[Influencing mechanism of stand age to the accumulation of microbial residue carbon in the plantations].

Clarifying the accumulation pattern of soil microbial residue carbon and its contribution to soil organic carbon (SOC) across stand age is helpful to understand the mechanism underlying soil carbon cycling. In this study, we analyzed the differences of amino sugar content, physicochemical properties and microbial composition in surface soil (0-10 cm) in young (6 a), middle-aged (13 a), near-mature (29 a), mature (38 a) and over-mature (57 a) plantations of subtropical China, quantified the microbial residue carbon content and its contribution to SOC, and discussed the mechanism. The results showed that SOC, total nitrogen, amorphous iron oxide and leucine aminopeptidase contents in the middle-aged plantation were significantly lower than those in the mature plantation.

Karst tiankeng shapes the differential composition and structure of bacterial and fungal communities in karst land.

Karst tiankeng are important biodiversity conservation reservoirs. However, the unique habitats of karst tiankeng affect microbial community structure remained poorly understood. In this study, we collected soil samples from karst tiankeng (TK) and karst land (KL) and subjected to high-throughput sequencing.

The characterization of microbial communities and associations in karst tiankeng.

The karst tiankeng is a special and grand negative terrain on the surface, that maintains a unique ecosystem. However, knowledge about bacterial and fungal communities in karst tiankengs is still limited. Therefore, soil samples from five karst tiankengs were collected and subjected to high-throughput sequencing of 16S rRNA and ITS genes, and multivariate statistical analysis.

Original karst tiankeng with underground virgin forest as an inaccessible refugia originated from a degraded surface flora in Yunnan, China.

Karst tiankengs are rare natural habitats, having a local microclimate different from surrounding regions. A contrast study on plant communities at the inside and outside of the primitive tiankeng was carried out by performing the qualitative analysis of species compositions of arborous and shrub layers. We found that plant communities in the primitive tiankeng belong to the subtropical moist evergreen broad-leaf forest, whereas those outside the tiankeng belong to subtropical semi-moist needle-broadleaved mixed forest.

Slope aspect affects the soil microbial communities in karst tiankeng negative landforms.

Background: Karst tiankeng is a large-scale negative surface terrain, and slope aspects affect the soil conditions, vegetation and microbial flora in the tiankeng. However, the influence of the slope aspect on the soil microbial community in tiankeng has not been elucidated.

Methods: In this study, metagenomic sequencing technology was used to analyze the soil microbial community structure and functional potentials on the shady and sunny slopes of karst tiankeng.

Metagenomic analysis reveals the different characteristics of microbial communities inside and outside the karst tiankeng.

Background: Karst tiankengs serve as a reservoir of biodiversity in the degraded karst landscape areas. However, the microbial diversity of karst tiankengs is poorly understood. Here, we investigated the composition and function of the microbial community in a karst tiankeng.

Heat Adaptive Capacity: What Causes the Differences Between Residents of Xiamen Island and Other Areas?

Extreme heat events caused by climate change have serious adverse effects on residents' health in many coastal metropolises in southeast China. Adaptive capacity (AC) is crucial to reduce heat vulnerability in the human-environment system. However, it is unclear whether changes in individual characteristics and socioeconomic conditions likely amplify or attenuate the impacts of residents' heat adaptive capacity (HAC) changes.

Functional traits of Fagaceae plants in shady and sunny slopes in karst degraded tiankeng.

In the negative terrain habitat of the karst degraded tiankeng, the shady and sunny slopes are dramatically different, which results in substantial variations in plant communities. With the degraded tiankeng Shenxiantang in Zhanyi, Yunnan as an example, we explored the functional traits of Fagaceae plants in the shady and sunny slopes, which would help reveal the value of tiankeng as species diversity conservation pool. The results showed that soil nutrients in the shady slope were more than those in the sunny slope.

Characteristics of the Soil Microbial Communities in Different Slope Positions along an Inverted Stone Slope in a Degraded Karst Tiankeng.

The underground forests developed on inverted stone slopes in degraded karst tiankengs are important areas for biodiversity conservation, but the microbial community profiles have not been sufficiently characterized. Thus, we investigated the soil microbial communities at four sites (at the bottom of the slope (BS), in the middle of the slope (MS), in the upper part of the slope (US) and outside the tiankeng (OT)) in the Shenxiantang tiankeng. The dominant phyla in the inverted stone slope were Proteobacteria, Actinobacteria, and Acidobacteria, and the relative abundance were different in different slope positions.

[Vertical distribution characteristics of plant community in shady slope of degraded tiankeng talus: A case study of Zhanyi Shenxiantang in Yunnan, China].

We investigated the characteristics of plant species diversity in tree and shurb layers and the main influencing factors in different slope positions of a shady slope of degraded tiankeng talus. The results showed that there were 21 species in 17 genera and 13 families in the tree layer, and 20 species in 20 genera and 14 families in shrub layer in the south side of the Shenxiantang. Plant communities were subtropical moist coniferous and broad-leaved mixed forest.

[Niche characteristics of understory dominant species of talus slope in degraded tiankeng].

We carried out niche monitoring and analysis of plant populations under the forest community in the talus slope ecotone of a typical moderate-degraded Bajiaxiantang tiankeng to provide scientific references for biodiversity conservation and vegetation restoration in degraded tiankeng area. The results showed that soil ammonium, available potassium, and available phosphorus signifi-cantly affected species distribution, which explained 37.4%, 32.