Reforestation enhanced landscape connectivity for thermal buffering in China

Abstract

Deforestation-induced landscape fragmentation causes habitat loss and isolation, modifies local climate, and therefore threatens biodiversity. While, on the contrary, how large-scale reforestation may improve the connectivity and thermal buffers of habitats is not well understood. We show that decades long large-scale reforestation in China has effectively increased the size and connectivity of forest patches by gradually filling gaps among isolated patches and creating more core forests. The core forests have a stronger capacity to cool the land surface, leading to a daily mean cooling effect of -0.42±0.23°C relative to nearby marginal forests. Moreover, the core forests reduce diurnal range and seasonal variation of land surface temperature by 1.41±0.23°C and 0.42±0.55°C, respectively, relative to nearby marginal forests. The thermal buffering capacity of large size core forest (>100km2) is more than twice that of small size (≤10km2). Despite their relatively low thermal buffering capacity, the marginal forests contribute about 73% to the increase of forest area in China during the last two decades and create buffer zones for the core forests to resist external disturbances, maintaining the internal stability of the forest ecosystem. We highlight that improving the integrity and connectivity of the forests with ecological restoration and succession can further enhance potential of forests to buffer local thermal environment under the current reforestation efforts, and thereby providing better connected thermal habitats for species to survive under climate change.

Does fragmentation contribute to the forest crisis in Germany?

“…The cooling functions of forest fragments increase with higher connectivity. This cooling effect was also observed in a study on reforestation (Huang et al, 2022). Our results regarding the correlation between high connectivity and increasing forest vitality, based on the NDVI in the temperate forest realm, correspond to other studies with similar results.…”

Evidence of time-lag in the provision of ecosystem services by tropical regenerating forests to coffee yields

“…Deforestation was related to an increase in coffee cover independently from coffee yields, which further reinforces the relevance of the main pattern observed in this study: maintaining older forest cover is crucial to provide adequate landscape conditions for higher coffee productivity. Moreover, the benefit of regenerating forests might not be limited exclusively to pollination and pest control services, as soil properties and climatic benefits are also being recovered in the proximity of regenerating forest fragments (Mendes and Prevedello 2020, Poorter et al 2021, Huang et al 2022. While we may not be able to underpin the process mediating such a relationship, the large-scale patter observed in our work may guide landscape management (Nelson and Burchfield 2021).…”

Changed ecosystem stability in response to climate anomalies in the context of ecological restoration projects

“…Therefore, using only the cumulative afforestation rate may underestimate the contributions of engineering measures in the ERPs to the changes in ecosystem stability, while the statistical data capture only the afforestation areas. Third, there is no doubt that the ERPs have dramatically changed the landscape patterns, which will directly affect ecosystem stability (Suding, 2011) and even the regional climate characteristics (Cao et al, 2015; Huang et al, 2022), which will thus influence the ecosystem stability. These effects are not addressed in our study because they require further research by using the process modeling method, which is beyond the scope of this work.…”