Navjot's nightmare revisited: logging, agriculture, and biodiversity in Southeast Asia
TL;DR: It is concluded that preventing agricultural conversion of logged forests is essential to conserving the biodiversity of this region and that conservation payments commensurate with combined returns from logging and subsequent agricultural production may be required to secure long-term forest protection.
Abstract: In 2004, Navjot Sodhi and colleagues warned that logging and agricultural conversion of Southeast Asia's forests were leading to a biodiversity disaster. We evaluate this prediction against subsequent research and conclude that most of the fauna of the region can persist in logged forests. Conversely, conversion of primary or logged forests to plantation crops, such as oil palm, causes tremendous biodiversity loss. This loss is exacerbated by increased fire frequency. Therefore, we conclude that preventing agricultural conversion of logged forests is essential to conserving the biodiversity of this region. Our analysis also suggests that, because Southeast Asian forests are tightly tied to global commodity markets, conservation payments commensurate with combined returns from logging and subsequent agricultural production may be required to secure long-term forest protection.
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TL;DR: In this paper, the authors report a spatially and temporally explicit quantification of Indonesian primary forest loss, which totalled over 602 Mha from 2000 to 2012 and increased on average by 47,600 ha per year.
Abstract: Extensive clearing of Indonesian primary forests results in increased greenhouse gas emissions and biodiversity loss However, there is no consensus on the areal extent and temporal trends of primary forest clearing in Indonesia Here we report a spatially and temporally explicit quantification of Indonesian primary forest loss, which totalled over 602 Mha from 2000 to 2012 and increased on average by 47,600 ha per year By 2012, annual primary forest loss in Indonesia was estimated to be higher than in Brazil (084 Mha and 046 Mha, respectively) Proportional loss of primary forests in wetland landforms increased and almost all clearing of primary forests occurred within degraded types, meaning logging preceded conversion processes Loss within official forest land uses that restrict or prohibit clearing totalled 40% of all loss within national forest land The increasing loss of Indonesian primary forests has significant implications for climate change mitigation and biodiversity conservation efforts Deforestation affects climate, biodiversity and other ecosystem services This study quantifies Indonesia’s increasing rate of primary forest loss, which runs counter to the declining rates of loss in Brazil The results highlight the value of thematically consistent and spatially and temporally explicit information in tracking forest change
810 citations
TL;DR: Tropical forests house over half of Earth’s biodiversity and are an important influence on the climate system, but ongoing pressures, together with an intensification of global environmental change, may severely degrade forests in the future unless new “development without destruction” pathways are established alongside climate change–resilient landscape designs.
Abstract: Tropical forests house over half of Earth’s biodiversity and are an important influence on the climate system. These forests are experiencing escalating human influence, altering their health and the provision of important ecosystem functions and services. Impacts started with hunting and millennia-old megafaunal extinctions (phase I), continuing via low-intensity shifting cultivation (phase II), to today’s global integration, dominated by intensive permanent agriculture, industrial logging, and attendant fires and fragmentation (phase III). Such ongoing pressures, together with an intensification of global environmental change, may severely degrade forests in the future (phase IV, global simplification) unless new “development without destruction” pathways are established alongside climate change–resilient landscape designs.
542 citations
TL;DR: In this article, the authors present the land cover and industrial plantations distribution in the peatlands of Peninsular Malaysia, Sumatra and Borneo in 2015 and analyse their changes since 1990.
363 citations
TL;DR: In this paper, a review of threats to regional biodiversity in the Southeast Asia region is presented, and the overall prognosis of regional biodiversity and priority actions to protect SE Asian biodiversity are discussed.
Abstract: Southeast Asia (SE Asia) is a known global hotspot of biodiversity and endemism, yet the region is also one of the most biotically threatened. Ecosystems across the region are threatened by an array of drivers, each of which increases the probability of extinction of species in a variety of ecosystems. These issues are symptomatic of the issues that face the global tropics; however, with around 4 billion people in the wider region and the associated pressures on biodiversity, this region may be under some of the greatest levels of biotic threat. Deforestation rates in SE Asia are some of the highest globally, additionally it has the highest rate of mining in the tropics, around the greatest number of hydropower dams under construction, and a consumption of species for traditional medicines which is a threat to biodiversity globally. In this review, the greatest threats to regional biodiversity in the SE Asian region are discussed. Tree-plantations and deforestation represent one of the most imminent threats, and some countries have already lost over half their original forest cover (i.e., the Philippines, parts of Indonesia), with projections of as much as 98% loss for some regions in the coming decade. Hunting and trade represent a significant threat as demand stems not only for food, but also for medicine, for ornamentation, and as a status symbol. Mining represents a frequently overlooked threat, as the Asian region is one of the greatest exporters of limestone and various minerals globally, and the cost of this to biodiversity is not only through the direct loss of areas for mines, but also through the development of roads that further fragment the landscape, the leakage of heavy metals, and the destruction of limestone karsts, which represent global endemicity hotspots. Reservoir construction, wetland drainage, fires, pollution, invasive species, disease, and finally climate change are also considered. Once each issue has been discussed, the overall prognosis of regional biodiversity and priority actions to protect SE Asian biodiversity in the future is discussed.
323 citations
Cites background from "Navjot's nightmare revisited: loggi..."
...Studies have also shown that tree plantations cannot sustain high diversity of forest-dependent species (Wilcove et al. 2013), and that ever expanding tree plantations therefore potentially have significant negative effects on native forest communities through habitat loss and fragmentation....
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TL;DR: It is concluded that natural timber-production forests typically retain most of their biodiversity and associated ecosystem functions, as well as their carbon, climatic, and soil-hydrological ecosystem services.
Abstract: Vast expanses of tropical forests worldwide are being impacted by selective logging. We evaluate the environmental impacts of such logging and conclude that natural timber-production forests typically retain most of their biodiversity and associated ecosystem functions, as well as their carbon, climatic, and soil-hydrological ecosystem services. Unfortunately, the value of production forests is often overlooked, leaving them vulnerable to further degradation including post-logging clearing, fires, and hunting. Because logged tropical forests are extensive, functionally diverse, and provide many ecosystem services, efforts to expand their role in conservation strategies are urgently needed. Key priorities include improving harvest practices to reduce negative impacts on ecosystem functions and services, and preventing the rapid conversion and loss of logged forests.
313 citations
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TL;DR: It is estimated that between 0.81 and 2.57 Gt of carbon were released to the atmosphere in 1997 as a result of burning peat and vegetation in Indonesia, equivalent to 13–40% of the mean annual global carbon emissions from fossil fuels, and contributed greatly to the largest annual increase in atmospheric CO2 concentration detected since records began in 1957.
Abstract: Tropical peatlands are one of the largest near-surface reserves of terrestrial organic carbon, and hence their stability has important implications for climate change1,2,3. In their natural state, lowland tropical peatlands support a luxuriant growth of peat swamp forest overlying peat deposits up to 20 metres thick4,5. Persistent environmental change—in particular, drainage and forest clearing—threatens their stability2, and makes them susceptible to fire6. This was demonstrated by the occurrence of widespread fires throughout the forested peatlands of Indonesia7,8,9,10 during the 1997 El Nino event. Here, using satellite images of a 2.5 million hectare study area in Central Kalimantan, Borneo, from before and after the 1997 fires, we calculate that 32% (0.79 Mha) of the area had burned, of which peatland accounted for 91.5% (0.73 Mha). Using ground measurements of the burn depth of peat, we estimate that 0.19–0.23 gigatonnes (Gt) of carbon were released to the atmosphere through peat combustion, with a further 0.05 Gt released from burning of the overlying vegetation. Extrapolating these estimates to Indonesia as a whole, we estimate that between 0.81 and 2.57 Gt of carbon were released to the atmosphere in 1997 as a result of burning peat and vegetation in Indonesia. This is equivalent to 13–40% of the mean annual global carbon emissions from fossil fuels, and contributed greatly to the largest annual increase in atmospheric CO2 concentration detected since records began in 1957 (ref. 1).
1,731 citations
01 Jan 2008
1,729 citations
Luke Gibson1, Tien Ming Lee2, Tien Ming Lee3, Lian Pin Koh4, Lian Pin Koh1, Barry W. Brook5, Toby A. Gardner6, Jos Barlow7, Carlos A. Peres8, Corey J. A. Bradshaw9, Corey J. A. Bradshaw5, William F. Laurance10, Thomas E. Lovejoy11, Navjot S. Sodhi1 •
National University of Singapore1, University of California, San Diego2, Yale University3, ETH Zurich4, University of Adelaide5, University of Cambridge6, Lancaster University7, University of East Anglia8, South Australian Research and Development Institute9, James Cook University10, National Institute of Amazonian Research11
TL;DR: It is found that biodiversity values were substantially lower in degraded forests, but that this varied considerably by geographic region, taxonomic group, ecological metric and disturbance type.
Abstract: Human-driven land-use changes increasingly threaten biodiversity, particularly in tropical forests where both species diversity and human pressures on natural environments are high. The rapid conversion of tropical forests for agriculture, timber production and other uses has generated vast, human-dominated landscapes with potentially dire consequences for tropical biodiversity. Today, few truly undisturbed tropical forests exist, whereas those degraded by repeated logging and fires, as well as secondary and plantation forests, are rapidly expanding. Here we provide a global assessment of the impact of disturbance and land conversion on biodiversity in tropical forests using a meta-analysis of 138 studies. We analysed 2,220 pairwise comparisons of biodiversity values in primary forests (with little or no human disturbance) and disturbed forests. We found that biodiversity values were substantially lower in degraded forests, but that this varied considerably by geographic region, taxonomic group, ecological metric and disturbance type. Even after partly accounting for confounding colonization and succession effects due to the composition of surrounding habitats, isolation and time since disturbance, we find that most forms of forest degradation have an overwhelmingly detrimental effect on tropical biodiversity. Our results clearly indicate that when it comes to maintaining tropical biodiversity, there is no substitute for primary forests.
1,640 citations
TL;DR: Compared crop yields and densities of bird and tree species across gradients of agricultural intensity in southwest Ghana and northern India, land sparing is a more promising strategy for minimizing negative impacts of food production, at both current and anticipated future levels of production.
Abstract: The question of how to meet rising food demand at the least cost to biodiversity requires the evaluation of two contrasting alternatives: land sharing, which integrates both objectives on the same land; and land sparing, in which high-yield farming is combined with protecting natural habitats from conversion to agriculture. To test these alternatives, we compared crop yields and densities of bird and tree species across gradients of agricultural intensity in southwest Ghana and northern India. More species were negatively affected by agriculture than benefited from it, particularly among species with small global ranges. For both taxa in both countries, land sparing is a more promising strategy for minimizing negative impacts of food production, at both current and anticipated future levels of production.
1,383 citations
TL;DR: The looming Southeast Asian biodiversity disaster demands immediate and definitive actions, yet such measures continue to be constrained by socioeconomic factors, including poverty and lack of infrastructure.
Abstract: Southeast Asia has the highest relative rate of deforestation of any major tropical region, and could lose three quarters of its original forests by 2100 and up to 42% of its biodiversity. Here, we report on the current state of its biota and highlight the primary drivers of the threat of extinction now faced by much of the unique and rich fauna and flora of the region. Furthermore, the known impacts on the biodiversity of Southeast Asia are likely to be just the tip of the iceberg, owing to the paucity of research data. The looming Southeast Asian biodiversity disaster demands immediate and definitive actions, yet such measures continue to be constrained by socioeconomic factors, including poverty and lack of infrastructure. Any realistic solution will need to involve a multidisciplinary strategy, including political, socioeconomic and scientific input, in which all major stakeholders (government, non-government, national and international organizations) must participate.
1,381 citations