DOCSLIB.ORG

Orbital-Scale Climate Forcing of Grassland Burning in Southern Africa

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Orbital-Scale Climate Forcing of Grassland Burning in Southern Africa Orbital-scale climate forcing of grassland burning in southern Africa Anne-Laure Daniaua,b,c,1, Maria Fernanda Sánchez Goñib, Philippe Martineza, Dunia H. Urregoa,b,c, Viviane Bout-Roumazeillesd, Stéphanie Despratb, and Jennifer R. Marlone aCentre National de la Recherche Scientifique (CNRS), Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), Unité Mixte de Recherche (UMR) 5805, Université Bordeaux 1, F-33400 Talence, France; bEcole Pratique des Hautes Etudes (EPHE), EPOC, UMR 5805, F-33400 Talence, France; and cCNRS, de la Préhistoire à l’Actuel: Culture, Environnement et Anthropologie (PACEA), UMR 5199, F-33400 Talence, France; dGéosystèmes UMR 8217 CNRS, Sciences de la Terre, Université Lille 1, 59655 Villeneuve d’Ascq, France; and eSchool of Forestry and Environmental Studies, Yale University, New Haven, CT 06511 Edited by William F. Ruddiman, University of Virginia, Charlottesville, VA, and accepted by the Editorial Board February 12, 2013 (received for review August 17, 2012) Although grassland and savanna occupy only a quarter of the rainfall, and vegetation changes to identify the primary controls world’s vegetation, burning in these ecosystems accounts for on biomass burning over the past 170,000 y. roughly half the global carbon emissions from fire. However, the There are two major types of fire-prone vegetation in southern processes that govern changes in grassland burning are poorly Africa: eastern grasslands and southwestern fynbos (Mediterra- understood, particularly on time scales beyond satellite records. nean evergreen hard-leaved scrub). Fire is absent from the desert We analyzed microcharcoal, sediments, and geochemistry in and semidesert regions (Fig. 1). The eastern half of southern a high-resolution marine sediment core off Namibia to identify Africa and the northern Cape regions, Namibia, and Botswana the processes that have controlled biomass burning in southern are dominated by arid savanna and grasslands that support sur- African grassland ecosystems under large, multimillennial-scale cli- face fires (9) (Fig. 1). These regions are under the influence of mate changes. Six fire cycles occurred during the past 170,000 y in the Intertropical Convergence Zone (ITCZ), and their climatic southern Africa that correspond both in timing and magnitude to regime is modulated by the South African monsoon, which the precessional forcing of north–south shifts in the Intertropical brings rainfall during the austral summer (November–March) SCIENCES Convergence Zone. Contrary to the conventional expectation that (11). Surface fires occur mainly during the peak of the dry season ENVIRONMENTAL fire increases with higher temperatures and increased drought, we from July to September (austral winter) and are highly de- found that wetter and cooler climates cause increased burning in pendent on the accumulated rainfall of the previous 2 y (which the study region, owing to a shift in rainfall amount and season- drives fuel loads), as well as on marked rainfall seasonality (i.e., ality (and thus vegetation flammability). We also show that char- a limited number of months with rainfall) (9). In general, the coal morphology (i.e., the particle’s length-to-width ratio) can be seasonality causes fuel build-up during the wet austral summers used to reconstruct changes in fire activity as well as biome shifts and increased fuel flammability during dry winters. Ignitions in over time. Our results provide essential context for understanding the region come from both lightning and humans today, but current and future grassland-fire dynamics and their associated lightning alone would provide an ample source of ignitions for carbon emissions. fires even in the absence of humans (12). In the southern and southwestern regions (western Cape), arge changes in the spatiotemporal patterns of wildfires in winter-rainfall fynbos provide woody fuels that support crown Lrecent decades raise concerns about how future changes in fires during the dry season of the western Cape (i.e., from De- fire might interact with climate change and human activities (1, cember to February), corresponding to the wet austral summer 2). Africa is the most fire-prone continent, and southern Africa is period when precipitation mainly falls in the eastern part of recognized as a climate change and biodiversity hotspot (3, 4). southern Africa. These fires burn dense sclerophyllous shrubs Under global warming, fire risk is projected to increase by the and small trees. They are most likely to occur after exceptional end of the 21st century in this region owing to a rise in tem- weather conditions, especially prolonged drought (9, 13, 14). fi peratures and austral winter dryness (5, 6). Projected wildfires, Large res are common in savanna and grassland, but in- however, vary substantially depending on the general circula- creasingly fragmented vegetation induced by human activities fi tion model (GCMs) and Intergovernmental Panel on Climate reduces landscape connectivity and wild re occurrences in these Change (IPCC) emission scenarios used (6). GCMs seldom take vegetation types (15). into account vegetation adjustments to climate changes, yet such Results and Discussion changes are vital for projecting reliable shifts in fuels and thus fi fire activity (6). Under increased aridity, for example, longer or Microcharcoal belongs to the ne sediment fraction and is more frequent droughts may promote burning in ecosystems that transported by winds and river plumes from southern African are not fuel limited. However, vegetation shifts toward fuel- combustion sites to the Atlantic Ocean. The main source of limited communities may reduce fire activity in the same region microcharcoal is not well constrained but is very likely limited to ’ (7, 8). southern Africa below 20°S. The Orange River s hydrographic Currently there are no empirical data to support the idea that a warming and drying climate would lead to an increase in bio- mass burning in southern Africa. In fact, a number of remotely Author contributions: A.-L.D. and M.F.S.G. designed research; A.-L.D. performed research; fi A.-L.D., P.M., and V.B.-R. contributed new reagents/analytic tools; A.-L.D., M.F.S.G., P.M., sensed data indicate that wetter periods result in increased re D.H.U., V.B.-R., S.D., and J.R.M. analyzed data; and A.-L.D., M.F.S.G., P.M., D.H.U., V.B.-R., in this region (8–10). To address this question, we examined S.D., and J.R.M. wrote the paper. microcharcoal from a marine sediment record that accumulated The authors declare no conflict of interest. during the past two climatic cycles off southwestern Africa and This article is a PNAS Direct Submission. W.F.R. is a guest editor invited by the covers several past warm periods. We analyzed the sediment to Editorial Board. confirm that variations in microcharcoal concentrations reflect 1To whom correspondence should be addressed. E-mail: [email protected]. biomass burning rather than transportation or depositional pro- This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10. cesses. We then compared the fire data with orbital parameters, 1073/pnas.1214292110/-/DCSupplemental. www.pnas.org/cgi/doi/10.1073/pnas.1214292110 PNAS Early Edition | 1of5 Downloaded by guest on September 25, 2021 10° 20° 30° 40° from either biogenic or terrigenous material do not significantly control microcharcoal concentrations variability. Today the Or- ange River is the primary source of smectite and kaolinite (23), whereas illite is transported by winds (23) toward the oceanic region where MD96-2098 was retrieved. Clay analyses (Fig. 2D) Namib desert -20° -20° show that similar illite/smectite ratios are either associated with 500 Kalahari 3000 peaks or troughs of microcharcoal concentration (i.e., micro- desert charcoal concentration variation is independent of changes in wind transport or river supply). As a result, variations in micro- fl MD96-2098 charcoal concentrations seem to re ect microcharcoal production Orange River and henceforth are interpreted as faithful records of changes in -30° -30° biomass burning and fire activity in southern Africa. The morphometric analysis showed that more elongated par- ticles are prevalent during periods of high fire activity. The mean elongation ratio is approximately 1.82 for high fire activity compared with approximately 1.65 for low activity (Fig. 2E, CCnb vs. elongation ratio, r = 0.4, P < 0.001). More elongated particles are found also during precession maxima (elongation 10° 20° 30° 40° ratio vs. precession, r = 0.71, P < 0.001). During a fire, charcoal Absence of fire Vegetation fragmentation occurs along axes derived from the anatomical Mediterranean evergreen forest hard-leaf scrub Semi-desert structure of plant species. The elongation degree is preserved Desert even when the particle is broken (24). Experimental analysis Steppe (grass, brush, and thicket) Brush-grass savanna conducted on burned grasses and wood from North America Deciduous forest-woodland savanna showed that charcoal from grasses has a greater elongation ratio Montane forest-tundra than charcoal derived from wood (24). We thus infer that the Temperate grassland and mountain grassland East Africa coastal forest increase in the mean elongation of microcharcoal particles is an indicator of low-intensity fires spreading in grass-dominated Fig. 1. Map of southern Africa with the location of marine core MD96- ’ fueled environments. An input of microcharcoal from fynbos 2098, the Orange River s hydrographic basin (dashed blue line), and sim- fires is negligible, owing to the absence of a clear correspondence plified vegetation distribution, after ref. 48. Arrows indicate mean annual wind direction (redrawn from National Centers for Environmental Pre- between increased biomass burning and Restionaceae pollen diction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis, percentages (mainly found in fynbos) from the close core mean annual 850-mb vector wind calculated over 1948–2012, www.esrl. GeoB1711 in the Atlantic Ocean (25) (Fig. S3). noaa.gov/psd/). Black dashed arrow indicates the Benguela current (17).
Load more

Recommended publications
  • Teleconnections of the Tropical Atlantic to the Tropical Indian and Pacific Oceans: a Review of Recent findings
    Meteorologische Zeitschrift, Vol. 18, No. 4, 445-454 (August 2009) Article c by Gebr¨uder Borntraeger 2009 Teleconnections of the tropical Atlantic to the tropical Indian and Pacific Oceans: A review of recent findings 1∗ 2 2 3 CHUNZAI WANG ,FRED KUCHARSKI ,RONDROTIANA BARIMALALA and ANNALISA BRACCO 1NOAA Atlantic Oceanographic and Meteorological Laboratory, Miami, Florida U.S.A. 2The Abdus Salam International Centre for Theoretical Physics, Earth System Physics Section Trieste, Italy 3School of Earth and Atmospheric Sciences Georgia Institute of Technology, Atlanta, Georgia, U.S.A. (Manuscript received November 12, 2008; in revised form February 16, 2009; accepted March 18, 2009) Abstract Recent studies found that tropical Atlantic variability may affect the climate in both the tropical Pacific and Indian Ocean basins, possibly modulating the Indian summer monsoon and Pacific ENSO events. A warm tropical Atlantic Ocean forces a Gill-Matsuno-type quadrupole response with a low-level anticyclone located over India that weakens the Indian monsoon circulation, and vice versa for a cold tropical Atlantic Ocean. The tropical Atlantic Ocean can also induce changes in the Indian Ocean sea surface temperatures (SSTs), especially along the coast of Africa and in the western side of the Indian basin. Additionally, it can influence the tropical Pacific Ocean via an atmospheric teleconnection that is associated with the Atlantic Walker circulation. Although the Pacific El Ni˜no does not contemporaneously correlate with the Atlantic Ni˜no, anomalous warming or cooling of the two equatorial oceans can form an inter-basin SST gradient that induces surface zonal wind anomalies over equatorial South America and other regions in both ocean basins.
    [Show full text]
  • Impacts of Climate Change on Fisheries and Aquaculture Impa on Fi
    ISSN 2070-7010 AO F APER TURE L P ISSN 2070-7010 627 TECHNICAL FISHERIES AND AQUACU AO F APER TURE L P 627 TECHNICAL FISHERIES AND AQUACU Synthesis of current knowledge, adaptation and mitigation options Impacts of climate change on fisheries and aquaculture Synthesis of current knowledge, adaptation and mitigation options on fisheries and aquaculture Impacts of climate change 627 Impacts of climate change on fisheries and aquaculture – Synthesis of current knowledge, adaptation and mitigation options FAO 627 Impacts of climate change on fisheries and aquaculture – Synthesis of current knowledge, adaptation and mitigation options FAO ISSN 2070-7010 I9705EN/1/06.18 306079 789251 ISSN 2070-7010 I9705EN/1/06.18 306079 9 ISBN 978-92-5-130607-9 789251 9 ISBN 978-92-5-130607-9 strategies and tools for mitigation. also includes chapters on disasters and extreme events (Chapter 23) and aquaculture sector, in the context of poverty alleviation. aquaculture sector, strategies and tools for mitigation. also includes chapters on disasters and extreme events (Chapter 23) and aquaculture sector, in the context of poverty alleviation. aquaculture sector, their fisheries (Chapters 18, 19 and 26), as well as aquaculture (Chapters 20 to 22). Technical Paper Technical the fisheries and aquaculture sector’s contributions to greenhouse gas emissions, as well as the fisheries and aquaculture sector’s The It covers marine capture fisheries and their environments (Chapters 4 to 17), inland waters and This FAO Technical Paper is aimed primarily at policymakers, fisheries managers and practitioners Technical This FAO and has been prepared particularly with a view to assisting countries in the development of their Nationally Determined Contributions (NDCs) to the Paris Climate Agreement, the next versions of (Chapter 26).
    [Show full text]
  • Mangrove Ecosystems of Latin America and the Caribbean: a Summary
    Project PD114!90 (F) Mangrove Ecosystems of Latin America and the Caribbean: a Summary 1 2 3 4 s 6 7 8 Lacerda, L.D. ; Conde, J.E. ; Alarcon, c. ; Alvarez-León, R. ; Bacon, P.R. ; D'Croz, L. ; Kjerfve, B. ; Polaina, J. & M. Vannucci9 1-Departamento de Geoquímica, Universidade Federal Fluminense, Niteroi, 24020-007, RJ, Brazil. 2- Centro de Ecología, Instituto Venezolano de Investigaciones Científicas, AP 21827, Caracas 1020A, Venezuela. 3- Centro de Investigaciones en Ecología y Zonas Áridas (CIEZA), Universidad Nadonal Experimental Francisco de Miranda, AP 7506, Coro, Falcón, Venezuela. 4- Promotora de Fomento Cultural de Costa Atlántica (PRODECOSTA), AA­ 1820, Cartagena, (Bol.) Colombia. 5- Department of Zoology, University of West Indies, 51. Augustine, Port of Spain, Trinidad & Tobago. 6- Departamento de Biología Acuática, Universidad de Panamá and Smithsonian Tropical Research Institute, Box 2074, Balboa, República de Panamá. 7- Marine Science Program, University of South Carolina, 29208, Columbia, SC, USA. 8- Centro Agronómico Tropical de Investigadon y Enseñanza, Tur­ rialba, Costa Rica. 9- Intemational Sodety for Mangrove Ecosystems (ISME), Okinawa, Japan. 1. Mangroves and Man in Pre-Columbian of soil by slash-and-burn farmers (Veloz Maggiolo & and Colonial America Pantel, 1976, cited in Sanoja, 1992). In various countries of the American continent, The nomadic human groups frequently formed there is strong archeological evidence of mangrove semi-permanent settlements along the coast, close to utilization by Pre-Columbian and even Pre-historical lagoons and bays, where an abundant and easy to human groups. Pre-Columbian inhabitants tradition­ collect protein-rich diet was provided by molluscs ally used mangroves for many purposes, including (Reichel-Dolmatoff, 1965).
    [Show full text]
  • Caribbean and Pacific Coastal Marine System
    C. Birkeland Caribbean and Pacific Coastal marine system: similarities and differences A goal that scientists set for themselves is to find general Magnitude of rate of nutrient input principles with broad relevance and applicability. This devotion to generality can lead to serious error. For A primary factor in bringing about differences in the example, the harvesting techniques that are very successful functional organization of coral-reef communities in on the temperate Great Plains may not be applicable to the different geographic regions is the magnitude of the rate of Amazonian rain forest. In the rain forest, where the nutrient input and the degree to which the input nutrients are bound into the biomass and are sparse in the is concentrated into pulses. John Ryther of Woods Hole soil, pruning may be a more workable pattern of resource Oceanographic Institute calculated that over half the world utilization than reaping. Reaping works well on the prairie, fishery catch comes from upwelling regions, although the but is likely to do extensive, practically irreparable, regions of upwelling occupy only about one-tenth of 1% damage to the tropical rain forest system. of the ocean surface. Coral-reef ecosystems are even more productive than are regions of upwelling in terms of rates Differences of gross primary productivity per unit area. Relatively pristine coral reefs maintain a large standing-stock Functional differences exist within types of tropical biomass of fish. Yet coral reefs are particularly vulnerable coastal ecosystems among different regions of the world to overexploitation while the regions of upwelling are that are analogous to the tropical rainforest/ temperate heavily exploited year after year.
    [Show full text]
  • Towards Characterising Microplastic Abundance, Typology and Retention in Mangrove-Dominated Estuaries
    water Article Towards Characterising Microplastic Abundance, Typology and Retention in Mangrove-Dominated Estuaries Joelene Govender 1,* , Trishan Naidoo 2 , Anusha Rajkaran 2 , Senzo Cebekhulu 1, Astika Bhugeloo 1 and Sershen 2,3 1 School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa; [email protected] (S.C.); [email protected] (A.B.) 2 Department for Biodiversity and Conservation Biology, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa; [email protected] (T.N.); [email protected] (A.R.); [email protected] (S.) 3 Institute of Natural Resources, P.O. Box 100396, Scottsville 3209, South Africa * Correspondence: [email protected]; Tel.: +27-32-945-1379 Received: 5 September 2020; Accepted: 1 October 2020; Published: 9 October 2020 Abstract: Plastic and, particularly, microplastic (MP) pollution is a growing research theme, dedicated largely to marine systems. Occurring at the land–sea interface, estuarine habitats such as mangroves are at risk of plastic pollution. This study compared MP pollution (level, morphotype, polymer composition, size and colour) across four South African estuaries, in relation to the built and natural environment. Mouth status, surrounding human population densities and land-use practices influenced the level and type of MP pollution. Systems that were most at risk were predominantly open estuaries surrounded by high population densities and diverse land use types. Microplastic levels and the diversity of types detected increased with increasing levels of anthropogenic disturbance. Overall, microfibres dominated in estuarine water (69%) and mangrove sediment (51%). Polyethylene (43%) and polypropylene (23%) were the dominant polymers overall.
    [Show full text]
  • State of the Climate in Latin America and the Caribbean 2020 WEATHER CLIMATE WATER CLIMATE WEATHER
    State of the Climate in Latin America and the Caribbean 2020 WEATHER CLIMATE WATER CLIMATE WEATHER WMO-No. 1272 WMO-No. 1272 © World Meteorological Organization, 2021 The right of publication in print, electronic and any other form and in any language is reserved by WMO. Short extracts from WMO publications may be reproduced without authorization, provided that the complete source is clearly indicated. Editorial correspondence and requests to publish, reproduce or translate this publication in part or in whole should be addressed to: Chair, Publications Board World Meteorological Organization (WMO) 7 bis, avenue de la Paix Tel.: +41 (0) 22 730 84 03 P.O. Box 2300 Fax: +41 (0) 22 730 81 17 CH-1211 Geneva 2, Switzerland Email: [email protected] ISBN 978-92-63-11272-9 Cover illustration: Mangroves in Los Haitises National Park (Dominican Republic): Anton Bielousov; Wildfires Brazil: Christian Braga; Hurricane Iota: NOAA; Perito Moreno Glacier in Argentina: AdobeStock (264550963) NOTE The designations employed in WMO publications and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of WMO concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. The mention of specific companies or products does not imply that they are endorsed or recommended by WMO in preference to others of a similar nature which are not mentioned or advertised. The findings, interpretations and conclusions expressed in WMO publications with named authors are those of the authors alone and do not necessarily reflect those of WMO or its Members.
    [Show full text]
  • Tropical Cyclones of the North Atlantic Ocean
    U.S. DEPARTMENT OF COMMERCE JOHN T. CoNNOR, Secretary WEATHER ·BUREAU RoBERT M. W BITE, Chief TECHNICAL PAPER NO. 55 Tropical Cyclones of the North Atlantic Ocean Tracks and Frequencies of Hurricanes and Tropical Storms, 1871-1963 GEORGE W. CRY Laboratory of Climatology, U.S. Weather Bureau WASHINGTON, D.C. 1965 For sale by the Superintendent of Documents, U,S. Government Printing Office, Washington, D.C., 20402 - Price 70 cents PREFACE Scope.-This paper seeks to consolidate records of the occur­ purpose of this paper is to provide this information in a convenient rences and paths of tropical cyclones of storm and hurricane force form. in the North Atlantic region, and to provide information on the U.S. Weather Bureau Technical Paper No. 36 [9] provided the frequencies and seasonal distributions of these relatively rare, but starting point for the present study. The general outline of that important, disturbances. work has been maintained, but additional material has been utilized Tropical cyclones are significant features of the climate of much of to extend information on tropical cyclones backward to include the the eastern and southern United States as well as of most other years 1871 through 1885 and forward to include the years 1959 areas bordering the western edge of the Atlantic, the Caribbean, and through 1963. New material also provided the basis for slight Gulf of Mexico. The destructive features of a single fully-developed modifications of a number of the tropical cyclone paths shown in hurricane-extremely strong winds, torrential rainfall, and high [9]. New text, tables, figures, and charts have been prepared, and tides and waves-may pose a threat to life and property over an a short discussion of possible trends in tropical cyclone frequencies area of more than 30,000 square miles, and to more than 30 million has been included.
    [Show full text]
  • Extended-Range Forecast of Atlantic Hurricane Activity for 2020
    EXTENDED RANGE FORECAST OF ATLANTIC SEASONAL HURRICANE ACTIVITY AND LANDFALL STRIKE PROBABILITY FOR 2020 We have maintained our above-average seasonal hurricane forecast for the 2020 Atlantic season. Current cool neutral ENSO conditions may transition to weak La Niña conditions by later this summer. Sea surface temperatures averaged across most of the tropical Atlantic and subtropical Atlantic are somewhat above normal. We anticipate an above-normal probability for major hurricanes making landfall along the continental United States coastline and in the Caribbean. As is the case with all hurricane seasons, coastal residents are reminded that it only takes one hurricane making landfall to make it an active season for them. They should prepare the same for every season, regardless of how much activity is predicted. (as of 7 July 2020) By Philip J. Klotzbach1, Michael M. Bell2, and Jhordanne Jones3 4 In Memory of William M. Gray This discussion as well as past forecasts and verifications are available online at http://tropical.colostate.edu Anne Manning, Colorado State University media representative, is coordinating media inquiries into this forecast. She can be reached at 970-491-7099 or [email protected]. Department of Atmospheric Science Colorado State University Fort Collins, CO 80523 Project Sponsors: 1 Research Scientist 2 Associate Professor 3 Graduate Research Assistant 4 Professor Emeritus 1 ATLANTIC BASIN SEASONAL HURRICANE FORECAST FOR 2020 Forecast Parameter and 1981-2010 Issue Date Issue Date Issue Date Observed Thru
    [Show full text]
  • Coastal Wetlands
    Southwest Florida Shelf Coastal Marine Ecosystem—Habitat: Coastal Wetlands Habitat: Coastal Wetlands '͘>LJŶŶtŝŶŐĂƌĚ h͘^͘'ĞŽůŽŐŝĐĂů^ƵƌǀĞLJ :ĞƌŽŵĞ:͘>ŽƌĞŶnj ƵĚƵďŽŶŽĨ&ůŽƌŝĚĂ In a nutshell: t Coastal wetlands form a critical ecotone at the boundary between freshwater and marine environments that help maintain water quality for the marine ecosystem and serve as a nursery and food source for many marine species. t People value coastal wetlands because they stabilize the coastline and provide protection from storm surge and flooding, improve water quality by filtering nutrients, provide critical habitat for protected species, and provide aesthetic, recreational, and tourism value. t In the barrier islands area, the coastal wetlands are threatened by development as mangroves and shorelines are replaced with an urban landscape. Throughout the southwest coastal region, anthropogenic changes in freshwater delivery are disturbing the salinity gradients necessary to maintain plant communities of the transition zone. t The primary threats to the coastal wetlands are their vulnerability to impacts from sea-level rise and altered freshwater flow and changes in intensity and frequency of coastal storms. Within the context of the SWFS ICEM, we have defined have divided the southwest Florida coastal wetlands into the coastal wetlands as the saltwater zone landward of the four provinces (Figure 1) based on their dominant coastal coastal margin, which includes the marshes, flats, and features: Barrier Islands, Ten Thousand Islands, Everglades/ mangroves and the intermittent creeks, channels, and Shark River Slough, and Cape Sable/White Water Bay. rivulets that flow through these areas (Figure 1). The entire These provinces are, for the most part, very similar and are region is characterized by gently-sloping topography with not specifically differentiated in the ICEM (Figure 2).
    [Show full text]
  • Evolutionary History of Lineages and Biotas UNCORRECTED PAGE PROOFS • © 2010 Sinauer Associates, Inc
    UNCORRECTED PAGE PROOFS • © 2010 Sinauer Associates, Inc. This material cannot be copied, reproduced, manufactured, or disseminated in any form without UNIT FOUR express written permission from the publisher. Evolutionary History of Lineages and Biotas UNCORRECTED PAGE PROOFS • © 2010 Sinauer Associates, Inc. This material cannot be copied, reproduced, manufactured, or disseminated in any form without express written permission from the publisher. Previous Page: The Hawaiian Islands. Courtesy of Jeff Schmaltz, MODIS Rapid Response Team, NASA/GSFC. 10 Th e Ge o g r a p h y o f Diversification In Unit 3, we learned that the evolutionary fates and distributions of The Fundamental Geographic species have been dynamic throughout the history of life on Earth. Patterns 362 New species have continuously evolved from ancestral species, Endemism and Cosmopolitanism 365 and occasionally, large numbers of species have been eliminated in The origins of endemics 368 an episode of mass extinction followed by the evolution of entirely Provincialism 370 new sorts of species. Species distributions often have changed, either through jump dispersal of founding individuals or populations across Terrestrial regions and provinces 370 a barrier, or through more gradual range expansion over continuous Marine regions and provinces 384 expanses of suitable habitats. Some of the most profound changes in Classifying islands 388 distributions have come when entire groups of species have crossed Quantifying similarity among biotas 392 from one biogeographic region to another following the erosion of Disjunction 396 a barrier. Additionally, we learned that the geology of the Earth it- Patterns 396 self changes continuously through time and that at various times and Processes 398 particularly over the past several million years, climatic cycles have Maintenance of Distinct Biotas 399 produced an exceedingly dynamic ecological arena.
    [Show full text]
  • Mangroves and Mollusks Along Brazil's Mangal Coast
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Portal de Revistas Eletrônicas da UniEVANGÉLICA (Centro Universitário de Anápolis) Between Land and Sea: Mangroves and Mollusks along Brazil’s Mangal Coast Judith A. Carney 1 ABSTRACT Westerners have long viewed mangroves as forbidding, pestilential landscapes. While modern medicine transformed their deadly reputation, the perception lingered of an environment that was little more than a tropical wasteland. The 1992 Earth Summit in Rio de Janeiro profoundly changed this view by drawing attention to the ecosystem as a habitat crucial to the life cycles of many species and endangered fauna yet increasingly at risk from deforestation. Conservation initiatives in the years since the Rio Summit, however, seldom recognize mangroves as a habitat that has also long supported human life. This is evident in the shell middens found along mangrove coasts and in the historical record of shellfish harvested for dietary protein. With a focus on Brazil, this article examines the shellfish that sustained Amerindians, enslaved Africans, and their descendants along the mangal coast since pre- Columbian times. The discussion contends that Brazil‟s mangrove forests cannot be separated from the history of the tropical peoples who have successively lived in and managed this ecosystem from ancient times to the present. Finally, the article concludes that a research focus on shellfish suggests broader linkages to South Atlantic history. Keywords: Mangroves; Human Habitat; Edible Shellfish; Coastal Brazil; African Diaspora; South Atlantic History. 1 Department of Geography, University of California Los Angeles; [email protected] Fronteiras: Journal of Social, Technological and Environmental Science • http://revistas.unievangelica.edu.br/index.php/fronteiras/ v.5, n.3, jul.-dez.
    [Show full text]
  • Ecological Baselines of the Southeast Atlantic and Southeast Pacific Status of Marine Biodiversity and Anthropogenic Pressures in Areas Beyond National Jurisdiction
    Ecological Baselines of the Southeast Atlantic and Southeast Pacific Status of Marine Biodiversity and Anthropogenic Pressures in Areas Beyond National Jurisdiction Citation Boteler, B., Wanless, R., Dias, M., Packeiser, T., Awad, A., Yannicelli, B., Zapata Padilla, L.A., Aburto, J., Seeger, I., Hampton, S., Jackson, L., Wienrich, N., Ajagbe, A., Hazin, C., Castellanos Galindo, G.A., German Naranjo, L., Fredy Suárez, C., Prussmann, J., Valenzuela, S., Gomez Giraldo, L.S., Higgins, M.L., Contreras, C., Luna, G., Luna, N., Munizaga, M., Sellanes, J., Tapia, C., Thiel, M., ‘Ecological Baselines for the Southeast Atlantic and Southeast Pacific: Status of Marine Biodiversity and Anthropogenic Pressures in Areas Beyond National Jurisdiction’, STRONG High Seas Project, 2019. Authors Ross Wanless, Maria Dias, Ademola Ajagbe and Carolina Hazin – BirdLife International Adnan Awad, Shannon Hampton and Lynn Jackson – International Ocean Institute – South Africa (IOI-SA) Ben Boteler, Isabel Seeger and Nicole Wienrich – Institute for Advanced Sustainability Studies (IASS) Luis Alonso Zapata Padilla, Gustavo Adolfo Castellanos Galindo, Luis German Naranjo, César Fredy Suárez, Johanna Prussmann, Sandra Valenzuela, Luz Stella Gomez Giraldo and Mary Lou Higgins – WWF Colombia Tim Packeiser – WWF Germany Beatriz Yannicelli, Jaime Aburto, Catalina Contreras, Guillermo Luna, Nicolás Luna, Martín Munizaga, Javier Sellanes, Carlos Tapia and Martin Thiel – Universidad Católica del Norte (UCN) With contributions from Fernando Felix – Secretariat of the Comisión
    [Show full text]