The exceptional value of intact forest ecosystems

Abstract

As the terrestrial human footprint continues to expand, the amount of native forest that is free from significant damaging human activities is in precipitous decline. There is emerging evidence that the remaining intact forest supports an exceptional confluence of globally significant environmental values relative to degraded forests, including imperilled biodiversity, carbon sequestration and storage, water provision, indigenous culture and the maintenance of human health. Here we argue that maintaining and, where possible, restoring the integrity of dwindling intact forests is an urgent priority for current global efforts to halt the ongoing biodiversity crisis, slow rapid climate change and achieve sustainability goals. Retaining the integrity of intact forest ecosystems should be a central component of proactive global and national environmental strategies, alongside current efforts aimed at halting deforestation and promoting reforestation.

Carbon sequestration and biodiversity co‐benefits of preserving forests in the western United States

“…, Watson et al. ), suggesting that preserving the high‐carbon‐priority forests would provide an added buffer against potential ecosystem transformation to future climate change.…”

Need for a global map of forest naturalness for a sustainable future

“…; Watson et al. ) and old‐growth forest patches (Frelich ). Forest takes a long time to recover, and as a result of global change the decrease in intact forests can only continue.…”

Watersheds and Trees Fall Together: An Analysis of Intact Forested Watersheds in Southern Patagonia (41–56° S)

“…IFWs for validation basins were located at mean elevations of 1500, 1250, and 900 m respectively (Figure 7a-c), distinctly higher elevations than the regional analysis ( Figure 5), and with the distribution notably skewed towards higher elevation systems. Most of the watersheds were under 5 km 2 for Yelcho and Serrano, but the Aysén basin presented a larger range in sizes, the largest IFW approximately 80 km 2 (Figure 7d-f). Representation within protected areas also varied across basins, with Yelcho approaching 40% (similar to the regional average, but largely due to protected areas in Argentina), Serrano somewhat higher with approximately 62% under conservation, while the Aysén basin was clearly lower at around 27% with conservation protection (Figure 7g-i).…”

“…Meanwhile 78.4% of this mature forest (or 63.7% of total forested area) contributed to intact forested watersheds in the region (following criteria in Figure 3a). The total area of potential IFWs was calculated as 134,176 km 2 Potential IFWs were more frequent at intermediate annual precipitation (500 to 2500 mm/year, Figures 4b and 5a), compared to the very broad climatic range in the region (200 to 7000+ mm/year), corresponding with the above mentioned spatial distribution (central cordillera and inner coast). Two distinct distributions were observed for pIFW elevation (Figure 5b).…”

“…Forests with limited human intervention, whether "pristine", ancient or old growth, are a limited and diminishing feature of modern landscapes [1,2]. They are essential in terms of conserving biodiversity, climate change mitigation, or as reference systems for forest management or restoration [3].…”