The recently established Hainan Tropical Rainforest National Park has designated the Hainan gibbon (Nomascus hainanus) as its flagship species, providing new hope for recovery of the last surviving population of the world's rarest primate. However, current monitoring methods are labour‐intensive and only conducted for discrete periods, meaning that detailed information is still lacking on key Hainan gibbon population parameters (such as movement patterns, sleeping site selection and home range size). Alternative monitoring techniques are therefore necessary to supplement traditional methods and provide more accurate estimates of population parameters. Here, we tested whether flying two drones (DJI MAVIC2 Enterprise Advanced), one in the understory and the other above the canopy, could provide new information on Hainan gibbon biology and ecology. During a total of 60 flights, we successfully collected clear RGB and thermal infrared footage of Hainan gibbons. These data provide new baseline information on gibbon movement within the understory and the canopy, their surface body temperatures (23.0–34.7°C), and their movement area during the survey period. The low cost of this equipment could reduce the running costs for Hainan gibbon monitoring. Although drone‐based monitoring has some limitations (e.g. monitoring efficiency could be affected by variation in forest structure and gibbon group size), this new method could complement existing monitoring approaches. Drone‐based monitoring, using multiple drones and a real‐time transmission network, could therefore contribute further towards Hainan Tropical Rainforest National Park's conservation planning for this Critically Endangered primate.

Mining is a major threat for tropical rainforests as it induces rapid land degradation. Reforestation of mined areas is important to mitigate degradation and biodiversity losses. Microbial diversity, which serve as a good indicator of environmental perturbations, is crucial for reforestation and ecosystem functioning. Yet, limited information is available on how it is influenced by mining. We investigated the bacterial and fungal taxonomic alpha (richness and abundance) and beta diversities (Bray–Curtis dissimilarities (BCD)), root traits and nutrients among mined, undisturbed, and reforested soils in a tropical rainforest in Hainan Island (China). Soil organic matter (SOM) content was highly associated with bacterial and fungal abundances, fungal species richness, and BCD. Mining‐led vegetation removal largely reduced the SOM, and it decreased bacterial and fungal abundances, fungal species richness, and BCD. After using mined soil to plant multiple fast‐growing tree species, the root traits functioned at the levels of an original secondary forest, and it quickly recovered SOM. This process restored bacterial and fungal abundance, fungal species richness, and BCD to originally undisturbed levels. We further conclude that (i) soil fungal diversity in tropical rainforest is more sensitive to mining and reforestation than bacterial diversity. This could be attributed to largely reduced/increased SOM resulting from loss/gain in vegetation during mining/reforestation, respectively. (ii) Reduced SOM, after mining and removal of vegetation, has profound negative influences on tropical rainforest. (iii) Use of mined soil as a post‐mining substrate along with fast‐growing tree species ensures the recovery of SOM during reforestation, which alleviates the negative impacts of mining on tropical rainforests.

1. Nitrogen (N) fertilization and warming are two crucial global change factors affecting the soil nematode communities. The effects of N fertilization and warming, however, on nematode communities in soils are inconsistent across ecosystems and maybe be even opposite.

Overgrazing by livestock is a global environmental problem, influencing global warming via soil N 2 O emissions. However, it remains unknown why overgrazing leads to increased N 2 O emissions. Here, we used a paired design of subalpine meadows in undisturbed and overgrazed sites at four different elevations (from 3000 to 3600 m) located over an area of $200 km 2 in the Qinghai-Tibetan Plateau (QTP), China, to evaluate relationships among plant diversity, soil ammonium and nitrate N, the abundance of soil nitrifiers (AOA and AOB) and denitrifiers (nirK, nirS and the N 2 O reductase gene [nosZ]) and soil N 2 O emissions. Using a generalized linear mixed effects modeling framework with Poisson error, we found that the influence of overgrazing on increased abundance of soil nitrifiers and denitrifiers and associated increased soil N 2 O emission was a general phenomenon in QTP. More importantly, by using forward selection analysis and structural equation models, we showed overgrazing decreased plant richness, and this resulted in decreased ammonium N, but increased nitrate N at all elevations. Accordingly, decreased ammonium N, but increased nitrate N led to increased abundance of soil nitrifiers (AOA and AOB) and denitrifiers (nirK and nirS), but decreased nosZ abundance, which finally gave rise to increased soil N 2 O emission at all the elevations. Our results highlight the key role of plant diversity in regulating soil N 2 O emissions from soils. Thus, performing active ecological restoration to recover native plant species in overgrazed sites may help mitigate the influence of overgrazing on global warming.