Global patterns of tropical forest fragmentation

Abstract

Remote sensing enables the quantification of tropical deforestation with high spatial resolution. This in-depth mapping has led to substantial advances in the analysis of continent-wide fragmentation of tropical forests. Here we identified approximately 130 million forest fragments in three continents that show surprisingly similar power-law size and perimeter distributions as well as fractal dimensions. Power-law distributions have been observed in many natural phenomena such as wildfires, landslides and earthquakes. The principles of percolation theory provide one explanation for the observed patterns, and suggest that forest fragmentation is close to the critical point of percolation; simulation modelling also supports this hypothesis. The observed patterns emerge not only from random deforestation, which can be described by percolation theory, but also from a wide range of deforestation and forest-recovery regimes. Our models predict that additional forest loss will result in a large increase in the total number of forest fragments-at maximum by a factor of 33 over 50 years-as well as a decrease in their size, and that these consequences could be partly mitigated by reforestation and forest protection.

Using the U‐net convolutional network to map forest types and disturbance in the Atlantic rainforest with very high resolution images

“…As fragmentation is increasing over all tropical forests (Taubert et al. ), our index D disturbance , in addition to the classical fragmentation analysis, can provide valuable information to guide the conservation of the Atlantic Rain Forest in particular and Neotropical forests in general.…”

“…Such resolution has revealed that fragmentation is increasing in all tropical forests (Taubert et al. ). However, it is still too coarse to retrieve information regarding species or the distribution of individual trees that can inform on the successional stage, diversity or disturbance levels of these ecosystems, which play key roles in maintaining environmental processes such as the water cycle, soil conservation, carbon sequestration and habitat protection (FAO, ).…”

Managing the middle: A shift in conservation priorities based on the global human modification gradient

“…We include a greater coverage of transportation infrastructure that is known to trigger human encroachment and accelerate ecosystem degradation (Ibisch et al, ) and extractive activities that increasingly cause large‐scale land change (Kiesecker & Naugle, ) and have high impact on biodiversity (Schulze et al, ). Unlike other approaches that rely on categorical land system mapping (Van Asselen & Verburg, ; Ellis & Ramankutty, ) or ad hoc categorical scoring (Sanderson et al, ), our cumulative human modification map (HM c ) supports thresholding along a continuous gradient of land modification values to evaluate landscape structure (Verburg, Asselen, Zanden, & Stehfest, ): a component essential for robust cumulative impact assessments (Halpern & Fujita, ) and fragmentation analyses (Haddad et al, ; Halpern & Fujita, ; Taubert et al, ).…”

Forest fragmentation in China and its effect on biodiversity

“…ecotones between forests and grasslands) from human‐created edges. Remote sensing from space provides an unprecedented perspective on changing forest cover, allowing continuous maps to be constructed and spatiotemporal patterns of fragmentation to be analysed (Taubert et al , ). Assessments of forest fragmentation have been completed for many countries including Canada, Chile, China, the Democratic Republic of Congo, India, Malaysia, Myanmar, New Zealand, North Korea, Tanzania, the United Kingdom and the USA (Leimgruber et al , ; Watts, ; Ewers et al , ; Kupfer, ; Abdullah & Nakagoshi, ; Echeverria et al , ; Wulder et al , ; Kang & Choi, ; Reddy et al , ; Kukkonen & Käyhkö, ; Shapiro et al , and Li et al , ).…”