Shelterbelt Project Research Articles

Divergent changes in microbial communities and nutrients upon forest floor humus layer of the sandy Pinus sylvestris var. mongolica plantation in northeast of China

AbstractThe sandy Pinus sylvestris var. mongolica plantation which is the boundary part of the Three North Shelterbelt Project in Northeast China has been well protected and prohibited disturbance for more than 10 years and thus bring about lots of forest floor litter and then humus layer (complete decomposed aboveground litter and not mixed into surface soil) during this restoration process. While humus layer accumulation could change the interface between litter and soil, its effects on litter and soil, and especially the interaction among them, were still poorly understood. Hence, three different treatments that included remove all forest floor litter and humus, double forest floor litter and humus layer, and retain forest floor litter and humus original (no treatment) were conducted, and the physicochemistry properties and microbial communities were monitored. Results showed that the humus layer increased forest floor litter decomposition rate and its total carbon, total nitrogen, and total phosphorus significantly, while it changed soil pH and nutrients differently and slightly. The abundances of bacterial groups at different taxonomic levels increased while its diversity indexes decreased in litter when the humus layer existed; however, the fungi community both in litter and soil varied insignificantly. The humus layer not only increased remarkably the proportions of common OTUs between humus and litter, humus and soil compared to litter and soil both for fungi and bacteria but also decreased the differences of the number of fungal and bacterial taxa statistics between litter and soil. It implied that the humus layer could play an important role in the recovery process of degraded forest ecosystem.

Poisoned for gold: Assessing the spatial extent of heavy metal contamination within the Tutua-Bura-Angoben Shelter Belt Forest Reserve in Ghana

The Tutua-Bura-Angoben Shelter Belt project in Ghana, aimed at combating desertification and land degradation, faces an unexpected threat from heavy metal contamination. This study investigates the levels and spatial distribution of arsenic (As), lead (Pb), copper (Cu), and zinc (Zn) within the forest reserve, focusing on the implications for environmental health and sustainable development goals (SDGs). Using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), 195 soil samples from the forest reserve were analyzed for heavy metal concentrations. The results reveal significant contamination, with arsenic levels ranging from 3.19 to 138.63 ppm, and an alarming 26 % of the reserve exceeding the 20 ppm threshold for arsenic. Copper, lead, and zinc showed lower contamination levels, with mean concentrations of 13.83 ppm, 7.63 ppm, and 27.53 ppm, respectively. Spatial interpolation using kriging in ArcGIS highlighted localized hotspots of arsenic contamination, primarily influenced by nearby Artisanal Small-Scale Gold Mining (ASGM) activities. The study underscores the urgent need for targeted environmental management strategies, including stricter waste management protocols, sustainable mining practices, and community engagement to mitigate the contamination risks and preserve the ecological integrity of the Tutua-Bura-Angoben Shelter Belt.

Conservation Effectiveness Assessment of the Three Northern Protection Forest Project Area

The Three-North Shelterbelt Project is the largest ecological engineering initiative in China to date, distinguished by its immense scale, extended construction period, and widespread benefits for the population. The gross ecosystem product (GEP) serves as a crucial indicator for assessing ecological benefits. This study focuses on the Three Northern Protection Forest Project Area, utilizing GEP calculations for the years 2000 to 2020. This study evaluates variations in the production values of different ecosystem services to reflect the ecological conservation benefits of the restoration project. Additionally, it analyzes the spatiotemporal evolution and trends of the GEP calculations, offering data references and decision support for the enduring efficacy of ecological restoration projects. The findings are as follows. (i) Between 2000 and 2020, the GEP of the Three-North region exhibited significant growth with continuous enhancement of various ecosystem service functions; the most substantial rate of change was observed in the water conservation function, followed by carbon sequestration and oxygen release, soil retention, windbreak and sand fixation, flood regulation, and environmental purification functions. (ii) The per-unit area value of different ecosystem types generally increased; the forest ecosystem displayed the largest growth rate at 61.18%, followed by shrubland ecosystems at 49.84%. (iii) The spatial distribution of ecosystem service in the Three-North region displayed a clustering trend alongside notable spatial heterogeneity. High-high clustering zones were identified in areas such as the Tianshan Mountains, Altai Mountains, Qilian Mountains, and Greater and Lesser Khingan Mountains. Conversely, low-low clustering areas were scattered, forming patchy distributions in regions like the Tarim Basin, northern Qinghai-Tibet Plateau, and the Hexi Corridor. This study, by analyzing the gross ecosystem product of the Three-North Shelterbelt Project region, unveils the spatial distribution characteristics, trends, and variations in ecosystem service values over the past two decades. It provides data support and decision guidance for the long-term efficacy of future ecological conservation and restoration projects. This study incorporates the GEP accounting method into the assessment of the effectiveness of major conservation projects. Compared to the traditional methods of effectiveness assessment, this represents a significant exploration and innovation.

Age Identification of Farmland Shelterbelt Using Growth Pattern Based on Landsat Time Series Images

Farmland shelterbelt, as a category of shelterbelt in forestry ecological engineering, has an important influence on agricultural sustainability in agricultural systems. Timely and accurate acquisition of farmland shelterbelt age is not only essential to understanding their shelter effects but also directly relates to the adjustment of subsequent shelterbelt projects. In this study, we developed an age identification method using growth pattern to extract the age of shelterbelt (i.e., years after planting) based on Landsat time series images. This method was applied to a typical area of shelterbelt construction in the north of Changchun, China. The results indicated that the accuracy of age identification reached a stable situation when the permissible age error exceeded 3 years, achieving an accuracy of approximately 90%. Moreover, the accuracy at different growth phases (1–3 years, 4–15 years, 16–30 years, and >30 years) decreased with increasing age, and the accuracy of each growth phase can reach more than 80% when the permissible age error is beyond 7 years. Compared to building the typically weak statistical relationship between the shelterbelt age and remote sensing characteristic information to derive age, this method presented a direct age identification method for fine-scale age extraction of the shelterbelt. It introduced a novel perspective for shelterbelt age identification and the assessment of shelterbelt project advancement on the regional scale.

Determinants and consequences of large-scale tree plantation projects: Evidence from the Great Plains Shelterbelt Project

This paper examines the determinants and consequences of the adoption of large- scale tree plantation projects on farmland using the experience of the Great Plains Shelterbelt Project in the late 1930s. I show how agricultural market pressure influenced the decision to plant shelterbelt trees on the cropland and how soil erosion has changed in the long run because of the large-scale tree plantation. I compile a primary database on shelterbelt adoption from the archives and use a difference- in-difference model to study the determinants of the county-level adoption rate. The main finding is that an increase in the market crop price reduces the adoption of shelterbelt trees. Agricultural factors such as tenancy, access to irrigation, and duration of the agricultural contract explain the variations in the decision process. I use an instrumental variable technique to study the persistent effects of the plantation project in the long run. I show that shelterbelt adoption in the 1930s decreases wind erosion even in the 2000s and that the effect is concentrated in pasture areas.

Reconstruction of Forest and Grassland Cover for the Conterminous United States from 1000 AD to 2000 AD

Spatially explicit reconstruction of historical land cover change is a prerequisite for a more comprehensive understanding of environmental changes. Anthropogenic activities have dramatically altered the land cover of the conterminous United States (CONUS), encroaching heavily on the primary vegetation. However, few datasets exist that depict the historical trajectory of forest and grassland cover changes in CONUS over the last millennium, and previous efforts have only focused on reconstructions for the last four centuries. By integrating remote sensing-derived land use/cover change (LUCC) data and potential vegetation data, we determined the potential extent of natural forest (PENF) and grassland (PENG) in CONUS. Based on a qualitative analysis of the trends and driving forces of forest and grassland changes, we devised a method of subtracting reconstructed historical cropland (1000–2000 AD) and built-up land (1850–2000 AD) from PENG and PENF to reconstruct a 5 min × 5 min grid dataset of forest and grassland cover at 13 time-points over the past millennium. The results showed that forest and grassland cover in CONUS underwent a slow decline (1000–1600 AD), an accelerated decline (1600–1800 AD), a dramatic decline (1800–1950 AD), and finally, a recovery (1950–2000 AD) over the study period. The modelled forest fraction decreased from 49% in 1000 AD to 33% in 2000 AD, representing a 32% area reduction, whereas the modelled grassland fraction decreased from 37% to 22%, representing a 42% area reduction. The reduction occurred primarily in the last 200 years, with forest and grassland reductions accounting for 86% and 97% of the total reduction over the millennium, respectively. Spatially, more than 80% of the land was originally covered by forests and grasslands, and the loss occurred mainly in the eastern CONUS and Great Plains over the past millennium. After the 1930s, farmland abandonment began in central and eastern CONUS, simultaneously with environmental protection laws. Federal government regeneration programs for forest and grassland resources and the Shelterbelt Project all contributed to a slowdown in forest and grassland decline and recovery in cover.

Spatio-Temporal Evolution of the Ecological Environment in a Typical Semi-Arid Region of Northeast China

Increasing trends of groundwater and soil salinization, as well as desertification, is characteristic of many arid and semi-arid regions under climatic and anthropogenic influences. This has led to the implementation of management strategies to protect the ecological environment. Changling County in Northeast China is a typical semi-arid area that has experienced these changes. Thus, management strategies such as the “Three North Shelterbelt Project” which involves planting trees to reduce wind speed and halt desertification, and the Changling local alkaline land restoration project, from the year 2000, involving fencing of grasslands have been implemented in the area. Premised on the dynamic nature of the ecological environmental problems, this study was undertaken to assess the spatio-temporal evolution of the ecological environment using hydro-geochemical, spatial, remote sensing, and statistical techniques from the year 2001 to 2019. It was found that groundwater salinity was stable within the period due to groundwater exploitation that declined depth to groundwater table (DWT) thus reducing the impact of evaporation concentration of salts in groundwater. Salinized land area increased by about 6706 ha at a rate of 0.06%/year as a result of the reduction in the size of water bodies and swampland as the declining water table exposed shallow water to more evaporation. The effect of the conversion of water bodies and swamplands to salinized land is believed to overshadow the climatic influence of decreased evaporation-precipitation ratio that normally decreases soil salinization. Most of the study area was stable in terms of desertification (98.22%, 56,3497 ha) as significantly degraded lands covered only 0.03% (148 ha) of the area while 1.67% (9556 ha) had significantly increased vegetation, respectively. Precipitation had an insignificant relationship with desertification with irrigation believed to be the main driver of significant vegetation improvement. Water-saving irrigation practices and the growing of salt-tolerant or semi-tolerant crop species are recommended to maximize food production while stemming the environmental degradation trend due to declining DWT.

Improved Vegetation Ecological Quality of the Three-North Shelterbelt Project Region of China during 2000–2020 as Evidenced from Multiple Remotely Sensed Indicators

Evaluation of the long-term effect of ecosystem recovery projects is critical for future ecological management and sustainable development. The Three-North Shelterbelt (TNS) is a large-scale afforestation project in a crucial region of China. Numerous researchers have evaluated the vegetation ecological quality (VEQ) of the TNS using a single vegetation indicator. However, vegetation ecosystems are complex and need to be evaluated through various indicators. We constructed the vegetation ecological quality index (VEQI) by downscaling net primary productivity, leaf area index, fractional vegetation cover, land surface temperature, vegetation moisture, and water use efficiency of vegetation. The spatiotemporal characteristics and main contributing factors of VEQ in the TNS from 2000 to 2020 were investigated using SEN+Mann−Kendall, Hurst exponent, geographical detector, and residual trend analysis testing. The results suggest that VEQ in the TNS showed an improving trend over the 21-year study period. The areas with significant improvements were concentrated in the central and eastern parts of the TNS. Significant deterioration occurred only sporadically in various urban areas. Characteristics of future unsustainable VEQ trends could be detected across the TNS. Precipitation, vegetation type, soil type, elevation, and solar radiation exhibited the greatest impact on VEQ throughout the TNS. Human activities (e.g., afforestation and government investments) were the dominant factors and had a relative contribution of 65.24% to vegetation area change. Our results provide clues for assessing environmental recovery and sustainable development in other regions.

Radial and seasonal variation of sap flow and its response to meteorological factors in sandy Pinus sylvestris var. mongolica plantations in the Three North Shelterbelt of China

Mongolian Scots pine (Pinus sylvestris var. mongolica) is one of the main afforestation tree species in the Three North shelterbelt project in China, and an accurate estimation of its transpiration is of importance for plantation scientific density management especially under future climate change scenarios. While radial variation in tree species sap flow is an important factor for estimating transpiration, it is usually neglected. Thus, this study selected Mongolian Scots pine of different ages (10a, 20a, 30a, 40a) to study its radial variation pattern of sap flow using the multipoint (probes of different specifications) thermal dissipation method; additionally, its response characteristics to meteorological factors in northeast China were also discussed. The results show that the radial distribution of the sap flux density varied with age and growing season. It gradually decreased from the outside to the inside of the sapwood of the 10a stand. In contrast, the sap flux densities of the 20a, 30a and 40a stands had all typical single-peak patterns, with the highest value at 15 mm from the outside of the sapwood, and then sharply decreased with increasing distance. The sap flux density in both the 10a and 20a stands slightly changed, while it a significantly change in both the 30a and 40a stands between the middle and end of the growing season occurred. Further estimation of transpiration by single point and multipoint analyses was undertaken. The single point analysis resulted in large errors of -18.81%-11.02%, -52.44%-133.47%, -10.26%-130.38% and -48.78%-162.11% in the 10a, 20a, 30a and 40a stands, respectively. However, Js15mm was significantly correlated with the mean sap flux density of a sapwood area (Jsmean) and exhibited a constant conversion coefficient. The sap flux densities of separate sapwood depths were significantly affected by meteorological factors and varied according to different meteorological factors.

The Optimum Calcium Concentration for Seedling Growth of Mongolian Pine (Pinus Sylvestris Var. Mongolica) Under Different Soil Types in Northern Semi-Arid Areas of China

Mongolian pine, as one of the major tree species of the Three-North Shelterbelt Project in the northern semiarid region of China, is very important for ensuring ecological and environmental security. Ca, as an imperative mineral element for plant development and a second messenger, partakes in photosynthesis and affects the growth of plants. However, the optimal calcium concentration for its growth in different soil types is still unclear. In this study, fifteen treatments with combinations of three different soils (e.g., sandy soil, cinnamon soil, dark brown soil) and five calcium concentration gradients (e.g., 0, 100, 200, 400, and 800 mg∙kg-1) were conducted to investigate this effect by measuring the indices of growth, biomass, photosynthetic pigment, gas exchange rate, photosynthates, chlorophyll fluorescence parameters and water use efficiency (iWUE) based on a pot experiment. The results showed that the optimal calcium concentration of Mongolian pine seedlings in sandy soil and cinnamon soil was 0–100 mg∙kg-1, and the optimal calcium concentration of Mongolian pine seedlings in dark brown soil was 100–200 mg∙kg-1. In other words, the results showed that there was an optimal calcium concentration for the growth of Mongolian pine seedlings, and the optimal calcium concentration was different under different soil types. And if the calcium concentration in the soil was too high, it would have an inhibitory effect on Mongolian pine seedlings, low calcium concentration maybe don’t work. The addition of an appropriate amount of exogenous calcium could promote the growth of Mongolian pine seedlings in different soil types. The plant height, basal diameter and biomass of Mongolian pine seedlings all increased significantly after applying an appropriate amount of calcium (p < 0.05); the addition of an appropriate amount of exogenous calcium could promote the photosynthetic characteristics of Mongolian pine seedlings in different soil types. Under sandy soil and cinnamon soil, the peaks for Pn, Gs, Tr, accumulation of soluble sugar and starch of Mongolian pine seedlings occurred at 0–100 mg∙kg-1, and the decreasing trend of the Fv/Fm value was significant in the case of exceeding 200 mg∙kg-1 (p < 0.05), indicating that the growth of Mongolian pine seedlings was affected when calcium concentrations higher than 200 mg∙kg-1 were applied. Moreover, under dark brown soil, the peaks for Pn, Gs, Tr, and accumulation of soluble sugar and starch of Mongolian pine seedlings occurred at 100–200 mg∙kg-1; similarly, the growth of Mongolian pine seedlings was affected when calcium concentrations higher than 200 mg∙kg-1 were applied. Compared with the treatment without calcium, after applying an appropriate amount of exogenous calcium, the water use efficiency of Mongolian pine seedlings in different soil types was significantly improved, though it was significantly reduced at 800 mg∙kg-1 (p < 0.05).

黄河流域内蒙古段植被时空变化特征及条带状分布成因

PDF HTML阅读 XML下载 导出引用 引用提醒 黄河流域内蒙古段植被时空变化特征及条带状分布成因 DOI: 10.5846/stxb202110112851 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 内蒙古自治区科技重大专项（2020ZD0009）；国家自然科学基金面上项目（41971232） Spatio-temporal variations and strip patterns of vegetation in the Inner Mongolia of Yellow River Basin Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:监测干旱、半干旱地区植被覆盖度的动态变化，评估大尺度区域地质背景，尤其是活动构造在植被变化过程中发挥的作用对植被时空格局的认识具有重要意义。黄河流域内蒙古段地处干旱半干旱区，植被多依赖于地下水；且该地区活动构造较发育，是认识植被非地带性特征的理想区域。基于中分辨率成像光谱仪（MODIS）、归一化植被指数（NDVI）、气象与土地利用数据，对2000-2018年黄河流域内蒙古段植被覆盖度（FVC）的时空变化及稳定性进行分析，在此基础上针对河套段植被条带状特征及其成因进行讨论。结果表明，近20年研究区的FVC总体表现为增加趋势。降雨增加是大黑河流域、浑河流域及十大孔兑区域FVC增加的主要原因，沙漠地区FVC的增加得益于三北防护林工程建设。大黑河与浑河流域水分条件较好，物种多样性丰富，植被覆盖度高，能较好的抵御气候变化；而十大孔兑区域和沙漠地区FVC较低，生态系统脆弱，对气候波动的响应较大。河套灌区受人类活动主导，对气候变化的敏感性较低。河套段山前植被赋存环境为条带状地下水溢出带，在地下水储量增多条件下呈条带状增加趋势；而在山前过渡带，新构造运动及其造成的较大地表高差使得土壤层薄且储水能力较差，表现为FVC的高波动。现今黄河干流沿岸植被受土地利用转变影响整体减少；且在河流摆动、河道变迁扰动下，稳定性较差。河套盆地与鄂尔多斯台地边界处，受隐伏断裂和地震活动影响，地下水易沿带状透水断裂下渗，难以维持浅表水分和稳定的补给条件，使得FVC呈线状显著降低，且稳定性较差。研究从宏观水文地质条件和地表过程的角度，更加深入认识了植被空间分布的非地带性特征，为相似地区的研究提供了较好的科学依据。 Abstract:It is of great significance to monitor the variations of fractional vegetation cover (FVC) and assess the impact of large-scale geological sets, especially the active tectonics on vegetation variability for a deep understanding of the spatio-temporal pattern of ecosystem. The Inner Mongolia section of the Yellow River Basin belongs to arid and semi-arid areas, where the vegetation is mostly dependent on groundwater and the active tectonics are frequent, so it is an ideal area for understanding the azonal characteristics of vegetation. Based on MODIS NDVI (Normalized Difference Vegetation Index), meteorological and land-use data, this paper analyzed the spatio-temporal variation and stability of FVC in the Yellow River Basin (Inner Mongolia section) from 2000 to 2018 and further explored the reasons for strip distribution of vegetation. The results showed an increasing trend of FVC in the past 20 years. The increase in rainfall was the main reason for the increased FVC in the Dahei River Basin, Hun River Basin, and Ten Kongdui Basin. The Three-North Shelterbelt Project contributed to increased FVC in the desert regions. Dahei River Basin and Hun River Basin had better water conditions and rich biodiversity with high FVC, helping to resist external disturbances. In contrast, the Ten Kongdui areas and deserts with lower FVC and fragile ecosystems were more sensitive to climate fluctuations. Hetao irrigation area is dominated by human activities, characterized by weak sensitivity of FVC to climate change. The vegetation grows along the groundwater overflow belt in the piedmont zone of Hetao. It increases as the groundwater storage increases. Over the piedmont transition zone, the soil layer is thin and its water storage capacity is poor due to large surface height difference caused by neotectonic movement, manifested as the high fluctuation of FVC. The vegetation along the mainstream of the Yellow River reduced due to land-use change and its stability was poor under the disturbance of river oscillation and channel migration. At the boundary between the Hetao Basin and the Ordos platform, groundwater tends to infiltrate along the permeable faults forced by seismic activities, which makes it difficult to maintain shallow water and stable recharge conditions, thus resulting in a significant linear decrease of FVC and poor stability. This study highlights the role of macroscopic geological background (i.e., hydrogeological conditions and surface processes) on vegetation pattern and has a deep insight into the azonal characteristics of vegetation, which provides a better scientific basis for similar studies. 参考文献 相似文献 引证文献

Suggestions for Revegetation over the Next 30 Years Based on Precipitation in the Three North Region of China

Afforestation in the Three North Region (TNR) of China has received wide concern due to the low survival rate and threats to water security associated with the lack of available precipitation for vegetation. It is crucial to provide a spatial layout for revegetation according to the available precipitation to achieve the vegetation cover target. This study investigated the spatial pattern of precipitation, determined the suitable vegetation distribution based on the ecological water requirements and precipitation, and proposed an optimized revegetation scheme by comparing the actual and suitable vegetation patterns. The results indicated that the actual vegetation that matched the pixel-level precipitation accounted for 67.24% of the total vegetation area in the TNR. However, 18.50% of the actual forest, 21.82% of the actual shrublands, and 19.95% of the actual grasslands were overloaded with respect to precipitation. The total suitable vegetation area was reduced slightly compared to the actual vegetation area. There is still some potential for the revegetation of forest and shrublands, mainly those in the eastern and south-eastern parts of the TNR. The optimized revegetation area in the TNR was 3.04 × 106 km2, including a maintenance management type of 2.19 × 106 km2, an upgrade type of 0.49 × 106 km2, and a degradation type of 0.37 × 106 km2. Maintenance management (natural restoration) and transformation to vegetation types with lower ecological water requirements were recognized as important revegetation practices in the TNR. This study provides guidelines to adjust the Three North Shelterbelt Project policies based on precipitation data to reduce the negative impact of revegetation on the hydrological cycle.

Protecting the Breadbasket with Trees? The Effect of the Great Plains Shelterbelt Project on Agriculture

Protecting the Breadbasket with Trees? The Effect of the Great Plains Shelterbelt Project on Agriculture

Protecting the Breadbasket with Trees? The Effect of the Great Plains Shelterbelt Project on Agriculture

Wind erosion is detrimental to agriculture. Planting shelterbelt trees is a common strategy to protect vulnerable areas. I estimate the impact of shelterbelts on agriculture while instrumenting the endogeneity of planted location with a designated zone under the Great Plains Shelterbelt Project—a massive tree-planting operation implemented in 1935–1942. I find a shift from cropland to pasture associated with higher shelterbelt coverage due to differential productivity changes in livestock and crop production. The revenue increase from livestock was contributed by cattle, while the decline in crop production mainly occurred in western counties owing to obstacles to adopting new irrigation technology.

An ecohydrological perspective of reconstructed vegetation in the semi-arid region in drought seasons

Desertification has long seriously threatened the ecological security of northern China, for which China has established the world's largest shelterbelt project. After 40 years of reconstruction of vegetation, the trend of desertification in northern China has been reversed. The shelterbelt forest project in northern China, however, at the same time, tells signs of degradation, and therefore its effectiveness has been questioned by scientists from various countries. In order to study the impact of the vegetation reconstruction process in the semi-arid area on the precipitation water redistribution process in this area, and how the reconstructed vegetation survives in dry season. This study selected the reconstruction Pinus sylvestris var. Mongolica (PSM) forest on Mu Us sandy land as the research object, and used new lysimeters, stem flow meters, miniature weather stations, etc. to monitor the deep soil water penetration, stem flux. The purpose of this current study is to find out how PSM forest changed the process of precipitation water redistribution in this area, and how PSM adjusts its own water storage capacity to adapt to the annual precipitation changes. In wet years such as 2017, DSR is only 0.4 mm, soil water storage is reduced by 16 mm, and evapotranspiration is 324.6 mm. In a wet year such as 2016, the DSR is 1.4 mm, the soil water storage is enlarged by 38.06 mm, and the evapotranspiration is 466.94 mm. The results showed that the water consumption of PSM in Mu Us area and the precipitation water replenishment in this area reached a balance but blocked precipitation to recharge deep soil water and groundwater. The rain-fed PSM stem can be used as a reservoir unit to supply water consumption and adjusting the evapotranspiration intensity to adapt to changes in annual precipitation. This research has advanced our understanding of the scale of reconstruction vegetation utilization of precipitation and the utilization mechanism of tree stem storage water in semi-arid areas.

Vegetation dynamics and their effects on surface water-energy balance over the Three-North Region of China

The Three-North Shelterbelt Project (TNSP) is one of the largest ecological restoration projects of the world. Although its important role in regulating the ecosystem of northern China has been acknowledged, how this project affects the surface water-energy balance deserves further evaluation. This study characterizes spatiotemporal variation of climate variables and vegetation coverage/density over the Three-North Region (TNR) of China using multiple datasets since the implementation of the TNSP. Of particular importance is that effects of vegetation restored during the TNSP on surface water-energy budget are examined for the study domain. Our results show that accompanied by a significant enhancement of vegetation coverage and density in the TNR, its annual air temperature and precipitation have increased 1.46 °C and 89.1 mm, respectively from 1982 to 2015. We find such rise in the air temperature and precipitation plays a positive role in the TNR’s vegetation restoration in a sense that the vegetation dynamics show positive correlation with its regional air temperature and precipitation, while more sensitive to precipitation. We also find carbon sequestration of the TNR increases at the cost of greater water consumption through evapotranspiration since the TNSP commences. In some arid regions, revegetation accelerates the water deficit due to an excessive rate of restoring vegetation; yet, no substantial water imbalance occurs as a result of enhanced precipitation and water use efficiency during this period. Although the solar radiation increases with decreases in surface albedo over the last few decades, our results do not reveal an appreciably increasing trend in the land surface temperature of the TNR. This is because the improved vegetation can assimilate CO2 (mitigating greenhouse gas emissions) and transpire water by photosynthesis, thereby increasing latent heat flux and reducing the warming effect. This study highlights a mixed consequence of the TNSP by inducing both positive and negative effects on the surface water-energy balance over the TNR.

落叶松、水曲柳、樟子松和农田土壤指标差异及其综合比较

PDF HTML阅读 XML下载 导出引用 引用提醒 落叶松、水曲柳、樟子松和农田土壤指标差异及其综合比较 DOI: 10.5846/stxb201603080412 作者: 作者单位: 东北林业大学，森林植物生态学教育部重点实验室,东北林业大学，森林植物生态学教育部重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 国家"十三五"重点研发项目（2016YFA0600802）；黑龙江省杰出青年基金（JC201401）；中央高校创新团队与重大项目培育资金项目（2572014EA01）；国家自然基金资助项目（41373075） Larch, ash, Scots pine, and farmland-induced differences on 17 soil parameters and their comprehensive analyses Author: Affiliation: Key Laboratory of Forest Plant Ecology Ministry of Education, Northeast Forestry University,Key Laboratory of Forest Plant Ecology Ministry of Education, Northeast Forestry University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:东北地区以大森林和大农业为主要特色，主要造林树种落叶松、水曲柳、樟子松及农田对土壤肥力、物理指标、盐碱度、碳截获等的影响差异是本文研究目的。选择秀水林场和帽儿山林场的4种植被类型进行0-60cm分层土壤采样，对根系密度、土壤pH、电导率、全氮、全磷、全钾、碱解氮、速效磷、速效钾、土壤真菌代谢产物（球囊霉素相关蛋白易提取球囊霉素EEG、总提取球囊霉素TG）、容重、比重、孔隙度、比表面积、SOC、有机碳矿化速率等17个指标进行研究。主要结论如下：植被类型间的差异在不同土层之间表现一致的指标所占比例很大，其中秀水林场13个指标，帽儿山林场全部17个指标。尽管不同地点间土壤差异较大，但也存在树种差异一致性。土壤物理性质（容重、比重、孔隙度、比表面积）维持方面，两个林场均显示水曲柳综合得分最高，说明其具有更好的土壤物理性质维持能力，且多通过土壤容重下降来实现。土壤固碳能力得分最高的也是水曲柳，并且两个研究地点结果类似，主要与其高根系密度有关。综合土壤肥力维持能力（N、P、K及其有效态及真菌代谢产物球囊霉素相关蛋白），不同地点间植被类型差异排序不同。降低土壤盐碱能力（pH和电导率）方面，樟子松得分最高，尽管不同地点不尽一致。不同植被类型对土壤影响尽管不同地点、不同土壤深度多不相同，但总体上存在规律性，特别是土壤物理性质维持和土壤固碳能力方面。进行造林绿化时应该根据造林目的进行树种选择，提升土壤物理性质应该考虑种植更能够维持良好土壤物理性质的树种（如水曲柳、樟子松等），而提升土壤碳截获则要考虑根系密度大的树种（如水曲柳）。相关研究结果对国家重大生态工程（三北防护林、退耕还林）工程生态功能评价以及后续管理、树种选择具有支撑作用。 Abstract:The main characteristics of Northeast China are large forests and agriculture. The effect of the primary afforestation species (larch: Larix gmelinii, ash: Fraxinus mandschurica, Scots pine: Pinus sylvestris var. mongolica) and farmland on soil fertility, physical properties, salinity, and carbon sequestration were analyzed. In the present study, four vegetation types were selected from Xiushui Forest and Maoershan Forest Farms, and samples from 0–60 cm soils were collected for measuring 17 parameters, including root density, soil pH, electrical conductance(EC), alkali-hydrolyzed nitrogen(AN), total nitrogen(TN), available phosphorus(AP), total phosphorus(TP), available potassium(AK), total potassium(TK), glomalin related soil protein (GRSP) (including easily extracted GRSP (EEG) and total GRSP (TG)), soil bulk density, soil specific gravity, soil porosity, soil specific surface area, soil organic carbon(SOC), and organic carbon mineralization rate. The main conclusions were as follows: inter-species differences between most of the measured indicators were consistent in different soil layers, including 13 indicators in the Xiushui Forest Farm and all 17 indicators in the Maoershan Forest Farm samples. Although there were considerable differences in soil between different locations, the inter-species differences were consistent. Through comprehensive analyses, standardized comprehensive scores of two forest farm-related indicators showed that ash had the highest scores regarding its ability to maintain the physical properties of soil. Therefore, ash had the greatest ability of all the trees and farmland to maintain the physical properties of soil, and depended primarily on decreased soil bulk density. Ash also showed the highest scores for soil carbon sequestration, with similar results at both locations, mainly related to its higher root density. The comprehensive soil fertility (N, P, K, and its effective state, and fungal metabolic product GRSP) indicated inter-species differences between the different locations. Scots pine had the highest scores for reducing the soil salinity (pH and EC). The effects of different vegetation types on the soil were not the same in different locations and soil depths, but there was a general regularity, especially regarding the soil physical properties and carbon sequestration. Therefore, the selection of tree species for afforestation should be planned depending on the particular purpose of afforestation. To improve the physical properties of soil, plant species with the ability to maintain the physical properties effectively (e.g.,ash, Scots pine) should be considered; and to enhance soil carbon sequestration, plant species with large root densities (e.g., ash) should be considered. The findings in this paper will enhance the evaluation of the national ecological projects of the Three-North Shelterbelt Project and Returning Farmland to Forest Project, and forest management including tree species selections. 参考文献 相似文献 引证文献

咸水滴灌下塔里木沙漠公路防护林土壤生化作用强度及微生物生态特征

PDF HTML阅读 XML下载 导出引用 引用提醒 咸水滴灌下塔里木沙漠公路防护林土壤生化作用强度及微生物生态特征 DOI: 10.5846/stxb201606131142 作者: 作者单位: 中国科学院新疆生态与地理研究所,中国科学院新疆生态与地理研究所,中国科学院新疆生态与地理研究所,中国科学院新疆生态与地理研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（41571498） Biochemical intensity and microbial eco-characterization of soils irrigated with saline water from the Tarim Desert Highway shelter-belt Author: Affiliation: Xinjiang Institute of Ecology and Geography,CAS,Xinjiang Institute of Ecology and Geography,CAS,Xinjiang Institute of Ecology and Geography,CAS,Xinjiang Institute of Ecology and Geography,CAS Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:土壤生化作用强度是表征土壤生物学活性的重要指标。选择传统研究方法，从氨化作用、硝化作用、固氮作用、纤维素分解、呼吸作用以及酶活性6个方面，揭示了咸水滴灌下塔里木沙漠公路防护林地土壤生化作用强度的分异规律。结果表明，（1）随防护林定植年限的增大，土壤氨化作用、固氮作用、纤维素分解和呼吸作用的强度均明显增强，其中氨化作用和呼吸作用变化尤为明显；而硝化作用强度有所减弱。（2）0-50 cm土体内，随土壤深度增大，生化作用强度提高，氨化作用、硝化作用、固氮作用、纤维素分解和呼吸作用强度的垂直差异均达极显著水平（F > F0.01）。（3）随防护林定植年限的增大，不同土壤酶活性的变化各异，其中，过氧化氢酶活性显著增大（F > F0.01），纤维素酶和蔗糖酶的活性明显提高（F > F0.05），而蛋白酶、磷酸酶和脲酶的活性变化不大（F < F0.05）。（4）回归分析表明，不同生化强度因子与土壤环境因子的最优回归方程不同，但决定系数均大于0.95；全盐、全氮和速效氮进入了所有回归方程，是决定塔里木沙漠公路防护林地土壤生化强度的关键土壤环境因子。因此，咸水滴灌条件下，塔克拉玛干沙漠腹地防护林土壤生化作用强度不断提高的趋势，这对于防护林工程的科学管理有重要指示意义。 Abstract:Biochemical intensity of soil is an important index for characterizing biological activity. In this study, traditional research methods were employed to determine the soil biochemical characteristics of the Tarim Desert Highway shelter-belt from six aspects, including ammonification, nitrification, azotification, cellulose decomposition, respiration, and enzymatic activity. The main experimental results were as follows:(1) With increasing years since planting, ammonification and respiration showed the greatest improvements; azotification and cellulose decomposition also showed significant improvements, but nitrification was weakened. (2) Vertical differences in ammonification, nitrification, azotification, cellulose decomposition, and respiration in the 0-50 cm soil layer reached highly significant levels (F > F0.01), and biochemical activity of the soil increased with depth. (3) As years since planting increased, catalase activity showed the greatest increase (F > F0.01), cellulose and invertase activity also significantly increased (F > F0.05), and protease, phosphatase, and urease activity only minimally increased (F < F0.05). (4) The optimal regression equations between different biochemical intensity factors and soil environmental factors differed, but the regression determination coefficients were > 0.95. Total salt, total nitrogen, and available nitrogen were included in all of the regression equations and were key factors in the determination of biochemical intensity of the soil in the Tarim Desert Highway shelter-belt. Therefore, in the hinterland of the Taklamakan Desert, biochemical intensity of soils from the shelter-belt lands that were drip-irrigated with saline water exhibited an increasing trend. This knowledge will aid in the scientific management of the shelter-belt project. 参考文献 相似文献 引证文献

Responses of Ecosystem Service to Land Use Change in Qinghai Province

Qinghai Province has a very fragile ecological environment and is an important component of the Qinghai-Tibet Plateau. To understand the disturbance caused by human activities to the local ecological system, it is necessary to evaluate the response of ecological service functions to land use change in Qinghai Province and to uncover the sensitivity of ecological service functions to land use change. This study uses a proxy-based method and proposes a sensitivity index to describe the degree of ecological service function response to the land use change in Qinghai Province. The findings were as follows. (1) From 1988 to 2008, the area of cultivated land, construction land and water in Qinghai Province increased, and forest land and grassland continuously decreased. The agricultural economy and the development of urbanization are the main driving factors in land use change in this area. Policies and eco-environmental engineering, such as the grain-for-green project, the Three-North shelterbelt project and the natural forest protection project, have certain effects on controlling the expansion of cultivated land. (2) The value of ecosystem services in Qinghai Province was 157.368 billion yuan, 157.149 billion yuan and 157.726 billion yuan in 1988, 2000 and 2008, respectively, decreasing and then increasing again. (3) The average sensitivity index values of ecological services in Qinghai Province for the periods 1988–2000 and 2000–2008 was 0.693 and 1.137, respectively. This means that for every 1% increase in land use change, the ecological service value fluctuated by 0.693% and 1.137% in those periods.

The politics of greening practice in contemporary rural China: a case study of Yang Village

This article takes Yang Village as a case to analysis what the specific implementation of the Three-North Shelterbelt Project is like. This village leader Laoyang gets afforestation projects through chasing project and mobilizes all the villagers by the method of economic benefits. While these afforestation projects promoted Yang Village economic income, it also ruins its local traditional pattern of production and living such as raising sheep. The study found the following conclusions: 1）Economy supremacy ideology plays a dual role. Not only does this strategy redirect the publics’ attention from environmental protection on to economic development, it also mobilizes the public’s will power to participate in such afforestation project. 2) Traditional rural culture and local production practice plays a subtle role in the designing and implementation process of environmental policies, projects and regulations. Keywords: environment, afforestation, The Three-North Shelterbelt Project, chase project, rural society, economy supremacy