About
73
Publications
77,788
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
6,998
Citations
Publications
Publications (73)
Roads are expanding at the fastest pace in human history. This is the case especially in biodiversity-rich tropical nations, where roads can result in forest loss and fragmentation, wildfires, illicit land invasions and negative societal effects1–5. Many roads are being constructed illegally or informally and do not appear on any existing road map6...
Road building has long been under-mapped globally, arguably more than any other human activity threatening environmental integrity. Millions of kilometers of unmapped roads have challenged environmental governance and conservation in remote frontiers. Prior attempts to map roads at large scales have proven inefficient, incomplete, and unamenable to...
Fire activity is declining globally due to intensifying land management, but trends remain uncertain for the humid tropics, particularly Equatorial Asia. Here, we report that rates of fire events deemed severe (≥75th severity percentile of 2002-2019) and very severe (≥90th percentile) for Indonesia declined 19-27% and 23-34% over 2002-2019, respect...
The forests of Borneo—the third largest island on the planet—sustain some of the highest biodiversity and carbon storage in the world. The forests also provide vital ecosystem services and livelihood support for millions of people in the region, including many indigenous communities. The Pan-Borneo Highway and several hydroelectric dams are planned...
Road development in tropical forest landscapes is contentious. Local preferences are often subordinated to global economic and environmental concerns. Opportunities to seek solutions based on local context are rare. We examined local perspectives on road development within Cambodia’s Keo Seima Wildlife Sanctuary to explore opportunities for optimiz...
Extensions of forest-transition theory to the tropics often depict sustained expansions of planted tree cover and corresponding long-term net gains in total tree cover. To explore the patterns and implications of continued tropical planted tree-cover expansion, we profiled sequences of tree-cover change over 1990–2010 according to Landsat imagery f...
The Heart of Borneo initiative has promoted the integration of protected areas and sustainably-managed forests across Malaysia, Indonesia, and Brunei. Recently, however, member states of the Heart of Borneo have begun pursuing ambitious unilateral infrastructure-development schemes to accelerate economic growth, jeopardizing the underlying goal of...
Tropical forest regions in equatorial Africa are threatened with degradation, deforestation and biodiversity loss as a result of land-cover change. We investigated historical land-cover dynamics in unprotected forested areas of the Littoral Region in south-western Cameroon during 1975–2017, to detect changes that may influence this important biodiv...
The island of New Guinea hosts the third largest expanse of tropical rainforest on the planet. Papua New Guinea—comprising the eastern half of the island—plans to nearly double its national road network (from 8,700 to 15,000 km) over the next three years, to spur economic growth. We assessed these plans using fine-scale biophysical and environmenta...
Forest transitions occur when net reforestation replaces net deforestation in places. Because forest transitions can increase biodiversity and augment carbon sequestration, they appeal to policymakers contending with the degrading effects of forest loss and climate change. What then can policymakers do to trigger forest transitions? The historical...
Abstract Indonesian Borneo (Kalimantan) sustains ~37 million hectares of native tropical forest. Numerous large-scale infrastructure projects aimed at promoting land-development activities are planned or ongoing in the region. However, little is known of the potential impacts of this new infrastructure on Bornean forests or biodiversity. We found t...
Tropical reforestation is a significant component of global environmental change that is far less understood than tropical deforestation, despite having apparently increased widely in scale during recent decades. The regional contexts defining such reforestation have not been well described. They are likely to differ significantly from the geograph...
Road-infrastructure development in Southeast Asia is opening new resource frontiers but also consolidating earlier investments in agriculture and trade, as illustrated by the 2,700-km Trans-Sumatra Highway planned for Sumatra, Indonesia. In contrast to earlier broadscale forest losses in Sumatra, driven historically in Sumatra infrastructure and ag...
The island of New Guinea harbours one of the world’s largest tracts of intact tropical forest, with 41% of its land area in Indonesian Papua (Papua and Papua Barat Provinces). Within Papua, the advent of a 4000-km ‘development corridor’ reflects a national agenda promoting primary-resource extraction and economic integration. Papua, a resource fron...
Carbon emissions from drained peatlands converted to agriculture in Southeast Asia (i.e. Peninsular Malaysia, Sumatra and Borneo) are globally significant and increasing. Here, we map the growth of Southeast Asian peatland agriculture and estimate CO2 emissions due to peat drainage in relation to official land‐use plans with a focus on the Reducing...
The Leuser Ecosystem in northern Sumatra, Indonesia is a globally-significant landscape for biodiversity conservation and ecosystem services. It is however increasingly threatened by infrastructure development, enabled by discordant forest governance amongst central and regional governments. Here we identify these infrastructure threats and related...
Nater, et al.[1] recently identified a new orangutan species (Pongo tapanuliensis) in northern Sumatra, Indonesia-just the seventh described species of living great ape. The population of this critically-endangered species is perilously small, at only ∼800 individuals [1], ranking it among the planet's rarest fauna. We assert that P. tapanuliensis...
Mapping ecosystem services (ES) over large scales is important for environmental monitoring but is often prohibitively expensive and difficult. We test a hybrid, low-cost method of mapping ES indicators over large scales in Pará State, Brazil. Four ES indicators (vegetation carbon stocks, biodiversity index, soil chemical quality index and rates of...
The 21st century will see an unprecedented expansion of roads, dams, power lines, and gas lines, as well as massive investments in mining and fossil fuel projects. At least 25 million kilometers of new roads are anticipated by 2050. Nine-tenths of all road construction is projected to occur in developing nations, including many tropical regions tha...
New forests are expanding around the world. In many regions, regrowth rates are surpassing deforestation rates, resulting in “forest transitions,” or net gains in forest cover. Typically measured only in terms of aggregate“’forest cover” change, these new forests are ecologically distinct from each other and from those originally cleared. We ask, w...
Tropical rainforests, naturally resistant to fire when intact, are increasingly vulnerable to burning due to ongoing forest perturbation and, possibly, climatic changes. Industrial-scale forest degradation and conversion are increasing fire occurrence, and interactions with climate anomalies such as El Niño induced droughts can magnify the extent a...
It is projected that 25 million km of new paved roads will be developed globally by 2050-enough to encircle the planet more than 600 times. Roughly 90% of new roads will be built in developing nations, frequently in tropical and subtropical regions with high biodiversity and environmental values. Many developing nations are borrowing from internati...
The Cross River State Government in Nigeria is proposing to construct a “Cross River Superhighway” that would bisect critical remaining areas of tropical rainforest in south eastern Nigeria. We offer and evaluate two alternative routes to the superhighway that would be less damaging to forests, protected areas, and biological diversity. The first a...
The first International Peat Congress (IPC) held in the tropics - in Kuching (Malaysia) - brought together over 1000 international peatland scientists and industrial partners from across the world (“International Peat Congress with over 1000 participants!,” 2016). The congress covered all aspects of peatland ecosystems and their management, with a...
This paper uses new, high resolution satellite-derived data to explore recent cross-national differences in expanding tree cover. Increases in tree cover have concentrated in nations with recent histories of extensive deforestation, humid climates, high crop yields, and small numbers of farm workers. The associations of expanded tree cover with hig...
The first International Peat Congress (IPC) held in the tropics - in Kuching (Malaysia) - brought together over 1000 international peatland scientists and industrial partners from across the world ("International Peat Congress with over 1000 participants!," 2016). The congress covered all aspects of peatland ecosystems and their management, with a...
The tropical deforestation literature advocates multi-agent enquiry in recognition that key dynamics arise from inter-agent interactions. Studies of tropical forest-cover gain have lagged in this respect. This article explores the roles and key aspects of interactions shaping natural forest regeneration and active reforestation in Eastern Panama si...
In sub-Saharan Africa, dozens of major "development corridors" have been proposed or are being created to increase agricultural production [1-4], mineral exports [5-7], and economic integration. The corridors involve large-scale expansion of infrastructure such as roads, railroads, pipelines, and port facilities and will open up extensive areas of...
Context
Tropical forest regeneration is increasingly prominent as agro-pastoral lands are abandoned. Regeneration is characterised as favouring ‘marginal’ lands; however, observations of its drivers are often coarse or simple, leaving doubt as to spatial dynamics and causation.
Objectives
We quantified the spatial dynamics of forest regeneration re...
The Global Forest Resources Assessment 2015 shows that deforestation has slowed and afforestation has increased globally during 1990-2015. Planted forests have increasingly provided goods and services hitherto derived from natural forests, and mosaic forests in agricultural landscapes are increasing. Forest gain is occurring at higher latitudes and...
Forest recovery is occurring in Panama and several other tropical countries following decades of deforestation. Theory on such ‘forest transitions’ describes urbanization and agricultural modernization as underling factors. Tropical country governments may seek to harness these factors to promote a tropical forest transition within the REDD+ scheme...
The number and extent of roads will expand dramatically this century. Globally, at least 25 million kilometres of new roads are anticipated by 2050; a 60% increase in the total length of roads over that in 2010. Nine-tenths of all road construction is expected to occur in developing nations, including many regions that sustain exceptional biodivers...
Trans-boundary haze events in Southeast Asia are associated with large forest and peatland fires in Indonesia. These episodes of extreme air pollution usually occur during drought years induced by climate anomalies from the Pacific (El Niño Southern Oscillation) and Indian Oceans (Indian Ocean Dipole). However, in June 2013 - a non-drought year - S...
The native forests of Borneo have been impacted by selective logging, fire, and conversion to plantations at unprecedented scales since industrial-scale extractive industries began in the early 1970s. There is no island-wide documentation of forest clearance or logging since the 1970s. This creates an information gap for conservation planning, espe...
The natural forest cover of Borneo has been impacted by timber extraction, converted to plantations or cleared for other uses at unprecedented scales since industrial-scale extractive industries began in early 1970s. Few accurate data describe where and how much forest area has been cleared and impacted by timber extraction. This creates an informa...
In 2011 Indonesia decreed a moratorium on forest licenses over 69 million hectares (Mha) in order to suspend haphazard forest exploitation. However, only ∼12–22 Mha were actually afforded new protection from licensing. Herein I observe a further 5.5 Mha of moratorium area overlapping forest licenses and therefore subject to excisement from the mora...
Tropical agriculture is expanding rapidly at the expense of forest, driving a global extinction crisis. How to create agricultural landscapes that minimise the clearance of forest and maximise sustainability is thus a key issue. One possibility is protecting natural forest within or adjacent to crop monocultures to harness important ecosystem servi...
The government of Indonesia, which presides over 10% of the world's tropical forests, has set ambitious targets to cut its high deforestation rates through an REDD+ scheme (Reducing Emissions from Deforestation and forest Degradation). This will require strong law enforcement to succeed. Yet, strategies that have accomplished this are rare and, alo...
Africa is on the verge of a mining boom. We review the environmental threats from African mining development, including habitat alteration, infrastructure expansion, human migration, bushmeat hunting, corruption, and weak governance. We illustrate these threats in Central Africa, which contains the vast Congo rainforest, and show that more than a q...
Combining protected areas with natural forest timber concessions may sustain larger forest landscapes than is possible via protected areas alone. However, the role of timber concessions in maintaining natural forest remains poorly characterized.
An estimated 57% (303,525 km2) of Kalimantan's land area (532,100 km2) was covered by natural forest in...
Supporting information describing how control variables were derived. This file includes Figure S1, Figure S2, and Figure S3.
(DOC)
Combining protected areas with natural forest timber concessions may sustain larger forest landscapes than is possible via protected areas alone. However, the role of timber concessions in maintaining natural forest remains poorly characterized.
An estimated 57% (303,525 km2) of Kalimantan's land area (532,100 km2) was covered by natural forest in...
Maps of tropical successional forest cover of the 1970s and 1980s are needed for long-term modelling of tropical forest-cover change, carbon flux and habitat change. Landsat Multispectral Scanner System (MSS) imagery may provide a basis for such maps, but its capability in this respect is poorly unexplored if not discounted. This article examines h...
Colombia is the fifth largest producer of palm oil in the world. The country's government and oil-palm farmers association target a sixfold increase of crude palm-oil production by 2020. We model the impacts of expanding oil-palm agriculture in Colombia through a spatially explicit scenario analysis. We demonstrate that the impacts of oil-palm expa...
Landsat can be used to map tropical forest cover at 15–60 m resolution, which is helpful for detecting small but important perturbations in increasingly fragmented forests. However, among the remaining Landsat satellites, Landsat-5 no longer has global coverage and, since 2003, a mechanical fault in the Scan-Line Corrector (SLC-Off) of the Landsat-...
The rapid disruption of tropical forests probably imperils global biodiversity more than any other contemporary phenomenon. With deforestation advancing quickly, protected areas are increasingly becoming final refuges for threatened species and natural ecosystem processes. However, many protected areas in the tropics are themselves vulnerable to hu...
In May 2010, Indonesia signed a $1-billion partnership with Norway to reduce deforestation and prepare for a global REDD+ scheme (Reducing Emissions from Deforestation and forest Degradation). A pillar of the pact is a moratorium on new agricultural and logging licenses in ∼535,294 km2 of species-rich dryland forest and ∼153,984 km2 of carbon-rich...
Koh and Ghazoul (1) model oil-palm expansion in Indonesia under multiple scenarios in which the probability of land cover conversion to oil palm is weighted by land cover qualities such as agricultural productivity and carbon content. Their goal was not a predictive model but rather a “broad model” that would make explicit to decision makers the tr...
We provide a cross-taxon and historical analysis of what makes tropical forest species vulnerable to extinction. Several traits have been important for species survival in the recent and distant geological past, including seed dormancy and vegetative growth in plants, small body size in mammals, and vagility in insects. For major past catastrophes,...
Reducing greenhouse gas emissions from deforestation and forest degradation (REDD) is likely to be central to a post-Kyoto climate change mitigation agreement. As such, identifying conditions and factors that will shape the success or failure of a reduced deforestation scheme will provide important insights for policy planning. Given that protected...
The forest-transition theory of expanding forest cover after prolonged periods of deforestation has typically examined forest regeneration apart from historic land-use patterns. In the Bayano-Darién agricultural frontier of Panama, this paper observes forest-cover expansion that is simultaneous to and successive of a preceding pattern of land-use/c...
Some authors have suggested that agricultural land in Fiji is ever scarcer and concentrated in the hands of a relative few, while others suggest that social forces owing to a felt land scarcity in native Fijian villages repress and reverse accumulation. This paper explores this idea by examining the relationships among felt land scarcity, communal...
The literature on tropical forest-cover change observes a set of drivers responsible for transitions toward reforestation – the so-called 'forest transition'. Uncertainty still exists over how the drivers behave in the transition and how trends in reforestation manifest in different contexts. Focusing on the Panamanian agricultural frontier of the...