Article

Climate Change, Deforestation, and the Fate of the Amazon

Environmental Change Institute, Oxford University Centre for the Environment, South Parks Road, Oxford OX1 3QY, UK.
Science (Impact Factor: 33.61). 02/2008; 319(5860):169-72. DOI: 10.1126/science.1146961
Source: PubMed

ABSTRACT

The forest biome of Amazonia is one of Earth's greatest biological treasures and a major component of the Earth system. This
century, it faces the dual threats of deforestation and stress from climate change. Here, we summarize some of the latest
findings and thinking on these threats, explore the consequences for the forest ecosystem and its human residents, and outline
options for the future of Amazonia. We also discuss the implications of new proposals to finance preservation of Amazonian
forests.

Download full-text

Full-text

Available from: Yadvinder Malhi
  • Source
    • "This study appears to support this idea. Our results, combined with projections for increased rainfall in the western Amazon during the December–February dry season[67], suggest that survival of territorial males and lek sizes of P. filicauda will decline in the future. Further research is needed to determine if and how synergies between climate, food availability and deforestation could reduce lek sizes below some key social threshold (i.e. "

    Full-text · Article · Jan 2016 · Proceedings of the Royal Society
  • Source
    • "The threats to biodiversity caused by the loss of tropical ecosystems are frequently documented and discussed (e.g., Malhi et al., 2008; Bradshaw et al., 2009), but the emphasis has generally been on the terrestrial component of these systems. Aquatic ecosystems within tropical regions are faced with a number of anthropogenic threats: overfishing (Batista et al., 1998), invasive alien species (Latini and Petrere, 2004; Pelicice and Agostinho, 2008a), hydroelectric dam-building (Finer and Jenkins, 2012; Araújo et al., 2013), deforestation (Phillips et al., 2009, Lobόn-Cerviá et al., 2015) and droughts caused by both deforestation "
    [Show abstract] [Hide abstract]
    ABSTRACT: The Amazon River Basin contains the world's highestfish species diversity, with a hydrologic cycle that creates a patchy distribution offloodplain lakes at low water and affords dispersal and colonization opportunities through reconnected lakes, rivers, andflooded forests during high water. This connectivity is increasingly threatened by dam construction and droughts caused by climate change. Although the metapopulation framework has not been widely applied to freshwater ecosystems, it should represent a fruitful approach to conservation of importantfish stocks and species diversity in Amazonianfloodplains. Our examination of the evidence for metapopulation structure reveals that: (1) Although many economically important migratory species are not currently metapopulations (either demographically or genetically), connectivity is crucial to their life histories and anthropogenic stresses may induce metapopulation structure in these species; (2) Some large migratory pimelodid catfish with homing behavior to natal headwater streams appear to be the most spatially expansive metapopulations in existence among freshwaterfish; (3) Non-migratory species are less well studied, but some (perhaps many) such species already exist as metapopulations and are vulnerable to disruptions in patterns of connectivity. Connectivity plays a crucial role in each of these cases, so the most promising conservation strategies involve: (1) reduction in dam building; (2) establishment of large enough protected areas to incorporate highβdiversity and maintain patterns of connectivity during anomalous low water events; (3) implementation of governmentally facilitated community-basedfishing agreements to curb overexploitation and monitor sustainable population levels and connectivity in protected areas.
    Full-text · Article · Jan 2016 · Biological Conservation
  • Source
    • "In the 2000s, for example, escaped fires from agricultural practices burned 85 000 km 2 of Amazonian forests, mostly during the drought events of 2005, 2007, and 2010 (Morton et al., 2013). As climate and land use change, widespread fires may become even more common due to four factors: (i) increased frequency of extreme weather events, (ii) warmer climatic conditions, (iii) greater forest fragmentation, and (iv) increased forest disturbances associated with logging and fire (Malhi et al., 2008; Nepstad et al., 2008). These likely changes in fire regimes could push portions of the southeast Amazonia into a new stable state (Nobre & Borma, 2009), potentially releasing to the atmosphere large amounts of carbon stored in these forests (Nepstad et al., 2004). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Global changes and associated droughts, heat waves, logging activities, and forest fragmentation may intensify fires in Amazonia by altering forest microclimate and fuel dynamics. To isolate the effects of fuel loads on fire behavior and fire-induced changes in forest carbon cycling, we manipulated fine fuel loads in a fire experiment located in southeast Amazonia. We predicted that a 50% increase in fine fuel loads would disproportionally increase fire intensity and severity (i.e., tree mortality and losses in carbon stocks) due to multiplicative effects of fine fuel loads on the rate of fire spread, fuel consumption, and burned area. The experiment followed a fully replicated randomized block design (N = 6) comprised of unburned control plots and burned plots that were treated with and without fine fuel additions. The fuel addition treatment significantly increased burned area (+22%) and consequently canopy openness (+10%), fine fuel combustion (+5%), and mortality of individuals ≥5 cm in diameter at breast height (dbh; +37%). Surprisingly, we observed nonsignificant effects of the fuel addition treatment on fireline intensity, and no significant differences among the three treatments for (i) mortality of large trees (≥30 cm dbh), (ii) aboveground forest carbon stocks, and (iii) soil respiration. It was also surprising that postfire tree growth and wood increment were higher in the burned plots treated with fuels than in the unburned control. These results suggest that (i) fine fuel load accumulation increases the likelihood of larger understory fires and (ii) single, low-intensity fires weakly influence carbon cycling of this primary neotropical forest, although delayed postfire mortality of large trees may lower carbon stocks over the long term. Overall, our findings indicate that increased fine fuel loads alone are unlikely to create threshold conditions for high-intensity, catastrophic fires during nondrought years.
    Full-text · Article · Jan 2016 · Global Change Biology
Show more