DOCSLIB.ORG

Sclerophyll Forests and Woodlands

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Sclerophyll Forests and Woodlands SCLEROPHYLL FORESTS AND WOODLANDS OF THE WET TROPICS BIOREGION CLARKE © CAMPBELL Syncarpia forests and woodlands (vegetation codes 60a-60g) Syncarpia glomulifera can range from an extremely tall Facts and figures forest tree to a stunted shrub as a direct responds to its surrounding environmental conditions. Very few species Vegetation alliances demonstrate such an ability to respond to environmental Syncarpia glomulifera forests and controlling factors with such plasticity in growth form. woodlands Variations in height are typically a response to edaphic Current extent in the controls although factors including climate and exposure bioregion 38,125ha also have a significant influence. Syncarpia dominated Area protected 29,466ha (77%) vegetation associations are widespread across the bioregion, being found from the wet coastal lowlands to the dry western uplands. Geography Association 60b represents a well developed lowland This is a widespread formation which varies structurally variant, typically found on alluvial flats to the south of across a range of topographic and climatic zones Cardwell with scattered occurrences in the Kuranda area. throughout the bioregion. Well developed tall open forest Observations suggest that Syncarpia glomulifera favours variants are found in dry to wet upland situations from better drained alluvial situations, being displaced by Tinaroo to Rollingstone and in lowland situations on the Eucalyptus pellita in swampier localities. coastal plain between Cardwell and Ingham. Lower stature Association 60c (Syncarpia glomulifera and Melaleuca woodland and open forest associations are widespread quinquenervia) has a restricted distribution and is only being governed to a large extent by soil development, for found in extremely wet, infertile conditions due to a example, associations 60d, 60e and 60f are found on steep combination of groundwater seepage and highly infertile escarpments with minimal soil development. Major quartzite geology. occurrences are mapped in the Ingham area (Mt Gardiner), Hinchinbrook Island and adjacent mainland ranges and on In comparison with 60a, the lower stature of associations the Rollingstone, Kirrama and Gordonvale map sheets. 60d, 60e and 60f is invariably the result of shallower soils Association 60c is only found on the Thornton Peak map and greater wind exposure. These variants can typically be sheet as a result of unique geological and hydrological defined by their association with various Allocasuarina spp. influences. Association 60e, which is found in wetter locations, forms an association with Allocasuarina torulosa. In areas of low Shrubland variants are restricted to the drier western soil fertility, poor soil development and/or in drier areas, upland portions of the bioregion on granites and rhyolites Syncarpia glomulifera is often found in association with from Mt Spurgeon in the North to Paluma in the south. Allocasuarina littoralis (60e). Association 60f typically occurs on sites with rudimentary soil development (rudosols) and generally in dry western portions of the bioregion with only scattered occurrences on the coastal escarpment. The association is typically dominated by Syncarpia glomulifera with various Eucalyptus spp. present as minor components. Syncarpia glomulifera shrubland associations are invariably found on the drier western margins of the bioregion where they are confined to upland areas on shallow soils derived from granites and rhyolites. Association 60g represents a complex floristic and structural association, although Syncarpia glomulifera is universally present in shrub form (generally below 3m in height). Internal variations are generally dependant on fire history and soil depth with families of Ericaceae, Proteaceae, Xanthorrhoeaceae and Myrtaceae commonly well represented in the floristic mix. © CAMPBELL CLARKE © CAMPBELL CLARKE © CAMPBELL Impacts and changes Threatening processes Major changes are generally associated with alteration of • Altered fire regimes and colonisation by fire retardant the structure and composition of sub-canopy and shrub rainforest species. layers due to changes in fire frequency and intensity, as well as alteration to structural and floristic integrity of canopy layers as a result of previous heavy logging Tenure regimes. Well represented in conservation estate including These effects are most apparent within the tall open forest Herberton Range NP, Mount Lewis NP, Danbulla NP, association 60a where changes to fire regimes has allowed Dinden NP, Fitzroy Island NP, Gadgarra FR, Gillies rainforest species to colonise the lower structural layers of Highway FR, Girringun NP, Goold Island NP, Grey Peaks wet sclerophyll forests. Heavy logging of these NP, Hinchinbrook Island NP, Kirrama NP, communities has undoubtedly influenced floristic Koombooloomba NP, Little Mulgrave NP, Malbon composition and it is likely that a canopy dominance of Thompson FR, Mount Hypipamee NP, Mount Spurgeon NP, Syncarpia glomulifera in some localities is an artefact of Mount Windsor NP, Girramay NP, Paluma Range NP, Tully the selective logging of the more desirable Eucalyptus Falls NP, Tully Gorge NP and Wooroonooran NP. resinifera and Eucalyptus grandis canopy species. The predominantly edaphic control on development of associations with lower stature places a limit on the Management considerations degree to which rainforest species can colonise the lower • Appropriate fire management and prescribed burning is structural layers of these communities. A thickening of important for the maintenance and dynamics of this sub-canopy and shrub layers can however be related to a extensive formation. lack of regular burning. The relative intolerance of Syncarpia glomulifera to extremely hot fires has undoubtedly contributed to floristic and structural changes within association 60e in areas subject to wildfires. The net result of wildfires on these communities may include the gradual removal of Syncarpia glomulifera from upper structural layers, suppression of the capacity for recruitment of Syncarpia glomulifera in shrub layers, and an increasing dominance of Allocasuarina littoralis throughout all structural layers. Key values • Important arboreal mammal habitat for species including the yellow-bellied glider (Petaurus australis) • Habitat for the endangered northern bettong (Bettongia tropica) • Habitat for a number of restricted plant species including Bertya polystigma, Pityrodia salviifolia, Pomaderris argyrophylla, Dodonaea uncinata, Phebalium longifolium, Persoonia tropica, Diuris oporina, Eucalyptus lockyeri, Homoranthus porteri and Prostanthera clotteniana. wettropics.gov.au.
Load more

Recommended publications
  • Vegetation on Fraser Island
    Vegetation On Fraser Island Imagine towering pines, rainforest trees with three metre girths, rare and ancient giant ferns, eucalypt forests with their characteristic pendulous leaves, lemon-scented swamp vegetation and dwarfed heathland shrubs covered in a profusion of flowers. Now imagine them all growing on an island of sand. Two of Fraser Island’s unique features are its diversity of vegetation and its ability to sustain this vegetation in sand, a soil that is notoriously low in nutrients essential to plant growth. Plants growing on the dunes can obtain their nutrients (other than nitrogen) from only two sources - rain and sand. Sand is coated with mineral compounds such as iron and aluminium oxides. Near the shore the air contains nutrients from sea spray which are deposited on the sand. In a symbiotic relationship, fungi in the sand make these nutrients available to the plants. These in turn supply various organic compounds to the fungi which, having no chlorophyll cannot synthesise for themselves. Colonising plants, such as spinifex, grow in this nutrient poor soil and play an integral role in the development of nutrients in the sand. Once these early colonisers have added much needed nutrients to the soil, successive plant communities that are also adapted to low nutrient conditions, can establish themselves. She-oaks ( Allocasuarina and Casuarina spp.) can be found on the sand dunes of the eastern beach facing the wind and salt spray. These hardy trees are a familiar sight throughout the island with their thin, drooping branchlets and hard, woody cones. She-oaks are known as nitrogen fixers and add precious nutrients to the soil.
    [Show full text]
  • The Coastal Scrub and Chaparral Bird Conservation Plan
    The Coastal Scrub and Chaparral Bird Conservation Plan A Strategy for Protecting and Managing Coastal Scrub and Chaparral Habitats and Associated Birds in California A Project of California Partners in Flight and PRBO Conservation Science The Coastal Scrub and Chaparral Bird Conservation Plan A Strategy for Protecting and Managing Coastal Scrub and Chaparral Habitats and Associated Birds in California Version 2.0 2004 Conservation Plan Authors Grant Ballard, PRBO Conservation Science Mary K. Chase, PRBO Conservation Science Tom Gardali, PRBO Conservation Science Geoffrey R. Geupel, PRBO Conservation Science Tonya Haff, PRBO Conservation Science (Currently at Museum of Natural History Collections, Environmental Studies Dept., University of CA) Aaron Holmes, PRBO Conservation Science Diana Humple, PRBO Conservation Science John C. Lovio, Naval Facilities Engineering Command, U.S. Navy (Currently at TAIC, San Diego) Mike Lynes, PRBO Conservation Science (Currently at Hastings University) Sandy Scoggin, PRBO Conservation Science (Currently at San Francisco Bay Joint Venture) Christopher Solek, Cal Poly Ponoma (Currently at UC Berkeley) Diana Stralberg, PRBO Conservation Science Species Account Authors Completed Accounts Mountain Quail - Kirsten Winter, Cleveland National Forest. Greater Roadrunner - Pete Famolaro, Sweetwater Authority Water District. Coastal Cactus Wren - Laszlo Szijj and Chris Solek, Cal Poly Pomona. Wrentit - Geoff Geupel, Grant Ballard, and Mary K. Chase, PRBO Conservation Science. Gray Vireo - Kirsten Winter, Cleveland National Forest. Black-chinned Sparrow - Kirsten Winter, Cleveland National Forest. Costa's Hummingbird (coastal) - Kirsten Winter, Cleveland National Forest. Sage Sparrow - Barbara A. Carlson, UC-Riverside Reserve System, and Mary K. Chase. California Gnatcatcher - Patrick Mock, URS Consultants (San Diego). Accounts in Progress Rufous-crowned Sparrow - Scott Morrison, The Nature Conservancy (San Diego).
    [Show full text]
  • 7. Shrubland and Young Forest Habitat Management
    7. SHRUBLAND AND YOUNG FOREST HABITAT MANAGEMENT hrublands” and “Young Forest” are terms that apply to areas Shrubland habitat and that are transitioning to mature forest and are dominated by young forest differ in “Sseedlings, saplings, and shrubs with interspersed grasses and forbs (herbaceous plants). While some sites such as wetlands, sandy sites vegetation types and and ledge areas can support a relatively stable shrub cover, most shrub communities in the northeast are successional and change rapidly to food and cover they mature forest if left unmanaged. Shrub and young forest habitats in Vermont provide important habitat provide, as well as functions for a variety of wildlife including shrubland birds, butterflies and bees, black bear, deer, moose, snowshoe hare, bobcat, as well as a where and how they variety of reptiles and amphibians. Many shrubland species are in decline due to loss of habitat. Shrubland bird species in Vermont include common are maintained on the species such as chestnut-sided warbler, white-throated sparrow, ruffed grouse, Eastern towhee, American woodcock, brown thrasher, Nashville landscape. warbler, and rarer species such as prairie warbler and golden-winged warbler. These habitat types are used by 29 Vermont Species of Greatest Conservation Need. While small areas of shrub and young forest habitat can be important to some wildlife, managing large patches of 5 acres or more provides much greater benefit to the wildlife that rely on the associated habitat conditions to meet their life requirements. Birds such as the chestnut- sided warbler will use smaller areas of young forest, but less common species such as golden-winged warbler require areas of 25 acres or more.
    [Show full text]
  • Grassland to Shrubland State Transitions Enhance Carbon Sequestration in the Northern Chihuahuan Desert
    Global Change Biology Global Change Biology (2015) 21, 1226–1235, doi: 10.1111/gcb.12743 Grassland to shrubland state transitions enhance carbon sequestration in the northern Chihuahuan Desert M. D. PETRIE1 ,S.L.COLLINS1 ,A.M.SWANN2 ,P.L.FORD3 andM.E. LITVAK1 1Department of Biology, University of New Mexico, Albuquerque, New Mexico, USA, 2Department of Biology, Sevilleta LTER, University of New Mexico, Albuquerque, New Mexico, USA, 3USDA Forest Service, Rocky Mountain Research Station, Albuquerque, New Mexico, USA Abstract The replacement of native C4-dominated grassland by C3-dominated shrubland is considered an ecological state tran- sition where different ecological communities can exist under similar environmental conditions. These state transi- tions are occurring globally, and may be exacerbated by climate change. One consequence of the global increase in woody vegetation may be enhanced ecosystem carbon sequestration, although the responses of arid and semiarid ecosystems may be highly variable. During a drier than average period from 2007 to 2011 in the northern Chihuahuan À2 À1 Desert, we found established shrubland to sequester 49 g C m yr on average, while nearby native C4 grassland À À was a net source of 31 g C m 2 yr 1 over this same period. Differences in C exchange between these ecosystems were pronounced – grassland had similar productivity compared to shrubland but experienced higher C efflux via ecosys- tem respiration, while shrubland was a consistent C sink because of a longer growing season and lower ecosystem respiration. At daily timescales, rates of carbon exchange were more sensitive to soil moisture variation in grassland than shrubland, such that grassland had a net uptake of C when wet but lost C when dry.
    [Show full text]
  • Learning the Boys' Eyes Widened and They Began to New Things, and the Colorful Pair of Socks One Ask Lots of Questions
    THE CHAPARRALIAN November 16, 2009 Volume 6, Issue 3 The Chaparralian #32 Contents 3 NASCENT THOUGHTS 6 The Chaparral Habitat For Young Chaparralians Richard W. Halsey 12 Poetry of a Kindred Spirit Nancy Jordan 14 The Walking Toothbrush The Chaparralian is the quarterly journal of the California Chaparral Institute, a non-profit organization that is Bill Howell dedicated to the preservation of native shrubland ecosystems and promoting an appreciation for the natural 16 UNFOLDINGS environment through science and education. To join the Institute and receive The Chaparralian, please fill out and Cover photograph: Two boys near the mail in the slip below or join on our website. We Monkey Temple, Kathmandu, Nepal. Inside welcome unsolicited submissions to The Chaparralian. Please send to [email protected] or via post to cover photo (above left), Jaipur, India. the address below. You can find us on the web at www.californiachaparral.org All photos by Richard W. Halsey unless indicated otherwise. Editor and Publisher.......................Richard W. Halsey Please Join the California Chaparral Institute and support our research and educational efforts to help promote a better understanding of and appreciation for the remarkable biodiversity found in shrubland ecosystems, especially the chaparral! ______$35 Citizen Naturalist: The Chaparralian plus one additional benefit (check preference below). ______$55 Chaparralian: The Chaparralian plus two benefits (check preferences below). ______$100 California Grizzly Bear: The Chaparralian plus all three benefits below. _____ Signed Book: “Fire, Chaparral and Survival in Southern California” _____ DVD of the KPBS/Huell Howser’s California’s Green “Secrets of the Chaparral” show _____ Special Chaparral edition of the California Native Plant Society’s journal, Fremontia.
    [Show full text]
  • Genera in Myrtaceae Family
    Genera in Myrtaceae Family Genera in Myrtaceae Ref: http://data.kew.org/vpfg1992/vascplnt.html R. K. Brummitt 1992. Vascular Plant Families and Genera, Royal Botanic Gardens, Kew REF: Australian – APC http://www.anbg.gov.au/chah/apc/index.html & APNI http://www.anbg.gov.au/cgi-bin/apni Some of these genera are not native but naturalised Tasmanian taxa can be found at the Census: http://tmag.tas.gov.au/index.aspx?base=1273 Future reference: http://tmag.tas.gov.au/floratasmania [Myrtaceae is being edited at mo] Acca O.Berg Euryomyrtus Schaur Osbornia F.Muell. Accara Landrum Feijoa O.Berg Paragonis J.R.Wheeler & N.G.Marchant Acmena DC. [= Syzigium] Gomidesia O.Berg Paramyrciaria Kausel Acmenosperma Kausel [= Syzigium] Gossia N.Snow & Guymer Pericalymma (Endl.) Endl. Actinodium Schauer Heteropyxis Harv. Petraeomyrtus Craven Agonis (DC.) Sweet Hexachlamys O.Berg Phymatocarpus F.Muell. Allosyncarpia S.T.Blake Homalocalyx F.Muell. Pileanthus Labill. Amomyrtella Kausel Homalospermum Schauer Pilidiostigma Burret Amomyrtus (Burret) D.Legrand & Kausel [=Leptospermum] Piliocalyx Brongn. & Gris Angasomyrtus Trudgen & Keighery Homoranthus A.Cunn. ex Schauer Pimenta Lindl. Angophora Cav. Hottea Urb. Pleurocalyptus Brongn. & Gris Archirhodomyrtus (Nied.) Burret Hypocalymma (Endl.) Endl. Plinia L. Arillastrum Pancher ex Baill. Kania Schltr. Pseudanamomis Kausel Astartea DC. Kardomia Peter G. Wilson Psidium L. [naturalised] Asteromyrtus Schauer Kjellbergiodendron Burret Psiloxylon Thouars ex Tul. Austromyrtus (Nied.) Burret Kunzea Rchb. Purpureostemon Gugerli Babingtonia Lindl. Lamarchea Gaudich. Regelia Schauer Backhousia Hook. & Harv. Legrandia Kausel Rhodamnia Jack Baeckea L. Lenwebia N.Snow & ZGuymer Rhodomyrtus (DC.) Rchb. Balaustion Hook. Leptospermum J.R.Forst. & G.Forst. Rinzia Schauer Barongia Peter G.Wilson & B.Hyland Lindsayomyrtus B.Hyland & Steenis Ristantia Peter G.Wilson & J.T.Waterh.
    [Show full text]
  • The Evolution of Bat Pollination: a Phylogenetic Perspective
    Annals of Botany 104: 1017–1043, 2009 doi:10.1093/aob/mcp197, available online at www.aob.oxfordjournals.org INVITED REVIEW The evolution of bat pollination: a phylogenetic perspective Theodore H. Fleming1,*, Cullen Geiselman2 and W. John Kress3 1Emeritus, Department of Biology, University of Miami, Coral Gables, FL 33124, USA, 2Institute of Systematic Botany, The New York Botanical Garden, Bronx, NY 10458, USA and 3Department of Botany, MRC-166, National Museum of Natural History, Smithsonian Institution, PO Box 37012, Washington, DC 20013-7012, USA Received: 2 April 2009 Returned for revision: 27 May 2009 Accepted: 13 July 2009 Published electronically: 29 September 2009 † Background Most tropical and subtropical plants are biotically pollinated, and insects are the major pollinators. A small but ecologically and economically important group of plants classified in 28 orders, 67 families and about 528 species of angiosperms are pollinated by nectar-feeding bats. From a phylogenetic perspective this is a derived pollination mode involving a relatively large and energetically expensive pollinator. Here its ecologi- cal and evolutionary consequences are explored. Downloaded from † Scope and Conclusions This review summarizes adaptations in bats and plants that facilitate this interaction and discusses the evolution of bat pollination from a plant phylogenetic perspective. Two families of bats contain specialized flower visitors, one in the Old World and one in the New World. Adaptation to pollination by bats has evolved independently many times from a variety of ancestral conditions, including insect-, bird- and non-volant mammal-pollination. Bat pollination predominates in very few families but is relatively common in certain angiosperm subfamilies and tribes.
    [Show full text]
  • Distribution Mapping of World Grassland Types A
    Journal of Biogeography (J. Biogeogr.) (2014) SYNTHESIS Distribution mapping of world grassland types A. P. Dixon1*, D. Faber-Langendoen2, C. Josse2, J. Morrison1 and C. J. Loucks1 1World Wildlife Fund – United States, 1250 ABSTRACT 24th Street NW, Washington, DC 20037, Aim National and international policy frameworks, such as the European USA, 2NatureServe, 4600 N. Fairfax Drive, Union’s Renewable Energy Directive, increasingly seek to conserve and refer- 7th Floor, Arlington, VA 22203, USA ence ‘highly biodiverse grasslands’. However, to date there is no systematic glo- bal characterization and distribution map for grassland types. To address this gap, we first propose a systematic definition of grassland. We then integrate International Vegetation Classification (IVC) grassland types with the map of Terrestrial Ecoregions of the World (TEOW). Location Global. Methods We developed a broad definition of grassland as a distinct biotic and ecological unit, noting its similarity to savanna and distinguishing it from woodland and wetland. A grassland is defined as a non-wetland type with at least 10% vegetation cover, dominated or co-dominated by graminoid and forb growth forms, and where the trees form a single-layer canopy with either less than 10% cover and 5 m height (temperate) or less than 40% cover and 8 m height (tropical). We used the IVC division level to classify grasslands into major regional types. We developed an ecologically meaningful spatial cata- logue of IVC grassland types by listing IVC grassland formations and divisions where grassland currently occupies, or historically occupied, at least 10% of an ecoregion in the TEOW framework. Results We created a global biogeographical characterization of the Earth’s grassland types, describing approximately 75% of IVC grassland divisions with ecoregions.
    [Show full text]
  • Chapter 10. Amphibians of the Palaearctic Realm
    CHAPTER 10. AMPHIBIANS OF THE PALAEARCTIC REALM Figure 1. Summary of Red List categories Brandon Anthony, J.W. Arntzen, Sherif Baha El Din, Wolfgang Böhme, Dan Palaearctic Realm contains 6% of all globally threatened amphibians. The Palaearctic accounts for amphibians in the Palaearctic Realm. CogĄlniceanu, Jelka Crnobrnja-Isailovic, Pierre-André Crochet, Claudia Corti, for only 3% of CR species and 5% of the EN species, but 9% of the VU species. Hence, on the The percentage of species in each category Richard Griffiths, Yoshio Kaneko, Sergei Kuzmin, Michael Wai Neng Lau, basis of current knowledge, threatened Palaearctic amphibians are more likely to be in a lower is also given. Pipeng Li, Petros Lymberakis, Rafael Marquez, Theodore Papenfuss, Juan category of threat, when compared with the global distribution of threatened species amongst Manuel Pleguezuelos, Nasrullah Rastegar, Benedikt Schmidt, Tahar Slimani, categories. The percentage of DD species, 13% (62 species), is also much less than the global Max Sparreboom, ùsmail Uøurtaû, Yehudah Werner and Feng Xie average of 23%, which is not surprising given that parts of the region have been well surveyed. Red List Category Number of species Nevertheless, the percentage of DD species is much higher than in the Nearctic. Extinct (EX) 2 Two of the world’s 34 documented amphibian extinctions have occurred in this region: the Extinct in the Wild (EW) 0 THE GEOGRAPHIC AND HUMAN CONTEXT Hula Painted Frog Discoglossus nigriventer from Israel and the Yunnan Lake Newt Cynops Critically Endangered (CR) 13 wolterstorffi from around Kunming Lake in Yunnan Province, China. In addition, one Critically Endangered (EN) 40 The Palaearctic Realm includes northern Africa, all of Europe, and much of Asia, excluding Endangered species in the Palaearctic Realm is considered possibly extinct, Scutiger macu- Vulnerable (VU) 58 the southern extremities of the Arabian Peninsula, the Indian Subcontinent (south of the latus from central China.
    [Show full text]
  • Texas Mangrove Research Symposium
    Texas Mangrove Thursday, February 28 9:00am - 5:00pm University of Texas Marine Science Institute Research Symposium PortEstuarine Aransas, Research Texas Center, Seminar Room 750 Channel View Dr. AGENDA 9:00 - 9:15 WELCOME AND INTRODUCTIONS 9:15 - 9:30 Dr. Kiersten Madden, Mission-Aransas National Estuarine Research Reserve Monitoring Mangroves: Applying the National Estuarine Research Reserve Approach to Texas 9:30 - 10:00 Tom Tremblay, Bureau of Economic Geology, University of Texas at Austin Baseline Mapping for Mangrove Monitoring in the Coastal Bend, Texas Gulf Coast 10:00 - 10:30 Dr. James Gibeaut, Harte Research Institute for Gulf of Mexico Studies, Texas A&M University – Corpus Christi Proposed Observatory for Understanding Coastal Wetland Change 10:30 - 10:45 BREAK 10:45 - 11:15 Dr. John Schalles, Creighton University The Mangroves of Redfish Bay: Field surveys and high resolution imagery to map distribution, canopy 11:15 - 11:45 Chrisheight, Wilson, and vegetation University response of Texas to the February,Marine Science 2011 freeze Institute Rhizophora mangle) trees along the coast of Texas 11:45 - 12:15 Dr.Colonization Anna Armitage, and age structure Texas A&M of red University mangrove ( – Galveston Ecological implications of black mangrove expansion into Texas salt marshes: Comparisons among 12:15 - 1:00 CATEREDmarsh and mangroveLUNCH habitats 1:00 - 1:30 Dr. Steven Pennings, University of Houston Ecological implications of black mangrove expansion into Texas salt marshes: Insights from a large- 1:30 - 2:00 Dr.scale Liz
    [Show full text]
  • A Synthetic Review of Feedbacks and Drivers of Shrub Encroachment in Arid Grasslands
    ECOHYDROLOGY Ecohydrol. 5, 520–530 (2012) Published online 20 October 2011 in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/eco.259 A synthetic review of feedbacks and drivers of shrub encroachment in arid grasslands Paolo D’Odorico,1,2* Gregory S. Okin3 and Brandon T. Bestelmeyer4 1 Department of Environmental Sciences, University of Virginia, Charlottesville, VA, 22904, USA 2 Laboratory EFLUM, Faculte’ ENAC, Ecole Polytechnique Federale Lausanne, Lausanne, Switzerland 3 Department of Geography, University of California, Los Angeles, CA, 90095, USA 4 USDA-ARS, Jornada Experimental Range, Las Cruces, NM, 88003, USA ABSTRACT Many arid grasslands around the world are affected by woody plant encroachment and by the replacement of a relatively continuous grass cover with shrub patches bordered by bare soil. This shift in plant community composition is often abrupt in space and time, suggesting that it is likely sustained by positive feedbacks between vegetation and environmental conditions (e.g. resource availability) or disturbance regime (e.g. fire or freeze). These feedbacks amplify the effects of drivers of shrub encroachment, i.e. of conditions favouring a shift from grass to shrub dominance (e.g. overgrazing, climate change). Here, we review some major drivers and feedbacks and identify the basic stages in the transition from grassland to shrubland. We discuss some possible scenarios of interactions between drivers and feedbacks that could explain the transition from a stage to the next and the potential irreversibility of the shift from grass to shrub dominance. We introduce a simplistic modelling framework that can integrate the various drivers to explain the emergence of bistability for shrub-encroached grassland systems.
    [Show full text]
  • Myrtle Rust Reviewed the Impacts of the Invasive Plant Pathogen Austropuccinia Psidii on the Australian Environment R
    Myrtle Rust reviewed The impacts of the invasive plant pathogen Austropuccinia psidii on the Australian environment R. O. Makinson 2018 DRAFT CRCPLANTbiosecurity CRCPLANTbiosecurity © Plant Biosecurity Cooperative Research Centre, 2018 ‘Myrtle Rust reviewed: the impacts of the invasive pathogen Austropuccinia psidii on the Australian environment’ is licenced by the Plant Biosecurity Cooperative Research Centre for use under a Creative Commons Attribution 4.0 Australia licence. For licence conditions see: https://creativecommons.org/licenses/by/4.0/ This Review provides background for the public consultation document ‘Myrtle Rust in Australia – a draft Action Plan’ available at www.apbsf.org.au Author contact details R.O. Makinson1,2 [email protected] 1Bob Makinson Consulting ABN 67 656 298 911 2The Australian Network for Plant Conservation Inc. Cite this publication as: Makinson RO (2018) Myrtle Rust reviewed: the impacts of the invasive pathogen Austropuccinia psidii on the Australian environment. Plant Biosecurity Cooperative Research Centre, Canberra. Front cover: Top: Spotted Gum (Corymbia maculata) infected with Myrtle Rust in glasshouse screening program, Geoff Pegg. Bottom: Melaleuca quinquenervia infected with Myrtle Rust, north-east NSW, Peter Entwistle This project was jointly funded through the Plant Biosecurity Cooperative Research Centre and the Australian Government’s National Environmental Science Program. The Plant Biosecurity CRC is established and supported under the Australian Government Cooperative Research Centres Program. EXECUTIVE SUMMARY This review of the environmental impacts of Myrtle Rust in Australia is accompanied by an adjunct document, Myrtle Rust in Australia – a draft Action Plan. The Action Plan was developed in 2018 in consultation with experts, stakeholders and the public. The intent of the draft Action Plan is to provide a guiding framework for a specifically environmental dimension to Australia’s response to Myrtle Rust – that is, the conservation of native biodiversity at risk.
    [Show full text]