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Analyzing the coupling relationship between biodiversity and environmental geology and exploring the factors affecting the coupling degree are of vital significance for the protection and restoration of the ecological environment. In this study, we selected five typical areas (i.e., Caohai, Chishui, Fanjingshan, Maolan, and Guanshanhu) to represent the whole Guizhou Province, China. Based on the coupling coordination degree model, we analyzed their coupling coordination trend. The results showed that the coordinated development stages of the Chishui and Fanjingshan areas both could be categorized as the synchronous development type of primary coordination because of their excellent nature conditions; the Maolan area was categorized as having restrained environmental geology because of its weak environmental geology condition; and the Guanshanhu and Weining areas were strongly affected by human activities, and both could be categorized as having restrained biodiversity. In combination with practical situation, Guizhou province can be categorized into the following three zones: an original ecological zone, a zone with fragile ecological environment, and a zone affected by human activities. Biodiversity conservation measures should be proposed according to the specific ecological situation of these different zones. In this way, the harmonious coexistence of economic development and the ecological environment can be realized. [ABSTRACT FROM AUTHOR]

Nitrogen (N) deposition, a major phenomenon of climate change, is increasing with industrialization and more human activity and can affect litter decomposition. Yet it remains unclear whether N deposition will accelerate or inhibit the decomposition of litter in karst regions, which are characterized by P‐limitation or N and P co‐limited stress conditions in soil. Here, to document the influence of simulated N deposition on litter decomposition in karst, the leaf litter of Cinnamomum migao was studied, this being a dominant perennial woody plant endemic to karst landforms. We conducted a 300‐d field decomposition experiment with four treatments: control (CK); addition of (+) N at 50 kg⋅ha−1⋅a−1 (N1); +N at 150 kg⋅ha−1⋅a−1 (N2), and +N at 300 kg⋅ha−1⋅a−1 (N3), in southwest Guizhou, the largest karst region in China (n = 4 treatments). From each treatment, the litter samples' remaining mass were measured during the decomposition period, in addition to their nitrogen (N), phosphorus (P), carbon (C), and potassium (K) concentrations, as well as that of soils; the soil's pH was also measured. The results showed that litter remaining mass increased significantly under nitrogen deposition, which, as expected, acidified the soil. Meanwhile, litter N, P, and K contents responded to nitrogen deposition, whereas C did not. Otherwise, no direct effects of nitrogen deposition upon soil nutrients were detected. The soil nutrient contents were related to the release of the elements in litter. In conclusion, nitrogen deposition suppressed the decomposition of C. migao litter in karst, but the nutrients of karst soil are mainly replenished by litter inputs. [ABSTRACT FROM AUTHOR]