Sandy Land Research Articles

Effect of Mulching on Growth and Yield of Peanut (Arachis hypogaea L.) on the Coastal Sandy Land in Nghe An Province, Vietnam

Background: Peanut (Arachis hypogaea L.) is one of the oil and cash crops in Vietnam. However, owing to the lack of appropriate management practices, the production and the area under cultivation of peanut have remained low. Mulches are the key factors contributing to promoting crop development and early harvest and increasing yields. Methods: The experiment consisted of three mulch treatments, viz., plastic mulch, straw mulch and no-mulch control. All the treatments were replicated thrice in a complete randomized block design. Result: In the conditions of mulch, the plant growth parameters (germination rate, growing time, plant height, number of branches per plant), leaf area index, the number of nodules per plant, dry matter accumulation, yield components and yield of peanut was much higher than that of no-mulch control. Among the mulches, plastic mulch was found superior to straw mulch in the pod yields and water-use efficiency and moisture conservation, thereby can be considered as a reliable practice for increasing the productivity of peanut on the coastal sandy land in Nghe An province, Vietnam.

Rare soil bacteria are more responsive in desertification restoration than abundant bacteria.

Soil microbes play key roles in ecosystem functions, especially in the recovery of ecosystems from disturbance, and exploring community assembly under changing environments has long been a central theme in microbial ecology. The response of abundant and rare bacteria in desertified land to restoration is still unclear. Here, we investigated the effects of vegetation restoration on the assemblage patterns of abundant and rare bacteria in soil across the four sandy lands (Hulunbeir, Horqin, Otindag, and Mu Us) in northern China. Our results revealed that abundant bacteria maintained a relatively stable state under restoration, whereas rare taxa were more responsive, indicating the higher resilience of the rare community to change. Our network analysis also showed that restoration promoted destabilizing properties in rare, but not in abundant, bacterial co-occurrence networks in soil. Environmental selection played a key role in abundant and rare community assembly under restoration. Of the two, the rare subcommunity was mainly affected by environmental filtering. The variations in the abundant and rare communities at the sampling sites under restoration were controlled mainly by plant species richness, and stronger effects were observed in the rare taxa. Overall, these results provide new insight into the mechanisms controlling bacterial community assembly in response to vegetation restoration.

Leaf Physiological Responses of Three Psammophytes to Combined Effects of Warming and Precipitation Reduction in Horqin Sandy Land, Northeast China.

The decreasing precipitation with global climate warming is the main climatic condition in some sandy grassland ecosystems. The understanding of physiological responses of psammophytes in relation to warming and precipitation is a possible way to estimate the response of plant community stability to climate change. We selected Lespedeza davurica, Artemisia scoparia, and Cleistogenes squarrosa in sandy grassland to examine the effect of a combination of climate warming and decreasing precipitation on relative water content (RWC), chlorophyll, proline, and antioxidant enzyme activities. We found that all experimental treatments have influenced RWC, chlorophyll, proline, and antioxidant enzyme activities of three psammophytes. L. davurica has the highest leaf RWC among the three psammophytes. With the intensification of precipitation reduction, the decreasing amplitude of chlorophyll from three psammophytes was L. davurica > C. squarrosa > A. scoparia. At the natural temperature, the malondialdehyde (MDA) content of the three psammophytes under severe drought treatment was much higher than other treatments, and their increasing degree was as follows: A. scoparia > C. squarrosa > L. davurica. At the same precipitation gradient, the proline of three psammophytes under warming was higher than the natural temperature. The differences in superoxide dismutase (SOD) among the three psammophytes were A. scoparia > L. davurica > C. squarrosa. Moreover, at natural temperature, more than 40% of precipitation reduction was most significant. Regardless of warming or not, the catalase (CAT) activity of A. scoparia under reduced precipitation treatments was higher than natural temperature, while the response of L. davurica was opposite. Correlation analyses evidenced that warming (T) was significant in L. davurica and precipitation (W) was significant in A. scoparia and C. squarrosa according to the Monte-Carlo permutation test (p = 0.002, 0.004, and 0.004). The study is important in predicting how local plants will respond to future climate change and assessing the possible effects of climate change on sandy grassland ecosystems.

Suitability Zoning and Layout Optimization of Forages in Uxin Banner Surrounded by the Mu Us Sandy Land in China

The Mu Us Sandy land is one of the four largest sandy lands in China and the main sources of sand dust in the Beijing-Tianjin area. Uxin Banner, located at the southernmost end of Inner Mongolia Autonomous Region, is surrounded by this sandy land. Nearly one third of the Mu Us sandy land is located in Uxin Banner. Irrational expansion of agricultural land, unordered layout and overgrazing have resulted in the degradation of grassland, which leads to serious ecological problems and makes this area one of the five typical ecological fragile zones in China. Previous studies mostly focused on regional resource carrying capacity and man-land relationship, but few studies were conducted on how to select excellent varieties which are suitable for local resource and environmental background conditions to promote the healthy development of herbage industry. The research methods and conclusions of this paper can make up for this deficiency. Based on GIS and SPSSAU data scientific analysis platform, this paper uses multi-source remote sensing, statistics, surveys and other data to study the suitability zoning of silage planting, comprehensive evaluation of forage varieties, pastoral area industrial planning, etc. The research conclusions and suggestions can promote a high-quality development of agriculture and animal husbandry in Uxin Banner, help farmers and herdsmen to increase income, and provide scientific support for rural revitalization in the new period.

基于SNIC-CNN-SVM模型的京津风沙源二期工程区土地利用/土地覆盖遥感识别研究

PDF HTML阅读 XML下载 导出引用 引用提醒 基于SNIC-CNN-SVM模型的京津风沙源二期工程区土地利用/土地覆盖遥感识别研究 DOI: 10.5846/stxb202109262707 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 中国林业科学研究院院基金重点项目（CAFYBB2019ZB004）；国家高分重大科技专项（21-Y30B02-9001-19/22-3） Remote sensing recognition of land use/land cover in the Beijing-Tianjin sandstorm source region based on SNIC-CNN-SVM model 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:稀疏植被覆盖（草地、沙地、戈壁）演变能够直接表征区域生态环境和人类活动的动态影响变化。但由于大尺度稀疏植被区一般都具有地理跨度大，景观结构复杂多样，破碎化程度高，现有地表覆盖分类产品针对性不足等问题，使得该区域内林草沙的遥感提取难度较大，精度普遍偏低，直接制约生态效应评价模型的应用效果。因此，以典型大尺度稀疏植被区--京津风沙源治理二期工程区为研究区，研建了SNIC-CNN-SVM （SCS）模型，实现了大尺度稀疏植被区林草沙典型要素的信息自动提取和主要土地利用/土地覆盖类型识别。研究结果表明：1）引入惩罚性机制优化后的SNIC分割算法，有效提升了稀疏植被区与沙地区的边界区分度，有助于分类精度的提升；2）基于改进SNIC-CNN-SVM模型方案的研究区总体分类精度达89.41%，较优化前提高了11.17%，特别是乔、灌、草、沙地和戈壁的分类识别精度显著提升，表明该优化方案在以研究区为代表的稀疏植被区域分类中具有较好的应用效果和推广价值；3）分类结果显示，2020年工程区草地面积最大，占到了一半以上（51.52%），沙地占比11.96%，稀疏植被覆盖（草地、沙地、戈壁）区域占比68.68%，表明工程区处在林地-稀疏植被-沙地的过渡地带，生态环境保护压力与防沙治沙形势依然严峻；4）近20年来，乔灌草等植被增加面积约占工程区20.64%，主要由沙化土地转化，沙化土地减少面积约占工程区的4.58%，表明研究区植被状况不断改善，实施的各项生态工程作用显著，能够更有效地服务于多维度生态系统服务功能评价。该研究以期能够为京津风沙源二期工程区的生态系统演变规律研究及生态工程评价等工作提供重要科学支撑。 Abstract:The evolution of sparse vegetation cover (grassland, sandy land, Gobi) can directly characterize the dynamic changes of the regional ecological environment and human activities. However, large-scale sparse vegetation areas generally have large geographic spans, complex and diverse landscape structures, high fragmentation, and insufficient pertinence of existing land cover classification products. These problems make it difficult to extract the forest, grass, and sand in this area by remote sensing, and the accuracy is generally low, which directly restrict the application results of the ecological effect evaluation model. Therefore, this study took the typical large-scale sparse vegetation area, the Beijing-Tianjin sandstorm source region (BTSSR) as the study area, and the SNIC-CNN-SVM (SCS) model is proposed. The forest, grass, sand element information is automatically extracted and the land use/land cover types are identified in the study area. The results show that:1) the SNIC segmentation algorithm was optimized by the penalty mechanism and can effectively increase the boundary discrimination between the sparse vegetation area and the sandy area, which is helpful to improve the classification accuracy; 2) the overall classification accuracy of the optimized model reached 89.41%, which is 11.17% higher than that before optimization, especially the classification and recognition accuracy of trees, shrubs, grasses, sandy land and Gobi is significantly improved, indicating that the optimization model has good application effect and promotion value in the classification of sparse vegetation areas represented by the study area; 3) in 2020, the grassland area in the study area was the largest, accounting for more than half (51.52%), sandy land accounted for 11.96%, and sparse vegetation coverage (grassland, sandy land, Gobi) accounted for 68.68%, indicating that the project area is in the transition zone of woodland-sparse vegetation-sandy land, and the pressure on ecological environment protection and the situation of desertification prevention and control are still severe; 4) in the past 20 years, the increased area of vegetation such as arbor, shrub and grass accounted for about 20.64% of the project, which is mainly derived from desertified land. The reduced area of desertified land accounted for about 4.58% of the project area, indicating that the vegetation conditions in the study area are continuously improving, and the implemented ecological projects have a significant effect. The method in this paper can be more effectively used for multi-dimensional ecosystem service function evaluation. This study is expected to provide important scientific support for the research on the evolution law of the ecosystem and the evaluation of ecological engineering in the BTSSR. 参考文献 相似文献 引证文献

Evolution of Desertification Types on the North Shore of Qinghai Lake

Land desertification is a widely concerned ecological environment problem. Studying the evolution trend of desertification types is of great significance to prevent and control land desertification. In this study, we applied the decision tree classification method, to study the land area and temporal and spatial change law of different types of desertification in the North Bank of Qinghai Lake area from 1987 to 2014, based on the current land use situation and TM remote sensing image data of Haiyan County, Qinghai Province, The results show that the area of mild desertification land and moderate desertification land in the study area has decreased, while the area of severe desertification land and extreme desertification land has increased significantly in the past 30 years. The area of desertification land decreased by 4.02 km2, of which the area of mild and moderate desertification land decreased by 39.73 km2 and 36.8 km2 respectively, and the area of severe and extreme desertification land increased by 32.78 km2 and 39.73 km2 respectively. As for the mutual transformation relationship, the transformation from severe desertification land to extreme desertification land is the main, and the junction of severe desertification land and extreme desertification land is the sensitive area of transformation. In the north shore of Qinghai Lake, the sandy land tends to expand eastward. The research provides reference basis for local land desertification monitoring, and has a great guidance for local effective land desertification and soil and water conservation.

Precipitation and Anthropogenic Activities Jointly Green the China–Mongolia–Russia Economic Corridor

Climate change and anthropogenic activities are widely considered the main factors affecting vegetation growth. However, their relative contributions are under debate. Within the non-climatic impact, detailed human activities, particularly government policy adjustments, are less investigated. In this study, we develop a fractional vegetation coverage (FVC) extraction method based on MODIS-EVI satellite data to analyze the spatiotemporal variation of vegetation and its attributions in the China–Mongolia–Russia Economic Corridor (CMREC). The average FVC has improved, with a general increase of 0.02/10a from 2000 to 2020. We construct a driving factor identification system for FVC change, based on partial and multiple correlation coefficients, and we divide the driving forces of FVC changes into seven climate-driven types and one non-climate-driven type. The results reveal that FVC changes caused by climatic factors account for 28.2% of CMREC. The most prominent greening (19.5%) is precipitation-driven, and is extensively distributed in Khentii Aimag, Mongolia; southeast Inner Mongolia; west Jilin Province; and southwest Heilongjiang Province, China. Moreover, we quantify the relative contribution of climatic and non-climatic factors to significant FVC change using the first-difference multivariate regression method. The results indicate that the effects of non-climatic factors on vegetation change outweigh those of climatic factors in most areas. According to the land cover change and regional policy adjustment, anthropogenic activities such as afforestation, reclamation, and planting structure adjustment explain most vegetation improvement in the Northeast Plain; eastern Inner Mongolia; and the Hetao Irrigation District, China. Meanwhile, both vegetation improvement and degradation disperse concurrently in the Mongolian and Russian parts of CMREC, where climate change and anthropogenic activities positively and negatively affect vegetation change, respectively. Despite the greening in most CMREC, it must be noted that human-induced greening is unsustainable to some degree. The overdevelopment of black soil area and sandy land, adverse effects of afforestation projects, and natural hazards related to weather and climate extremes altogether threaten the local ecological security in the long run. Therefore, governments should develop new desertification countermeasures in accordance with the laws of nature, and enhance international cooperation to guarantee the ecological safety of CMREC.

Spatiotemporal differentiation and driving factors of coupling coordination degree of economic-ecological-social benefits from desertification control in the Mu Us Sandy Land

Spatiotemporal differentiation and driving factors of coupling coordination degree of economic-ecological-social benefits from desertification control in the Mu Us Sandy Land

樟子松固沙林生长对土壤磷素变化的影响

磷是森林生态系统重要养分元素之一, 是干旱半干旱地区植物生长的限制性因子。然而沙质草地转化为人工林生态系统后, 林分的生长对沙地土壤磷素的变化及其影响机理还不清晰, 为沙地合理经营和管理人工林带来了不确定性。以辽宁省章古台地区各生长阶段(幼龄林、中龄林、成熟林和过熟林阶段)的20块樟子松固沙林样地(在各生长阶段林分附近寻找1块天然草地作为对照样地)为研究对象, 取样并测定样地各土层(0-10、10-20、20-40、40-60、60-80、80-100 cm)的土壤磷(全磷和速效磷)、土壤氮(全氮和速效氮)、土壤钾(全钾及速效钾)、土壤有机碳等含量以及土壤含水率、土壤pH值、土壤质地、土壤容重等因子值, 并进行统计分析。结果表明：沙质草地营造樟子松人工林后, 土壤全磷含量随林龄的增加而逐渐递增, 成熟林时期达到最高, 过熟林地全磷降低，且土壤全磷对土层深度不敏感。成熟林地的速效磷含量略高于幼林和中龄林；虽然与幼林、中龄林没有显著差异, 但过熟林的土壤速效磷含量是所有林分中最低的。除了林分生长影响外, 草地营造樟子松林后, 土壤全磷的变化还受土壤容重和土壤速效氮含量的影响, 而土壤速效磷的变化受土壤有机碳和pH值影响。综上所述, 沙质草地营造樟子松人工林后, 林分生长促进了土壤全磷含量的增加, 但导致土壤速效磷轻微的降低, 而樟子松过熟林的生存与生长导致了土壤速效磷的过渡消耗, 使得土壤速效磷低于草地, 经营中应引起重视, 以确保樟子松人工林经营的健康发展。;Phosphorus is one of the important nutrient elements in the forest ecosystem and a limiting factor for plant growth in arid and semi-arid regions. However, after the sandy grassland is transformed into an artificial forest ecosystem, how the growth of artificial forests affects the changes of sandy soil phosphorus is still unclear, which brings uncertainty to the rational management of artificial forests on sandy land. This study chose 20 samples of Pinus sylvestris var. mongolica sand-fixing forests at different growth stages (including young forest, middle-age forest, mature forest and over-mature forest) in Zhanggutai area of Liaoning Province (with 4 adjacent natural grasslands as controls) as objects, sampled and measured the soil chemical factor values--soil phosphorus (total phosphorus and available phosphorus), soil nitrogen (total nitrogen and available nitrogen), soil potassium (total potassium and available potassium), soil organic carbon, pH value etc. and the soil physical properties--soil moisture content, soil particle size distribution, soil bulk density etc. of the 0-10, 10-20, 20-40, 40-60, 60-80, and 80-100 cm layer of the sample plot, and performed statistical analysis. The results show that: after plantation of P. sylvestris var. mongolica plantation on sandy grassland, the content of soil total phosphorus gradually increases with the stand age, and reaches the highest level in mature period. However, total phosphorus is not sensitive to soil depth. The soil available phosphorus content in mature period is higher than that in the young and middle-age period. The available phosphorus content in over-mature period is the lowest, but shows few significant differences with young and middle-age forests. In addition to, after the grassland is planted with P. sylvestris var. mongolica forest, the total phosphorus is also mainly affected by soil bulk density and soil available nitrogen, and the available phosphorus is mainly affected by soil organic carbon and pH value. In summary, after planting P. sylvestris var. mongolica plantation on sandy grassland, stand growth has promoted the increase of the soil total phosphorus content, while has a slight decrease of the soil available phosphorus content. The survival and growth of the over-mature P. sylvestris var. mongolica forest has led to the excessive consumption of the soil available phosphorus, making the content of soil available phosphorus lower than that of the grassland. Attentions should be paid to this aspect to ensure the rational management and healthy development of P. sylvestris var. mongolica plantation.

Effects of ecological restoration measures on vegetation and soil properties in semi-humid sandy land on the southeast Qinghai-Tibetan Plateau, China

Land desertification directly impacts the services and functions of grassland ecosystems globally, especially in alpine regions. Ecological restoration measures (e.g., erecting fences, establishing plant barriers, and planting native shrubs and grasses) are essential for combating desertification and restoring functions of degraded alpine grassland on the Qinghai-Tibetan Plateau (QTP). However, the combined effects of ecological restoration measures on the plant-soil system have yet to be systematically evaluated and compared in the alpine-cold semi-humid area. In this study, we compared vegetation and soil properties upon the application of three typical restoration measures [i.e., fencing enclosure (FE), establishing Salix cupularis sandy barrier (SCSB), and establishing Salix cupularis sandy barrier plus planting grasses (SCSBPPG)], along with severely degraded sandy land as a control (CK). Soil physicochemical (i.e., particle-size distribution, water content (SWC), bulk density (SBD), soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), and total potassium (TK)), and microbiological properties [i.e., microbial biomass carbon (MBC), nitrogen (MBN), phosphorus (MBP), urease, dehydrogenase, catalase, acid phosphatase, polyphenol oxidase, and β-glucosidase activities] were measured in soil layers at depths of 0–10, 10–20, and 20–30 cm. The results showed that the vegetation coverage, aboveground biomass, Margalef richness index, and Shannon–Weiner diversity index significantly increased by 13.54, 13, 3.09, and 1.80 times with FE, and by 11.24, 10.50, 1.05, and 0.83 times with SCSBPPG, respectively (P < 0.05), in comparison to CK. At the same time, SCSB had no significant influence on these four indexes. In addition, the most pronounced improvements of soil clay content, SOM, TN, and TP occurred in the 10–20 cm soil layer, with enhancements by 419%, 243.62%, 93.94%, and 68.97% in FE, and by 73%, 118.46%, 45.45%, and 41.38% in SCSBPPG, respectively. Moreover, MBC and the activities of urease, dehydrogenase, acid phosphatase, and polyphenol oxidase were higher with the artificial recovery interventions than those in CK, with the most significant increases found in 10–20 cm at 22.04%, 44.80%, 46.84%, 44.58%, and 87.50% for FE, and 17.85%, 34.30%, 47.43%, 31.78%, and 41.85% for SCSBPPG, respectively. Finally, SCSB significantly decreased the SOM, TN, TP, MBC, MBN, MBP, and the activities of urease, dehydrogenase, polyphenol oxidase, and β-glucosidase. Our study showed that FE is an efficient management measure for restoring semi-fixed dunes. Combining this with planting grasses and shrubs, rather than establishing plant barriers, is recommended to restore moving dunes in alpine-cold semi-humid sandy regions. This research can provide a reference for optimizing the ecological restoration measures and designing sustainable environmental strategies for conserving grassland at risk of desertification in QTP, China.

新疆三种独尾草的适宜分布及其对未来气候变化的响应

PDF HTML阅读 XML下载 导出引用 引用提醒 新疆三种独尾草的适宜分布及其对未来气候变化的响应 DOI: 10.5846/stxb202110152910 作者: 作者单位: 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（41561007，41261011）；新疆维吾尔自治区草原总站草原生态修复治理补助项目（XJCYZZ202007） Suitable distributions of three species of Eremurus in Xinjiang and their responses to future climatic changes 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:研究国内仅分布于新疆的3种短命植物阿尔泰独尾草（Eremurus altaicus）、粗柄独尾草（Eremurus inderiensis）和异翅独尾草（Eremurus anisopterus）的适宜分布及其对未来气候的可能响应，对新疆短命植物资源的分布、利用与科学保护具有重要意义。共收集了64个自然分布点，筛选了6个气候因子和2个地形因子数据，利用MaxEnt模型和地理信息系统ArcGIS软件模拟了当前气候情景下3种独尾草的生态适宜性，探讨影响3种植物分布的主导因子及其数值范围，预测3种独尾草的适宜分布对未来气候变化（2001-2040年、2041-2080年，基于温室气体中等排放情景：SSP2-4.5共享社会经济路径）的可能响应。结果表明：（1）基准气候下，3种独尾草在新疆的适宜分布存在较大差异：阿尔泰独尾草主要分布于伊犁河谷、天山北麓、阿尔泰山中段和准噶尔西部山地；两种沙生独尾草均分布于天山中段的绿洲-荒漠区过渡带，古尔班通古特沙漠西南部沙地；（2）最干月降水量（1-25mm）主要限制了阿尔泰独尾草的适宜分布；温度季节性变动指数（1150-1672）主要限制了两种沙生独尾草的适宜分布；（3）2001-2040年和2041-2080年，3种独尾草的适宜分布整体均呈缩减趋势：阿尔泰独尾草向天山北麓和准噶尔西部山地略微缩减；粗柄独尾草和异翅独尾草向古尔班通古特沙漠南缘略微缩减。 Abstract:In China,Eremurus altaicus,Eremurus inderiensis and Eremurus anisopterus are only distributed in Xinjiang.It is of great significance to the distribution, utilization and scientific protection of ephemeral plant resources in Xinjiang to study the suitable distributions of Eremurus altaicus, Eremurus inderiensis and Eremurus anisopterus and their possible responses to future climatic changes. A total of 64 natural distribution sites, 6 climate factors and 2 topographic factors were collected in this study. MaxEnt model and ArcGIS software were used to simulate the ecological suitability of the three species of Eremurus under current climate scenario. To investigate the dominant factors influencing the distribution of the three species and their numerical ranges, and to predict the possible responses of the suitable distribution of the three species to future climatic changes (2001-2040、2041-2080,the society is a medium greenhouse gas emission scenario:based on SSP2-4.5 shard socio-economic path).The research results show that:(1) Under the basic climate, there is great differences in the suitable distribution of the three species in Xinjiang:Eremurus altaicus is mainly distributed in Ili River Valley, northern foot of the Tianshan Mountain, middle of the Altai Mountain and the Western Junggar Mountains. Both of psammophytes are distributed in the oasis-desert transition zone in the central Tianshan Mountains and the sandy land in the southwest of Gurbantunggut Desert; (2) The maximum monthly precipitation (1-25mm) mainly limited the suitable distribution of Eremurus altaicus, the temperature seasonal variation index (1150-1672) mainly limited the suitable distribution of Eremurus inderiensis and Eremurus anisopterus; (3) During 2001-2040 and 2041-2080, the suitable distribution of the three species of Eremurus show a decreasing trend as a whole:the Eremurus altaicus is reduced slightly towards the northern foot of the Tianshan Mountain and the Western Junggar Mountains; Eremurus inderiensis and Eremurus anisopterus shrink slightly towards the southern edge of the Gurbantunggut Desert. 参考文献 相似文献 引证文献

沙丘微地形生境蚁丘分布特征及其对恢复过程的响应

PDF HTML阅读 XML下载 导出引用 引用提醒 沙丘微地形生境蚁丘分布特征及其对恢复过程的响应 DOI: 10.5846/stxb202201210204 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 宁夏自然科学基金重点项目（2020AAC02014，2021AAC03047）；宁夏重点研发计划项目（2021BEG03007）；国家自然科学基金项目（41867005） Distribution of ant mounds in sand dune microtopographic habitats and their responses to the restoration process 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:为了阐明沙丘微地形生境蚁丘特征及分布规律对沙丘固定过程的响应规律，以科尔沁沙地为研究区，选择不同固沙阶段沙丘的4个方位（西北、东南、西南、东北）布设调查样地，测定了不同样地的蚁丘密度、直径和高度，分析了不同样地蚁丘特征及空间分布规律。结果表明：（1）流动沙丘背风向（即东南方位）蚁丘密度显著高于其他方位，但从流动沙丘到半流动沙丘，背风向（即东南方位）蚁丘密度显著低于其他方位；从半固定沙丘开始，半固定和固定沙丘微地形对蚁丘密度分布的影响较小。（2）在流动沙丘、半流动沙丘、半固定沙丘，不同微地形生境中蚁丘直径和高度均呈现出相似的分布规律，即东南方位均小于其他方位。在固定沙丘，蚁丘高度表现为东南方位亦较低，但蚁丘直径表现为西南和东北方位显著小于西北方位。（3）在流动沙丘，西北、西南和东南方位上蚁丘空间分布均表现为均匀分布型，而在半流动、半固定和固定沙丘，4个方位上蚁丘空间分布均表现为聚集分布型。（4）相关性分析表明，不同固沙阶段不同微生境下蚁丘密度、高度、直径与植物密度、多样性间的相关性不同。随着固沙阶段演替，不同微生境下蚁丘特征与植物密度、多样性的相关性增强。研究表明，在科尔沁沙地，随着流动沙丘固定和生境逐渐恢复，沙丘不同空间方位上蚁丘密度分布差异缩小，而蚁丘直径和高度仍存在沙丘微地形间显著差异性，并且蚁丘空间方位上均呈现聚集分布状态。 Abstract:The objective of this study was to clarify the distribution of ant mounds in sand dune microtopographic habitats and their responses to the restoration process. In Horqin sandy land, four dune aspects (i.e., northwest, southeast, southwest, and northeast) of dune were selected as sampling sites in mobile sand dune, semi-mobile sand dune, semi-fixed sand dune, and fixed sand dune. The density, diameter and height of ant mounds were measured, and the distribution of ant mounds sand dune microtopographic habitats were analyzed. The results showed that:(1) from mobile dune to semi-mobile dune, there was an opposite distribution of ant mound density between the four habitats of dune aspects. The density of ant mounds in mobile dunes was significantly higher on leeward aspect (i.e., southeast direction) than that on other aspects, whereas the density of ant mounds in semi-mobile dunes was significantly lower on leeward aspect (i.e., southeast direction) than that on other aspects. However, there was a little effect of dune aspects on ant mound density in both semi-fixed and fixed sandy dunes. (2) There was a similar distribution of ant mound diameter and height between dune aspects in mobile dune, semi-mobile dune, and semi-fixed dune; the ant mound diameter and height was significantly lower on the southeast aspect than on the other aspects. In fixed sand dune, the height of ant mounds was significantly lower on the southeast aspect, but the diameter of ant mounds was significantly lower on the southwest and northeast aspects than on the other aspects. (3) The spatial distribution of ant mounds indicated a pattern of uniform in the northwest, southwest and southeast dune aspects in mobile sand dune. However, it indicated a pattern of clumped distribution in the four dune aspects in semi-mobile, semi-fixed, and fixed sand dunes. (4) The correlation analysis showed that the correlation coefficients between the density, height and diameter of ant mounds and the plant density and diversity in different dune aspects differed between mobile, semi-mobile, semi-fixed, and fixed sand dunes. The correlation coefficients in different dune aspects increased along with the ecological restoration process of mobile sand dunes. In conclusion, with the fixation of mobile dunes, the differences of ant mound density between dune aspects decreased from mobile and semi-mobile sand dunes toward semi-fixed and fixed sand dunes in Horqin sandy land. The distribution of ant mount diameter and height was still significantly different among the four micro-topography of sand dunes. The spatial distribution of ant mounds indicated a similar pattern of clumped distribution during the restoration process. 参考文献 相似文献 引证文献

Long-Term Mowing and Burning Have Higher Effects on Soil Fungal Communities than Bacteria in a Semiarid Sandy Land

Long-Term Mowing and Burning Have Higher Effects on Soil Fungal Communities than Bacteria in a Semiarid Sandy Land

Increased and Highly Variable Atmospheric Evapotranspiration Demand Intensified Drought in Semi-Arid Sandy Lands

Increased and Highly Variable Atmospheric Evapotranspiration Demand Intensified Drought in Semi-Arid Sandy Lands

Optically Stimulated Luminescence Dating and Paleoclimatic Implications of the Holocene Dune Sands in the Hunshandake Sandy Land, Ne China

Optically Stimulated Luminescence Dating and Paleoclimatic Implications of the Holocene Dune Sands in the Hunshandake Sandy Land, Ne China

Role of different types of protective forest stands in fodder productivity of rangeland in the Western Caspian region

Forest pastures with different tree crown cover were studied. The seasonal dynamics of the yield and nutritional value of grass and twig-leaf fodder of forest pasture was studied. The unsystematic use of pastures in arid territories has increased the process of degradation and has become one of the factors of depletion of their natural vegetation. The use of forest reclamation in the 70s and 90s on sandy lands and pastures in the Western Caspian region made it possible to create significant areas of forest pasture land with strip and massive stands of Ulmus pumila L. and Robinia pseudoacacia L. Different types of tree stands created on pastures not only improve the microclimate and form a comfortable environment for grazing animals, but also are an additional source of valuable twig feed. The aim of the research was to study forage productivity of forest pastures with different types of plantings on the sands of the Western Caspian region. The objects of the research were forest pastures with different species composition and tree crown cover. Studies on the forage productivity of forest-reclaimed pastures were conducted in 2018-2020 on the basis of the North Caucasus branch of Federal Scientific Centre of Agroecology, Complex Melioration and Protective Af-forestation of the Russian Academy of Sciences. The research was based on field experiments and laboratory analyses. According to the results of the study, forest-reclaimed pastures with unsystematic grazing had 1.52-fold increase in productivity compared to natural ones. The largest amount of twig-leaf feed was formed in broad-band Robinia stands in summer-autumn period. The total gross stock of natural pastures of the Western Caspian region did not exceed 0.30.4 t/ha of dry weight, the consumed stock was 0.20.3 t/ha. With the help of strip and massive plantings on degraded pasture lands, it is possible to increase significantly their productivity and quality with the achievement of 7 MJ of exchange energy and 0.260.29 feed units in 1 kg of elm and robinia twig-leaf feed during droughts.

Effects of soil properties on vegetation community composition across a semiarid ecosystem

Identifying environmental factors that influence the vegetation community formation of various habitats in semiarid regions is imperative for managing these fragile ecosystems. The objective of this study was to quantify the relationships between selected environmental factors and vegetation community composition (VCC) in meadow and sand dune habitats using a structural equation model (SEM). Ecological data from 48 sample sites in semiarid sandy land were analyzed. The selected latent environmental variables included soil water (SW), topsoil salinity and sodicity, topsoil nutrients, topsoil texture (TT) and topography feature (TF). SW was the most influential factor for the Phragmites communis, Agriophyllum squarrosum, and Caragana microphylla communities composition. TT was the most influential factor for the Artemisia halodendron and Artemisia frigida - Agropyron desertorum communities composition. TF was the most influential factor for the Carex duriuscula and Phragmites communis - Bolboschoenus yagara communities composition. Considering the direct and indirect impact relationship, for the meadow habitat, TF was the primary factor causing the community distribution. For the sand dune habitat, TT was the primary factor causing the community distribution. As expected, the quantitative relationships between VCC and influencing factors differ depending on the ecological scales of interest.

Aeolian soils on the eastern side of the Horqin Sandy Land, China: A provenance and sedimentary environment reconstruction perspective

There are many stabilized sand dunes along the East and West Liao rivers in the eastern side of the Horqin Sandy Land, and they pose a threat to the surrounding ecological environment and the livelihood of inhabitants once the ecological balance is destroyed. In order to explore the sediment provenance, dynamic mechanism and sedimentary environment of these aeolian soils, and to provide assistance in desertification prevention, two aeolian soil profiles and some topsoil samples were collected for grain size, loss on ignition and phytolith analysis in the East and West Liao River and Horqin Sandy Land, respectively. After end-member analysis of the grain size data, it is concluded that the aeolian soil profiles along the East Liao River and West Liao River have similar provenance and dynamic mechanism. The river-floodplain contributes most to the formation of these aeolian soils and then the Horqin Sandy Land and the interior of Eurasia, and the sediments were transported to the river banks by creep, saltation and suspension in different proportions. The Ic index reconstructed by phytolith, combined with the surrounding sedimentary environmental reconstruction records, the climate experienced several warm-wet and cold-dry periods from 7,720 to 400 cal yr BP, and it significantly influenced the percentages of each component of the profile in each period. The research suggests that planting drought-tolerant shrub plants along the rivers to form shrub belts can effectively prevent the transport of aeolian soils along the rivers, and planting trees and grass on the aeolian soils to increase the vegetation cover, combined with publicity and management, is viable for desertification prevention.

Technological Breakthrough for the Afforestation of Populus euphratica in the Mu Us Desert in China

The Mu Us Desert (MUD) is one of the four largest sandy lands in China. On 22 April 2020, the Shaanxi Forestry Bureau announced that the desertification land control rate in Yulin reached 93.24%, which means that the Mu Us Desert was about to “disappear” from the territory of Shaanxi. However, the problem of biological diversity, mostly for Pinus sylvestris and shrubs in the Mu Us Desert, remains serious. In order to consolidate the current forest conservation efforts, Populus euphratica has been considered an ideal candidate since the 1950s. However, the low survival rate and conservation rate of Populus euphratica in the MUD led us to perform further large-scale introduction for over 70 years. In this study, by using root control seedling technology, the survival and the conservation rate of Populus euphratica were increased to more than 90%. This study makes possible the introduction of Populus euphratica in the MUD, and the successful introduction of Populus euphratica will provide a new barrier for forest ecosystem stability in the desertification control project in the Yulin area.

Spatial variability of the physicochemical characteristics of surface sediments in the “Three Rivers and One Dune” Region in the Kuye River Basin, Mu Us Sandy Land, China

Eolian-fluvial interactions are a common geomorphic phenomenon and Earth surface process in arid regions. We selected the “Three Rivers and One Dune” region, in the Kuye River Basin, in the northeastern Mu Us Sandy Land in Northern China, for a study of eolian-fluvial interactions, based on a geomorphological survey and analysis of the grain size and chemical element contents of surface sediments. The results showed that the interactions of wind and water flow enhanced have caused the mixing of the surface sediments, which is reflected by the spatial heterogeneity of their physicochemical properties, which are different from those of the local parent rock and local sandy environments. In detail, the variations of the chemical weathering-related indicators, including the CIA, CIW, CPA, Na/K and Rb/Sr, along four transects all indicated that the degree of chemical weathering was generally low in the region (CIA < 50), implying that the materials are unweathered or in an incipient chemical weathering state. Combined with the grain size results, in the upper reaches (transect KYH-1) the mean grain size was coarser, the degree of sorting was lower, and there was a lower degree of chemical weathering. Transect KYH-4, located in the most southeasterly part of the study area, has the lowest mean grain size and is relatively well sorted; hence, it has undergone a greater degree of chemical weathering. Transects KYH-2, KYH-3 and KYH-4 span the “Three Rivers”, and their sediments are relatively well mixed and heavily influenced by locally-derived materials. The differences in physicochemical properties between the transects can be attributed to the diversity of slope directions and of the angles between the wind direction and the river flow. Overall, our results, combined with regional comparisons, indicate that the sand sources of the dunes in the study area are mainly locally derived.