DOCSLIB.ORG

Chapter 4: IPCC SRCCL

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Chapter 4: IPCC SRCCL Final Government Distribution Chapter 4: IPCC SRCCL 1 Chapter 4: Land Degradation 2 3 Coordinating Lead Authors: Lennart Olsson (Sweden), Humberto Barbosa (Brazil) 4 Lead Authors: Suruchi Bhadwal (India), Annette Cowie (Australia), Kenel Delusca (Haiti), Dulce 5 Flores-Renteria (Mexico), Kathleen Hermans (Germany), Esteban Jobbagy (Argentina), Werner Kurz 6 (Canada), Diqiang Li (China), Denis Jean Sonwa, (Cameroon), Lindsay Stringer (United Kingdom) 7 Contributing Authors: Timothy Crews (United States of America), Martin Dallimer (United 8 Kingdom), Joris Eekhout (The Netherlands), Karlheinz Erb (Italy), Eamon Haughey (Ireland), Richard 9 Houghton (United States of America), Mohammad Mohsin Iqbal (Pakistan), Francis X. Johnson 10 (United States of America), Woo-Kyun Lee (Korea), John Morton (United Kingdom), Felipe Garcia 11 Oliva (Mexico), Jan Petzold (Germany), Muhammad Rahimi (Iran), Florence Renou-Wilson (Ireland), 12 Anna Tengberg (Sweden), Louis Verchot (Colombia/United States of America), Katharine Vincent 13 (South Africa) 14 Review Editors: José Manuel Moreno Rodriguez (Spain), Carolina Vera (Argentina) 15 Chapter Scientist: Aliyu Salisu Barau (Nigeria) 16 Date of Draft: 28/04/2019 17 Subject to Copy-editing Do Not Cite, Quote or Distribute 4-1 Total pages: 184 Final Government Distribution Chapter 4: IPCC SRCCL 1 2 Table of Contents 3 Chapter 4: Land Degradation ......................................................................................... 4-1 4 4.1 Executive Summary ............................................................................................. 4-4 5 4.2 Introduction ........................................................................................................ 4-8 6 4.2.1 Scope of the chapter ...................................................................................... 4-8 7 4.2.2 Perspectives of land degradation...................................................................... 4-8 8 4.2.3 Definition of land degradation......................................................................... 4-9 9 4.2.4 Land degradation in previous IPCC reports ......................................................4-10 10 4.2.5 Sustainable land management and sustainable forest management .......................4-11 11 4.2.6 The human dimension of land degradation and forest degradation .......................4-14 12 4.3 Land degradation in the context of climate change ...................................................4-15 13 4.3.1 Processes of land degradation ........................................................................4-16 14 4.3.2 Drivers of land degradation ...........................................................................4-25 15 4.3.3 Attribution in the case of land degradation .......................................................4-26 16 4.3.4 Approaches to assessing land degradation ........................................................4-30 17 4.4 Status and current trends of land degradation...........................................................4-33 18 4.4.1 Land degradation .........................................................................................4-33 19 4.4.2 Forest degradation........................................................................................4-36 20 4.5 Projections of land degradation in a changing climate ...............................................4-40 21 4.5.1 Direct impacts on land degradation .................................................................4-40 22 4.5.2 Indirect impacts on land degradation ...............................................................4-45 23 4.6 Impacts of bioenergy and technologies for CO2 removal (CDR) on land degradation .....4-46 24 4.6.1 Potential scale of bioenergy and land-based CDR..............................................4-46 25 4.6.2 Risks of land degradation from expansion of bioenergy and land-based CDR ........4-46 26 4.6.3 Potential contributions of land-based CDR to reducing and reversing land degradation 27 4-47 28 4.6.4 Traditional biomass provision and land degradation ..........................................4-48 29 4.7 Impacts of land degradation on climate...................................................................4-49 30 4.7.1 Impacts on greenhouse gases .........................................................................4-50 31 4.7.2 Physical impacts ..........................................................................................4-51 32 4.8 Impacts of climate-related land degradation on poverty and livelihoods .......................4-52 33 4.8.1 Relationships between land degradation, climate change and poverty ...................4-53 34 4.8.2 Impacts of climate related land degradation on food security...............................4-55 35 4.8.3 Impacts of climate-related land degradation on migration and conflict..................4-56 36 4.9 Addressing land degradation in the context of climate change ....................................4-57 Subject to Copy-editing Do Not Cite, Quote or Distribute 4-2 Total pages: 184 Final Government Distribution Chapter 4: IPCC SRCCL 1 4.9.1 Actions on the ground to address land degradation ............................................4-59 2 4.9.2 Local and indigenous knowledge for addressing land degradation........................4-63 3 4.9.3 Reducing deforestation and forest degradation and increasing afforestation ...........4-63 4 4.9.4 Sustainable forest management and CO2 removal technologies............................4-65 5 4.9.5 Policy responses to land degradation ...............................................................4-67 6 4.9.6 Resilience and thresholds.............................................................................4-69 7 4.9.7 Barriers to implementation of sustainable land management ...............................4-70 8 4.10 Case-studies .......................................................................................................4-73 9 4.10.1 Urban green infrastructure .............................................................................4-74 10 4.10.2 Perennial Grains and Soil Organic Carbon .......................................................4-75 11 4.10.3 Reversing land degradation through reforestation ..............................................4-78 12 4.10.4 Degradation and management of peat soils.......................................................4-81 13 4.10.5 Biochar ......................................................................................................4-83 14 4.10.6 Management of land degradation induced by tropical cyclones............................4-86 15 4.10.7 Saltwater intrusion .......................................................................................4-87 16 4.10.8 Avoiding coastal maladaptation......................................................................4-89 17 4.11 Knowledge gaps and key uncertainties ...................................................................4-90 18 Frequently Asked Questions ...........................................................................................4-91 19 References ...................................................................................................................4-92 20 21 Subject to Copy-editing Do Not Cite, Quote or Distribute 4-3 Total pages: 184 Final Government Distribution Chapter 4: IPCC SRCCL 1 4.1 Executive Summary 2 Land degradation affects people and ecosystems throughout the planet and is both affected by 3 climate change and contributes to it. In this report, land degradation is defined as a negative trend in 4 land condition, caused by direct or indirect human-induced processes including anthropogenic climate 5 change, expressed as long-term reduction or loss of at least one of the following: biological 6 productivity, ecological integrity, or value to humans. Forest degradation is land degradation which 7 occurs in forest land. Deforestation is the conversion of forest to non-forest land and can result in land 8 degradation. {4.2.3} 9 Land degradation adversely affects people’s livelihoods (very high confidence) and occurs over a 10 quarter of the Earth’s ice-free land area (medium confidence). The majority of the 1.3 to 3.2 billion 11 affected people (low confidence) are living in poverty in developing countries (medium 12 confidence). Land use changes and unsustainable land management are direct human causes of land 13 degradation (very high confidence), with agriculture being a dominant sector driving degradation (very 14 high confidence). Soil loss from conventionally tilled land exceeds the rate of soil formation by >2 15 orders of magnitude (medium confidence). Land degradation affects humans in multiple ways, 16 interacting with social, political, cultural and economic aspects, including markets, technology, 17 inequality and demographic change (very high confidence). Land degradation impacts extend beyond 18 the land surface itself, affecting marine and freshwater systems, as well as people and ecosystems far 19 away from the local sites of degradation (very high confidence). {4.2.6, 4.3.1, 4.3.3, 4.4, 4.7.1, 4.8, 20 Table 4.1} 21 Climate change exacerbates the rate and magnitude of several ongoing land degradation 22 processes and introduces new degradation patterns (high confidence). Human-induced global 23 warming has already caused observed changes in two drivers of land degradation: increased frequency, 24 intensity and/or amount of heavy precipitation (medium confidence),
Load more

Recommended publications
  • Protect Us from Climate Change
    INTRODUCTION This project documents both the existing value and potential of New England’s working forest lands: Value – not only in terms of business opportunities, jobs and income – but also nonfinancial values, such as enhanced wildlife populations, recreation opportunities and a healthful environment. This project of the New England Forestry Foundation (NEFF) is aimed at enhancing the contribution the region’s forests can make to sustainability, and is intended to complement other efforts aimed at not only conserving New England’s forests, but also enhancing New England’s agriculture and fisheries. New England’s forests have sustained the six-state region since colonial settlement. They have provided the wood for buildings, fuel to heat them, the fiber for papermaking, the lumber for ships, furniture, boxes and barrels and so much more. As Arizona is defined by its desert landscapes and Iowa by its farms, New England is defined by its forests. These forests provide a wide range of products beyond timber, including maple syrup; balsam fir tips for holiday decorations; paper birch bark for crafts; edibles such as berries, mushrooms and fiddleheads; and curatives made from medicinal plants. They are the home to diverse and abundant wildlife. They are the backdrop for hunting, fishing, hiking, skiing and camping. They also provide other important benefits that we take for granted, including clean air, potable water and carbon storage. In addition to tangible benefits that can be measured in board feet or cords, or miles of hiking trails, forests have been shown to be important to both physical and mental health. Beyond their existing contributions, New England’s forests have unrealized potential.
    [Show full text]
  • Forest Dieback/Damages in European State Forests and Measures to Combat It Several EUSTAFOR Members Have Recently Experienced An
    Forest dieback/damages in European State Forests and measures to combat it Several EUSTAFOR members have recently experienced and reported on severe cases of forest dieback, caused by different biotic and abiotic agents. To get a better overview of these events and their consequences, with a view to a possible exchange of experiences among EUSTAFOR members as well as the development of proposals on how to communicate on these issues, the EUSTAFOR Office sent a short questionnaire to SFMOs in Europe. What follows is a comprehensive summary of the key information we received from our members. Results Out of 19 responses, 17 experienced forest dieback/damage to their forests. Only Romania and Ireland reported no forest dieback. However, Coillte (Ireland) is experiencing the problem with certain species, so they answered accordingly. Due to EUSTAFOR’s membership structure in some countries, we received input from more than one organization in that country. For example, in Germany, five different regional forest enterprises responded to the survey and, in Bulgaria, information came from two sources: the governing body - Executive Forest Agency (Ministry of Agriculture and Foods) and from one of the regional forestry enterprises. The reporting period relates to the most current available data. For the majority of the reports, this is 2018-2019. A few members, however, reported data that is a bit older. Figure 1: Map of members that answered the survey European State Forest Association AISBL Phone: +32 (0)2 239 23 00 European Forestry House Fax: +32 (0)2 219 21 91 Rue du Luxembourg 66 www.eustafor.eu 1000 Brussels, Belgium VAT n° BE 0877.545.
    [Show full text]
  • FAO Forestry Paper 120. Decline and Dieback of Trees and Forests
    FAO Decline and diebackdieback FORESTRY of tretreess and forestsforests PAPER 120 A globalgIoia overviewoverview by William M. CieslaCiesla FADFAO Forest Resources DivisionDivision and Edwin DonaubauerDonaubauer Federal Forest Research CentreCentre Vienna, Austria Food and Agriculture Organization of the United Nations Rome, 19941994 The designations employedemployed and the presentation of material inin thisthis publication do not imply the expression of any opinion whatsoever onon the part ofof thethe FoodFood andand AgricultureAgriculture OrganizationOrganization ofof thethe UnitedUnited Nations concerning the legallega! status ofof anyany country,country, territory,territory, citycity oror area or of itsits authorities,authorities, oror concerningconcerning thethe delimitationdelimitation ofof itsits frontiers or boundarboundaries.ies. M-34M-34 ISBN 92-5-103502-492-5-103502-4 All rights reserved. No part of this publicationpublication may be reproduced,reproduced, stored in aa retrieval system, or transmittedtransmitted inin any form or by any means, electronic, mechani-mechani­ cal, photocopying or otherwise, without the prior permission of the copyrightownecopyright owner.r. Applications for such permission, withwith aa statement of the purpose andand extentextent ofof the reproduction,reproduction, should bebe addressed toto thethe Director,Director, Publications Division,Division, FoodFood andand Agriculture Organization ofof the United Nations,Nations, VVialeiale delle Terme di Caracalla, 00100 Rome, Italy.Italy. 0© FAO FAO 19941994
    [Show full text]
  • The Effect of Alternative Forest Management Models on the Forest Harvest and Emissions As Compared to the Forest Reference Level
    Article The Effect of Alternative Forest Management Models on the Forest Harvest and Emissions as Compared to the Forest Reference Level 1,2, 1 3 1, 1 Mykola Gusti * , Fulvio Di Fulvio , Peter Biber , Anu Korosuo y and Nicklas Forsell 1 International Institute for Applied Systems Analysis (IIASA), Schlossplatz 1, A-2361 Laxenburg, Austria; [email protected] (F.D.F.); [email protected] (A.K.); [email protected] (N.F.) 2 International Information Department of the Institute of Applied Mathematics and Fundamental Sciences, Lviv Polytechnic National University, 12 Bandera Str., 79013 Lviv, Ukraine 3 Chair of Forest Growth and Yield Science, Technical University of Munich, Hans-Carl-von-Carlowitz-Platz 2, 85354 Freising, Germany; [email protected] * Correspondence: [email protected] Current affiliation: European Commission, Joint Research Centre, TP 261, Via E. Fermi 2749, y I-21027 Ispra, Italy. Received: 2 June 2020; Accepted: 21 July 2020; Published: 23 July 2020 Abstract: Background and Objectives: Under the Paris Agreement, the European Union (EU) sets rules for accounting the greenhouse gas emissions and removals from forest land (FL). According to these rules, the average FL emissions of each member state in 2021–2025 (compliance period 1, CP1) and in 2026–2030 (compliance period 2, CP2) will be compared to a projected forest reference level (FRL). The FRL is estimated by modelling forest development under fixed forest management practices, based on those observed in 2000–2009. In this context, the objective of this study was to estimate the effects of large-scale uptake of alternative forest management models (aFMMs), developed in the ALTERFOR project (Alternative models and robust decision-making for future forest management), on forest harvest and forest carbon sink, considering that the proposed aFMMs are expanded to most of the suitable areas in EU27+UK and Turkey.
    [Show full text]
  • Limiting the High Impacts of Amazon Forest Dieback with No-Regrets Science and Policy Action PERSPECTIVE David M
    PERSPECTIVE Limiting the high impacts of Amazon forest dieback with no-regrets science and policy action PERSPECTIVE David M. Lapolaa,1, Patricia Pinhob, Carlos A. Quesadac, Bernardo B. N. Strassburgd,e, Anja Rammigf, Bart Kruijtg, Foster Brownh,i, Jean P. H. B. Omettoj, Adriano Premebidak, Jos ´eA. Marengol, Walter Vergaram, and Carlos A. Nobren Edited by B. L. Turner, Arizona State University, Tempe, AZ, and approved October 1, 2018 (received for review May 8, 2018) Large uncertainties still dominate the hypothesis of an abrupt large-scale shift of the Amazon forest caused by climate change [Amazonian forest dieback (AFD)] even though observational evidence shows the forest and regional climate changing. Here, we assess whether mitigation or adaptation action should be taken now, later, or not at all in light of such uncertainties. No action/later action would result in major social impacts that may influence migration to large Amazonian cities through a causal chain of climate change and forest degradation leading to lower river-water levels that affect transportation, food security, and health. Net-present value socioeconomic damage over a 30-year period after AFD is estimated between US dollar (USD) $957 billion (×109) and $3,589 billion (compared with Gross Brazilian Amazon Product of USD $150 bil- lion per year), arising primarily from changes in the provision of ecosystem services. Costs of acting now would be one to two orders of magnitude lower than economic damages. However, while AFD mitigation alternatives—e.g., curbing deforestation—are attainable (USD $64 billion), their efficacy in achieving a forest resilience that prevents AFD is uncertain.
    [Show full text]
  • Russian Forests and Climate Change
    Russian forests and What Science Can Tell Us climate change Pekka Leskinen, Marcus Lindner, Pieter Johannes Verkerk, Gert-Jan Nabuurs, Jo Van Brusselen, Elena Kulikova, Mariana Hassegawa and Bas Lerink (editors) What Science Can Tell Us 11 2020 What Science Can Tell Us Sven Wunder, Editor-In-Chief Georg Winkel, Associate Editor Pekka Leskinen, Associate Editor Minna Korhonen, Managing Editor The editorial office can be contacted at [email protected] Layout: Grano Oy Recommended citation: Leskinen, P., Lindner, M., Verkerk, P.J., Nabuurs, G.J., Van Brusselen, J., Kulikova, E., Hassegawa, M. and Lerink, B. (eds.). 2020. Russian forests and climate change. What Science Can Tell Us 11. European Forest Institute. ISBN 978-952-5980-99-8 (printed) ISBN 978-952-7426-00-5 (pdf) ISSN 2342-9518 (printed) ISSN 2342-9526 (pdf) https://doi.org/10.36333/wsctu11 Supported by: This publication was produced with the financial support of the European Union’s Partnership Instrument and the German Federal Ministry for the Environment, Na- ture Conservation, and Nuclear Safety (BMU) in the context of the International Cli- mate Initiative (IKI). The contents of this publication are the sole responsibility of the European Forest Institute and do not necessarily reflect the views of the funders. Russian forests and What Science Can Tell Us climate change Pekka Leskinen, Marcus Lindner, Pieter Johannes Verkerk, Gert-Jan Nabuurs, Jo Van Brusselen, Elena Kulikova, Mariana Hassegawa and Bas Lerink (editors) Contents Authors ..............................................................................................................................
    [Show full text]
  • 4 Air Pollution Impacts on Forests in a Changing Climate
    GLOBAL ENVIRONMENTAL CHANGES 4 Air Pollution Impacts on Forests in a Changing Climate Convening lead author: Martin Lorenz Lead authors: Nicholas Clarke and Elena Paoletti Contributing authors: Andrzej Bytnerowicz, Nancy Grulke, Natalia Lukina, Hiroyuki Sase and Jeroen Staelens Abstract: Growing awareness of air pollution effects on forests has, from the early 1980s on, led to intensive forest damage research and monitoring. This has fostered air pollution control, especially in Europe and North America, and to a smaller extent also in other parts of the world. At several forest sites in these regions, there are first indications of a recovery of forest soil and tree conditions that may be attributed to improved air quality. This caused a decrease in the attention paid by politicians and the public to air pollution effects on forests. But air pollution continues to affect the structure and functioning of forest ecosystems not only in Europe and North America but even more so in parts of Russia, Asia, Latin America, and Africa. At the political level, however, attention to climate change is focussed on questions of CO2 emission and carbon sequestration. But ecological interactions between air pollution including CO2 and O3 concentrations, extreme temperatures, drought, insects, pathogens, and fire, as well as the impact of ecosystem management practices, are still poorly under- stood. Future research should focus on the interacting impacts on forest trees and ecosystems. The integrative effects of air pollution and climatic change, in particular elevated O3, altered nutrient, temperature, water availability, and elevated CO2, will be key issues for impact research. An important improvement in our understanding might be obtained by the combination of long-term multidisciplinary experiments with ecosystem-level monitoring, and the integration of the results with ecosystem modelling within a multiple-constraint framework.
    [Show full text]
  • Predicting Forest Dieback in Maine, USA: a Simple Model Based on Soil Frost and Drought
    687 Predicting forest dieback in Maine, USA: a simple model based on soil frost and drought Allan N.D. Auclair, Warren E. Heilman, and Blondel Brinkman Abstract: Tree roots of northern hardwoods are shallow rooted, winter active, and minimally frost hardened; dieback is a winter freezing injury to roots incited by frost penetration in the absence of adequate snow cover and exacerbated by drought in summer. High soil water content greatly increases conductivity of frost. We develop a model based on the sum of z-scores of soil frost (December–February) and drought in summer (May–September) that accurately predicts timing and severity of dieback on sugar maple (Acer saccharum Marsh.), Betula spp., Fraxinus spp., and red spruce (Picea rubens Sarg.) in Maine, USA, during 1920–1995. Discrepancies between predicted and actual dieback relate largely to tree popu- lation dynamics. Extraordinary levels of dieback on Betula during 1935–1950 occurred under low stress but in mature pop- ulations; under high climate stress during 1951–1975, younger surviving Betula proved resistant and showed little dieback. Severe dieback in Acer stands during 1975–1995 may relate to extensive partial cutting, leaving stands open to frost and high water tables. Widespread use of forwarder feller/buncher and wheeled skidders after 1960 commonly left hummocky, irregular surfaces subject to pooling and accelerated frost penetration. Silvicultural applications include modifying harvest- ing practices to minimize frost complications and use of the model to track and map climatic risk to avoid conditions and locales subject to dieback. Re´sume´ : Les racines des feuillus nordiques sont peu profondes, actives en hiver et a` peine endurcies au froid; le de´pe´ris- sement est le re´sultat de dommages aux racines dus au gel hivernal qui pe´ne`tre dans le sol a` cause d’un couvert nival in- suffisant et ces dommages sont aggrave´s par la se´cheresse estivale.
    [Show full text]
  • Potential Streamflow Changes from Forest Decline Due to Air Pollution
    Internationales Symposion INTERPRAEVENT 1988 – GRAZ Tagungspublikation, Band 1, Seite 51-65 Potential Streamflow Changes from Forest Decline Due to Air Pollution Mögliche Änderungen des Abflusses durch Waldsterben in Zusam- menhang mit Luftverschmutzung R.M.Rice and J.Lewis, Arcata, CA, U.S.A. SUMMARY In recent years, serious die-back of forest trees has been reported in western Europe and eastern North America. One presumed cause of the forest decline is air pollution and acid deposition. Concern has been expressed that adverse hydrolo- gic responses might occur in forested watersheds as the result of reduced evapotranspiration and increased discharge. Accor ding to one hypothesis, elevated soil-water storage might increase peak flows and cause stream channel damage or down- stream flooding. This hypothesis is explored by reviewing the literature, recomputing published data, and simulating the effects of forest removal on streamflow. This study suggests that, although significant increases in water yield may result form a reduction in forest cover, hydrologic changes are un- likely to be large enough to cause downstream damage. This optimistic conclusion is based on the small increases that might be expected with even the most abrupt reduction in forest cover, and the likelihood that changes will be gradual and that pollution-intolerant trees will be replaced by more resistant plants through natural selection. – 51 – ZUSAMMENFASSUNG In vergangenen Jahren wurde in Westeuropa and östlichen Nordamerika über schwerwiegendes Absterben der Waldbäume be- richtet. Eine der Hauptursachen dieses Waldsterbens ist die Luftverschmutzung and sauereAblagerungen. Es ist der Befürch- tunq Ausdruck gegeben worden, daβ sich die hydrologischen Verhältnisse in den bewaldeten Einzugsgebieten ändern werden.
    [Show full text]
  • Changing Climate Reallocates the Carbon Debt of Frequent‐Fire Forests
    Received: 11 June 2020 | Accepted: 24 July 2020 DOI: 10.1111/gcb.15318 PRIMARY RESEARCH ARTICLE Changing climate reallocates the carbon debt of frequent-fire forests 1 2,3 4 Marissa J. Goodwin | Malcolm P. North | Harold S. J. Zald | Matthew 1 D. Hurteau 1Department of Biology, University of New Mexico, Albuquerque, NM, USA Abstract 2Pacific Southwest Research Station, USDA Ongoing climate change will alter the carbon carrying capacity of forests as they Forest Service, Mammoth Lakes, CA, USA adjust to climatic extremes and changing disturbance regimes. In frequent-fire forests, 3Department of Plant Sciences, University of California, Davis, CA, USA increasing drought frequency and severity are already causing widespread tree mortal- 4Department of Forestry and Wildland ity events, which can exacerbate the carbon debt that has developed as a result of fire Resources, Humboldt State University, exclusion. Forest management techniques that reduce tree density and surface fuels Arcata, CA, USA decrease the risk of high-severity wildfire and may also limit drought-induced mortal- Correspondence ity by reducing competition. We used a long-term thinning and burning experiment in Matthew D. Hurteau, Department of Biology, University of New Mexico, a mixed-conifer forest to investigate the effects of the 2012–2015 California drought Albuquerque, NM 87131, USA. on forest carbon dynamics in each treatment, including the carbon emissions from Email: [email protected] a second-entry prescribed fire that followed the drought. We assessed differences Funding information in carbon stability and tree survival across treatments, expecting that both carbon California Department of Forestry and Fire Protection, Grant/Award Number: stability and survival probability would increase with increasing treatment intensity 8GG14803 (decreasing basal area).
    [Show full text]
  • Exploring the Likelihood and Mechanism of a Climate-Change-Induced Dieback of the Amazon Rainforest
    Exploring the likelihood and mechanism of a climate-change-induced dieback of the Amazon rainforest Yadvinder Malhia,1, Luiz E. O. C. Araga˜ oa, David Galbraithb, Chris Huntingfordc, Rosie Fisherd, Przemyslaw Zelazowskia, Stephen Sitche, Carol McSweeneya, and Patrick Meirb aEnvironmental Change Institute, School of Geography and the Environment, University of Oxford, South Parks Road, Oxford OX1 3QY, United Kingdom; bSchool of GeoSciences, University of Edinburgh, Edinburgh EH8 9XP, United Kingdom; cCentre for Ecology and Hydrology, Wallingford OX10 8BB, United Kingdom; dDepartment of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, United Kingdom; and eMet Office Hadley Centre, Joint Centre for Hydro-Meteorological Research, Wallingford OX10 8BB, United Kingdom Edited by Hans Joachim Schellnhuber, Potsdam Institute for Climate Impact Research, Potsdam, Germany, and approved December 15, 2008 (received for review June 10, 2008) We examine the evidence for the possibility that 21st-century nonlinearities, thresholds, and feedbacks and determine which climate change may cause a large-scale ‘‘dieback’’ or degradation components of this system are open to manipulation and man- of Amazonian rainforest. We employ a new framework for eval- agement in a manner beneficial to the long-term sustainability of uating the rainfall regime of tropical forests and from this deduce the Amazonian social ecological system. precipitation-based boundaries for current forest viability. We In this paper, we ask 3 questions. First, what are the climatic then examine climate simulations by 19 global climate models thresholds that favor the current presence of a forest as opposed (GCMs) in this context and find that most tend to underestimate to savanna? Second, what do climate models say about the likely current rainfall.
    [Show full text]
  • Changes in Species Composition in Alder Swamp Forest Following Forest Dieback
    Article Changes in Species Composition in Alder Swamp Forest Following Forest Dieback Remigiusz Pielech 1,* ID and Marek Malicki 2 1 Department of Forest Biodiversity, Institute of Forest Ecology and Silviculture, Faculty of Forestry, University of Agriculture, 29 Listopada 46, 31-425 Kraków, Poland 2 Department of Botany, Institute of Environmental Biology, Faculty of Biological Sciences, University of Wrocław, ul. Kanonia 6/8, 50-328 Wrocław, Poland; [email protected] * Correspondence: [email protected]; Tel.: +48-794-765-791 Received: 11 May 2018; Accepted: 31 May 2018; Published: 2 June 2018 Abstract: It is generally hypothesized that forest dieback is a characteristic of alder swamp forests (alder carrs, Alnion glutinosae alliance). Different internal and external factors may trigger this process, including human disturbance, changes in river discharge, unusually severe and prolonged flooding, terminal age of an even-aged alder forest (ca. 100–150 years) and others. Although forest dieback in this type of forest may cause major changes in environmental conditions, the influence of this change on the floristic composition has not been well recognized. The study aimed to detect any possible changes in floristic variation in alder swamp forest following forest dieback. Vegetation plots in alder swamp forests affected by forest dieback were resurveyed 20 years after a previous study. PERMANOVA was used to test the significance of the compositional change and nonmetric multidimensional scaling (NMDS) with passively fitted means of the Ellenberg’s Indicator Values were used to interpret its ecological meaning. In addition, different structural and diversity indices were compared, including species richness, percentage cover of vegetation layers, Shannon and Simpson diversity and evenness.
    [Show full text]