应用生态学报最新文献

Soil nitrogen transformation processes, such as nitrogen mineralization, nitrification, and denitrification, are important links in nitrogen biogeochemical cycling. Previous studies on the impact of nitrogen deposition on nitrogen transformation process in forest soils have mostly relied on simulating nitrogen deposition under forest canopy, neglecting the interception effect of the canopy and failing to truly reflect the effects of nitrogen deposition. This study focused on the field simulation of canopy understory nitrogen deposition in Phyllostachys edulis forest soil over three years. There were four treatments: canopy nitrogen deposition (CN, nitrogen application rate of 50 kg·hm^-2·a^-1), understory nitrogen deposition (UN, nitrogen application rate of 50 kg·hm^-2·a^-1), canopy control (CCK, water equivalent to simulated nitrogen deposition solution), and understory control (UCK, water equivalent to simulated nitrogen deposition solution). We measured soil net nitrogen mineralization and net nitrification rates, as well as soil denitrification rates, to explore the impact mechanisms of different nitrogen deposition methods on key processes of soil nitrogen transformation. The results showed that both canopy and understory nitrogen deposition significantly increased soil net nitrogen mineralization, net nitrification, and denitrification rates, with CN showing an increase of 43.4%, 44.9%, and 33.0% compared to CCK, respectively. The growth rates of UN compared to UCK were 48.6%, 48.7%, and 41.2%, respectively. The increase in soil net nitrogen mineralization rate under nitrogen deposition was mainly caused by the increases in soil soluble organic nitrogen, microbial biomass nitrogen (MBN), and urease activity. The increase in net nitrification rate was mainly attributed to the abundance of ammonia oxidizing archaea, the activity of nitrifying enzymes, and the increase in MBN. The increase in denitrification rate following nitrogen deposition was induced by the promotion of nitrogen mineralization and nitrification, as well as an increase in the abundance of denitrification functional genes (nirK). In addition, there was no significant difference in soil net nitrogen mineralization and net nitrification rates between CN and UN treatments, but the denitrification rate of soil treated with UN was significantly higher than that of CN, mainly due to the higher abundance of nirK genes.

The ecological protection and restoration technology system and its standards serve as crucial support for achieving systematic governance of mountains, rivers, forests, fields, lakes, grasslands, and deserts. We evaluated the current status and problems of ecological protection and restoration technology system and standards construction in China, by comparing and analyzing the technology systems and standards of the United States (America) and the United Kingdom (Europe) with those of China. We further proposed optimization paths. The natural resource protection and ecological restoration technology systems in European and American countries demonstrate a high degree of systematicness and refinement, with technical standards covering the entire process. They emphasize ecological benefits and biodiversity conservation, and highlight the collaborative participation of multiple stakeholders. In contrast, the standards of such system in China face deficiencies in terms of quantity, structure, timeliness, and systematicness. These problems manifest as a limited number of technical standards, an excessively high proportion of comprehensive construction-related technical standards, a lack of key technical standards for management and protection, as well as precision ecological restoration, and insufficient consideration of the ecological environmental impacts of technology implementation. To address these problems, we proposed countermeasures and suggestions, such as constructing a hierarchical and classified technology standard system, improving technology guidelines based on natural solutions, promoting the transformation of national key research and development project outcomes, establishing a dynamic revision mechanism, constructing an ecological protection and restoration technology database, and formulating technical practice ecological compensation standards.

The construction of multi-scale ecological security patterns, as a crucial spatial approach for coordinating ecological protection and economic development, is of great significance for ensuring the integrity, adaptability, and sustainability of regional ecosystems. In the context of the reconstruction of the territorial space planning system, we assessed the construction and optimization of 'regional-municipal-urban' multi-scale ecological security pattern across the Dongting Lake Ecological Economic Zone (regional scale), Changde City (city scale), and the central urban area of Changde City (urban scale), integrating interdisciplinary methods such as minimum cumulative resistance model, ArcGIS spatial analysis, and circuit theory. The results showed that the conduction efficiency of ecological sources in the study area presented a characteristic of scale-decay. The regional-municipal scale coupling degree decreased by 20.1% compared to the municipal-urban scale, and among them, 15 ecological sources became spatial connection blank areas during cross-scale conduction. The conduction efficiency of ecological corridors was low due to insufficient cognition of multi-values. Among the 18 cross-scale ecological corridors, only four achieved effective connection, and 14 potential ecological corridors required priority restoration to enhance connectivity. The conduction efficiency of key ecological nodes attenuated due to insufficient scale correlation. There were four and five common ecological pinch points at the regional-municipal and municipal-urban scales, respectively. 16 common ecological barrier points formed cross-scale barrier zones. We employed a 'pattern identification-nesting diagnosis-collaborative optimization' full-process analytical framework to propose a targeted optimization scheme based on identifying potential problems in the foundational pattern, and ultimately constructed a multi-scale nested ecological security pattern comprising 38 ecological sources, 52 ecological corridors, and 158 ecological nodes. Our results would provide important theoretical support and practical guidance for the ecological protection and restoration, optimal allocation of land resources, and smart management of the ecosystem in the Dongting Lake Ecological Economic Zone.

Mycorrhizae play an important role in driving soil phosphorus (P) transformation, while intercropping or phosphate application influences rhizosphere mycorrhizal traits and enzyme activity. However, the mycorrhizal-mediated mechanism through which intercropping promotes P activation in red soil remains poorly understood. Based on a 7-year field experiment, we analyzed the effects of maize//soybean intercropping on maize yield, soil P fractions, mycorrhizal colonization, and the rhizosphere alkaline phosphatase activity (APA) with two plantation models, maize monoculture and maize//soybean intercropping under four phosphate application rates (0, 26.2, 39.3, and 52.4 kg P·hm^-2). We further explored the mycorrhizal-mediated role of intercropping on promoting phosphorus activation. The results showed that maize//soybean intercropping significantly increased maize yield, the proportion and content of liable P pools, P activation, and mycorrhizal colonization. Under the four different P application levels, intercropping increased maize yield by 21.1%, 60.0%, 58.5%, and 44.3%, respectively. The proportion of liable phosphorus pools under intercropping increased significantly by 27.3%, 18.2%, 10.6%, and 9.2%, respectively. The Resin-P content increased by 13.7%, 31.3%, 22.9% and 18.4%. NaHCO₃-Pi content increased by 15.9%, 28.8%, 16.1% and 6.9%. NaHCO₃-Po content increased by 23.8%, 19.5%, 11.8% and 2.6%. The P activation coefficient (PAC) increased by 36.7%, 51.4%, 19.8% and 14.1%. Intercropping increased the colonization rate by 35.2%, 42.9%, 28.8% and 25.9%, hyphal density by 21.7%, 67.5%, 27.5% and 6.0%, spore density by 30.8%, 35.7%, 28.2% and 21.9%, total glomalin by 8.3%, 30.2%, 25.1%, and 17.3%, and rhizosphere APA by 20.6%, 24.6%, 16.8%, and 13.8%, respectively. Random forest analysis indicated that the liable phosphorus pools, Resin-P, NaHCO₃-Po, NaHCO₃-Pi, were the most important factors driving soil P activation. Key factors influencing P fractions, in descending order of importance, were total glomalin, alkaline phosphatase, hyphal density, mycorrhizal colonization rate, and spore density. Structural equation modeling further demonstrated that maize//soybean intercropping promoted P activation primarily by enhancing mycorrhizal colonization and rhizosphere alkaline phosphatase activity, which in turn increased the content and proportion of both liable organic and inorganic phosphorus.

The albic soil (profile stratification: black soil layer, albic layer, and illuvial layer) has low permeability and a compacted albic layer, which is a typical low-yielding soil with constraint factors in Heilongjiang Province. Subsoiling techniques can disturb the albic soil layer and improve water conditions in the rooting zone. In this study, we investigated the effect of two subsoiling techniques, i.e. surface soil interlayer mixing (mixing the albic layer with the illuvial layer) and subsoil interlayer mixing (mixing the black soil layer with the albic layer), on soil water distribution and storage through monitoring soil water dynamics during the maize growth period. Results showed that the albic layer of control exhibited a bulk density 23.6% higher than that of the black soil layer and an extremely low saturated hydraulic conductivity (0.0013 cm·h^-1). This impeded upward water movement during the seedling stage of maize when rainfall was scarce, resulting in the formation of dryness in top and albic layers. During the frequent rainfall period after the jointing stage, the low permeability of the albic layer caused water retained in the upper soil layers. After using the subsoiling techniques, the average saturated hydraulic conductivity for 0-60 cm soil layer reached 12.29 cm·h^-1 under surface soil interlayer mixing and 14.09 cm·h^-1 under subsoil interlayer mixing treatments, being 4.9 to 5.7 times of the control. Compared to the control, both techniques increased soil water content in the albic layer by 93.2% during the maize seedling stage. During periods of the jointing stage with frequent rainfalls (July 15 to July 19), the average soil water content in the 0-30 cm layer decreased by 10.3% and 8.3% respectively, and soil water infiltration was improved. Water storage capacity in the rooting zone (0-60 cm) increased by 5.5% during the growing season. Our results indicated that subsoiling techniques ameliorate the uneven soil water distribution within the albic soil profile during the maize growing season, with the subsoil interlayer mixing showing the better efficacy.

Albic soil is a typical low-yield soil with obstacles in the Northeast China Black Soil Region. It has a thin layer of black soil on the surface, low nutrient content in the soil body, and a compact and dense albic layer that hinders root penetration of crops and water infiltration. Those characteristics result in poor soil permeability and make the surface soil vulnerable to drought and flood disasters, which severely restricts grain yield. Eliminating the albic layer obstacle and increasing crop yield have become the main goals. We systematically summarized the research progress of albic soil obstacle reduction, discussed the advantages and disadvantages of current technologies from three aspects of chemical, biological, and mechanical improvement. We further analyzed the mechanism and improvement effect of each improvement technology on the physical properties of albic soil such as hardness, bulk density, soil pore structure and aggregates, as well as the chemical properties such as organic matter content, nutrient composition, and pH. In view of the problems existing in the research on albic soil obstacle reduction, we suggested that future research should focus on four directions: innovation and optimization of soil improvement machinery, policy support and assistance, promotion and application of modern soil improvement technologies, and response to obstacle reduction technologies under climate change and post-effect sustainability assessment, in order to provide a reference for the quality improvement of albic soil.

As a natural geographical unit centered on water resources, watersheds serve as critical entities for coordinating the development and protection of territorial spaces. Establishing an ecological compensation mechanism based on the "water-land" relationship has become a vital approach to reconcile the conflicts between environmental conservation and socio-economic development in watersheds. It plays a significant role in advancing mo-dern watershed governance and achieving green, high-quality development. Xin'an River Watershed is the first cross-provincial ecological compensation pilot in China. With it as a case, we adopted a comprehensive research approach centered on scenario analysis and logical deduction to systematically examine the evolutionary trajectory of the compensation mechanism, diagnose shortcomings in the existing compensation system, and construct a dynamic compensation framework based on the disturbance of the "water-land" relationship. We found that the current compensation mechanism was lacking in whole-process management under the "post-event compensation" model and was insufficient for self-sustaining development due to its unitary compensation approach. An integrated watershed assessment system, based on the linkage of water quality "effect value", "measured value", and "target value", could overcome the limitations of traditional evaluations that rely solely on measured values and thus enable precise tracing of water and land environmental issues. Differentiated targeted compensation pathways, informed by diagnostic results from water and land environment assessments, could help enhance the focus and sustainability of governance measures. The systematically constructed dynamic compensation framework would facilitate the institutional transition of the ecological compensation mechanism from "post-event remediation" to "whole-process governance". This study would provide new perspectives, ideas, and methodologies for the integrated governance of watersheds and territorial spaces.

Seedlings and saplings are vital elements of understory vegetation, the accurate biomass estimation of which is important for quantifying carbon storage within forest ecosystems. With data of 620 seedlings and saplings individuals from six species-Acer mono, Populus davidiana, Ulmus laciniata, Fraxinus mandschurica, Quercus mongolica, and Syringa amurensis-across 101 broadleaf mixed forest plots in Maoershan Mountain, we developed power-function biomass models utilizing basal diameter, plant height, and crown area as independent variables and identify the optimal models as the base models. We further assessed the error structure of each base model through likelihood analysis, and established a biomass equation system for the six species using seemingly unrelated regression (SUR). The results showed that the univariate model utilizing only basal diameter was the most effective for F. mandschurica. For S. amurensis, the ternary model that encompassed basal diameter, plant height, and crown area was superior. For the other species, the binary biomass models that included basal diameter and plant height yielded the best results. The adjusted coefficients of determination (R_a²) varied from 0.716 to 0.990, while the root mean square errors (RMSE) ranged from 0.060 to 6.403, with all model parameters showing significance. The error structure for both component and total biomass across the species was found to be multiplicative (ΔAICc>2). Consequently, linear biomass models following logarithmic transformation were employed to develop the SUR biomass models for the six species. These models had high R_a² values (0.713-0.987) and low RMSE values (0.062-7.408), suggesting they were appropriate for accurately estimating the biomass of seedlings and saplings in the understory.

To evaluate the actual effects of different ecological restoration technologies on high and steep rock slopes in the dry-hot valley area, we compared three typical slope ecological restoration techniques, vegetation concrete (VC), soilless spraying (SPF), and vegetation trough (VS) on the high and steep rock slope of Baihetan Hydropower Station. We conducted a one-year monitoring of soil physical and chemical indicators and vegetation characteristics from January to December 2022, and calculated the ecological restoration index (ERI) using the minimum dataset method, which were used to comprehensively evaluate the ecological restoration effects of each technique. The results showed that: 1) During the maintenance monitoring period, soil physical characteristics (bulk density, porosity, moisture content), soil organic matter, and nutrient (total nitrogen, total phosphorus, available phosphorus) contents of the three remediation techniques showed a fluctuating trend with seasons. Plant characteristics (plant height, plant diameter, vegetation coverage coefficient, aboveground biomass) increased from 3.6-9.3 cm, 0.98-2.16 mm, 0.12-0.61, and 42.80-163.56 g·m^-2 to 11.5-14.7 cm, 2.85-4.05 mm, 0.68-0.98, and 368.00-421.12 g·m^-2, respectively, while cation exchange capacity increased from 6.13-13.94 cmol·kg^-1 to 13.94-20.42 cmol·kg^-1. Soil pH decreased from 7.56-8.05 to 7.17-7.51. VC was generally superior to SPF and VS in enhancing soil structure and plant growth. 2) The minimum dataset consisted of plant height, available phosphorus, vegetation coverage, bulk density, and total nitrogen, which were significantly positively correlated with the entire dataset (R²=0.733) and could effectively replace the entire dataset for ecological restoration evaluation. 3) The restoration process of slopes presented a restoration path of "soil matrix construction plant growth and reproduction". The contribution rate of soil ERI of the three restoration techniques in spring was 66.3%-70.5%, that in summer was 43.7%-58.4%, with the contribution rate of vegetation to ERI being 41.6%-56.3%. The contribution rate of vegetation to ERI in autumn and winter exceeded that of soil, ranging from 54.7% to 64.1% and 55.6% to 61.0%, respectively. 4) The annual average ERI values of three typical slope ecological restoration techniques were ranked as VC (0.576)>SPF (0.549)>VS (0.452), and the final values showed the same trend (0.676>0.639>0.538), indicating that VC had the best ecological restoration effect.

The realization of the value of ecological products offers a novel pathway for achieving high-quality economic development and facilitating green industrial transformation. Building upon the connotations of ecological products and their value, we constructed a three-dimensional indicator system covering supply-based, regulatory, and cultural categories to measure the value realization level of ecological products in 30 provinces of China except Hong Kong Special Administrative Region, Macao Special Administrative Region, Taiwan Province and Tibet Autonomous Region from 2013 to 2022. By comprehensively applying kernel density estimation, the Gini coefficient, and σ and β convergence models, we analyzed the spatiotemporal evolution, regional differentiation, and convergence characteristics of ecological product value. The results showed that from 2013 to 2022, the overall realization rate of ecological product value exhibited a continuous upward trend, with the mean value increasing from 0.25 to 0.68. However, there were significant gradient disparities among regions, manifesting as a spatially decreasing gradient pattern of "higher in the east and lower in the west." The kernel density estimation results showed that the ecological product value index demonstrated an upward trend for the national level and for the three major regions (eastern, central and western regions). Notably, there was little inter-provincial difference in the development level of ecological products within the eastern and central regions, with pronounced inter-provincial development imba-lances within the western region. The Gini coefficient and its decomposition results showed that inter-regional differences constituted the primary source of variation in the realization rate of ecological product value in China. Meanwhile, intra-regional differences within the eastern, central, and western regions showed a slight upward trend. σ convergence was observed in the realization rate of ecological product value across regions from 2017 to 2021. Moreover, β convergence was identified at the national level and within the eastern and central regions from 2013 to 2022, albeit at a relatively slow pace. The results would be helpful for accurately identifying the spatial imbalance of ecological product value realization, and provide scientific basis for the formulation of differentiated ecological policies and the promotion of regional coordinated development in China and its three major regions.