Spatiotemporal analysis of deforestation patterns and drivers reveals emergent threats to tropical forest landscapes

As deforestation breaches into new tropical frontiers, proactive conservation strategies require a trifecta of information on where deforestation is accelerating (emergent), how drivers of deforestation vary spatiotemporally, and where to focus limited conservation resources in protecting the most integral yet threatened forested landscapes. Here we introduce Emergent Threat Analysis, a process integrating Emerging Hot Spot Analysis of deforestation, visual classification of deforestation outcomes over time, and spatial quantification of contemporary forest condition. We applied Emergent Threat Analysis to tropical Southeast Asia, a global epicentre of biodiversity threatened by deforestation. We found that emergent hot spots (EHS)-a subset of hot spots characterized by strong, recent, and clustered patterns of deforestation-accounted for 26.1% of total forest loss from 1992 to 2018, with deforestation within EHS proceeding at 2.5 times the regional rate of gross loss. Oil palm and rubber plantation expansion were the principal drivers of deforestation within EHS of insular and mainland SE Asia, respectively. Over the study period, oil palm shifted in importance from Sumatra and Sarawak to Papua and Kalimantan, whereas rubber became prominent in Cambodia and Tanintharyi from 2006 to 2015. As of 2019, more than 170 000 km(2) of SE Asia's remaining forest occurred within EHS, of which 21.7% was protected. High and medium-integrity forest constituted 19.2% and 49.1% of remaining EHS forest, respectively, but of these, 35.0% of high-integrity and 23.9% of medium-integrity EHS forest were protected. Because we anticipate that tree plantation expansion will continue to drive deforestation in SE Asia, significantly heightened protection is needed to secure the long-term preservation of high and medium-integrity forest, especially in highly contested forest frontier regions. Finally, as a flexible, integrated process, Emergent Threat Analysis is applicable to deforestation fronts across the global tropics.Peer reviewe

EMERGING HOTSPOTS OF DEFORESTATION IN SOUTHEAST ASIA

Master'sMASTER OF SCIENCE (RSH-FOS

Last stand : Application of a criteria-based framework to inform conservation of a critically threatened tropical lowland forest fragment

Investing resources into protecting small, isolated tropical forest fragments can require considerable justification, especially in the context of limited resources and competing development pressures. Nevertheless, fragments may be suitable targets for conservation if they offer irreplaceable biodiversity outcomes and align with conservation aspirations. This is particularly true for island systems such as Oceania, where tropical lowland forest fragments may be the last remaining representatives of critical habitat due to agriculture or urban expansion on limited flat land. Despite this urgency, the decision to invest significant resources into a permanent conservation investment should be informed by a systematic framework to evaluate relevant conservation criteria for one or multiple sites. Here we present a case study where we applied the criteria-based framework of the Forest Legacy Program of the United States Forest Service, to assess the importance, threat, and strategic benefits of the last known remnant (9.33 ha) of lowland lava flow forest in American Samoa (Polynesia). We expounded on the FLP framework by providing examples of potential evidence and corresponding datasets that could inform the conservation criteria. For the case study, we conducted a comprehensive high-precision tree census to quantify forest structure and composition and compare with other forest types in the country, which revealed high conservation importance based on unique community composition and irreplaceable tree species representations, including Pometia pinnata, Dendrocnide harveyi, and two banyan figs Ficus obliqua and F. prolixa. Analysis of historical (70-year) aerial imagery and recent land cover maps, evidence of recent small-scale incursions, documented attempts by the landowners to obtain development permits, and the need for a court-imposed injunction and a conservation lease to prevent further encroachment, all indicated a high likelihood of conversion (threat) if left unprotected. Finally, we found that protection of this fragment would strategically align with the conservation, management, and education portfolios of the American Samoa government, and provide significant cultural and well-being benefits to the public, specific to the fact that this is the last representative of lava flow forest and is easily accessible to the public. We conclude that there is strong justification for conservation of Naumati forest, which in this case would be through a land purchase. More broadly, criteria-based approaches are often broad and flexible and can be widely applied, but they require significant work to collect data and generate evidence that is meaningful to conservation practitioners working on-the-ground. Effectively linking data to evidence to criteria and ultimately to decision-making is key to justifying sound conservation investments.Peer reviewe

Last stand : Application of a criteria-based framework to inform conservation of a critically threatened tropical lowland forest fragment

Investing resources into protecting small, isolated tropical forest fragments can require considerable justification, especially in the context of limited resources and competing development pressures. Nevertheless, fragments may be suitable targets for conservation if they offer irreplaceable biodiversity outcomes and align with conservation aspirations. This is particularly true for island systems such as Oceania, where tropical lowland forest fragments may be the last remaining representatives of critical habitat due to agriculture or urban expansion on limited flat land. Despite this urgency, the decision to invest significant resources into a permanent conservation investment should be informed by a systematic framework to evaluate relevant conservation criteria for one or multiple sites. Here we present a case study where we applied the criteria-based framework of the Forest Legacy Program of the United States Forest Service, to assess the importance, threat, and strategic benefits of the last known remnant (9.33 ha) of lowland lava flow forest in American Samoa (Polynesia). We expounded on the FLP framework by providing examples of potential evidence and corresponding datasets that could inform the conservation criteria. For the case study, we conducted a comprehensive high-precision tree census to quantify forest structure and composition and compare with other forest types in the country, which revealed high conservation importance based on unique community composition and irreplaceable tree species representations, including Pometia pinnata, Dendrocnide harveyi, and two banyan figs Ficus obliqua and F. prolixa. Analysis of historical (70-year) aerial imagery and recent land cover maps, evidence of recent small-scale incursions, documented attempts by the landowners to obtain development permits, and the need for a court-imposed injunction and a conservation lease to prevent further encroachment, all indicated a high likelihood of conversion (threat) if left unprotected. Finally, we found that protection of this fragment would strategically align with the conservation, management, and education portfolios of the American Samoa government, and provide significant cultural and well-being benefits to the public, specific to the fact that this is the last representative of lava flow forest and is easily accessible to the public. We conclude that there is strong justification for conservation of Naumati forest, which in this case would be through a land purchase. More broadly, criteria-based approaches are often broad and flexible and can be widely applied, but they require significant work to collect data and generate evidence that is meaningful to conservation practitioners working on-the-ground. Effectively linking data to evidence to criteria and ultimately to decision-making is key to justifying sound conservation investments

Integrating Analytical Frameworks to Investigate Land-Cover Regime Shifts in Dynamic Landscapes

Regime shifts—rapid long-term transitions between stable states—are well documented in ecology but remain controversial and understudied in land use and land cover change (LUCC). In particular, uncertainty surrounds the prevalence and causes of regime shifts at the landscape level. We studied LUCC dynamics in the Tanintharyi Region (Myanmar), which contains one of the last remaining significant contiguous forest areas in Southeast Asia but was heavily deforested between 1992⁻2015. By combining remote sensing methods and a literature review of historical processes leading to LUCC, we identified a regime shift from a forest-oriented state to an agricultural-oriented state between 1997⁻2004. The regime shift was triggered by a confluence of complex political and economic conditions within Myanmar, notably the ceasefires between various ethnic groups and the military government, coupled with its enhanced business relations with Thailand and China. Government policies and foreign direct investment enabling the establishment of large-scale agro-industrial concessions reinforced the new agriculture-oriented regime and prevented reversion to the original forest-dominated regime. Our approach of integrating complementary analytical frameworks to identify and understand land-cover regime shifts can help policymakers to preempt future regime shifts in Tanintharyi, and can be applied to the study of land change in other regions

Conservation beyond the existing protected area network is required to improve species and habitat representation in a global biodiversity hotspot

10.1016/j.biocon.2021.109105Biological Conservation25710910