DOCSLIB.ORG

The Response of Banksia Roots to Change in Water Table Level in a Mediterranean-Type Environment

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Response of Banksia Roots to Change in Water Table Level in a Mediterranean-Type Environment Edith Cowan University Research Online Theses: Doctorates and Masters Theses 2011 The response of Banksia roots to change in water table level in a Mediterranean-type environment Caroline Canham Edith Cowan University Follow this and additional works at: https://ro.ecu.edu.au/theses Part of the Ecology and Evolutionary Biology Commons, and the Plant Sciences Commons Recommended Citation Canham, C. (2011). The response of Banksia roots to change in water table level in a Mediterranean-type environment. https://ro.ecu.edu.au/theses/389 This Thesis is posted at Research Online. https://ro.ecu.edu.au/theses/389 Edith Cowan University Copyright Warning You may print or download ONE copy of this document for the purpose of your own research or study. The University does not authorize you to copy, communicate or otherwise make available electronically to any other person any copyright material contained on this site. You are reminded of the following: Copyright owners are entitled to take legal action against persons who infringe their copyright. A reproduction of material that is protected by copyright may be a copyright infringement. Where the reproduction of such material is done without attribution of authorship, with false attribution of authorship or the authorship is treated in a derogatory manner, this may be a breach of the author’s moral rights contained in Part IX of the Copyright Act 1968 (Cth). Courts have the power to impose a wide range of civil and criminal sanctions for infringement of copyright, infringement of moral rights and other offences under the Copyright Act 1968 (Cth). Higher penalties may apply, and higher damages may be awarded, for offences and infringements involving the conversion of material into digital or electronic form. THE RESPONSE OF BANKSIA ROOTS TO CHANGE IN WATER TABLE LEVEL IN A MEDITERRANEAN-TYPE ENVIRONMENT Caroline Canham B. Sc. (Hons.) This thesis is presented in fulfilment of the requirements for the degree of Doctor of Philosophy Faculty of Computing, Health and Science Edith Cowan University May, 2011 USE OF THESIS The Use of Thesis statement is not included in this version of the thesis. Abstract For phreatophytic plants to persist in a given habitat they need to maintain a functional connection to the water table, and the capacity for roots to respond to changes in the water table is a key aspect of this. If root growth is limited by season, plants may not be able to grow roots to adjust to changes in the water table at a particular time of the year. The redistribution of roots, particularly the capacity for roots to follow the water table down in summer and autumn months, is vital for phreatophytic plants to maintain a functional connection with the water table. Root activity by phreatophytic Banksia in south-west Western Australia was assessed using root in-growth bags, with above- ground plant phenological processes observed simultaneously. The root in-growth bag technique that was used showed that Banksia roots are able to grow, provided soil conditions are conducive and there are no endogenous limitations to root growth at different times of the year, such as a dormancy period. The ability to grow at any time in response to soil conditions might be an essential prerequisite for phreatophytes if they are to survive fluctuating water table conditions in seasonally water-limited environments. Assuming that roots follow a seasonally dynamic watertable, a further study using chemical tracers assessed water uptake from the capillary fringe at contrasting times of the year. Lithium chloride was used in spring and 15N in autumn, to avoid contamination between the two sampling periods. There was some indication that the phreatophytic Banksia study species were utilising groundwater. This was evident from observation of tracer uptake from the capillary fringe during spring, when the water table was at its highest level. However, water uptake from the capillary fringe by Banksia was not evident during the autumn sampling period. This is likely to be due to methodological constraints, as plants did not demonstrate any signs of water stress despite the low water content in the vadose zone. These physiological indicators suggest that plants were still accessing groundwater at this time of the year. iii Quantifying the rate of root elongation for a particular species may give some indication of the rate of water table decline that they are able to survive. Root elongation rates and response to rapid water table decline were observed in rhizopods, allowing for the maintenance and manipulation of a water table under glasshouse conditions. The maximum rates of root elongation were found to be 36.7 mm day-1 and 18.2 mm day-1 for Banksia attenuata and Banksia littoralis respectively. These rates of root elongation may be regarded as rapid in comparison to the rates of water table decline that the species are likely to experience over summer and autumn water table decline. Such rapid rates of root elongation indicate that plants can potentially maintain contact with a water table decline at far greater rates than those that occur during a normal seasonal cycle of water table fluctuations. Based on the rates of root elongation by phreatophytic Banksia, it was expected that plants would maintain a functional connection with a rapidly decreasing water table. However, despite plant-available water being present in the soil profile, there was very limited root extension following rapid water table drawdown. In addition to little root elongation response, seedlings demonstrated a rapid drought response to water table decline, quickly reducing stomatal conductance, transpiration and photosynthesis. It is likely that the lack of root elongation response to a declining water table by the phreatophytic Banksia study species was due to plants being unable to meet their water requirements once the water table fell below the rooting depth of the plants. It was found that the response of phreatophytic Banksia to rapid water table decline depends on the availability of other water sources, and the rate of water table decline. iv Copyright and access declaration I certify that this thesis does not, to the best of my knowledge and belief: (i) incorporate without acknowledgment any material previously submitted for a degree or diploma in any institution of higher education; (ii) contain any material previously published or written by another person except where due reference is made in the text of this thesis; or (iii) contain any defamatory material. Signed Date 23 May 2011 v Acknowledgements I first would like to thank my two supervisors, A. Prof. Ray Froend and Prof. Will Stock. I can unreservedly say that without their patient support, guidance and encouragement I would not have made it this far. I wish to acknowledge the Water Corporation and Australian Research Council, who provided the financial support to make this project possible. The study site was located at Whiteman Park, and I would like to thank their Land & Environment Manager Chris Rafferty for her assistance with access and information. I am indebted to a large number of research assistants and other students who have assisted me in the field, laboratory and glasshouse. In particular, I wish to acknowledge Muriel Davies who has assisted me in many different aspects throughout the preparation of this thesis, including many long hours of field work. I am grateful for the assistance of Coral Newman for proofreading this thesis at short notice and for providing helpful and encouraging feedback. Thank you to my friends and family for their support throughout. Finally, thank you to Andrew Rafty for your never-ending help, encouragement and support over the years. vi TABLE OF CONTENTS USE OF THESIS ii ABSTRACT iii DECLARATION v ACKNOWLEDGEMENTS vi TABLE OF CONTENTS vii CHAPTER 1 General Introduction 1 CHAPTER 2 Study area and species descriptions 8 Dynamics of Banksia root growth relative to a seasonally CHAPTER 3 19 fluctuating water table. Introduction 19 Materials and Methods 24 Results 31 Discussion 43 Seasonal groundwater uptake by dominant canopy CHAPTER 4 50 species in a Banksia woodland. Introduction 50 Materials and Methods 53 Results 57 Discussion 62 Seedling root elongation rates for two phreatophytic CHAPTER 5 66 Banksia species with contrasting water requirements Introduction 66 Materials and Methods 69 Results 77 Discussion 83 Root response of phreatophytic Banksia exposed to rapid CHAPTER 6 86 rates of water table decline. Introduction 86 Materials and Methods 90 Results 95 Discussion 103 CHAPTER 7 General Discussion 109 REFERENCES 114 Chapter One General Introduction Groundwater accounts for more than 30% of the earth’s fresh water (Shiklomanov 1998), and a variety of ecosystems have developed in the presence of groundwater (Eamus et al. 2006). Groundwater may be defined as part of the soil profile that has reached maximum water holding capacity, with all soil pores filled with water, also referred to as the zone of saturation (Freeze & Cherry 1979; Eamus et al. 2006; Fig. 1.1). Plants which use groundwater are referred to as phreatophytic, from the Greek ‘phreatos’ – a well, and ‘phyte’, denoting a plant having a particular characteristic (Meinzer 1923). Phreatophytes can access groundwater either directly from the water table (the upper surface of groundwater) or from the capillary fringe, which sits above the water table and contains groundwater held by capillary action (Freeze & Cherry 1979; Eamus et al. 2006). Phreatophytes are prevalent in water-limited environments, where annual evapotranspiration exceeds annual rainfall, resulting in a net deficit in water availability (Abrahams & Parsons 1994; Cui & Shao 2005). This water deficit is exacerbated in habitats with soils that have low water-holding capacity, such as coarse sands (Sperry et al. 2002). In such environments, water availability in the unsaturated (vadose) zone is often unreliable, and, as a result, many species develop deep root systems to access deeper water sources, such as groundwater (Stone & Kalisz 1991; Canadell et al.
Load more

Recommended publications
  • List of Plants Used by Carnaby's Black Cockatoo
    Plants Used by Carnaby's Black Cockatoo List prepared by Christine Groom, Department of Environment and Conservation 15 April 2011 For more information on plant selection or references used to produce this list please visit the Plants for Carnaby's Search Tool webpage at www.dec.wa.gov.au/plantsforcarnabys Used for Soil type Soil drainage Priority for planting Sun Species Growth form Flower colour Origin for exposure Carnaby's Feeding Nesting Roosting Clayey Gravelly Loamy Sandy drained Well drained Poorly Waterlogged affected Salt Acacia baileyana (Cootamundra wattle)* Low Tree Yellow Australian native Acacia pentadenia (Karri Wattle) Low Tree Cream WA native Acacia saligna (Orange Wattle) Low Tree Yellow WA native Agonis flexuosa (Peppermint Tree) Low Tree White WA native Araucaria heterophylla (Norfolk Island Pine) Low Tree Green Exotic to Australia Banksia ashbyi (Ashby's Banksia) Medium Tree or Tall shrub Yellow, Orange WA native Banksia attenuata (Slender Banksia) High Tree Yellow WA native Banksia baxteri (Baxter's Banksia) Medium Tall shrub Yellow WA native Banksia carlinoides (Pink Dryandra) Medium Medium or small shrub White, cream, pink WA native Banksia coccinea (Scarlet Banksia) Medium Tree Red WA native Banksia dallanneyi (Couch Honeypot Dryandra) Low Medium or small shrub Orange, brown WA native Banksia ericifolia (Heath-leaved Banksia) Medium Tall shrub Orange Australian native Banksia fraseri (Dryandra) Medium Medium or small shrub Orange WA native Banksia gardneri (Prostrate Banksia) Low Medium
    [Show full text]
  • Mycorrhiza Helper Bacterium Streptomyces Ach 505 Induces
    Research MycorrhizaBlackwell Publishing, Ltd. helper bacterium Streptomyces AcH 505 induces differential gene expression in the ectomycorrhizal fungus Amanita muscaria Silvia D. Schrey, Michael Schellhammer, Margret Ecke, Rüdiger Hampp and Mika T. Tarkka University of Tübingen, Faculty of Biology, Institute of Botany, Physiological Ecology of Plants, Auf der Morgenstelle 1, D-72076 Tübingen, Germany Summary Author for correspondence: • The interaction between the mycorrhiza helper bacteria Streptomyces nov. sp. Mika Tarkka 505 (AcH 505) and Streptomyces annulatus 1003 (AcH 1003) with fly agaric Tel: +40 7071 2976154 (Amanita muscaria) and spruce (Picea abies) was investigated. Fax: +49 7071 295635 • The effects of both bacteria on the mycelial growth of different ectomycorrhizal Email: [email protected] fungi, on ectomycorrhiza formation, and on fungal gene expression in dual culture Received: 3 May 2005 with AcH 505 were determined. Accepted: 16 June 2005 • The fungus specificities of the streptomycetes were similar. Both bacterial species showed the strongest effect on the growth of mycelia at 9 wk of dual culture. The effect of AcH 505 on gene expression of A. muscaria was examined using the suppressive subtractive hybridization approach. The responsive fungal genes included those involved in signalling pathways, metabolism, cell structure, and the cell growth response. • These results suggest that AcH 505 and AcH 1003 enhance mycorrhiza formation mainly as a result of promotion of fungal growth, leading to changes in fungal gene expression. Differential A. muscaria transcript accumulation in dual culture may result from a direct response to bacterial substances. Key words: acetoacyl coenzyme A synthetase, Amanita muscaria, cyclophilin, ectomycorrhiza, mycorrhiza helper bacteria, streptomycetes, suppression subtractive hybridization (SSH).
    [Show full text]
  • Proteaceae (Banksia Species)
    Proteaceae (Banksia Species) Information: 90% of all Banksia species occur in South Western Australia. The two most com- mon Banksia species in the Perth region are the Firewood Banksia (Banksia menziesii) and the Slender or Candle Banksia (Banksia attenuata). These two species each flower throughout the two halves of the year and are an important source of food for countless animals. Large Banksias such as these as well as B. grandis, B. ilicifolia B. Prionotes and B. littoralis produce an abun- dance of nectar from their large flower spikes that sustain countless species and have traditionally been used as a source of food and drink by indigenous Australians. Banksias are highly adapted to a nutrient poor environment with harsh, dry climate having sunken stomata to preserve water and cluster roots to enhance nutrient uptake in Phosphorus deficient soils. Firewood Banksia (Banksia menziesii) with parasitic ’witches broom’ (insert) Pictures by A. Price Candle Banksia (Banksia attenuata) feeding a Honey Possum (Tarsipes rostratus) Picture courtesy of Kwongan Foundation Associated Life: Many animals drink nectar from Banksia flower heads including Perching birds such as Honeyeaters, Spinebills, robins and Wagtails as well as the Honey Possum, the worlds only nectarvorious marsupial. Bull Banksia European Honeybees are commonly (Banksia Grandis) found in or near flower spikes as are wee- vils and jewel beetles. Picture courtesy of Friends of Queens Park Bushland The seeds of the B.grandis are eaten by Carnaby’s black-cockatoo and the red- capped parrot. The Twig-mound ant builds its nest at the base of B. ilicifolia. Some moth species larvae burrow into Banksia cones and leaves.
    [Show full text]
  • Friends of the UC Davis Arboretum & Public Garden October 12, 2019
    Friends of the UC Davis Arboretum & Public Garden October 12, 2019 Second Fall Plant Sale (Public: 9 a.m. - 1 p.m.) Final Availability Availability subject to change Cate- Bed Botanical Name Qty Common Name Description Price Size gory # forms large clumps of 12" rosettes. Bronzy-pink foliage. Branched inflorescences up to 2' hold yellow flws with × Graptoveria 'Fred Ives' 11 graptoveria orange/red centers, summer. Good drainage. $7.50 4" P, + C12 × Heucherella 'Dayglow Pink' hybrid coral bells and foam to 16"; glowing pink flws on starry wands, spring. Purple foliar PP12164 34 flower color, winter. Bright shade, average water for best growth. $11.00 1G S C2 16"x 14"; spikes of pnk flws, lt sprng; heavy bloomer. Grn lvs × Heucherella 'Pink Revolution' Pink Revolution w/brgndy veins; pt shd; med wtr; well-drained soil; attracts PPAF 13 heucherella hmmngbrds. $11.00 1G S C2 Mounding perennial to 10", bronze lvs w/ reddish ceters, dk × Heucherella 'Pumpkin Spice' PPAF 2 Pumpkin Spice foamy bells red stems, white fls in spring $11.00 1G S C2 × Heucherella 'Solar Eclipse' Up to 16". Drk purple lvs w ring of chartreuse grn. White flws PP23647 21 foamy bells late spring. Pt sun to light shade. $11.00 1G S C2 7" x 16". Blue-green foliage turns darker as the weather cools hybrid coral bells and foam in fall; dark veins. Foamy pink flowers, spring. Shade. Deer × Heucherella 'Tapestry' PP21150 30 flower resistant. $11.00 1G S C2 × Mangave 'Bad Hair Day' PP30279 to 10"x20"; arching, narrow, flat, lime-green lvs w/red spots; (Mad About Mangave® Collection) 60 Bad Hair Day mangave full sun-bright shd; med-low wtr.
    [Show full text]
  • Rhizosphere Processes and Nutrient Management for Improving Nutrient
    HORTSCIENCE 54(4):603–608. 2019. https://doi.org/10.21273/HORTSCI13643-18 macadamia production is still in its infancy. Many guide brochures on the Macadamia grower’s handbook have been used in Aus- Rhizosphere Processes and Nutrient tralia and America (Bittenbender and Hirae, 1990; O’Hare et al., 2004). The technical Management for Improving guidelines mentioned in these books are not well adapted to the local soil and climatic Nutrient-use Efficiency in conditions in China. Moreover, the unique characteristics of cluster roots of macadamia have been greatly ignored, leading to uncou- Macadamia Production pling of crop management in the orchard with Xin Zhao and Qianqian Dong root/rhizosphere-based nutrient management. Department of Plant Nutrition, China Agricultural University, Key Enhancing nutrient-use efficiency through op- timizing fertilizer input, improving fertilizer Laboratory of Plant–Soil Interactions, Ministry of Education, Beijing formulation, and maximizing biological in- 100193, P. R. China teraction effects helps develop healthy and sustainable orchards (Jiao et al., 2016; Shen Shubang Ni, Xiyong He, Hai Yue, and Liang Tao et al., 2013). Yunnan Institute of Tropical Crops, Jinghong 666100, Yunnan, P. R. China This paper discusses the problems and challenges of macadamia production and de- Yanli Nie velopment in China as well as other parts of The General Station of Forestry Technology Extension in Yunnan Province, the world, analyzes how cluster root growth Yunnan, P. R. China affects the rhizosphere dynamics of macad- amia, thus contributing to efficient nutrient Caixian Tang mobilization and use, and puts forward the Department of Animal, Plant and Soil Sciences, AgriBio – Centre for strategies of nutrient management for im- AgriBioscience, La Trobe University, Bundoora, Victoria 3086, Australia proving nutrient-use efficiency in sustainable macadamia production.
    [Show full text]
  • Freschet Et Al., 2018), Sometimes Across Different Belowground Entities (Freschet & Roumet, 2017)
    A starting guide to root ecology: strengthening ecological concepts and standardizing root classification, sampling, processing and trait measurements Gregoire Freschet, Loic Pagès, Colleen Iversen, Louise Comas, Boris Rewald, Catherine Roumet, Jitka Klimešová, Marcin Zadworny, Hendrik Poorter, Johannes Postma, et al. To cite this version: Gregoire Freschet, Loic Pagès, Colleen Iversen, Louise Comas, Boris Rewald, et al.. A starting guide to root ecology: strengthening ecological concepts and standardizing root classification, sampling, processing and trait measurements. 2020. hal-02918834 HAL Id: hal-02918834 https://hal.archives-ouvertes.fr/hal-02918834 Preprint submitted on 21 Aug 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. A starting guide to root ecology: strengthening ecological concepts and standardizing root classification, sampling, processing and trait measurements Grégoire T. Freschet1,2, Loïc Pagès3, Colleen M. Iversen4, Louise H. Comas5, Boris Rewald6, Catherine Roumet1, Jitka Klimešová7, Marcin Zadworny8, Hendrik Poorter9,10, Johannes A. Postma9, Thomas S. Adams11, Agnieszka Bagniewska-Zadworna12, A. Glyn Bengough13,14, Elison B. Blancaflor15, Ivano Brunner16, Johannes H.C. Cornelissen17, Eric Garnier1, Arthur Gessler18,19, Sarah E. Hobbie20, Ina C. Meier21, Liesje Mommer22, Catherine Picon-Cochard23, Laura Rose24, Peter Ryser25, Michael Scherer- Lorenzen26, Nadejda A.
    [Show full text]
  • COMITÉ ADMINISTRATIVO Y JURÍDICO Cuadragésima
    S CAJ/41/4 ORIGINAL: Francés FECHA: 20 de enero de 2000 UNIÓN INTERNACIONAL PARA LA PROTECCIÓN DE LAS OBTENCIONES VEGETALES GINEBRA COMITÉ ADMINISTRATIVO Y JURÍDICO Cuadragésima primera sesión Ginebra, 6 de abril de 2000 NOCIÓN DE ÁRBOLES Y VIDES A LOS FINES DE LAS DISPOSICIONES SOBRE NOVEDAD Y DURACIÓN DE LA PROTECCIÓN Documento preparado por la Oficina de la Unión Introducción 1. En sus trigésima novena y cuadragésima sesiones, el Comité Administrativo y Jurídico examinó las nociones de árboles y vides a los fines de las disposiciones sobre novedad y duración de la protección. 2. En su cuadragésima sesión, el Comité decidió: a) que la Oficina de la Unión debía preparar un documento revisado que incluyese indicaciones más precisas sobre la anatomía y la morfología de los géneros y las especies, a fin de formular una recomendación a los Estados miembros; b) que examinaría las reglas que se podrían adoptar, en el momento oportuno, cuando se suprimiese el trato particular de los árboles y las vides (véase el párrafo 22 del documento CAJ/40/6). \\web1\upov\orgupov\shared\document\caj\41\41-4(s).doc CAJ/41/4 página 2 Bases jurídicas y prácticas El Convenio 3. El Artículo 6.1)b) del Acta de 1978 del Convenio y el Artículo 6.1) del Acta de 1991 prevén que los actos de explotación de la variedad objeto de una solicitud de protección realizados en territorio extranjero no afectan a la novedad de la variedad si han tenido lugar dentro de los plazos siguientes, que finalizan en la fecha de presentación de la solicitud: a) seis años “en el caso de las vides, árboles forestales, árboles frutales y árboles ornamentales, con inclusión, en cada caso, de sus portainjertos” (Acta de 1978) o “en el caso de árboles y vides ” (Acta de 1991); b) cuatro años en el caso de otras plantas.
    [Show full text]
  • Adenanthos Pungens Subsp. Effusus)
    SPRAWLING SPIKY ADENANTHOS (ADENANTHOS PUNGENS SUBSP. EFFUSUS) RECOVERY PLAN Department of Environment and Conservation Kensington Recovery Plan for Adenanthos pungens subsp. effusus FOREWORD Interim Recovery Plans (IRPs) are developed within the framework laid down in WA Department of Conservation and Land Management (CALM), now Department of Environment and Conservation (DEC) Policy Statements Nos. 44 and 50. Note: the Department of CALM formally became the Department of Environment and Conservation (DEC) in July 2006. DEC will continue to adhere to these Policy Statements until they are revised and reissued. IRPs outline the recovery actions that are required to urgently address those threatening processes most affecting the ongoing survival of threatened taxa or ecological communities, and begin the recovery process. DEC is committed to ensuring that Threatened taxa are conserved through the preparation and implementation of Recovery Plans (RPs) or IRPs, and by ensuring that conservation action commences as soon as possible and, in the case of Critically Endangered (CR) taxa, always within one year of endorsement of that rank by the Minister. This IRP results from a review of, and replaces, IRP No. 78 Adenanthos pungens subsp. effusus (Evans, Stack, Loudon, Graham and Brown 2000). This Interim Recovery Plan will operate from May 2006 to April 2011 but will remain in force until withdrawn or replaced. It is intended that, if the taxon is still ranked as Critically Endangered (WA), this IRP will be reviewed after five years and the need for a full Recovery Plan will be assessed. This IRP was given regional approval on 13 February, 2006 and was approved by the Director of Nature Conservation on 22 February, 2006.
    [Show full text]
  • Seedling Water Stress Response of Two Sandplain Banksia Speciesdiffering
    JournalJournal of Mediterranean of Mediterranean Ecology Ecology vol.3, vol.3, No. 4No. 2002: 4 2002 3-9 © Firma Effe Publisher, Reggio Emilia, I Seedling water stress response of two sandplain Banksia species differing in ability to tolerate drought Philip K. Groom Centre for Ecosystem Management, School of Natural Sciences, Edith Cowan University, 100 Joondalup Drive, Joondalup 6027, Western Australia Current contact details: Centre for Horticulture and Plant Sciences, University of Western Sydney, Locked Bag 1797, Penrith South DC, NSW 1797, Australia - Fax: + 61 2 4570 1314 - E-mail: [email protected] Keywords: Banksia, drought tolerance, sandplain, soil moisture content, stomatal conductance, water stress Abstract Effects of water stress on xylem water potential, stomatal conductance and growth were assessed experimentally on 7- month-old seedlings of Banksia menziesii R.Br. (Firewood Banksia) and Banksia littoralis R.Br. (Swamp Banksia) (Pro- teaceae) grown in 1 m deep tubes filled with course sand and subjected to 140 days of drought. Both are tree species of the sandplains of mediterranean southwestern Australia. B. littoralis is restricted to low-lying, winter damp areas, inclu- ding the fringe of seasonal and permanent wetlands, whereas B. menziesii inhabits a range of habitats ranging from mid- upper slopes of deep, sandy dunes to dune crests. It was hypothesised that differences in their water relations and growth responses would reveal drought adaptation attributes that relates to their contrasting habitat preferences. For both spe- cies drought caused significant decreases in stomatal conductance and predawn xylem water potential. B. menziesii seedlings had a low stomatal conductance (< 0.1 mol m-2 s-1) and exhibited a desiccation avoidance response to drought by maintaining relatively higher water potential.
    [Show full text]
  • Chapter 19 Role of Root Clusters in Phosphorus
    CHAPTER 19 ROLE OF ROOT CLUSTERS IN PHOSPHORUS ACQUISITION AND INCREASING BIOLOGICAL DIVERSITY IN AGRICULTURE H. LAMBERS AND M.W. SHANE School of Plant Biology, Faculty of Natural and Agricultural Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia. E-mail: [email protected] Abstract. Soils in the south-west of Western Australia and South Africa are among the most phosphorus- impoverished in the world, and at the same time both of these regions are Global Biodiversity Hotspots. This unique combination offers an excellent opportunity to study root adaptations that are significant in phosphorus (P) acquisition. A large proportion of species from these P-poor environments cannot produce an association with mycorrhizal fungi, but, instead, produce ‘root clusters’. In Western Australia, root- cluster-bearing Proteaceae occur on the most P-impoverished soils, whereas the mycorrhizal Myrtaceae tend to inhabit the less P-impoverished soils in this region. Root clusters are an adaptation both in structure and in functioning; characterized by high densities of short lateral roots that release large amounts of exudates, in particular carboxylates (anions of di- and tri-carboxylic acids). The functioning of root clusters in Proteaceae (’proteoid’ roots) and Fabaceae (‘cluster’ roots) has received considerable attention, but that of ‘dauciform’ root clusters developed by species in Cyperaceae has barely been explored. Research on the physiology of ‘capillaroid’ root clusters formed by species in Restionaceae has yet to be published. Root-cluster initiation and growth in species of the Cyperaceae, Fabaceae and Proteaceae are systemically stimulated when plants are grown at a very low P supply, and are suppressed as leaf P concentrations increase.
    [Show full text]
  • Seedling Growth and Physiological Responses of Two Sandplain Banksia Species Differing in Flood Tolerance
    Journal of the Royal Society of Western Australia, 87:115–121, 2004 Seedling growth and physiological responses of two sandplain Banksia species differing in flood tolerance P K Groom Centre for Ecosystem Management, School of Natural Sciences, Edith Cowan University, 100 Joondalup Drive, Joondalup, WA 6027 Current address: Centre for Horticulture and Plant Sciences, University of Western Sydney, Locked Bag 1797, Penrith South DC, NSW 1797 [email protected] (Manuscript received: March 2004; accepted February 2005) Abstract Banksia littoralis (Proteaceae) inhabits winter-wet locations and wetland fringes that are prone to seasonal flooding events on the Swan Coastal Plain. To survive in these locations, B. littoralis seedlings must be able to tolerate periods of flooding or complete submergence if establishment is to be successful. Flood tolerance was assessed in seedlings of B. littoralis subjected to 104 days of continual soil waterlogging by comparing changes in seedling growth and leaf ecophysiology with those of well-watered plants. Flood tolerance was also assessed in seedlings of Banksia prionotes, a species that grows in drier locations on the Swan Coastal Plain. As expected, B. prionotes was unable to survive long periods of soil waterlogging or submergence (97% mortality after 72 days of flooding). Both species responded to flooding by closing their stomates and reducing photosynthetic capacity, although B. littoralis was able to recover lost photosynthetic potential when flooded conditions subsided. After 72 days of flooding, there was a substantial decrease in relative growth rate in flooded B. prionotes seedlings, compared to that of well-watered plants, although this was not associated with significant differences in biomass allocation.
    [Show full text]
  • Foliar Nutrient-Allocation Patterns in Banksia Attenuata and Banksia
    Foliar nutrient-allocation patterns in Banksia attenuata and Banksia sessilis differing in growth rate and adaptation to low-phosphorus habitats Zhongming Han1, Jianmin Shi2, Jiayin Pang3, Li Yan4, Patrick Finnegan4, and Hans Lambers3 1Jilin Agricultural University 2Jiangxi Agricultural University 3The University of Western Australia 4University of Western Australia June 24, 2020 Abstract We compared the use of phosphorus (P) and nitrogen (N) in slow-growing Banksia attenuata (Proteaceae), which resprouts after fire and naturally occurs on deep sand, with faster-growing opportunistic B. sessilis, which is killed by fire and occurs on shallow sand over laterite or limestone. We carried out pot experiments with plants on substrates with different P availability. We measured foliar nutrient concentrations, and P allocated to major biochemical fractions. The two species had similar foliar total P concentrations, but distinct patterns of P allocation to P-containing fractions. The foliar total N concentration of B. sessilis was greater than that of B. attenuata on all substrates. The foliar total P and N concentrations in both species decreased with decreasing P availability. The relative growth rate of both species was positively correlated with both foliar nucleic acid P and total N concentrations, but there was no correlation with other P and N fractions. Faster-growing B. sessilis allocated more P to nucleic acids than B. attenuata did, but other fractions were similar. We conclude that the nutrient-allocation patterns in faster-growing opportunistic B. sessilis and slower-growing B. attenuata revealed different strategies in response to soil P availability, which matched their contrasting growth strategy. INTRODUCTION Understanding strategies of nutrient allocation and their underlying mechanisms in plants adapted to phos- phorus (P)-impoverished soils is an important topic in plant physiological ecology (Lambers et al.
    [Show full text]