Farmland Shelterbelts Research Articles

Soil bacterial community characteristics and influencing factors in different types of farmland shelterbelts in the Alaer reclamation area.

To investigate the effects of various types of farmland shelterbelts on soil quality and soil bacterial community diversity, this study focused on soil samples from four different shelterbelt types in the Alaer reclamation area, including Populus euphratica Oliv.- Populus tomentosa Carrière (PP), Elaeagnus angustifolia L.- Populus euphratica Oliv. (EP), Populus alba var. pyramidalis Bunge (P), and Salix babylonica L. (S). We analyzed their physical, chemical, biological properties as well as the differences in bacterial community structure, and explored the influencing factors on soil microbial community characteristics through microbial correlation network analysis. The results showed that: (1) There were significant differences in soil properties among the four types of farmland shelterbelts (p < 0.05), with P soils exhibiting the highest levels of organic matter, total nitrogen, and total phosphorus contents. (2) The Alpha diversity indices of soil bacteria showed significant differences among the four types of farmland shelterbelts (p < 0.05), with the P soils displayed the highest Chao1 and Shannon indices. (3) There were differences in the composition and abundance of dominant soil bacterial communities among different farmland shelterbelts, notably, the abundances of Verrucomicrobia, Acidobacteria, and Planctomycetes were significantly higher in P soils compared to the other three types. (4) The complexity of the correlation network between microbial species and environmental factors was highest in EP soils, soil microbial biomass nitrogen and available phosphorus were the main influencing factors. These findings indicated that different types of farmland shelterbelts had significant impacts on soil properties and soil bacterial communities. Soil bacterial communities were regulated by soil properties, their changes reflected a combined effect of soil characteristics and tree species.

Enhanced Blue Band Vegetation Index (The Re-Modified Anthocyanin Reflectance Index (RMARI)) for Accurate Farmland Shelterbelt Extraction

Farmland shelterbelts are aimed at farmland protection and productivity improvement, environmental protection and ecological balance, as well as land use planning and management. Farmland shelterbelts play a vital role in determining the structural integrity and overall effectiveness of farmland, and assessing the dynamic changes within these protective forests accurately and swiftly is essential to maintaining their protective functions as well as for policy formulation and effectiveness evaluation in relevant departments. Traditional methods for extracting farmland shelterbelt information have faced significant challenges due to the large workload required and the inconsistencies in the accuracy of existing methods. For example, the existing vegetation index extraction methods often have significant errors, which remain unresolved. Therefore, developing a more efficient extraction method with greater accuracy is imperative. This study focused on Youyi Farm in Heilongjiang Province, China, utilizing satellite data with spatial resolutions ranging from 0.8 m (GF-7) to 30 m (Landsat). By taking into account the growth cycles of farmland shelterbelts and variations in crop types, the optimal temporal window for extraction is identified based on phenological analysis. The study introduced a new index—the Re-Modified Anthocyanin Reflectance Index (RMARI)—which is an improvement on existing vegetation indexes, such as the NDVI and the improved original ARI. Both the accuracy and extraction results showed significant improvements, and the feasibility of the RMARI was confirmed. The study proposed four extraction schemes for farmland shelterbelts: (1) spectral feature extraction, (2) extraction using vegetation indexes, (3) random forest extraction, and (4) RF combined with characteristic index bands. The extraction process was implemented on the GEE platform, and results from different spatial resolutions were compared. Results showed that (1) the bare soil period in May is the optimal time period for extracting farmland shelterbelts; (2) the RF method combined with characteristic index bands produces the best extraction results, effectively distinguishing shelterbelts from other land features; (3) the RMARI reduces background noise more effectively than the NDVI and ARI, resulting in more comprehensive extraction outcomes; and (4) among the satellite images analyzed—GF-7, Planet, Sentinel-2, and Landsat OLI 8—GF-7 achieves the highest extraction accuracy (with a Kappa coefficient of 0.95 and an OA of 0.97), providing the most detailed textural information. However, comprehensive analysis suggests that Sentinel-2 is more suitable for large-scale farmland shelterbelt information extraction. This study provides new approaches and technical support for periodic dynamic forestry surveys, providing valuable reference points for agricultural ecological research.

Biodegradable microplastics can cause more serious loss of soil organic carbon by priming effect than conventional microplastics in farmland shelterbelts

Abstract Globally, the widespread utilization of plastic products has resulted in the accumulation of microplastics (MPs) in the soil. MPs have the potential to impact the loss of soil organic carbon (SOC). Nevertheless, the influence of different types of MPs on SOC loss remains uncertain. In this study, a 38 day incubation experiment with two kinds of conventional MPs (polyethylene, polypropylene) as well as two kinds of biodegradable MPs (polyhydroxyalkanoate [PHA], polylactic acid [PLA]) were added into three types of soil (loam, sandy loam, and sandy soil) in farmland shelterbelts, and the sources of CO2 emissions was distinguished by the difference in 13C isotope abundance between the biodegradable MPs (PHA and PLA) (−10.02‰ to −9.92‰) and the soil (−24.39‰ to −22.86‰) (&gt;10‰). In conjunction with the structural characterization of MPs, as well as soil physicochemical properties and microbial characteristics, we observed that the conventional MPs did not degrade in short term incubation, but significantly enhance soil‐derived CO2 emissions by altering the dissolved N content (‐N and dissolved total N [DTN]) and reducing microbial biomass carbon content only in sandy loam soil (p &lt; 0.05). Biodegradable MPs degraded significantly, and enhanced soil‐derived CO2 emissions by reducing soil DTN and ‐N contents in loam, sandy loam and sandy soil (p &lt; 0.05). Overall, the input of biodegradable MPs causes a more serious loss of SOC than conventional MPs as the soil sand content increased in short term incubation, which needs to be considered in predicting the global impact of increasing biodegradable MPs pollution. Read the free Plain Language Summary for this article on the Journal blog.

Identification of Damaged Canopies in Farmland Artificial Shelterbelts Based on Fusion of Unmanned Aerial Vehicle LiDAR and Multispectral Features

With the decline in the protective function for agricultural ecosystems of farmland shelterbelts due to tree withering and dying caused by pest and disease, quickly and accurately identifying the distribution of canopy damage is of great significance for forestry management departments to implement dynamic monitoring. This study focused on Populus bolleana and utilized an unmanned aerial vehicle (UAV) multispectral camera to acquire red–green–blue (RGB) images and multispectral images (MSIs), which were fused with a digital surface model (DSM) generated by UAV LiDAR for feature fusion to obtain DSM + RGB and DSM + MSI images, and random forest (RF), support vector machine (SVM), maximum likelihood classification (MLC), and a deep learning U-Net model were employed to build classification models for forest stand canopy recognition for the four image types. The model results indicate that the recognition performance of RF is superior to that of U-Net, and U-Net performs better overall than SVM and MLC. The classification accuracy of different feature fusion images shows a trend of DSM + MSI images (Kappa = 0.8656, OA = 91.55%) &gt; MSI images &gt; DSM + RGB images &gt; RGB images. DSM + MSI images exhibit the highest producer’s accuracy for identifying healthy and withered canopies, with values of 95.91% and 91.15%, respectively, while RGB images show the lowest accuracy, with producer’s accuracy values of 79.3% and 78.91% for healthy and withered canopies, respectively. This study presents a method for identifying the distribution of Populus bolleana canopies damaged by Anoplophora glabripennis and healthy canopies using the feature fusion of multi-source remote sensing data, providing a valuable data reference for the precise monitoring and management of farmland shelterbelts.

Shelterbelt effects on soil redistribution on an arable slope by wind and water

Soil erosion is the most severe form of land degradation globally. Farmland shelterbelts are important for reducing erosion, especially erosion caused by the co-occurrence of water and wind. However, few studies have focused on how the distance from the shelterbelt associated with farmland topography affects the redistribution of soil quality indicators. The aims of this study is to reveal the relative importance of these two factors to soil quality under typical wind and water erosion conditions concurrent with the Songnen Plain, China. Topsoils (0–10 cm) were sampled at seven distances from the shelterbelt with three replicates, where topography heterogeneity was also considered. We found that the silt/clay content and soil nutrients at sites farther from the shelterbelt were significantly greater than those at sites closer to the shelterbelt (P < 0.05). Similarly, deposition was dominant at sites farther from the shelterbelt and downslope positions, while erosion was dominant at sites closer to the shelterbelt and upslope positions. Moreover, we discovered that the relative influence of distance from the shelterbelt and farmland elevation varied with individual soil quality indicators. Soil nutrients increased through the deposition of more fine-textured soil (silt/clay) positions farther from the shelterbelt. The downslope region responds to soil deposition by enhancing the plough pan thickness and lowering the bulk density and pH. Overall, distance from the shelterbelt and farmland elevation had interactive effects on soil quality, and erosion was primarily affected by distance from the shelterbelt (63.4 %), followed by elevation (22.7 %). Furthermore, the sites closer to the shelterbelt (i.e., 20 to 420 m) warrant particular attention due to the deposition of coarse-texture materials here. This work is crucial for an improved understanding of the synergistic effects of long-term water and wind co-occurrence on soil quality evolution.

Seasonal transpiration dynamics and water use strategy of a farmland shelterbelt in Gurbantunggut Desert oasis, northwestern China

Farmland shelterbelts provide an ecological barrier to oases, but their growth is inhibited or even dies under water scarcity. Therefore, it is necessary to understand the response of farmland shelterbelts to environmental changes for their own survival in order to promote the long-term healthy development of agroforestry systems and improve water management in oases in the northwest arid region. In this study, we measured the sap flow and environmental factors to determine the transpiration dynamics and its influencing factors. The seasonal variations in water use strategy of Populus alba var. pyramidalis Bunge were identified by using stable isotopes of δ18O in xylem, soil water and groundwater coupled with the Iso-Source model. The results showed that the transpiration of the populus was significantly higher in the growing season (more than 80% of the total transpiration) than in the non-growing season, and the transpiration was closely related to air temperature, vapor pressure deficit, soil water content, and soil temperature. The water use strategy had seasonal variations. The populus obtained water predominantly from 0–40 cm soil water (approximately 75%) in the wet spring and then switched to deeper water sources (40–150 cm soil water and groundwater) as the season progressed. The contribution of deeper water sources increased to 84–92% in summer and autumn. This suggested that Populus alba var. pyramidalis Bunge has ecological plasticity, as it could explore deeper water sources as the water stress increased. The ability to switch rapidly among different water sources could put a plant at an advantage if competition for water occurs within the ecosystem. Our findings can provide insights into temporal transpiration dynamics as well as the strategy adopted by farmland shelterbelts to counteract the drought stress associated with the shallow soils in desert oasis ecosystems.

Shelterbelt construction in the scenario of coordinated development of mountain, river, forest, farmland, lake, grassland, and sandy land ecosystems in semi-arid wind-sand areas: Principles and methods

We established the systematic concept framework of shelterbelt construction, with "shelterbelts" as the core concern in the construction of integrated ecosystems including mountain, river, forest, farmland, lake, grassland and sandy-land in semi-arid wind-sand areas. In the construction of shelterbelts, it is necessary to adhere to the principles of scientific coordination and systematic management, considering the carrying capacity of water resources, the demand for dust control, the greening and beautification effects, as well as the principle of improving economic benefits. In practice, the construction methods should base on the types and temporal-spatial distribution of shelterbelts, following the shelterbelts construction theory and technology to form different structure and service functions, achieving the functional goals of shelterbelts. By focusing on the key elements including people, forests, grass, fields, water, and sand, we put forward the timeliness, practicality, and scientificity of shelterbelt construction, proposing construction methods for farmland shelterbelts, pastureland shelterbelts, windbreak and sand-fixing forests and protective forest around village (city), which might provide production technical support for the high-quality construction of green ecological barrier in northern China.

Assessment of the Declining Degree of Farmland Shelterbelts in a Desert Oasis Based on LiDAR and Hyperspectral Imagery

Assessment of the Declining Degree of Farmland Shelterbelts in a Desert Oasis Based on LiDAR and Hyperspectral Imagery

The Relationships between Root Traits and the Soil Erodibility of Farmland Shelterbelts in the Bashang Region of China

Soil erodibility by wind is not only affected by the basic physical and chemical properties of the soil but also the functional traits of plant roots. However, the roles played by the morphological and architectural traits of plant roots on wind-based soil erodibility in the Bashang region of China are still unclear. Therefore, two typical tree shelterbelts and two shrub shelterbelts in the Bashang region were selected to assess and determine how the root traits affected soil erodibility, especially characteristics such as dry aggregate, soil organic matter, and shearing resistance. The results showed that the soil dry aggregates of the two shrubs (Lycium barbarum and Caragana korshinskii) had higher geometric mean diameters (0.40 ± 0.03 mm) and mean weight diameters (0.82 ± 0.08 mm) but a lower erodible fraction (81.81% ± 1.62%) compared to the two trees (Populus simonii and Ulmus pumila). The mean weight diameter (MWDd) and geometric mean diameter (GMDd) of dry soil aggregates were negatively correlated with the soil erodible fraction (EFd), but these parameters were positively correlated with shearing resistances. The specific root length (SRL) and surface area (SSA) of plant roots were positively correlated with the GMDd of the soils, though these two parameters negatively correlated with the soil erodible fraction. The root branching intensity (BI) was negatively correlated with the MWDd and GMDd of dry soil aggregates. The total carbon or nitrogen of the soil displayed significantly positive and negative correlations to the geometric mean diameters and erodible fractions of the soils, respectively. The findings showed that plant roots with higher SRLs, as well as lower root diameters and BIs, played positive key roles in soil stability. The same applied to soils with higher nitrogen, carbon, and water content. The results from this study suggest that L. barbarum is superior to the other three species based on root traits and wind erosion resistance. These findings provide critical information for selecting plants for the sustainable management of windbreak and sand fixation.

Extraction of farmland shelterbelts from remote sensing imagery based on a belt-oriented method

IntroductionFarmland shelterbelts play a positive role in ensuring food security and ecological safety. The absence or degradation of shelterbelt structures can lead to fragmentation of the remotely extracted results. Conversely, shelterbelt maintenance and management system considers these shelterbelts as entire units, even if they are divided into several parts by the gaps in them. It is essential to propose a remote extraction method to fill in fragmented results and accurately represent the distribution of farmland shelterbelts.MethodsIn this study, random forest algorithm was employed to classify land cover from ZY-3 (ZiYuan-3 satellite from China) imagery. Then, a thinning algorithm of mathematical morphology was applied to extract farmland shelterbelts, and the straight-line connection algorithm was used to connect central lines belonging to the same belt. Finally, the result was validated using nine uniformly distributed training sample areas across the entire region.Results and discussionThis method achieved a correct identification rate of 94.9% within the training areas. Among the different regions, the highest identification accuracy recorded was 98.4% and the lowest was 87.7%. In conjunction with cropland information and the shape index of forest patches, it was possible to remove information for non-farmland shelterbelts without introducing external information. This approach achieved a more refined extraction of forestland information. The combination of the thinning algorithm and straight-line connection algorithm addressed the issue of fragmented results in farmland shelterbelt extraction, compensating for the limitations of relying solely on mathematical morphology for belt connectivity. The research method can provide technical support for the monitoring and management of farmland shelterbelts.

Sustainable Management Behavior of Farmland Shelterbelt of Farmers in Ecologically Fragile Areas: Empirical Evidence from Xinjiang, China

The farmland shelterbelt is an important artificial ecological project for improving farmland microclimates, ensuring agricultural production, and promoting sustainable development in China’s ecologically fragile areas. Due to the quasi-public attribute, farmland shelterbelts were mainly constructed and managed by the government in the past. In recent years, the reform of the separation of three rights in collective forestland and the mechanism of “private supply of public goods” have prompted farmers to participate in the modern forest management system. However, there is a lack of consistency between farmers’ management intentions and actual contract operation and management behaviors, resulting in weakened management and protection in many places, which seriously restricts the construction efficiency of farmland shelterbelts. Therefore, based on the survey data and planning behavior theory (TPB) of 1106 farmers in 16 major agricultural production areas (counties) in Xinjiang, this study aims to explore the key factors affecting farmers ‘forestry management and production decision making and to verify the transformation mechanism of farmers’ behavior through path analysis. The results show that the management decisions of farmers in ecologically fragile areas follow the path form of “cognitive → intention → behavior”, in which the multi-dimensional cognition of farmers has a significant impact on farmers’ behavioral intention, while the effect on behavioral response is relatively small, which currently depends on the promotion of ecological compensation and government behavior. Finally, this study puts forward countermeasures and suggestions for continuously stimulating the farmers’ forest operation behavior and provides policy reference for promoting the sustainable development of farmland shelterbelts in ecologically fragile areas put forward countermeasures and suggestions for continuously stimulating farmers’ forestry behavior.

Effects of Shelterbelt Transformation on Soil Aggregates Characterization and Erodibility in China Black Soil Farmland

Farmland shelterbelts are widely used to reduce wind erosion, maintaining the ecological and food security of the black soil plain region of northeast China. In recent years, the protective effect of shelterbelts has been reduced due to tree degeneration. Efforts have been made to transform the construction of shelterbelts to conserve the stability of soil aggregates and enhance protection against erosion, however, the results are not well understood. To evaluate the impact of shelterbelt transformation on the stability of farmland soil aggregates and soil erodibility, three transformation modes of shelterbelts were selected, including pure Pinus sylvestris var. mongolica (ZC), pure Picea asperata (YS), and mixed Populus × xiaohei–Pinus sylvestris var.mongolica (ZY), with a degraded Populus × xiaohei shelterbelt (TYC) used as a control. We set up soil sampling points at 0.5H, 1H, 1.5H, 3H, 5H, 7H, and 9H from the shelterbelts and analyzed aggregate composition, mean weight diameter (MWD), geometric mean diameter (GMD), fractal dimension (D), soil erodibility (K-value), and their relationships to soil properties of the 0–10 cm, 10–20 cm and 20–40 cm soil layers and the shelterbelt structure by using dry and wet sieving and equation estimation methods. The results show that dry (d) sieved soil samples from the transformed shelterbelt-protected farmlands are mainly composed of 2–5 mm and &gt;5 mm grain size aggregates; the sum of the two particle sizes ranged from 48.67% to 51.27%, significantly larger than in the degraded shelterbelts (15.37%), decreasing with increasing distance from the shelterbelts. The effect is most obvious in the 0–10 cm soil layer. Wet (w) sieved soil samples are all dominated by &lt;0.25 mm and 0.25–0.5 mm grain size aggregates; the sum of the two particle sizes ranged from 78.25% to 80.82%, which do not vary significantly with the mode of shelterbelts. The dMWD and dGMD show significantly higher mean values in samples from transformed shelterbelt-protected farmland than in soil from degraded shelterbelt-protected farmland; their magnitudes differ depending on the transformation mode, showing a pattern of ZC &gt; ZY &gt; YS and decreasing with increasing distance from shelterbelts, while the opposite is true for D and K. The difference between wMWD and wGMD for different shelterbelts protected farmland is not significant and is significantly lower than that between dMWD and dGMD. Clay and silt content was highly significantly positively correlated with aggregates dMWD and dGMD, weakly positively correlated with wMWD, wGMD and wD, and highly significantly negatively correlated with dD and K values. This shows that particle composition parameters can be used to reflect the sensitivity of agricultural soils to wind erosion. Farmland shelterbelt porosity is the main factor driving changes in soil aggregates stability, soil erodibility, and other soil properties. The transformation of degraded farmland shelterbelts can decrease the porosity and reduce wind speed, resulting in improved stability and erosion resistance of the farmland soil aggregates by increasing the clay content of the farmland soils. These results are useful in renovating degraded shelterbelts, providing novel insights into how to regulate the stability of soil aggregates and soil erodibility characteristics at the shelterbelt network scale.

Estimating the impact of shelterbelt structure on corn yield at a large scale using Google Earth and Sentinel 2 data

A shelterbelt is an important measure to protect farmland and increase crop yield. However, how a shelterbelt structure affects crop yield is still unclear due to the difficulties accessing sufficient data from traditional field observations. To address this problem, we developed an innovative framework to estimate the shelterbelt structure and crop yield profile at a regional scale based on Google Earth and Sentinel-2 data. Using this method, we quantified the impact of the shelterbelt structure on the corn yield at 302 shelterbelts in the Northeast Plain of China. Generally, the corn yield increased (by 2.41% on average) within a distance of 1.2–15 times the tree height from the shelterbelt. Such an effect was particularly prominent within a distance of two to five times the tree height, where the corn yield was significantly increased by up to 4.63%. The structure of the shelterbelt has a significant effect on the magnitude of increase in yield of the surrounding corn. The increment of corn yields with high-, medium-high-, medium- and low-width-gap grade shelterbelt were 2.01%, 2.21%, 1.99%, and 0.91%, respectively. The medium-high grade shelterbelt achieved the largest yield increase effect. The location of the farmland relative to the shelterbelt also affected the yield, with a yield increase of 2.39% on the leeward side and 1.89% on the windward side, but it did not change the relationship between the yield increase effect and the shelterbelt structure. Our findings highlight the optimal shelterbelt structure for increasing corn yield, providing practical guidance on the design and management of farmland shelterbelts for maximizing yield.

A Quantitative Analysis of Factors Influencing Organic Matter Concentration in the Topsoil of Black Soil in Northeast China Based on Spatial Heterogeneous Patterns

Black soil is fertile, abundant with organic matter (OM) and is exceptional for farming. The black soil zone in northeast China is the third-largest black soil zone globally and produces a quarter of China’s commodity grain. However, the soil organic matter (SOM) in this zone is declining, and the quality of cultivated land is falling off rapidly due to overexploitation and unsustainable management practices. To help develop an integrated protection strategy for black soil, this study aimed to identify the primary factors contributing to SOM degradation. The geographic detector, which can detect both linear and nonlinear relationships and the interactions based on spatial heterogeneous patterns, was used to quantitatively analyze the natural and anthropogenic factors affecting SOM concentration in northeast China. In descending order, the nine factors affecting SOM are temperature, gross domestic product (GDP), elevation, population, soil type, precipitation, soil erosion, land use, and geomorphology. The influence of all factors is significant, and the interaction of any two factors enhances their impact. The SOM concentration decreases with increased temperature, population, soil erosion, elevation and terrain undulation. SOM rises with increased precipitation, initially decreases with increasing GDP but then increases, and varies by soil type and land use. Conclusions about detailed impacts are presented in this paper. For example, wind erosion has a more significant effect than water erosion, and irrigated land has a lower SOM content than dry land. Based on the study results, protection measures, including conservation tillage, farmland shelterbelts, cross-slope ridges, terraces, and rainfed farming are recommended. The conversion of high-quality farmland to non-farm uses should be prohibited.

Can Land Consolidation Reduce the Soil Erosion of Agricultural Land in Hilly Areas? Evidence from Lishui District, Nanjing City

The hilly areas of China have experienced soil erosion and are also typical land consolidation (LC) regions. Using the RUSLE model and the multiple regression model, this study evaluated the soil erosion of agricultural land and assessed the effects of LC on soil erosion in Lishui District, a typical district in the Ning-Zhen-Yang hilly area. The soil erosion of agricultural land ranged from 0 to 385.77 t·ha−1·yr−1 with spatial heterogeneity due to the topography, land cover, and vegetation cover. Overall, carrying out LC reduced soil erosion due to the construction of protection forests, farmland shelterbelts, and different kinds of land engineering. Furthermore, the different types of LC had different impacts on soil erosion, where farmland consolidation resulted in more serious soil erosion than land development. Nevertheless, the potential risks brought by LC to soil erosion reduction could not be overlooked, and more attention should be paid to ecological environment protection during the process of LC. This study presents findings regarding the positive impacts and potential risks of LC for soil erosion reduction in agricultural land in hilly areas.

A model integrating the system dynamic model with the risk based two-stage stochastic robust programming model for agricultural-ecological water resources management

This paper combines a risk-based two-stage stochastic robust programming (RTSRP) model into an agricultural-ecological system dynamics (AESD) to conduct agricultural-ecological water resources management. It integrates the chance- constrained programming, conditional risk-at-value, two-stage stochastic robust programming with the AESD model. The RTSRP model improves upon the TSRP model by introducing the risk control measurements. The agricultural-ecological dynamic system (AEDS) model can build water connections amid wheat, field corn, seed corn, economic crops, woodland, meadow, and city greening and farmland shelterbelts. Besides, the ecological service value is transformed into the irrigation benefit of ecological sector to guide water allocation amid sub-ecological sectors at a more applicable detailed scale. It can tradeoff relationships between economic benefit and ecological recovery by formulating two enlarging ecological areas scenarios. The combinations of the RTSRP model and the AEDS model can get optimal water allocation schemes, and simulate future sustainable degree (SD) of optimal water allocation schemes and explore relationships amid water allocation, economic benefit, and SD and risk and robustness of model. It is used to the middle reaches of the Heihe River Basin in China to verify its application. The results show that water allocation schemes have different responses on various risk scenarios. Higher water allocation corresponds to bigger water shortage risk and higher robustness of the model. The economic benefit positive with water allocation is contradictory with SD. Enlarging ecological areas contributes to improvements of economic benefit and ecological recovery, but not the SD under the condition of enough water resources.

Spatio-temporal changes in water-related ecosystem services provision and trade-offs with food production

A key challenge for sustainability is protecting water-related ecosystems and the services (WESs) they provide while enhancing food security. Food production usually drives land use change, which results in ecosystem services provision being altered. However, the underlying mechanisms are still unclear and relevant research is scarce. In this study, a spatio-temporal assessment framework was developed to assess the impact of food production-driven land use change on WESs and to analyze tradeoffs between food production and WESs provision, taking Songhua River Basin (SRB) as a case study. The results showed that: 1) food production increased from 0.497×108tons to 0.798×108tons despite area of cultivated land decreasing from 23.61×104km2 to 23.40×104km2 during the study period (2000–2015). 2) Water yield and soil retention both showed a downward trend, while nitrogen and phosphorus exports showed an increasing trend, in 2000–2015.3) Food production showed a trade-off relationship with soil retention and water yield, but a synergistic relationship with nitrogen and phosphorus export. This is important empirical evidence of the impact of food production-driven land use change on WESs. For simultaneous development of food production and WESs, a form of sustainable agricultural production must be established, with intensification of existing land use and establishment of farmland shelterbelts. This critical knowledge can be applied in developing practical ecosystem protection measures and land management strategies for food security in China and beyond.

Quantifying farmland shelterbelt impacts on catchment soil erosion and sediment yield for the black soil region, northeastern China

AbstractAs one part of the ‘Three Norths’ forest protection system, dense farmland shelterbelt networks in northeastern China could greatly modify water and sediment flows. In this paper, catchment soil erosion rate and sediment yield (SY) that are impacted by farmland shelterbelts were estimated using WaTEM/SEDEM model. The shelterbelts reduced catchment soil erosion and SY to some extent. The mean soil erosion rate and specific sediment yield (SSY; defined as the ratio of SY to catchment area; t km−2 yr−1) of the 25 reservoir catchments decreased from 351.6 and 93.9 t km−2 yr−1 under the supposed scenario without shelterbelts to 331.1 t km−2 yr−1 and 86.3% t km−2 yr−1 under the current situation with shelterbelts. The sediment trap efficiencies (STEs) varied from 0.01% to 23.6% with an average value of 7.6%. The STEs were significantly correlated with shelterbelt density, catchment perimeter, topographic factors, RUSLEP‐factor and land use patterns including patch density (PD), patch cohesion index (COHESION), Shannon's diversity index (SHDI) and aggregation index (AI). The multiple regression equation involving factors of catchment's topography and morphology and land use pattern has a satisfactory performance, and mean slope gradient (MSG) and AI explained most of the variability of shelterbelts’ STE. This information can help land managers to better design shelterbelts and to reduce water‐derived soil loss at catchment scale.

Diversity and Functional Potential of Soil Bacterial Communities in Different Types of Farmland Shelterbelts in Mid-Western Heilongjiang, China

The diversity and function of surface soil bacterial community in farmland shelterbelts of five forest types and one abandoned wilderness area were analyzed by collecting 36 soil samples at depths of 0–10 cm (the upper soil layer) and 10–20 cm (the lower soil layer), extracting DNA from the samples and amplifying and sequencing the bacterial 16S rDNA V3~V4 region. Dominant bacterial phyla in forest soils included the Actinomycetes, Proteobacteria, Acidobacteria, Chlorobacteria, and Bacillus. The number of unique bacterial OTUs (operational taxonomic units) was higher in the upper versus lower soil layer and greater in the abandoned cropland than in the shelterbelts. The number of total bacterial OTUs was highest in the mixed Pinus sylvestris var. mongholica Litv. and Larix gmelinii (Rupr.) Kuzen. forest. At the phyla level, Actinomycetes showed the greatest variation in abundance among forest types, while at the genus level, Actinoplanes varied most among forest types in the upper soil layer and Krasilnikovia varied most in the lower soil layer. Soil bacteria were more strongly correlated and more intense competition in the upper soil layer than in the lower soil layer; Actinoplanes and Krasilnikovia were key genera in bacterial networks. Functional predictions for bacterial community genes indicated that soil fertility potential was strong in the mixed Fraxinus mandshurica Rupr. and Larix gmelinii (Rupr.) Kuzen. forest, weak in the mixed Pinus sylvestris var. mongholica Litv. and Larix gmelinii (Rupr.) Kuzen. forest, and in the Populus×xiaohei forest, and intermediate in the Larix gmelinii (Rupr.) Kuzen. and Pinus sylvestris var. mongholica Litv. forests. This study provides a new theoretical basis for the sustainable management of soil fertility in the agroforestry system.

我国沿海防护林优化配置模式划分探讨—以浙江省沿海防护林为例

沿海防护林是有生命的生态基础设施，是沿海防灾减灾体系的重要组成部分，是老百姓的“救命树”。文中根据森林的生态、经济、景观、社会四大效益和健康森林理论，以及浙江省沿海防护林建设的实践，为有利于沿海防护林设防，提出将我国沿海防护林按“三道防线”布局和分类，分为消浪林带、基干林带(第一道防线)，通道防护林、农田防护林、村镇防护林(第二道防线)，山地丘陵防护林(第三道防线)等6种二级林种，在此基础上，再细分为24种优化配置模式，即基干林带分生态式、景观式、生态景观式和生态经济式等4种，消浪林带分纯林式、混交式等2种模式，通道防护林分生态式、生态景观式、生态文化景观式、树圃景观兼用式、绿道式、隔离林带式等6种，农田防护林分农田林网、生态果树兼用式、速生丰产林等3种，村镇防护林分生态式、生态文化式、经济林式、景观式、森林水景式、田园式、混合式等7种，山地丘陵防护林分生态公益林、商品林等2种，并对其主要特征进行论述，以方便建设管理；对各模式示范林带进行例说和佐证，以期引起全社会对沿海防护林建设的重视。 Coastal shelter belt is an important part of the coastal disaster prevention and mitigation system; we call it the living ecological infrastructure and people’s “life-saving trees.” This paper deals with the “three defense lines” classification of costal shelter belts of China to optimize the coastal shelter belt fortification, which bases on the four benefits of ecology, economy, landscape, society and healthy forestry theory of the forest, as well as the experience of the costal shelter belt construction over the past decades of Zhejiang Province. The three defense lines contain six forest-types. The first defense line consists of wave-eliminating forest belt and backbone forest belt. The green channel shelter belt, farmland shelter belt and village shelter belt are the second defense line. The third defense line is hilly and mountainous areas shelter belt. For the further research and optimal configuration, we subdivide the six forest-types into twenty four modes and describe each mode with classic example. The 4 kinds of backbone forest belts: ecological type, landscape type, eco- landscape type and eco-economic type, the 2 kinds of wave-eliminating forest belts: pure forest type and mixed forest type, the 6 kinds of green channel shelter belts: ecological type, eco-land- scape type, eco-cultural landscape type, trees nursery landscape type, green way type and isolated forest type, the 3 kinds of farmland shelter belts: farmland shelter belt type, ecological fruit tree type, fast growing forest type, the 7 kinds of village shelter belts: ecological type, eco-cultural type, economic forestry type, landscape type, forest waterscapes type, garden type, combination type, the 2 kinds of hilly and mountainous areas shelter belts: public good forest belt and commodity forest belt. The study has been started in the hope of arousing more attention of the whole society to the construction of coastal shelter belt.