Flora and geographic pattern of mountain forests at community level in Taihang Mountains: Results based on plant community survey

Contrasting latitudinal diversity and co-occurrence patterns of soil fungi and plants in forest ecosystems

Modern pollen-vegetation relationships in the Taihang Mountains: Towards the quantitative reconstruction of land-cover changes in the North China Plain

A significant research focus is placed on identifying animal species and areas at future risk to human-induced alterations of the environment and long-term changes in climatic conditions. Yet, the extent to which exposure to extreme climatic events and intense human pressure can increase the risk of harmful impacts on species remains poorly investigated. Focusing on terrestrial mammals in China, one of the world's megadiverse countries, we investigated patterns of contemporary exposure to floods and human pressures and determined their taxonomic representation and distribution across three major area-based conservation schemes, namely, national nature reserves (NNRs), priority areas for biodiversity conservation (PABCs), and key biodiversity areas (KBAs). Among the 440 species assessed with moderate or high exposure to floods, 327 (∼75%) also qualified as moderate or high in exposure to intense human pressure. These species mainly belong to the orders Chiroptera, Eulipotyphla, and Rodentia. Likewise, there were 305, 311, and 311 species with moderate or high exposure to flood and intense human pressure represented across NNRs, PABCs, and KBAs, respectively. Our findings support the prioritization of KBAs for expansion of site-based protection efforts such as NNRs in China, considering threats to species from exposure to adverse effects from both extreme climate and human pressure.

Understanding diversity patterns requires accounting for the roles of both historical and contemporary factors in the assembly of communities. Here, we compared diversity patterns of two moth assemblages sampled from Taihang and Yanshan mountains in Northern China and performed ancestral range reconstructions using the Multi-State Speciation and Extinction model, to track the origins of these patterns. Further, we estimated diversification rates of the two moth assemblages and explored the effects of contemporary ecological factors. From 7,788 specimens we identified 835 species belonging to 23 families, using both DNA barcode analysis and morphology. Moths in Yanshan mountains showed higher species diversity than in Taihang mountains. Ancestral range analysis indicated Yanshan as the origin, with significant historical dispersals from Yanshan to Taihang. Asymmetrical diversification, population expansion, along with frequent and considerable gene flow were detected between communities. Moreover, dispersal limitation or the joint effect of environment filtering and dispersal limitation were inferred as main driving forces shaping current diversity patterns. In summary, we demonstrate that a multiscale (community, population and species level) analysis incorporating both historical and contemporary factors can be useful in delineating factors contributing to community assembly and patterning in diversity.

A combination of rapid industrialization, economic development and urbanization has caused a series of issues such as resource shortages, ecosystem destruction, environmental pollution and tension between human needs and land conservation. In order to promote balanced development of human, resources, ecosystems, the environment, and the economy and society, it is vital to conceptualize ecological spaces, production spaces and living spaces. Previous studies of ecological-production-living spaces focused mainly on urban and rural areas; few studies have examined mountainous areas. The Taihang Mountains, a key area between the North China Plain and Beijing-Tianjin-Hebei area providing ecological shelter and the safeguarding of crucial water sources, suffer from increasing problems of fragile environment, inappropriate land use and tensions in the human-land relationship. However, studies of the ecological, production, and living spaces in the Taihang Mountains are still lacking. Therefore, this study, based on the concept of ecological-production-living spaces and using data from multiple sources, took the Taihang Mountains as the study area to build a functional land classification system for ecological-production-living spaces. After the classification system was in place, spatial distribution maps for ecological, production and living spaces were delineated. This space mapping not only characterized the present land use situation, but also established a foundation for future land use optimization. Results showed that the area of ecological space was 78,440 km2, production space 51,861 km2 and living space 6,646 km2, accounting for 57.28%, 37.87% and 4.85% of the total area, respectively. Ecological space takes up the most area and is composed mainly of forests and grasslands. Additionally, most of the ecological space is located in higher elevation mountainous areas, and plays an important role in regulating and maintaining ecological security. Production space, mostly farmlands sustaining livelihoods inside and outside the region, is largely situated in lower elevation plains and hilly areas, as well as in low-lying mountainous basins. Living space has the smallest area and is concentrated mainly in regions with relatively flat terrain and convenient transportation for human settlements.

Water yield, one of the most valuable and important ecological indicators, reflects the renewable capacity of regional water resources. The Taihang Mountains are a natural ecological barrier and an important source of water production for the North China Plain. Two large-scale projects involving returning farmland to forest and grassland have significantly changed the distribution of land use in the Taihang Mountains, and also affect the water production characteristics of the Taihang Mountains. Taking the Hutuo River Basin, a typical river in the Taihang Mountainous region, as the study area, the InVEST model is utilized to calculate the spatial and temporal changes in water yield capacity in the Hutuo River basin, and four scenarios were set to judge the impact of different ecological projects on the water yield of the mountainous watershed of the Hutuo River. The results showed that the water yield in the five study periods was 218.58–376.44 mm. The interannual variations in both precipitation and water yield of the study area in the last decade were large. The water yield is mainly concentrated in the northeast region of the upper reaches of the basin, and the smallest is the northwest and central regions of the upper reaches. The water yield in each year in the study area is mainly less than 400 mm, accounting for more than 60% of the study area, and the water yield has shown a large regional expansion in the past 10 years. Grassland has the largest water yield capacity of all land use types, and climate change has basically no effect on the water yield capacity of different land use types. The ecological project of returning farmland to forestland has a negative impact on the water yield capacity, whereas the water yield capacity increases after returning farmland to grassland. The water conservancy project of river training has a negative impact on the water yield capacity of the Hutuo River mountainous basin. The research results provide theoretical data for judging the relationship between vegetation restoration and water yield in mountainous watersheds, a scientific basis for evaluating the implementation effect of major projects, and strong data support for water resource management in the North China Plain.

Taihang Mountain region is the recharge area for groundwater in the North China Plain (NCP). In recent years, the elevated nitrate concentration in the groundwater in the Taihang Mountain has often been associated with the increased area of farmland and the excessive application of nitrogen. Thus, it is significant to study the soil nitrogen leaching process in typical farmland. In this study, the root zone water quality model (RZWQM) was used to simulate the nitrate nitrogen leaching of winter wheat/summer maize rotation systems in the Hilly Ecosystem Experimental Station in Taihang Mountain. The results showed that during the 2015-2016 winter wheat/summer maize season, the nitrate nitrogen from the soil leaching occurred mainly in the summer maize season (rainy season), with the nitrate nitrogen leaching amount reaching 59.9 kg·hm-2, while the nitrate nitrogen leaching amount during the winter wheat season was only 2.12 kg·hm-2. The soil nitrate nitrogen leaching condition was simulated using the RZWQM model for different nitrogen contents and years with different rainfall. Significant linear correlations were observed between nitrogen use and nitrate leaching in winter wheat/summer maize rotation systems. In summary, the results showed that the nitrate nitrogen leaching values were 10.5, 59.9, and 136.5 kg·hm-2 for nitrogen fertilizer applications of 0, 300, and 450 kg·hm-2, respectively, during extreme precipitation in a wet year (2015). The value of nitrate nitrogen leaching in the maize season of 2013 (dry year), 2015 (normal year), and 2016 (wet year) accounted for 9%, 10%, and 20% for the 300 kg·hm-2 of nitrogen fertilizer applied, respectively. However, the value of nitrate nitrogen leaching in the maize season of 2013 (dry year), 2015 (normal year), and 2016 (wet year) accounted for 11%, 17% and 30% of the 450 kg·hm-2 of nitrogen fertilizer applied. These results show that extreme precipitation events not only greatly recharge the groundwater, but also increase the leaching of accumulated nitrate nitrogen and potential nitrate contamination in the groundwater.

Basin-scale reconstruction of late Pleistocene-Holocene fluvial landform evolution and its mechanisms in transitional areas between Taihang Mountain and North China Plain

Objective Human activities and climate change have changed the living environment of species, accelerated the rate of species extinction, and global biodiversity is facing a huge threat. The objective of this study is to determine the resource protection strategy of freshwater planarian by systematically exploring the population genetics and pedigree geography of the planarian population in the four mountain systems of Henan Province and Taihang Mountains. Methods Taking the Japanese planarian in the four mountain systems of Henan Province and Taihang Mountains as an example, DNA was extracted with the help of mitochondrial cytochrome c oxidase subunit I gene (COI), mitochondrial cytochrome b gene (Cytb), and nuclear gene internal transcribed spacer-1 (ITS-1), amplified by polymerase chain reaction and sequenced, and genetic diversity, genetic structure, and pedigree geographical pattern were analyzed by single-gene analysis and polygene joint analysis. Results The corresponding length of Cytb, COI, and nuclear gene ITS-1 sequences in the four mountains of Henan Province is 308, 805, and 632 bp, respectively, and the nucleotide diversity and haplotype diversity are 0.00212 and 0.975, respectively. The gene length of ITS-1 and Cytb in Taihang Mountains is 668 and 315 bp, respectively, with a total length of 984 bp. There are 10 shared haplotypes and 36 unique haplotypes. The values of all nucleic acid diversity and haplotype diversity were 0.00156 and 0.965, respectively, and the genetic variation coefficients between populations and groups were 20.28% and 16.40%, respectively (P < 0.05). Different haplotypes of the four mountain systems in Henan Province and Taihang Mountains are scattered in different geographic populations, and there is no correlation between them and their geographic locations, which is consistent with the results of phylogeny. Conclusion The genetic diversity of Trionychia japonica population in the four mountain systems of Henan Province and Taihang Mountains shows high haploid diversity and low nucleotide diversity, and phylogenetic analysis has not found obvious pedigree geographical pattern.

祁连山国家公园植被时空变化及其对人类活动的响应

Spatial evaluation of the ecological value importance of national park in Yarlung Tsangpo Grand Canyon

As a key ecological function area and a priority area for biodiversity conservation in China, Qilian Mountain National Park is facing a severe test of its ecological environment, and the study of its landscape ecological risk is of great significance to the construction and high-quality development of the Qilian Mountain National Park. In this research, based on land use data from six periods (i.e., year in 1995, 2000, 2005, 2010, 2015, and 2020) in the Qilian Mountain National Park, we divided the ecological risk plots, calculated the landscape pattern, and constructed the landscape ecological risk index to deeply explore the temporal and spatial heterogeneity of landscape ecological risk in Qilian Mountain National Park by using ArcGIS, Fragstats and GeoDa. The results showed that: Grassland is the predominant land use type, the area covered by woodland and grassland have exhibited a significant increase since 1995. Landscape fragmentation and disturbance indices exhibit fluctuations across different years, but showed an overall decreasing trend, and landscape stability was improved in the study area. There were obvious differences in the disturbance indices of different landscape types, with grassland and bare land having the highest values. Ecological risk in the study area is heterogeneous, with an overall low ecological risk and a shift to a lower risk level, and a decreasing trend in ecological risk, which is positively correlated spatially and mainly manifested as a “low-low” aggregation. Global warming and unreasonable human activities have exacerbated the ecological degradation of Qilian Mountain National Park, but a series of ecological restoration strategies after the establishment of the national park have gradually improved the regional ecological environment.

Human activities may lead to land degradation, and then influences diversity and function of ecosystems. Understanding the plant community assembly processes and diversity patterns along human activities‐related gradients are an important facet of ecological research and can be used to reveal vegetation dynamics under land degradation on the Loess Plateau. In this study, we evaluated the net relatedness index, phylogenetic diversity, and species diversity along habitat (elevation, slope, aspect, residential distance, succession time) and comprehensive disturbance gradients on the Loess Plateau, China. We found that community assembly processes were mainly influenced by slope and succession time linked to human activity. Study regions with slope >20°or succession time > 35 years showed no environmental filtering effect during community assembly processes, because these region usually had fewer cropland development activities. Although phylogenetic and species diversity showed a dissimilar pattern along gradients, we also summarized human activities rather than habitat factors drive diversity patterns. In summary, we demonstrate that human activities mainly influence community assembly processes and diversity patterns. With reduction of human disturbance in future, land degradation will be ameliorated on Loess Plateau.

In accordance with the China Meteorological Administration definition, this study considered a weather process with a maximum surface temperature of ≥35°C for more than three consecutive days as a heatwave event. Based on a dataset of daily maximum temperatures from meteorological stations on the North China Plain, including ordinary and national basic/reference surface stations, the intensity-area-duration method was used to analyze the spatiotemporal distribution characteristics of heatwave events on the North China Plain (1961–2017). Moreover, based on demographic data from the Statistical Yearbook and Greenhouse Gas Initiative (GGI) Population Scenario Database of the Austrian Institute for International Applied Systems Analysis (IIASA), population exposure to heatwave events was also studied. The results showed that the frequency, intensity, and area of impact of heatwave events on the North China Plain initially decreased (becoming weaker and less extensive) and then increased (becoming stronger and more extensive). Similarly, the trend of population exposure to heatwave events initially decreased and then increased, and the central position of exposure initially moved southward and then returned northward. Population exposure in the eastern Taihang Mountains was found significantly higher than in the western Taihang Mountains. In relation to the change of population exposure to heatwave events on the North China Plain, the influence of climatic factors was found dominant with an absolute contribution rate of >75%. Except for 2011–2017, increase in population also increased the exposure to heatwaves, particularly in the first half of the study period. Interaction between climatic and population factors generally had less impact on population exposure than either climatic factors or population factors alone. This study demonstrated a method for assessing the impact of heatwave events on population exposure, which could form a scientific basis for the development of government policy regarding adaption to climate change.

The North China plain (NCP) is an important production base for winter wheat and summer maize in China. Severe droughts seriously restrict agricultural production in this region, threatening food security. Based on the standardized precipitation evapotranspiration index (SPEI), this study explored the spatial and temporal drought characteristics during the winter wheat and summer maize growing seasons in the region. The study found that: 1) From 1980 to 2013, the drought trend of the winter wheat growing season in the NCP has intensified, with Huang-Huai Plain agricultural area (HH_P) showing the most significant drought trend. However, the summer maize growing season has become wetter, with the Shandong hilly agricultural and forestry area (SD_Q) showing the most significant wetting trend. 2) After the year 2003, the results from Mann-Kendall trend analysis revealed that the drought trend of HH_P during the winter wheat growing season became particularly pronounced, but the wetting trend of SD_Q and HH_P during the summer maize growing season became more evident. 3) The dominant spatial patterns observed in the NCP during the growing seasons of winter wheat and summer maize were marked by a consistent distribution of drought and wetness conditions. For winter wheat, the southern regions of the foothill plain area of Yanshan and Taihang Mountains (YT_P) and the low-lying plain area of Hebei, Shandong, and Henan (JLY_P) were more sensitive to the changes of drought and wet conditions. For summer maize, SD_Q was more sensitive to the changes of the drought and wet conditions. The results of this study could provide references for the formulation of drought relief strategies of winter wheat and summer maize in the NCP.