应用生态学报最新文献

To complete the life cycle, species exhibit corresponding functional traits in morphology, physiology, ecology, etc. The eigenvalues, variation, and distribution of functional traits are the functional components of biodiversity, namely functional diversity, could maintain the service function and healthy operation of ecosystems. The application of functional diversity broadens our understanding of biodiversity and its temporal and spatial variations, and provides a breakthrough to the problem of how to combine morphological structure with ecological function. I reviewed the research process of functional diversity from the perspective of proposing, calculating, and applying the parameters of functional diversity, as well as the application of functional diversity from different purposes and perspectives. I put forward the challenges and countermeasures of related studies. In the future, researches should pay attention to establish a set of effective trait indicators, discover the internal and external mechanisms driving functional diversity variations, and map the redistribution of traits under environmental changes.

Photodegradation driven by solar radiation has been confirmed as an important driving factor for litter decomposition. However, previous single-site studies could not quantify the relative contribution of variation in solar radiation to litter decomposition. To address it, we conducted a field experiment in Heshan National Field Research Station of Forest Ecosystem, Guangdong (Heshan Station, south subtropical climate), Jigongshan Ecological Research Station, Xinyang, Henan (Jigongshan Station, north subtropical climate) and Daqinggou Ecological Research Station, Institute of Applied Ecology, Chinese Academy of Sciences (Daqinggou Station, temperate climate) at intervals of 10 degrees. We examined litter decomposition of Populus davidiana and Larix olgensis, two species with significant differences in initial litter quality through an in-situ spectral-attenuation experiment. Treatments included full-spectrum, No-UV-B (attenuating UV-B radiation <315 nm) and No-UV & Blue (attenuating all UV and blue wavelengths <500 nm). After nearly 1-year decomposition, litter dry mass remaining of P. davidiana and L. olgensis under full-spectrum treatment was lowest at Heshan (30.2% and 36.3%), and highest at Jigongshan (37.3% and 45.8%). Among all sites, litter dry mass remaining was lowest under the full-spectrum, and lower than that of No-UV-B and No-UV & blue. UV and blue light significantly increased litter mass loss of P. davidiana and L. olgensis, with contributions of 59.7% and 57.0% (Heshan), 46.4% and 42.1% (Jigongshan), and 39.0% and 45.9% (Daqinggou), respectively. The contribution of UV-A and blue light (315-500 nm) was greater than UV-B (280-315 nm); the cumulative irradiance, soil temperature and moisture were the main driving factors for litter photodegradation.

For a long time, intercropping and rotation of leguminous with non-leguminous crops is widely used to reduce the application of nitrogen fertilizer and increase yield in agroecosystems. At present, most researchers considered that this management measure is helpful for reducing fertilizer consumption and increasing its efficiency, as it can improve nutrient supply of legumestonon-legumes, the spatial nutrient utilization efficiency by enhancing soil spatial heterogeneity, and improve soil structure and disease resistance. However, current theories cannot fully explain the positive effect of crop rotation and inter-cropping systems involving legumes. A large amount of hydrogen (H₂) can be produced as an obligatory by-product of nitrogenase responsible for nitrogen (N₂) fixation in the root nodules of leguminous plants. Despite of substantial amounts of H₂ enriched in the rhizosphere of legumes, only a minor proportion of H₂ is found to leak to soil surface. Increasing evidence showed that most H₂ released in soil is immediately depleted in the surrounding of N₂-fixing nodules by H₂-oxidizing bacteria (HOB) thriving in soil. HOB can use H₂ as an electron donor to assimilate and fix CO₂ through redox reactions to synthesize cellular substances and consequently promote plant growth. To date, however, little is known about the biological mechanism and ecological process behind the "hydrogen fertilizer effect". Therefore, we review the H₂-induced plant growth-promoting effects and its microbiological mechanisms. Our aims were to explore a new way for enhancing agroecosystem production, and to provide scientific basis for future utilization of H₂ in agricultural production practices.

The turnover and stabilization of soil organic carbon are tightly associated with the properties of litter input. Due to the complexity of litter decomposition and the high heterogeneity of forest soils, there are considerable uncertainties about how soil minerals, microorganisms, and environmental factors jointly regulate the transformation and stability of litter-derived soil organic carbon. Here, we present an overview of the "microbial efficiency-matrix stabilization" framework centered on microbial metabolism and organic carbon transformation, as well as the new "microbial carbon pump" and "mineral carbon pump" theories in forest soil organic carbon transformation and stabilization. We specifically highlighted a differential mechanism of "organo-organic interfaces" from the "organo-mineral interfaces" in the effects on soil organic carbon accumulation. We further expounded the transformation processes and stability of soil organic carbon based on the "carbon material cycling" and "energy fluxes", aiming to provide theoretical support for the research on carbon sequestration in forest soils.

Vascular plants exert significant effects on micro-environment, thereby affecting the distribution of biological soil crusts (biocrusts). The relationship between vascular plants and the spatial distribution characteristics of biocrusts is largely unknown. We investigated the distribution characteristics of biocrusts under the canopy of vascular plants in the water-wind erosion crisscross area of the Loess Plateau, where larger areas of biocrusts had been formed since the implantation of "Grain for Green" project. We analyzed the relationship between the canopy characteristics of different vascular plants and the spatial distribution of biocrusts using correlation analysis and random forest importance ranking methods, and further constructed a predictive model for the area of biocrusts under the canopy of vascular plants. The results showed that: 1) Cyanobacteria crust was the predominant biocrusts, followed by moss crust. 2) The canopy of vascular plants affected the spatial distribution of biocrusts, with notable differences in distribution pattern across different directions under the canopy of vascular plants. Biocrusts were primarily distributed in the 270°-315° and 315°-360° directions, while was less frequent in the 90°-135° and 135°-180° directions. 3) Radially, the coverage of biocrusts gradually increased from the root-base to the edge of the canopy of vascular plants. 4) The coverage of biocrusts under canopy was significantly related to the characteristics of vascular plants, including canopy area, long crown width, short crown width, litter area and plant height. 5) The relative importance of canopy area, long crown width, and short crown width to the biocrusts under the canopy was 13.7%, 12.1%, and 11.9%, respectively, while the relative importance of plant height and species type was relatively low, being 6.7% and 4.4%, respectively. 6) Results of the random forest model demonstrated strong predictive performance for biocrusts distribution based on canopy characteristics of vascular plants, with a prediction accuracy of 0.59 (R²) and a root mean square error of 1.2 m². This model could be applied to predict and estimate the area of biocrusts under the canopy of vascular plants. This study provided a theoretical basis for in-depth understanding of the relationship between vascular plants and biocrusts in semi-arid climate regions, as well as for predicting the spatial distribution of biocrusts.

The Loess Plateau is renowned for its deep soil layer and rich in organic carbon (C). In recent years, numerous ecological restoration projects have been undertaken on the Loess Plateau, with consequence on the stability of soil organic carbon (SOC). The SOC stability is pivotal for its capacity to sequestrate and store C. However, comprehensive review on the characteristics of SOC stability and its mechanisms during vegetation restoration on the Loess Plateau is scarce. Therefore, we summarized the dynamics of SOC stability during vegetation restoration on the Loess Plateau, discussed the mechanisms of SOC stabilization, including mineral protection, physical protection, and biological mechanisms. Furthermore, we prospected the future development directions and research focus of SOC stability research during vegetation restoration on the Loess Plateau to provide scientific support for theory and technology of soil C sequestration and stabilization during vegetation restoration, and to provide scientific reference for achieving the "double-carbon" goals.

In the past decade, research on the relationships between the supply and demand of ecosystem services has been flourishing. To address issues such as the misuse of supply and demand concepts, methods, and results in current research, we proposed five key aspects that need to be considered to enhance the scientific rigor and practical value in assessing relationships between ecosystem service supply and demand. Firstly, it is essential to clarify the distinctions and connections between the concepts related to ecosystem service supply and demand, which are crucial prerequisites and starting points for assessing their relationships. Secondly, it is necessary to integrate relevant environmental standards or policy objectives to develop reliable methods for assessing the demand for ecosystem regulating services. Furthermore, it is important to properly address the modifiable areal unit problem by determining the most appropriate spatial scale and unit for evaluating relationships between ecosystem service supply and demand. Additionally, it is crucial to differentiate between quantitative and qualitative methods for characterizing (im)balances or (mis)matches between ecosystem service supply and demand, particularly avoiding the use of qualitative methods to represent quantitative relationships between supply and demand. Lastly, it is imperative to integrate ecosystem service flows into the assessment of supply and demand relationships, and evaluate the dynamic supply and demand relationships of regional ecosystem services from a coupled "supply-flow-demand" perspective.

In this study, we applied thermal dissipation probe technology to examine sap flow in various directions (east, south, west, and north) and at different depths (0-2, 2-4, 4-6 cm) within the stem of natural Picea mongolica trees in the eastern of Otindag Sandy Land to provide a scientific basis for accurately quantifying water consumption of P. mongolica forests through transpiration and to enhance the understanding of water relations. The results showed that the diurnal variation of sap flow in different directions displayed a unimodal curve, with the sap flow sequence being south>east>west>north. The sap flow at different sapwood depths exhibited an obvious unimodal curve, with a significant decrease as sapwood depth increased. Compared with that calculated from the mean sap flux density in four directions (23.57 kg·d^-1), water consumption calculated using the mean value in south-east, east-west, south-west, north-east, north-south, and north-west was overestimated by 10.2%, 5.5%, 14.5%, and underestimated by 12.3%, 8.2%, 9.8%, respectively. The water consumption calculated using the values from the east, south, and west was overestimated by 6.1%, 14.4%, and 15.4%, respectively, and underestimated by 30.7% in the north. In addition, compared with the water consumption calculated from the mean value in three sapwood depths (48.51 kg·d^-1), that calculated using sap flux density at sapwood depths of 0-2, 2-4, and 4-6 cm were overestimated by 18.8%, underestimated by 1.7%, and underestimated by 62.9%, respectively. These results indicated that sap flow of P. mongolica had significant azimuthal and radial variations, which considerably influence the estimation of tree water consumption. Installing probes at 0-2 cm simultaneously in both the north and east of the trunk could effectively reduce the estimation error of whole-tree water consumption by 4.2%. This approach enabled the accurate quantification of water consumption of individual P. mongolica trees in sandy areas, thereby improving the precision of transpiration water consumption estimates scaling up from individual level to stand level.

Collar rot caused by Fusarium spp. is a serious threat to the production of Passiflora edulis. However, biocontrol methods are lacking. Trichoderma spp., as the most widely applied biocontrol fungus, can be effective in managing crop diseases. The effectiveness is significantly influenced by environmental factors, such as soil pH. To screen potential biocontrol strains against collar rot of P. edulis, and to explore the effect of pH on the inhibition rate of Trichoderma spp., we selected four Trichoderma species and four Fusarium species isolated from P. edulis planting area in Xishuangbanna. The growth dynamics of different strains under different pH conditions were determined using the mycelial growth rate method. The effect of pH on the growth inhibition of Fusarium spp. by Trichoderma spp. was investigated using the plate confrontation assay. The results showed that the optimal growth pH range was 4-6 for Trichoderma spp. and 7-9 for Fusarium spp. All four Trichoderma strains exhibited significant inhibitory effects on the growth of the four Fusarium strains. T. harzianum showed the most notable inhibition, reaching up to a 72% inhibitory rate. Moreover, pH significantly influenced the inhibitory effect of Trichoderma spp., with variations observed depending on the specific species of Trichoderma spp. and Fusarium spp. Therefore, it is essential to consider the environmental pH impact on the efficacy of biocontrol agents when applying biological control measures in the field, tailored to the specific pathogen and biocontrol agent involved.