organisms present in all landforms, such as mollusc shells, mostly in the BC horizons, prove the marine origin of the soil basis. The second group consists mainly of four dominant cyanobacteria (Pushkareva et al., 2015). They form bacterial crusts that influence the topsoil behavior. The lichens have less effects on the soils but influence the weathering rates of exposed rocks and produce valuable nutrients for the other organisms (Øvstedal et al., 2009). No direct evidence of effects on the water availability were noticed in the field. The mosses and larger (vascular) plant species have been grouped in this research and form the main constituent of the variable ‘vegetation cover’. They have large reciprocal influences on the soils.
5.2.4. Calcaric nodules The calcaric nodules are present in situ in all soil types and their origin can be diverse (Reinhardt and Sigleo, 1988), but is presumably from the drying out of the calcareous upper water table (Friend and Moody-Stuart, 1970) when the sea retreated. Their porous structure in the flow paths of percolating water leads to a relatively fast dissolution. Logically they are found solely in young and/or dry positions. The nodules are several milimeters up to 5 centimeters large and disorthic, which suggests that they have been influenced by cryoturbic processes. If their origin is indeed of an easily soluble carbonate from the groundwater, a relation between their presence and the age and soil moisture of the soil was to be expected (Figure 23). A similar relation with soil moisture was verbally explained in Nodules within the B-horizons. In wet trough soils the nodules dissolve twice as fast as in ridge soils, from 6000-8000y to 4000 years or even less.
5.2.5 Calcaric precipitation In the desert environment six stages of calcium precipitation are described ranging from a thin layer on some rocks up until a completely impenetrable petricalcic horizon (Monger et al., 2009). In Spitsbergen not more than stage II is reached as described in Figure 20. The limitations of the precipitation are still not completely understood. However, the process occurs on all landforms and gravels or rocks are necessary for accumulation because precipitation only occurs on the bottom of these larger soil constituents. Larger and flatter rocks have more precipitation than smaller gravels. A larger fine fractions decrease calcaric precipitation rates, which is for a large part a biogenic process. The origin of parts of the calcite and all aragonite precipitation (Figure 20, right) as occurring in Spitsbergen is of organic origin such as from mollusks (A. Borealis) (Long et al., 2012). 5.3 Silt redistribution When assessing the silt dynamics in the marine terrace soils, it is important to understand where the silt comes from. The silt from the B-horizon is not only silt but more of a sandy loam, consistent with Forman and Miller (1984). The aeolian sediments contain mostly sandy material and small amounts of silt, however the dolomite from the marine parent material weathers into silt (Ford and Williams, 2013, Mann et al., 1986) and significant amounts of silt were already present during deposition in the marine environment (Bernardová and Košnar, 2012).
The Bk horizon is found overlying the Blk-horizon, whilst the Bl-horizons are generally found in a profile without a Blk-horizon. Bk-horizons form below other B-horizons such as the Blk. This suggests that silt dynamics occur earlier and form more compact than calcaric dissolution. This is because all water steadily dissolves carbonates but only peak events transport silt. The silt eluviation from the A- horizon is faster than the silt creation through weathering, which is visible by a decrease in the silt fraction in older soils. The silt illuviation in the B-horizon has unclear relations due to the large variety of variables influencing the transport rates. In general it can be said that the illuviation depth increases and age. This is consistent with Forman and Miller (1984) who stated that a Bl-horizon between 15-35cm developed for terraces between 16-44masl up to 105cm thick at 80masl. Another problem with the quantification of the silt accumulation is the variables that were measured. The
55 only method that was able to quantify this to a larger extent, was taking the center of gravity of the silt (Figure 34). This relation clearly shows the effect of age on the silt transport. What Forman and Miller (1984) did not mention, perhaps due to the small number of soil profiles, is that the depth of the illuviation and the silt fraction vary strongly even within the same horizon and terrace (Figure 19). Moisture availability and other factors, such as particle size distribution, intensity of cryic processes and meteorological extreme events play a role, that have yet to be quantified. The silt withholds the soil moisture in the soil (capillary barrier) and thus decreases the percolation rate, which can ultimately lead to cryogenic processes disturbing the horizon formation (Mann et al., 1986). 5.4 Soil formation in marine terraces Taking into account the earlier feedback systems, a decision tree can be made to distinguish how a soil at a certain location has formed and potentially will develop. The landform is the most important characteristic, followed by the moisture regime and then the age. This has been done for terrace soils only, because the amount of samples taken in the river terrace and the colluvial area were too few for a decision tree. They have been assessed individually.
Table 9: Soil type differentiation.
Landform Hydrology Soil Type Age/Height Qualifiers
Ridge Dry Calcisol - Episkeletic
Wet (>15%) Cryosol Young Calcic, episkeletic, turbic
Old (>30m) Abruptic [silt], calcic, endoskeletic, rendzic, turbic
Slope Dry Calcisol - Episkeletic
Wet (>15%) Chernozem - Abruptic [silt], endoskeletic
Very wet Cryosol - Abruptic [silt], mollic, (gelic), turbic (>25%)
Trough Dry Calcisol Young Skeletic
Moist Chernozem Old (>30m) Abruptic [silt] (+/-15%)
Wet (>15%) Cryosol Young Abruptic [silt], endoskeletic, (rendzic)
Old (>25m) Calcic, endoskeletic, rendzic, (turbic)
Very wet Phaeozem - Abruptic [silt], (gleyic) (>25%)
If the cryosols would not be taken into account, all 17 cryosols would be five other soil types. When the soils are young they would be calcisols. When they are very wet they would be phaeozems. When they are moderately wet and old, they are chernozems. One would be a gleysol and one would be a cambisol.
An important point of discussion are the so called mollic and rendzic horizons. Their definition is based upon the organic matter content and largely recognized on colour, but even a nearly undeveloped BC has a sufficient colour.
56
5.5 River soils Originally river soils and colluvial soils were investigated mainly to find relations with terrace soil development. One of the expected relations, the distance to the river (Klimowicz and Uziak, 1996b), was not applicable on terrace soils, but also not on the river soils. The old meander band was much wetter than the soils closer to the river. Because all soils were about the same age, no time dependancy could be established for river specific processes.
The salts that formed on top of the soil indicate that the evaporation (estimated <70mm/y, (Kabala and Zapart, 2009)) in the area is relatively high, creating a subpercolative regime even with the low sun angle. This contrasts my findings on water availability and insolation (by vegetation) on the terraces, also confirmed by Migała et al. (2014). The salts from both marine sediments (calcaric) and the sea (sodium)(Friend and Moody-Stuart, 1970) illustrate the high evaporation gradient induced by dry air and constant wind (Ugolini, 1986). Apparently the potential evaporation exceeds the actual terrace evapotranspiration when moisture availability is unlimited, which emphasizes the difference between a percolating (P:ET=2.1, (Kabala and Zapart, 2009)) or subpercolating regime (P:ET<1). The insolation of vegetation and crusts has a huge influence herein. Silt dynamics and calcaric transport were much less than on young terraces, but still present in the underlying marine terrace horizon. This might be explained by the high groundwater table or the subpercolating evapotranspiration. If the assumption of the creation of nodules by lowering of the groundwater table (Friend and Moody-Stuart, 1970) is correct, the presence of high amounts of nodules suggests that this process occured in the river bed as well. However the location of the nodules, close to the river, indicated that it maybe still occurs.
The ‘aeolian’ horizon on top of all river soils consists at least partially of glaciofluvial sediments. This distinguishment was impossible to make without microscopic sediment analysis. The cost inexpensive method that was chosen proved time costly and not precies enough for proper analysis.
Finally the vegetated sediment humps that typically form in the wetter areas (Figure 36) are mainly caused by Carex subspathacea and are a result of several stages of vegetation succession. Prach et al. (2012) suggests these humps are caused by cryogenic processes but I found that this plant species typically accumulates sediments in tussocks due to flooding, instead of cryic processes, concurring with Lawrence and Zedler (2011). Most cryic processes aren’t active in the river area, presumably by the temperature buffering of continuous (ground)water flow. 5.6 Colluvial soils Purely colluvial soils are rare because active weathering still buries the soils under new colluvium and inhibits pedogenesis. The mountain slopes assure a regular water supply leading to wetter vegetation species such as high moss coverage, and stronger cryic effects such as well-developed mud boils. The larger temperature fluctuations in the colluvium lead to stronger weathering rates, partially indicated by well-developed cryic effects such as cryoturbation and high clay fractions. The organic matter content is only high in purely colluvial soils. The interaction between soil moisture and organic matter as stated for terrace soils was not applicable in this landform. J13 was different from most other soils (except J05) because the organic matter accumulation was higher in the B-horizon than in the A-horizon. Solifluction occurs in more areas, such as the slopes, as well, but never resulted in such contrast, possibly indicating a landslide occurrence. The colluvial soils confirmed that leaching of the topsoil, indicated by the HCl-reaction, is an indication of time without disturbance. The petrochemical smell was only noticable in one soil pit, and as in other soils only on terrace based soils. The cause of this strong odour has remained unknown.
57
6. Conclusions A framework could be established that explains the soil forming processes, their interactions and relative contributions to creating an A-horizon in marine terraces (Figure 40). The landform (morphology) determines the soil moisture availibility that in turn determines the habitat niche for a wide variation of species. Vascular vegetation and bryophytes have strong positive feedbacks improving their own environment by insolating the hydrological conditions. The sum of various effects of the bacterial soil crust populations on hydrology and vegetation remains unknown. All species improve the organic matter content and increase weathering rates in the soil. The aeolian sedimentation regime is strongly depositional when the surface cover (>40%) and soil moisture content (10 Another framework was created to understand the processes responsible for carbonate dynamics in the subsoil (Figure 44). Percolating water effectively leaches the aeolian carbonates and dissolves the parent material that is continuously subjected to diverse weathering processes. The fine fraction increases the weathering rate but the erosion of fines in ridge soils inhibits this self-reinforcing effect there and increases the effect for lower depositional environments. After 5000y gravels have weathered away in the topsoil of troughs but even after 15000y ridge soils are still comprised mostly of gravel, mainly due to erosion. Cryic processes in the marine terraces are less strong than expected. Organic processes play a very important role in increasing the weathering rates. Calcaric nodules, of which the origin remains uncertain, weather away within 4000y in trough soils and 8000y in ridge soils. The silt eluviation from the A-horizon is faster than the silt creation through weathering of the marine sediments. The method of Forman and Miller (1984) for evaluating silt illuviation (thickness of Bl) does not account for local variation and therefore only represents a very coarse average development. The peak of silt accumulation describes evolution of the siltification better (Figure 34). Extreme events such as the annual snow melt peak dominate the silt dynamics. The divergence of soil development can be predicted fairly accurately based upon the location (landform, possible disturbance), hydrology (vegetation species) and age (height) consistent with Table 9. Calcisols and cryosols dominate the area but chernozems, kastanozems, phaeozem and gleysols and fluvisols are found as well. Distance to the river is not an important characteristics for soil formation in any landform, (relative) height dominates herein. Flooding in combination with swamp vegetation does create sediment humps. Evapotranspiration fluctuates extremely between landforms and surface covers. The oldest marine terraces are about 15ka old and influenced by colluvial material typically characterized by weathering into clays. The frameworks illustrate the complex interactions of the soils and the organisms in and on it. The many ecosystem services are illustrated per location and what are factors of change. The carbon sequestration in the terrace soils is relatively low; when a certain value is reached that is characteristic for a specific hydrological regime and vegetation cover, it doesn’t differ with age. Assessing the time scales upon which soil formation takes place, has succeeded for some processes such as the dissolution of nodules. The goal of quantifying weathering rates without the use of models, proved often impossible due to the large variation and influence of all the variables. The effects of water on the soils has been intensively studied in this thesis. The effect of minor differences in soil moisture was large. The vulnerability of the system to such changes as can be achieved by climate change will be severe. 58 Recommendations The effects of bacterial soil crusts (and possibly also fungi) on the topsoil behavior is stronger than most geomorphologists recognize and should be taken into account more often in soil research in the (semi-)arid climates. Evapotranspiration estimates range from 10% of precipitation (permafrost) up to subpercolation (>100% of P, river areas). Accurate annual evapotranspiration measurements on several vegetation covers in Spitsbergen will result in the closing of a huge knowledge gap in hydrological and biological research that was found continuously through literature. Spitsbergen is a beautiful place, I recommend to visit it (while it is still a polar area). Acknowledgement This thesis has been performed with the help of Marijn van der Meij (preparations, fieldwork and verbal discussion) and my supervisor and advisor Arnaud Temme who helped start the fieldwork. The Soil geography and landscape chairgroup of Wageningen University and Research has kindly made financial aid available for the performance of field work and OSL dating in the lab. The vast majority of soil science in Spitsbergen has been done by Polish Universities and they kindly were interested in foreign collaboration. The knowledge and expertise in different (new) topics from the Wageningen University, and the long experience and vast geomorphological knowledge from the Adam Mickiewicz University in Poznań, have been combined in our research agreement for the year 2014. The Polish detail in their studies was remarkable and their research proved very valuable for this thesis. Our research has led to a publication in the special edition on the Arctic in the journal ‘SOIL’ (van der Meij et al., 2015). 59 References All unreferenced photos and figures and tables are taken or created by Christian de Kleijn (Canon 1100D, 18-55mm lense). ANDERSON, R., DENSMORE, A. & ELLIS, M. 1999. The generation and degradation of marine terraces. Basin Research, 11, 7-19. ARNALDS, O., THORARINSDOTTIR, E. F., METUSALEMSSON, S., JONSSON, A., GRETARSSON, E. & ARNASON, A. 2001. Soil Erosion in Iceland. Feb. 2001 ed. BÄR, M., HARDENBERG, J., MERON, E. & PROVENZALE, A. 2002. Modelling the survival of bacteria in drylands: the advantage of being dormant. Proceedings of the Royal Society of London B: Biological Sciences, 269, 937-942. BARANOWSKI, S. 1997. Changes of Spitsbergen Glaciation at the end of the Pleistocene and in the Holocene, Poznan, Quaestiones. Geographicae. BERGERO, R., GIRLANDA, M., VARESE, G., INTILI, D. & LUPPI, A. 1999. Psychrooligotrophic fungi from arctic soils of Franz Joseph Land. Polar biology, 21, 361-368. BERNARDOVÁ, A. & KOŠNAR, J. 2012. What do Holocene sediments in Petuniabukta, Spitsbergen reveal? Polish Polar Research, 33, 329-345. BIRKS, H. H., PAUS, A., SVENNDSE, J., ALM, T., MANGERUD, J. & LANDVIK, J. 1994. Late Weichselian environmental change in Norway, including Svalbard. Journal of Quaternary Science, 9, 133- 145. BOCKHEIM, J. 2015. Cryopedology, Springer. BOCKHEIM, J. G. & UGOLINI, F. C. 1990. A review of pedogenic zonation in well-drained soils of the Southern Circumpolar Region. Quaternary Research, 34, 47-66. BONDEVIK, S., MANGERUD, J., RONNERT, L. & SALVIGSEN, O. 1995. Postglacial sea-level history of Edgeoya and Barentsoya, eastern Svalbard. Polar Research, 14, 153-180. BURGA, C. A., KRÜSI, B., EGLI, M., WERNLI, M., ELSENER, S., ZIEFLE, M., FISCHER, T. & MAVRIS, C. 2010. Plant succession and soil development on the foreland of the Morteratsch glacier (Pontresina, Switzerland): Straight forward or chaotic? Flora - Morphology, Distribution, Functional Ecology of Plants, 205, 561-576. CHAMIZO DE LA PIEDRA, S., CANTÓN CASTILLA, Y. & DOMINGO POVEDA, F. 2012. The role of physical and biological soil crusts on the water balance in semiarid ecosystems. PhD, Estación Experimental de Zonas Áridas. CLEMMENSEN, K., BAHR, A., OVASKAINEN, O., DAHLBERG, A., EKBLAD, A., WALLANDER, H., STENLID, J., FINLAY, R., WARDLE, D. & LINDAHL, B. 2013. Roots and associated fungi drive long-term carbon sequestration in boreal forest. Science, 339, 1615-1618. DALLMANN, W.K., PIEPJOHN, K., BLOMEIER, D. 2004. Geological map of Billefjorden, Central Spitsbergen, Svalbard with geological excursion guide 1:50,000. Norwegian Polarinstitutt Tematkart. DOLNICKI, P., GRABIEC, M., PUCZKO, D., GAWOR, Ł., BUDZIK, T. & KLEMENTOWSKI, J. 2013. Variability of temperature and thickness of permafrost active layer at coastal sites of Svalbard. Polish Polar Research, 34, 353-374. DRAGON, K., MARCINIAK, M., SZPIKOWSKI, J., SZPIKOWSKA, G. & WAWRZYNIAK, T. 2015. The hydrochemistry of glacial Ebba River (Petunia Bay, Central Spitsbergen): Groundwater influence on surface water chemistry. Journal of Hydrology, 529, Part 3, 1499-1510. DREDGE, L. A. 1992. Breakup of Limestone Bedrock by Frost Shattering and Chemical Weathering, Eastern Canadian Arctic. Arctic and Alpine Research, 24, 314-323. EGLI, M., DAHMS, D. & NORTON, K. 2014. Soil formation rates on silicate parent material in alpine environments: Different approaches–different results? Geoderma, 213, 320-333. EGLI, M., MERKLI, C., SARTORI, G., MIRABELLA, A. & PLÖTZE, M. 2008. Weathering, mineralogical evolution and soil organic matter along a Holocene soil toposequence developed on carbonate-rich materials. Geomorphology, 97, 675-696. 60 FAO 2006. Guidelines for soil description - fourth edition. Rome: Food and agriculture organization of the United Nations. FISCHER, Z. 1990. The influence of humidity and temperature upon the rate of soil metabolism in the area of Hornsund (Spitsbergen). Pol. Polar Res, 11, 17-24. FORD, D. & WILLIAMS, P. D. 2013. Karst hydrogeology and geomorphology, John Wiley & Sons. FORD, D. C. & WILLIAMS, P. W. 1989. Karst geomorphology and hydrology, Unwin Hyman London. FORMAN, S. L. 1999. Infrared and red stimulated luminescence dating of Late Quaternary near-shore sediments from Spitsbergen, Svalbard. Arctic, Antarctic, and Alpine Research, 34-49. FORMAN, S. L. & MILLER, G. H. 1984. Time-dependent soil morphologies and pedogenic processes on raised beaches, Bröggerhalvöya, Spitsbergen, Svalbard Archipelago. Arctic and Alpine Research, 381-394. FRIEND, P. F. & MOODY-STUART, M. 1970. Carbonate deposition on the river floodplains of the Wood Bay Formation (Devonian) of Spitsbergen. Geological Magazine, 107, 181-195. GILE, L. H., HAWLEY, J. W. & GROSSMAN, R. B. 1981. Soils and Geomorphology in the Basin and Range Area of Southern New Mexico: Guidebook to the Desert Project, New Mexico Bureau of Mines & Mineral Resources. GORNIAK, A. & PIROZNIKOW, E. 1992. Changes in the characteristics of the soil and vegetation during the primary succession in the marginal zone of the Werenskiold glacier, Spitsbergen. Polish Polar Research, 13, 16-26. GREEN, D. & SISSON, M. 2016. Svalbard Spring Special. Natures Images UK. GULIŃSKA, J., RACHLEWICZ, G., SZCZUCIŃSKI, W., BARAŁKIEWICZ, D., KÓZKA, M., BULSKA, E. & BURZYK, M. 2003. Soil contamination in high Arctic areas of human impact, central Spitsbergen, Svalbard. Polish Journal of Environmental Studies, 12, 701-707. GUTERCH, A., PERCHUĆ, E. & JANUSZA, K. 1990. Seismic crustal structure of the sedimentary basin of Central Spitsbergen (discussion of results). Polish Polar Research, 11, 267-276. HANSSEN-BAUER, E. J. F. I. 2003. Climate variations and implications for precipitation types in the Norwegian Arctic. Norwegian Meterological Institute. HARLAAR, P. 2015. Soil evolution analysis on a geomorphically active glacial forefield using a high resolution DEM. Masters, Wageningen University. HARLAND, W. B., ANDERSON, L. M., MANASRAH, D., BUTTERFIELD, N. J., CHALLINOR, A., DOUBLEDAY, P. A., DOWDESWELL, E. K., DOWDESWELL, J. A., GEDDES, I. & KELLY, S. R. 1997. The geology of Svalbard. HEIRI, O., LOTTER, A. F. & LEMCKE, G. 2001. Loss on ignition as a method for estimating organic and carbonate content in sediments: Reproducibility and comparability of results. 25, 101-110. HITZ, C., EGLI, M. & FITZE, P. 2001. Below-ground and above-ground production of vegetational organic matter along a climosequence in alpine grasslands. 164, 389-397. HOLLAND, M. F. W. 1961. The geology of certain parts of eastern Spitsbergen. Norsk PolarInstitutt Skrifter, Nr. 122. HUDSON, B. D. 1994. Soil organic matter and available water capacity. Journal of Soil and Water Conservation, 49, 189-194. INGÓLFSSON, Ó. Outline of the geography and geology of Svalbard [Online]. INGÓLFSSON, Ó. & LANDVIK, J. Y. 2013. The Svalbard–Barents Sea ice-sheet – Historical, current and future perspectives. Quaternary Science Reviews, 64, 33-60. ITYEL, E., LAZAROVITCH, N., SILBERBUSH, M. & BEN-GAL, A. 2011. An artificial capillary barrier to improve root zone conditions for horticultural crops: physical effects on water content. Irrigation science, 29, 171-180. JENNY, H. 1994. Factors of soil formation: a system of quantitative pedology, Courier Corporation. JONES, A., STOLBOVOY, V., TARNOCAI, C., BROLL, G., SPAARGAREN, O. & MONTANARELLA, L. 2010. Soil Atlas of the Northern Circumpolar Region, Luxembourg, Publications Office of the European Union. 61 JÓNSDÓTTIR, I. S., AUSTRHEIM, G. & ELVEBAKK, A. 2006. Exploring plant-ecological patterns at different spatial scales on Svalbard In: JÓNSDÓTTIR, I. S. (ed.) UNIS Publication Series. Longyearbyen: UNIS. JORGENSON, M. T., SHUR, Y. L. & PULLMAN, E. R. 2006. Abrupt increase in permafrost degradation in Arctic Alaska. Geophysical Research Letters, 33, L02503. KABALA, C. & ZAPART, J. 2009. Recent, relic and buried soils in the forefield of Werenskiold Glacier, SW Spitsbergen. Polish Polar Research, 30, 161-178. KABALA, C. & ZAPART, J. 2012. Initial soil development and carbon accumulation on moraines of the rapidly retreating Werenskiold Glacier, SW Spitsbergen, Svalbard archipelago. Geoderma, 175, 9-20. KÄMPF, M. H., T.; MONTENEGRO, H. Inspection and Numerical Simulations of Flow Processes in Capillary Barrier Cover Systems. 3rd Int. Conference on Hydroscience and Engineering, ICHE, proceedings, 1998. KARCZEWSKI, A. 1995. Contemporary glaciation of the Petuniabukta area against the background of late-Vistulian and Holocene deglaciation (western Olav V Land, Spitsbergen). Quaestiones Geographicae, 133-138. KARCZEWSKI, A., BORÓWKA, M., GONERA, P., KASPRZAK, L., KŁYSZ, P., KOSTRZEWSKI, A., LINDNER, L., MARKS, L., RYGIELSKI, W., STANKOWSKI, W., WOJCIECHOWSKI, A. & WYSOKIŃSKI, L. 1990. Geomorphology – Petuniabukta, Billefjorden, Spitsbergen 1: 40.000. Poznan: Adam Mickiewicz University Press, Poznan. KARCZEWSKI, A., KOSTRZEWSKI, A. & MARKS, L. 1981a. Morphogenesis of subslope ridges to the north of Hornsund, Spitsbergen. Polish Polar Research, 2, 29-38. KARCZEWSKI, A., KOSTRZEWSKI, A. & MARKS, L. 1981b. Raised marine terraces in the Hornsund area (northern part), Spitsbergen. Pol. Polar Res, 2, 39-50. KARNIELI, A. & TSOAR, H. 1995. Spectral reflectance of biogenic crust developed on desert dune sand along the Israel-Egypt border. International Journal of Remote Sensing, 16, 369-374. KLIMOWICZ, Z. & BANAŚ, J. 1995. Typological variation of soil depending on plant succession in area of lowest marine terrace (Spitsbergen). UMCS. KLIMOWICZ, Z. & UZIAK, S. 1996b. Soil and vegetation conditions in small valleys at southern coast of Bellsund, Spitsbergen. Polish Polar Research, 17, 91-104. KLIMOWICZ, Z. U., STANISLAW 1996a. Arctic soil properties associated with micro-relief forms in the Bellsund region ( Spitsbergen). KŁYSZ, P. 1985. Glacial forms and deposits of Ebba Glacier and its foreland (Petuniabukta region, Spitsbergen). Polish Polar Research, 6, 283-299. KÖPPEN, W. P. 1931.Grundriss der Klimakunde [Online]. Berlin: W. de Gruyter. LAMBECK, K. 1995. Constraints on the Late Weichselian ice sheet over the Barents Sea from observations of raised shorelines. Quaternary Science Reviews, 14, 1-16. LAMBECK, K. 1996. Limits on the areal extent of the Barents Sea ice sheet in Late Weichselian time. Global and Planetary Change, 12, 41-51. LAMBECK, K., PURCELL, A., FUNDER, S., KJÆR, K., LARSEN, E. & MÖLLER, P. 2006. Constraints on the Late Saalian to early Middle Weichselian ice sheet of Eurasia from field data and rebound modelling. Boreas, 35, 539-575. LAMBECK, K., PURCELL, A., ZHAO, J. & SVENSSON, N. O. 2010. The Scandinavian ice sheet: from MIS 4 to the end of the Last Glacial Maximum. Boreas, 39, 410-435. LAMBERS, H., CHAPIN III, F. S. & PONS, T. L. 1998. Plant water relations, Springer. LANDVIK, J. Y., BONDEVIK, S., ELVERHØI, A., FJELDSKAAR, W., MANGERUD, J., SALVIGSEN, O., SIEGERT, M. J., SVENDSEN, J.-I. & VORREN, T. O. 1998. The last glacial maximum of Svalbard and the Barents Sea area: ice sheet extent and configuration. Quaternary Science Reviews, 17, 43-75. LÁSKA, K., WITOSZOVÁ, D. & PROŠEK, P. 2012. Weather patterns of the coastal zone of Petuniabukta, central Spitsbergen in the period 2008–2010. Polish Polar Research. 62 LAWRENCE, B. A. & ZEDLER, J. B. 2011. Formation of tussocks by sedges: effects of hydroperiod and nutrients. Ecological Applications, 21, 1745-1759. LONG, A. J., STRZELECKI, M. C., LLOYD, J. M. & BRYANT, C. L. 2012. Dating High Arctic Holocene relative sea level changes using juvenile articulated marine shells in raised beaches. Quaternary Science Reviews, 48, 61-66. MANGERUD, J., BOLSTAD, M., ELGERSMA, A., HELLIKSEN, D., LANDVIK, J. Y., LØNNE, I., LYCKE, A. K., SALVIGSEN, O., SANDAHL, T. & SVENDSEN, J. I. 1992. The last glacial maximum on Spitsbergen, Svalbard. Quaternary Research, 38, 1-31. MANGERUD, J. & SVENDSEN, J. I. 1992. The last interglacial-glacial period on Spitsbergen, Svalbard. Quaternary Science Reviews, 11, 633-664. MANN, D., SLETTEN, R. & UGOLINI, F. 1986. Soil development at Kongsfjorden, Spitsbergen. Polar Research, 4, 1-16. MARCINIAK, M., DRAGON, K. & CHUDZIAK, Ł. 2014. Water circulation within a high-Arctic glaciated valley (Petunia Bay, Central Spitsbergen): Recharge of a glacial river. Journal of Hydrology, 513, 91-100. VAN DER MEIJ, W. M. 2015. Development and distribution of soil properties on marine terraces on central Spitsbergen - Comparing performance and results of two models. MSc, Wageningen University. VAN DER MEIJ, W. M., TEMME, A. J. A. M., DE KLEIJN, C. M. F. J. J., REIMANN, T., HEUVELINK, G. B. M., ZWOLIŃSKI, Z., RACHLEWICZ, G., RYMER, K. & SOMMER, M. 2015. Arctic soil development on a series of marine terraces on Central Spitsbergen, Svalbard: a combined geochronology, fieldwork and modelling approach. SOIL Discuss., 2015, 1345-1391. MELKE, J. 2007. Weathering processes in the soils of tundra of Western Spitsbergen. Polish Journal of Soil Science, 40, 2. MELKE, J. & CHODOROWSKI, J. 2006. Formation of arctic soils in Chamberlindalen, Bellsund, Spitsbergen. Polish Polar Research, 27, 119-132. MELKE, J. & UZIAK, S. 1989. Dynamics of moisture, redox potential and oxygen diffusion rate of some soils from Calypsostranda, Spitsbergen. Polish Polar Research, 10, 91-104. MELKE, J., WITKOWSKA-WALCZAK, B. & BARTMIŃSKI, P. 2013. Water retention of arctic zone soils (Spitsbergen). International Agrophysics, 27. MICHAELSON, G. J., PING, C. L. & KIMBLE, J. M. 1996. Carbon Storage and Distribution in Tundra Soils of Arctic Alaska, U.S.A. Arctic and Alpine Research, 28, 414-424. MIGAŁA, K., WOJTUŃ, B., SZYMAŃSKI, W. & MUSKAŁA, P. 2014. Soil moisture and temperature variation under different types of tundra vegetation during the growing season: A case study from the Fuglebekken catchment, SW Spitsbergen. Catena, 116, 10-18. MONGER, H. C., DAUGHERTY, L. A., LINDEMANN, W. C. & LIDDELL, C. M. 1991. Microbial precipitation of pedogenic calcite. Geology, 19, 997-1000. MONGER, H. C., GILE, L. H., HAWLEY, J. W. & GROSSMAN, R. B. 2009. The Desert Project: An Analysis of Aridland Soil-Geomorphic Processes, NM State University, Agricultural Experiment Station, College of Agricultural, Consumer and Environmental Sciences. MUSIAŁ, A. 1985. Traces of the glaciations in the northwest part of Nordenskiold Land (West Spitsbergen). POLISH POLAR RESEARCH (POL. POLAR RES.), 6, 497-513. NASA 2009. ASTER RGB-2 UTM33N. NASA. NASA VISIBLE EARTH 2015. Svalbard Wide 2015. Nasa. OLECH, M., WĘGRZYN, M., LISOWSKA, M., SŁABY, A. & ANGIEL, P. 2011. Contemporary Changes in Vegetation of Polar Regions. Papers on Global Change IGBP. ØVSTEDAL, D., TØNSBERG, T. & ELVEBAKK, A. 2009. The lichen flora of Svalbard. Sommerfeltia. PEREVERZEV, V. & LITVINOVA, T. 2010. Soils of sea terraces and bedrock slopes of fiords in Western Spitsbergen. Eurasian Soil Science, 43, 239-247. PEREVERZEV, V. N. 2012. Soils developed from marine and moraine deposits on the Billefjord coast, West Spitsbergen. Eurasian Soil Science, 45, 1023-1032. 63 PEREVERZEV, V. N. & LITVINOVA, T. I. 2012. Soils developed from alluvial and proluvial deposits in the Gröndalselva River valley in West Spitsbergen. Eurasian Soil Science, 45, 488-495. PIEPJOHN, K. S., ROLF; & JOCHMANN, M. H., CHRISTIANE Die Geologie von Longyearbyen. PRACH, K., KLIMEŠOVÁ, J., KOŠNAR, J., REDČENKO, O. & HAIS, M. 2012. Variability of contemporary vegetation around Petuniabukta, central Spitsbergen. Polish Polar Research, 33, 383-394. PRACH, K. & RACHLEWICZ, G. 2012. Succession of vascular plants in front of retreating glaciers in central Spitsbergen. Polish Polar Research, 33, 319-328. PRICE, L. W. 1971. Vegetation, Microtopography, and Depth of Active Layer on Different Exposures in Subarctic Alpine Tundra. Ecology, 52, 638-647. PRZYBYLAK, R., ARAŹNY, A., NORDLI, Ø., FINKELNBURG, R., KEJNA, M., BUDZIK, T., MIGAŁA, K., SIKORA, S., PUCZKO, D. & RYMER, K. 2014. Spatial distribution of air temperature on Svalbard during 1 year with campaign measurements. International Journal of Climatology, 34, 3702- 3719. PULINA, M., BURZYK, J. & BURZYK, M. 2003. Carbon dioxide in the tundra soils of SW Spitsbergen and its role in chemical denudation. Pol. Polar Res, 24, 243-260. PUSHKAREVA, E., PESSI, I. S., WILMOTTE, A. & ELSTER, J. 2015. Cyanobacterial community composition in Arctic soil crusts at different stages of development. FEMS microbiology ecology, 91, fiv143. RACHLEWICZ, G. 2007a. Floods in high Arctic valley systems and their geomorphologic effects (examples from Billefjorden, Central Spitsbergen). Landform Analysis, 5, 66-70. RACHLEWICZ, G. 2007b. Petuniabukta: from glacial to paraglacial processes in Ebbadalen–Leader Grzegorz Rachlewicz. Landform Analysis, 5. RACHLEWICZ, G. 2010. Paraglacial Modifications of Glacial Sediments Over Millennial to Decadal Time-Scales in the High Arctic (Billefjorden, Central Spitsbergen, Svalbard). Quaestiones Geographicae, 29. RACHLEWICZ, G., SZCZUCIŃSKI, W. & EWERTOWSKI, M. 2007. Post−“Little Ice Age” retreat rates of glaciers around Billefjorden in central Spitsbergen, Svalbard. Polish Polar Research, 28, 159- 186. REINHARDT, J. & SIGLEO, W. R. 1988. Paleosols and weathering through geologic time: principles and applications, Geological Society of America. RYMER, K. 2014. Characteristics of aeolian and niveo-aeolian deposits in central Spitsbergen (Ebba valley). Poznan: Adam Mickiewicz University. SARSBY, R. W. A. M., T. 2001. The exploitation of natural resources and the consequences. SAXTON, K. & RAWLS, W. 2006. Soil water characteristic estimates by texture and organic matter for hydrologic solutions. Soil science society of America Journal, 70, 1569-1578. SCALENGHE, R. & CERTINI, G. 2007. Soil forming factors (to Vasily Dokuchaev) [Online]. 2015]. SCHOSTAG, M., STIBAL, M., JACOBSEN, C. S., BÆLUM, J., TAŞ, N., ELBERLING, B., JANSSON, J. K., SEMENCHUK, P. & PRIEMÉ, A. 2015. Distinct summer and winter bacterial communities in the active layer of Svalbard permafrost revealed by DNA-and RNA-based analyses. Frontiers in microbiology, 6. SJÖBLOM, A. 2015. Weather conditions on Svalbard (College lecture). Department of Arctic Geophysics - UNIS. STANKOWSKA, A. 1989. Hydrochemistry of water basins on raised marine terraces in the lower part of Ebbadalen, Billefjorden, central Spitsbergen. Polish Polar Research, 10, 465-473. STIPP, S. 1998. Observations of hydration, hydrolysis and recrystallization on calcite surfaces exposed only to air. Mineralogical Magazine. STRZELECKI, M. 2011. Cold shores in warming times - current state and future challenges in High Arctic coastal geomorphological studies. Quaestiones Geographicae. STRZELECKI, M. C. B. 2012. High Arctic Paraglacial Coastal Evolution in Northern Billefjorden, Svalbard. SYSSELMANNEN PÅ SVALBARD. 2015. The Governor of Svalbard [Online]. Available: http://www.sysselmannen.no/ 2015]. 64 SZPIKOWSKI, J., SZPIKOWSKA, G., ZWOLIŃSKI, Z., RACHLEWICZ, G., KOSTRZEWSKI, A., MARCINIAK, M. & DRAGON, K. 2014. Character and rate of denudation in a High Arctic glacierized catchment (Ebbaelva, Central Spitsbergen). Geomorphology, 218, 52-62. TARNOCAI, C., CANADELL, J., SCHUUR, E., KUHRY, P., MAZHITOVA, G. & ZIMOV, S. 2009. Soil organic carbon pools in the northern circumpolar permafrost region. Global biogeochemical cycles, 23. TEDROW, J. C. F., DREW, J. V., HILL, D. E. & DOUGLAS, L. A. 1958. MAJOR GENETIC SOILS OF THE ARCTIC SLOPE OF ALASKA1. Journal of Soil Science, 9, 33-45. TEMME, A. J. A. M., LANGE, K. & SCHWERING, M. 2014. Pro-glacial soil variability and geomorphic activity – the case of three Swiss valleys. EARTH SURFACE PROCESSES AND LANDFORMS. TOMCZYK, A. & EWERTOWSKI, M. 2010. Changes of Arctic landscape due to human impact, north part of Billefjorden area, Svalbard. Quaestiones Geographicae. UGOLINI, F. C. 1986. Pedogenic zonation in the well-drained soils of the arctic regions. Quaternary Research, 26, 100-120. UZIAK, S., WILGAT, M. & KLIMOWICZ, Z. 1999. Mineral composition of arctic soils in the Bellsund region, Spitsbergen. Polish Polar Research, 20, 33-41. VAN GENUCHTEN, M. T. 1980. A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil science society of America journal, 44, 892-898. VAN VLIET-LANOË, B. 1998. Frost and soils: implications for paleosols, paleoclimates and stratigraphy. Catena, 34, 157-183. VAN DER WAL, R., SJÖGERSTEN, S., WOODIN, S. J., COOPER, E. J., JÓNSDÓTTIR, I. S., KUIJPER, D., FOX, T. A. D. & HUISKES, A. D. 2007. Spring feeding by pink-footed geese reduces carbon stocks and sink strength in tundra ecosystems. Global Change Biology, 13, 539-545. WEBSTER, R. 2001. Statistics to support soil research and their presentation. 52, 331-340. WOJTUŃ, B., SAMECKA-CYMERMAN, A., KOLON, K., KEMPERS, A. & SKRZYPEK, G. 2013. Metals in some dominant vascular plants, mosses, lichens, algae, and the biological soil crust in various types of terrestrial tundra, SW Spitsbergen, Norway. Polar Biology, 36, 1799-1809. WORSLEY, D. 1986. The Geological history of Svalbard: evolution of an arctic archipelago, Den norske stats oljeselskap a.s. WRB 2014. World Reference Base for Soil Resources 2014 - International soil classification system for naming soils and creating legends for soil maps. In: 2014, U. W. G. W. (ed.) World Soil Resources Reports No. 106. Rome: FAO. YOSHITAKE, S., UCHIDA, M., KOIZUMI, H., KANDA, H. & NAKATSUBO, T. 2010. Production of biological soil crusts in the early stage of primary succession on a High Arctic glacier foreland. New Phytologist, 186, 451-460. YOSHITAKE, S., UCHIDA, M., OHTSUKA, T., KANDA, H., KOIZUMI, H. & NAKATSUBO, T. 2011. Vegetation development and carbon storage on a glacier foreland in the High Arctic, Ny- Ålesund, Svalbard. Polar Science, 5, 391-397. ZAADY, E., GROFFMAN, P. & SHACHAK, M. 1998. Nitrogen fixation in macro- and microphytic patches in the Negev desert. Soil Biology and Biochemistry, 30, 449-454. ZAADY, E., KATRA, I., YIZHAQ, H., KINAST, S. & ASHKENAZY, Y. 2014. Inferring the impact of rainfall gradient on biocrusts’ developmental stage and thus on soil physical structures in sand dunes. Aeolian Research, 13, 81-89. ZWOLIŃSKI, Z., GIŻEJEWSKI, J., KARCZEWSKI, A., KASPRZAK, M., LANKAUF, K. R., MIGOŃ, P., PĘKALA, K., REPELEWSKA-PĘKALOWA, J., RACHLEWICZ, G. & SOBOTA, I. 2013a. Geomorphological settings of Polish research areas on Spitsbergen. Landform Analysis, 22, 125-143. ZWOLIŃSKI, Z., KOSTRZEWSKI, A. & PULINA, M. 2013b. Ancient and modern geoecosystems of Spitsbergen, Póznan, Uni-druk, Lubon k. Poznania. 65 Appendix A – Spitsbergen soils The following table contains the location of Polish Soil Research facilities. Some of the research that has been performed there considering soils or sedimentology bordering on soil profiling. The minimum number of pits per area, which is calculated as the sum of soil profiles per author (some authors use the same pits multiple times). The FAO soil profile descriptor and in the last column the specifiers that were given in literature, of which many often go together such as eutric skeletic cryosol. About sample locations, the Hornsund lies in the south, the Bellsund in the west, Kongsfjorden in the north west and Petuniabukta in the center. A few other locations have also been sampled incidentally. Two notes should be made on this aspect. Literature stated the following for Hornsund; Leptosols or Gleysols, and soils having permafrost in subsoil are classified as Cryosols, usually with Turbic properties, not a Eutric Cambisols but a Cryosol or perhaps Brunic Regosol. And secondary the so called “Arctic Brown Earth Soils”, commonly found in literature, presumably resemble Eutric Cambisols, Thaptocambic Cryosol or a Brunic regosol. Soil temperature < 0 °C (pergelic soil temperature regime) so acryic horizon and Gelic qualifier, the most common specifier. Table 10: Soil science Spitsbergen - Literature summary Location Research Min. total Soil profile Specifier nr. of pits (Including ‘old’ names) Hornsund Angiel 1994, 40 Cambisols Gelic Fischer 1990, 1995, Cryosols Eutric Haplic Gorniak 1992, Hyperskeletic Kabala 2009, 2012, Reductaquic Turbic Klimowicz 1996b, Fluvisols Migala 2014, Gleysols Gelic Plichta 1977, Histosols Geli Skiba 2002 Leptosols Eutric and Szymanski 2013 Lithic Rendzic Regosols Leptic Ornithic “Tundra gleyey cryogenic soil (Pergelic Cryaquent)” “Tundra peatysoil (Pergelic Histosot)” “Arctic desert soil (Pergelic Cryorthent)” Bellsund Klimowicz 1988, 163 Cambisol Gelic 1991, 1993, 1995, 1996a, 1997, 2009, Cryosol Arenic Brunic Melke 1989, 2006a, Siltic 2006b, 2007 Skeletic and Uziak 1999 Turbic Fluvisol Gelic Gleysol Gelic 66 Histosol Gelic Leptosol Gelic Lithic Rendzinas (Leptosol) Lithi-Renzic Paleosol Regosols Gelic (Hyper)Skeletic “Arctic brown soils”, “Striped Soil”, Kongsfjorden Dziadowiec 1994, 28 Cambisol Gelic Forman 1984, Gleysol Gelic Mann 1986, Histosol Regosol Gelic Plichta 1991 and Yoshitake 2011 Petuniabukta Lindner 1990, 16 Cambisols Eutric Long 2012, Cryosol Calcaric Fluvic Kabala 2009, 2012, Reductaquic Pereverzev 2012, Skeletic Thaptocambic Rachlewicz 2007 Turbic and Zwolinski 2013 Gleysols Calcaric Leptic Skeletic Turbic Leptosol Calcaric Gleyic Skeletic Regosol Arenic Brunic Eutric Turbic “raw_humus soddy soils” “Arctic Brown earth soils” Longyearbyen; Bibus 1976, W. Spitsbergen; Humlum 2005, Pereverzev 2010, 2012 67 Table 11: Soil classification (FAO) of all 44 sampled Petuniabukta soils. Nr. Landform FAO Soil Type Skeletic Carbonates OM Abruptic Other Ridge Cryosol Endoskeletic Calcic Rendzic Abruptic Turbic Ridge Cryosol Episkeletic Calcic - Turbic 10 Ridge Calcisol Episkeletic + - Slope Cryosol - 3 Mollic Abruptic Gelic, Turbic Slope Chernozem Endoskeletic + + Abruptic 3 Slope Calcisol Episkeletic + - Valley Cryosol Episkeletic Calcic - Abruptic Turbic Valley Cryosol Endoskeletic Calcic Rendzic Abruptic 2 Valley Cryosol Endoskeletic Calcic Rendzic Turbic Valley Cryosol Endoskeletic Calcic Rendzic Valley Cryosol Endoskeletic 5 Rendzic Abruptic 2 Valley Cryosol Endoskeletic Calcic Rendzic Valley Cryosol Endoskeletic 5 - Valley Cryosol - Calcic Rendzic Abruptic Turbic Valley Cryosol - 3 Mollic Abruptic Valley Calcisol Endoskeletic + - Valley Calcisol Episkeletic + - Valley Chernozem Endoskeletic + + Abruptic Valley Chernozem Endoskeletic + + Valley Chernozem Episkeletic + + Valley Kastanozem Endoskeletic Calcic + Abruptic Valley Phaeozem Endoskeletic 4 + Abruptic Valley Phaeozem - 2 + Gleyic River Gleysol Episkeletic Calcic - 2 River Fluvisol Episkeletic Calcaric - Colluvium Cryosol Episkeletic 4 Rendzic Abruptic Colluvium Cryosol Episkeletic 5 - Densic, Turbic Colluvium Cryosol - 4 Rendzic Densic, Turbic Colluvium Calcisol Episkeletic + - Colluvium Chernozem - + + The 44 soils that have been sampled, sorted per landform. The number that every soil classification, including qualifiers was found is noted in the first column. The amount of rocks is illustrated with the skeletic level. The amount of carbonate precipitation as either calcic or calcaric when relevant. In Cryosols this is not relevant but the level of Forman calcification is noted. A + means that its presence is included in the main soil classification. The state of organic matter and siltification are noted and finally any other qualifiers. 68 Appendix B – Soil description form The numbers refer to the page in the FAO-guide where the applied method is described (FAO, 2006, WRB, 2014). SOIL DESCRIPTION FORM - Spitsbergen 2014 Adjusted Site no: GPS–reading (WGS 84 UTM 33N coordinates) Date: UTM Zone 33 X Easting [m]: Northing [m]: Altitude [m]: Waypoint nr.: Surveyor: Marijn / Christian / Both Picture Nr. Before: After: Picture of Soil itself: Presumed Location: Terrace (nr. ) / Moraine (nr. ) / Other: Landscape Setting: 10-11 Slope [%] Inclinometer Surface stoniness [%] Effective depth Depth of Siltated layers/Pebble layers Profile curvature 12 Gravel: Stone: Bould: Rock: Rooting Depth Silt: Plan curvature 12 21-22 24-25 Pebbles: Aspect [°] Compass 12 Parent material: 16-18 Erosion / Deposition: 22-23 Crusts 23 Drainage class: 50-52 Vegetation type: 16 Coverage [%] Salts 24 Permeability: 50-52 Sample Bag nr.: Expected main soil forming processes: Remarks: Differences in Parent Material: Soil Profile Description Carbonate Horizon Colour Mottles Texture Stones in prof. Structure HCL Soil Moist Siltation Bulk Density (Forman) Symb Depth (cm) Moist % Type Class % Nodules Type Grade Size Class Class [%] Class g/100cm3 Measurement Forman 67 33-34 35- 37 25-29 29- 31 44- 48 38 SM-meter Forman Ring/Scale tape FAO Classification: Specifiers: 69 The following characteristics have not or very scarcely been used in further analysis. I purposely chose to add them in this report for future research to benefit from it and completeness of the interpretation or lack thereof for certain measured variables, which were expected to possibly sort an effect on the soil formation, processes and time scales. - Aspect The aspect of most soil pits has been measured. Nearly the whole area (mainly terraces) generally faced in the same direction (west) and although in other areas close by, differences between especially vegetation cover were clearly noticeable for different aspects, our area did not have enough variation for this variable to result in statistically significant differences. - Permeability and drainage The field estimations were performed hastily and the variation showed no consistency. In the field it became obvious that hydrology is indeed an important and soil/landscape forming factor in both large and small scale, so the lack of any trend in the data mostly strengthens the idea that the method to assess these values in the field and mostly the application thereof, was of insufficient quality, unfortunately. - In situ soil moisture Measurements in the field were very difficult due to the high stoniness of most soils. In the lab many soil monsters that have been taken were analyzed for their water content. There is a pretty strong co-linearity between the two, which is generally that the field soil-moisture content is about twice as high as the value measured in the lab. Because it was a known fact that the soil moisture meter used in the field was a little bit of and not calibrated, in most cases the lab value is used. In some cases the lab measurement went wrong. There a statistical soil moisture content was created from the field measurement. - Soil structure The soil structure has been assessed in the field, no useful application was found for this variable during the analysis for my research. Expected to prove valuable to find differences between the aeolian horizon and the marine terrace A-horizon, which was rarely the case. - Odour Many terrace soils had a petrochemical smell in the B or mostly BC-horizon. During fieldwork and literature studies no other explanation for this smell has been found than the presence of a deep oil layer, found by Russian drilling tests. The implications of this on the soils has remained uninvestigated by me. - Sediment form and distribution In order to make sure that the ‘aeolian horizon’ really is aeolian, the sediment form and distribution needed to be assessed. Of nearly all soils and most A-horizons, sediment samples were taken. Also specifically for the purpose of parent material verification, eight other ‘pure sediment’ samples have been taken in the valley. Quick investigation under a microscope showed clear differences between origins and this method proved plausible for the research goal. However many samples had a mixed origin and the time for investigation and comparison per sample was relatively long. 70 Appendix C – Background information Ebbadalen Figure 46: Edited for Ebbadalen relevance from original (Dallmann and Blomeier, 2004). 71 “The bedrock geology of the region is diverse and determined by dislocations along the Billefjiorden fault zone. The faults, which have a longitudinal orientation, have caused a wide variety of rock types to outcrop in the study area. The mountain massif close to the glacier (the eastern part) is composed mainly of metamorphic rocks (amphibolites and gneisses), while in the middle part of the region, gypsum, dolomite and anhydrite prevail. Sandstone, dolomite and limestone dominate the area near the seaside. The slope deposits are primarily composed of rocks that originated from the surrounding mountain massifs covering the Ebba Valley. The part of the valley closest to the sea is dominated by marine shore deposits. In the central part of the valley, near the Ebba River, fluvial and glaciofluvial deposits occur. The slope deposition that covers the valley area thaws seasonally and forms a shallow active layer, which enables the flow of subsurface water. When the temperature rises above 0 °C, the flow of water start. During the melting season, the thickness of the active layer increases. The maximum thickness usually occurs at the end of the summer, and it varies between 0.3 and 1.6 m. During the study period the thickness of active layer varied in the valley area from 0.47 to 1.0 m. Streams that flow from the mountain massifs surrounding the Ebba valley recharge the groundwater that occurs in the active layer. In some parts of the valley, these streams disappear and form subsurface flows in the upper portions of the slopes. In other cases the flow is overland. At the end of summer, when the temperature drops below 0 °C (usually in September) the active layer freezes up and water stays locked up until the next season.” (Marciniak et al., 2014) Figure 47: Aerial photograph of the Ebba valley showing the location of the marine terraces and erosion gullies. The aerial photograph is from 2009 edited by Van der Meij (van der Meij, 2015). 72 Figure 48: Time series of daily means of global solar radiation, albedo, ground surface temperature, 2m air T., and relative humidity at Petuniabukta in the period 2008–10 (Láska et al., 2012). 73