应用生态学报最新文献

Litter layer, serving as the "skin" of forest soil, plays a crucial role in conserving water resources and maintaining soil and water conservation. We analyzed the relationship of tree species richness, community weighted mean traits, and functional diversity with the standing mass, maximum water holding rate, and effective water sto-rage capacity of litters from various tree species including Liquidambar formosana, Mytilaria laosensis, Castanopsis sclerophylla, Castanopsis hystrix, Cunninghamia lanceolata, Pinus massoniana, Fokienia hodginsii, Taxus wallichiana and their combinations of mixed forests in subtropical region. The results showed that across various tree species combinations, the ranges of maximum water holding rate, standing litter mass and effective water storage capacity of undecomposed layer were 0-419%, 0-0.58 t·hm^-2, and 0-1.66 t·hm^-2, respectively. For the semi-decomposition layer, these values spanned in 0-375%, 0-6.14 t·hm^-2, and 0-16.03 t·hm^-2, respectively. Tree species richness and community weighted mean specific leaf area had significantly positive effects on standing mass of litter and effective water storage capacity, while community weighted mean leaf N content had significantly negative effect on standing mass of litter. The maximum water holding rate increased with the increases of functional diversity of specific leaf area and community weighted mean specific leaf area, decreased with the increase of community weighted mean leaf thickness. Results of structural equation model showed that tree species richness increased litter water holding capacity by increasing functional diversity of specific leaf area. The community weighted mean specific leaf area increased the water holding capacity of litter layer by increasing standing mass of litter and the maximum water holding rate. It is necessary to consider planting mixed forest with higher community weighted mean specific leaf area in the management of subtropical artificial forest, so as to improve the water holding capacity of litter layer.

We assessed the diversity, composition, and distribution of bird species in patches of semi-humid evergreen broad-leaved forest by selecting eight natural forest communities in the central Yunnan Plateau, which is a representative distribution area of semi-humid broad-leaved evergreen forest. Field observations were conducted from April to August 2023 by the sample line and sample point method, and eight survey routes of 3-4 km in length were established. The results showed that 1) A total of 1286 birds were recorded, belonging to 102 species in 7 orders and 30 families. The three most abundant families were Muscicapidae (14 species), Leiothrichidae (9 species), and Phylloscopidae (7 species); 2) Species of Oriental origin, Palaearctic origin, and widespread species accounted for 81.4%, 4.9%, and 13.7% of observations, respectively; 3) The average number of bird species surveyed in forest patches was 32.0±3.5; the Shannon index of birds was lower in secondary, semi-humid evergreen broad-leaved forests (1.536±0.110) than in primary forest communities (2.037±0.100); 4) Species composition exhibited considerable variation between patches, with the presence of dominant and common species, and the difference in rare species; 5) Considering the ecological groups of birds based on diet, invertebrate-eating and omnivorous birds, herbivorous birds, and carnivorous birds accounted for 84.3%, 11.8%, and 3.9%, respectively. The coexistence of birds with similar diets was maintained by diluting interspecific competition, mainly through partitioning of the vertical feeding space. For the conservation of bird species diversity and rare species, all patches of native semi-humid evergreenbroad-leaved forest are of conservation value.

Water ecological restoration zoning, which involves articulating goals for restoring water ecosystems upwards and guiding the spatial layout of restoration projects downwards, is key to achieving systematic restoration of water resource elements. There are many challenges in water ecological restoration zoning, including disparate hierarchical systems, incomplete indicators, and vague boundaries. With Guangxi Hechi, a karst ecologically fragile region, as a case, we developed a multidimensional zoning system framework based on "watershed natural unit-dominant ecological function-ecological stress risk". The first-level zoning employed river systems and geomorphic types as indicators and delineated the sub-watershed unit as the boundary. The second-level zoning adopted a "top-down" division method to clarify the goal of water ecological restoration based on watershed natural geography and select three indicators (water conservation, biodiversity, and landscape cultural services) for evaluation. We used the K-means clustering method to identify dominant ecological functions in spatial units, with the sub-watershed unit demarcating second-level zoning boundaries. The third-level zoning was the specific implementation unit for ecological restoration projects. We used three indicators (soil erosion, flooding risk, and human interference) to characterize water ecosystem risk from external coercion, and defined the third-level zoning. We delineated 11 primary water ecological zones, four secondary zones, and three tertiary zones. Synthesizing tertiary zoning results accounted for spatial differentiation characteristics of watershed natural geography, dominant ecological functions, and ecological coercion risks, and combining sub-watershed and township administrative units determined zoning boundaries, water ecological restoration zoning was comprehensively classified into five categories and 32 sub-ecological zones. Corresponding ecological restoration strategies were proposed based on zoning and classification.

A comprehensive understanding of the evolution of soybean climate potential productivity and its response to climate change in Heilongjiang Province can offer reference and basis for further tapping soybean production potential and realizing stable and high yield of soybean in the frigid region. Based on meteorological data from 80 meteorological stations in Heilongjiang Province from 1961 to 2020, we estimated photosynthesis, light temperature, and climate potential productivity of soybean by the stepwise correction method, examined the spatiotemporal variations by spatial interpolation and statistical analysis methods, and analyzed the impact of changes in climate factors such as radiation, temperature, and precipitation on climate potential productivity. The results showed that during the study period, the average values of photosynthesis potential productivity (Y_Q), light-temperature potential productivity (Y_T), and climate potential productivity (Y_W) of soybean in Heilongjiang Province were 7533, 6444, and 3515 kg·hm^-2, respectively. The temporal changes of those variables showed significant increasing trends, with increases of 125.9, 182.9, and 116.1 kg·hm^-2·(10 a)^-1, respectively. For the spatial distribution, Y_Q, Y_T, Y_W were characterized by high values in plains and lower in the mountains, and gradually decreased from southwest to northeast. Compared with that during 1961-1990, the high value zone of Y_W in period 1991-2020 expanded by 7.1%, and the low value zone decreased by 5.1%. Y_W showed a significant response to climate change. The potential temperature growth period was extended due to climate warming. The continuous increase in thermal resources, combined with relatively sufficient precipitation, effectively alleviated the negative impact of the decline in light resources on soybean production in Heilongjiang Province. The projected "warm and humid" climate would comprehensively boost climate potential productivity of soybean in Heilongjiang Province.

The construction of road infrastructure has resulted in the degradation of wildlife habitat and the decrease of ecological network connectivity and stability. Studying the impacts of road infrastructure on wildlife life and migration is significant for regional wildlife conservation and ecological network optimization. We assessed the impacts of road infrastructure on habitat suitability using the MaxEnt model based on wildlife occurrence point data in the Guangdong-Hong Kong-Macao Greater Bay Area. We constructed the ecological networks and identified ecological breakpoints using the minimum cumulative resistance model, and compared the ecological network connectivity of different scenarios with the landscape connectivity index and graph theory index. The results showed that railway and motorway significantly affected habitat suitability, causing a decrease in wildlife habitat suitability. Affected by road infrastructure, the fragmentation of ecological sources intensified, the resistance of ecological corridors increased, and the ecological network connectivity and stability significantly decreased. A total of 536 ecological breakpoints were identified, which were concentrated in the area adjacent to ecological sources. The results would provide important scientific references for wildlife habitat conservation and ecological restoration in the Guangdong-Hong Kong-Macao Greater Bay Area.

Spatial variability of throughfall (i.e. the non-uniform characteristics of throughfall at different canopy positions) and its temporal persistence (i.e. time stability) are related to the quantity and efficiency of soil moisture replenishment, and affect plant competition and community succession dynamics by affecting resource availability. We carried out a meta-analysis with 554 papers (from 2000 to 2022) retrieved from Web of Science and China National Knowledge Infrastructure (CNKI) based on keyword search, quantified and compared the amount, spatial heterogeneity, and temporal stability characteristics of penetrating rain in different climate zones and plant functional types. Our results that throughfall proportion was lower in arid regions (72.0%±13.6%) than humid (75.1%±9.3%) and semi-humid areas (79.9%±10.4%). Cold climates had lower values (74.1%±14.6%) than temperate (74.2%±7.5%) and tropical climates (80.9%±14.6%). Shrubs (68.9%±14.9%) generally had lower throughfall proportion than trees (76.7%±9.1%). Broad-leaved trees (75.2%±11.1%) and conifers (75.1%±9.9%) showed similar throughfall proportions, as did evergreen (76.7%±10.0%) and deciduous species (74.7%±11.9%). Additionally, spatial variability (coefficient of variation) did not significantly differ across rainfall zones, temperature zones, or vegetation types. The spatial distribution of throughfall was relatively stable. Canopy structure was the dominant factor affecting temporal stability of throughfall. However, there was a lack of comparison between typical geographic units (i.e. spatial units with basically consistent geographical environmental conditions) at various temporal scales. Future research should expand upwards to the summary of global spatial scale rules and downwards to the analysis of process based temporal scale mechanisms, to depict the dynamic distribution of penetrating rain and unify observation standards to enhance comparability of different studies, in order to efficiently promote research on canopy penetrating rain and provide ecological and hydrological basis for protecting nature, managing artificial activities, and restoring degraded ecosystems.

We analyzed multidimensional biodiversity (including species diversity, functional diversity, and phylogenetic diversity) of needle-broadleaf mixed forests of Abies fargesii var. faxoniana-Betula spp. and needleleaf forests of A. fargesii var. faxoniana in the subalpine regions of eastern edge of Qinghai-Tibet Plateau. We measured leaf functional traits including leaf area, leaf thickness, leaf dry matter content, and specific leaf area. The results showed that leaf thickness (0.28 mm) and leaf dry matter content (319.86 mg·g^-1) in the needle-broadleaf mixed forests were significantly lower than in the needleleaf forest (0.39 mm and 371.33 mg·g^-1, respectively), while specific leaf area (192.74 cm²·g^-1) was significantly higher (100.91 cm²·g^-1). Leaf area showed no significant difference between the two forest communities (27.88 and 26.63 cm², respectively). The phylogenetic signals of all leaf functional traits were significant, except for leaf thickness. The phylogenetic structure of the needle-broadleaf mixed forests and needleleaf forest communities tended toward divergence. Shannon diversity index, Simpson diversity index, species richness, functional richness, functional dispersion, Rao's quadratic entropy, and phylogenetic diversity in the needle-broadleaf mixed forests were all significantly higher than in the needleleaf forest, and these indices were significantly positively correlated. Competitive exclusion played a major role in the assembly of subalpine forest communities, and species diversity, functional diversity, and phylogenetic diversity exhibited synchrony.

Aiming for clarifying the potential distribution characteristics of canopy rainfall partitioning of the loess area, we explored the process of rainfall partitioning across eight typical forest stands (Pinus tabuliformis forest, Robinia pseudoacacia forest, Platycladus orientalis forest, mixed forest of Robinia pseudoacacia-Pinus tabuliformis, mixed forest of Platycladus orientalis-Robinia pseudoacacia, Quercus wutaishanica forest, Populus davidiana forest, mixed forest of Quercus wutaishanica-Populus davidiana), and used boosted regression trees (BRT) to quantify the relative influences of stand structures and meteorological environment factors. We established multiple regression relationships according to the most influential factors extracted by BRT, and applied to the dataset of mining to verify the performance of the BRT-derived predictive model. The results showed that the percentages of throughfall (TF), stemflow (SF), and canopy interception (I_c) in total precipitation were 24.5%-95.1%, 0-13.6%, and 0.7%-55.7% among eight typical forest stands, respectively. For the individual rainfall threshold of TF, coniferous forest (3.06±1.21 mm) was significantly higher than broad-leaved forest (1.97±0.52 mm), but there was no significant difference between coniferous forest and broad-leaved mixed forest (3.01±0.98 mm). There was no significant difference in the individual rainfall threshold of SF among different composition stands. BRT analysis showed that stand structure factors accounted for a relatively small proportion for TF and SF, respectively. By contrast, stand structure factors dominated the I_c. Rainfall was the most important factor in determining TF and SF. Tree height was the most important factor in determining I_c, followed by rainfall, canopy area, diameter at breast height, and stand density. Compared with the general linear function and the power function, the prediction effect of BRT prediction model constructed here on TF and SF had been further improved, and the prediction of canopy interception still needed to explore. In conclusion, the BRT model could better quantitatively evaluate the effects of stand structure and meteorological environmental factors on rainfall partitioning components, and the performance of the BRT predictive model could satisfy and lay the foundation for the optimization strategy for stand configuration.

Accurate assessment of material and energy exchange between land and atmosphere is essential for water resources management and sustainable development of agriculture. To understand the characteristics of energy distribution and the dynamic change process of water and heat fluxes within the maize farmland ecosystem in the old course of Yellow River and their response to meteorological factors, we utilized the eddy covariance measurements and the full-element automatic weather station to continuously observe energy fluxes and conventional meteorological elements of summer maize farmland in the old course of Yellow River during 2019-2020. We analyzed the variation of energy fluxes and the effects of environmental factors, such as temperature, precipitation, and wind speed. Additionally, we calculated the energy closure rate and the proportion of energy distribution during the growth stage. The results showed that the peaks of net radiation, sensible heat flux, and latent heat flux occurred between 11:00 and 14:00, and the peak of soil heat flux occurred between 14:00 and 15:00. In terms of energy distribution, energy consumption of summer maize farmland during the whole growth period was dominated by latent heat flux and sensible heat flux. Energy was mainly consumed by sensible heat flux at sowing-emergence stage, accounting for 37.1% of net radiation, respectively. Energy in the rest of growth stages was dominated by latent heat flux. The energy closure rate during the whole growth period was better, with a coefficient of determination of 0.83, and the closure rate was higher in day and lower at night. Precipitation affected latent heat flux and sensible heat flux, and latent heat flux was more sensitive to precipitation. The increase of latent heat flux after rainfall was lower in late growth stage than in early growth stage. During the whole growth period of summer maize, solar radiation was the most significant meteorological factor affecting both sensible heat flux and latent heat flux, followed by vapor pressure deficit. The contribution of temperature and vapor pressure deficit to latent heat flux was significantly higher than sensible heat flux, while the relative contribution of wind speed, relative humidity, and solar radiation to latent heat flux was lower than sensible heat flux. Leaf area index and fractional vegetation cover had a significant positive correlation with latent heat flux and a significant negative correlation with sensible heat flux. Our results could deepen the understanding of water and heat transfer law of summer maize farmland in the old course of Yellow River, providing a theoretical basis for efficient water use of crops.

We conducted in a common garden experiment to explore the differences in soil enzyme activity, stoichiometry, and their influencing factors among a secondary Castanopsis carlesii forest, 10-year-old C. carlesii plantation, and Cunninghamia lanceolata plantation. The results showed that compared to the secondary forest, the soil organic carbon, total nitrogen, and dissolved organic carbon significantly decreased by 42.6%, 47.4%, and 60.9% in C. carlesii plantation, and by 42.9%, 36.7%, and 61.1% in C. lanceolata plantation. Soil microbial biomass C, microbial biomass N (MBN), and microbial biomass phosphorus decreased significantly by 40.6%, 35.5%, and 45.9% in C. carlesii plantation, and by 53.7%、56.4%, and 61.7% in C. lanceolata plantation. Compared to the secondary forest, soil enzymes activities in C. carlesii plantation did not change significantly, but in C. lanceolata plantation, the activities of β-1,4-glucosidase and cellobiohydrolase significantly decreased by 51.2% and 59.8%, β-N-acetyl glucosaminidase and acid phosphatase decreased significantly by 41.0% and 29.8%, and enzymatic C:N acquisition ratio and enzymatic C:P acquisition ratio significantly decreased by 11.3% and 7.7%, respectively. Results of redundancy analysis indicated that MBN and NO₃^--N were the primary factors influencing soil enzyme activity and enzymic stoichiometry. Collectively, there were significant differences in soil enzyme activity and microbial nutrient demands among different forest stands. Compared to secondary forests, the establishment of C. lanceolata plantations would intensify nutrient competition between plants and microbes, and exacerbate the N and P limitations for microbes.