Modification of forests by people means only 40% of remaining forests have high ecosystem integrity

Abstract

Many global environmental agendas, including halting biodiversity loss, reversing land 45 degradation, and limiting climate change, depend upon retaining forests with high ecological 46 integrity, yet the scale and degree of forest modification remains poorly quantified and mapped. 47 Page 3 of 54By integrating data on direct and indirect forest pressures and lost forest connectivity, we generate 48 the first globally-consistent, continuous index of forest condition as determined by degree of 49 anthropogenic modification, which we term 'forest health'. Globally, only 17.4 million km 2 of 50 forest (40.5%) can be considered in high health (mostly found in Canada, Russia, the Amazon, 51Central Africa and New Guinea) and only 27% of this area is found in nationally-designated 52 protected areas. Of all the world's forests found within protected areas, only 56% can be 53 considered in high health. Ambitious policies that prioritize the retention of forest health are now 54 urgently needed alongside current efforts aimed at restoring the health of forests globally. 55 56 MAIN TEXT 57 58 65bodies (e.g. 5), and it is now essential that the scientific community develop improved tools and 66 data to facilitate the consideration of the degree of forest modification in decision-making. 67Mapping and monitoring this globally will provide essential information for coordinated global, 68 national and local policy-making, planning and action, to help nations and other stakeholders 69 achieve the Sustainable Development Goals (SDGs) and implement other shared commitments 70 such as the United Nations Convention on Biological Diversity (CBD), Convention to Combat Ecosystem integrity is foundational to all three of the Rio Conventions (UNFCCC, UNCCD, 74 CBD ). As defined by Parrish et al. ( 6), it is essentially the degree to which a system is free from 75 anthropogenic modification of its structure, composition and function. Such modification causes 76 the degradation of many ecosystem benefits, and is often also a precursor to outright deforestation 77 (7, 8). Forests largely free of significant forest modification (i.e. forests having high ecosystem 78 integrity), typically provide higher levels of many forest benefits than modified forests of the 79 same type (9), including; carbon sequestration and storage (10), healthy watersheds (11), 80 traditional homelands for imperiled cultures (12), contribution to local and regional climate 81 processes (13), and forest-dependent biodiversity (14-17). Industrial-scale logging, fragmentation 82 by infrastructure, farming (including cropping and ranching) and urbanization, as well as less 83 visible forms of modification such as over-hunting, wood fuel extraction and changed fire or 84 hydrological regimes (18, 19), all degrade the degree to which forests still support these benefits, 85 as well as their long-term resilience to climate change (9). There can be trade-offs however, 86 between the benefits provided by less-modified forests (e.g., carbon sequestration) and those 8...

Limiting the loss of terrestrial ecosystems to safeguard nature for biodiversity and humanity

“…With ongoing losses a certainty, and numerous questions around the capacity of many ecosystems to recover (at least in timeframes congruent with human lifetimes/several generations, let alone time-bound international environmental agreements), balancing losses with gains to achieve net outcomes cannot be relied upon to maintain ecosystems at the required retention amount. Moreover, the extensive degradation within remaining natural ecosystems - almost 60% of forests globally have compromised ecological integrity and are in a degraded state (Grantham et al 2020) - further underscores that the retention values we present should be considered as conservative targets. Retaining vegetation well above the apex target will act as a buffer for the (inevitable) net losses incurred as a result of continued land use change, resource extraction and degradation.…”

Comparing global and regional maps of intactness in the boreal region of North America: Implications for conservation planning in one of the world’s remaining wilderness areas

“…Other recent related initiatives have aimed to characterize landscape patterns, forest fragmentation, and forest change at regional (Raiter et al 2017), national (Wulder et al 2008, Pasher et al 2013, Guindon et al 2014, White et al 2017) and global scales (Hansen et al 2013). Regional datasets also afford greater sophistication by integrating information on context, connectivity, habitat, and species (e.g., Plumptre et al 2019, Grantham et al 2020, Mokany et al 2020). As an indication of the importance of considering intact areas in conservation planning, a major international conference on “Intact Forests in the 21st Century” recently took place in Oxford in 2018 1 to discuss regional and global approaches.…”

Towards monitoring ecosystem integrity within the Post-2020 Global Biodiversity Framework

“…In the absence of direct measurement of ecosystem structure, function, and composition, previous work has used human pressure as a full proxy for EI (Beyer et al 2020), or as a proxy for one of its three components (Hansen et al 2020). While there is evidence to support the use of pressures as a proxy for ecosystem condition (e.g., Di Marco et al 2018;Grantham et al 2020), the relationships between human drivers and ecosystem components are often non-linear, ecosystem-specific, and not well understood (Nicholson et al In Review). Ultimately, monitoring both human pressure and direct ecosystem properties is required for achieving biodiversity goals (Díaz et al 2020).…”