Research Progress on N₂O Emissions from Soil in Facility Vegetable Plot

N2O is one of the important greenhouse gases that cause global warming. N2O emissions from the soil of the facility vegetable land are an important source. It is important to summarize the research on the N2O emissions from the soil in the facility vegetable land, and is also of great significance to study on the emission mechanism of N2O in China’s agricultural fields. This paper summarizes the development status of the facility vegetable plot in China, tracks the progress of soil N2O emission research in the facility vegetable plot, and makes a prospect of the research in this field.

CERN生物长期样地背景和植被分类特征本底数据集

中国生态系统研究网络(Chinese Ecosystem Research Network,CERN)生物长期样地背景和植被分类特征本底数据集是22个CERN自然生态系统生态站95个长期样地的本底数据的综合集成。基于对CERN生态站长期样地地理位置、建立时间、面积、样地代表性等背景信息的梳理,依据样地建立之初的植物群落调查数据,参照最新的中国植被分类系统,对每个样地植物群落所属的植被型组、植被型、植被亚型进行了明确划分,并依据每个样地的优势种名单,对样地植被所属群系和群丛进行了鉴定和命名。本数据集构建通过了多轮的专家审核-台站核查-专家复审-台站接受等过程,包含生态站代码、生态站名称、样地代码、样地名称、样地类别、样地代表性、地理位置、海拔高度、样地面积及形状、样地建立时间和设计使用年数、植被型组、植被型、植被亚型、群系、群丛、优势种等信息。本数据集可以为植物区系、植被资源分布、生物多样性保护等方面的研究提供基础数据支持。

餐厨有机肥对设施菜地土壤理化性质的影响

为探讨餐厨有机肥对设施菜地土壤理化性质的影响,使用商品有机肥料为对照,开展了设施菜地餐厨有机肥的田间试验。结果显示,施用餐厨有机肥料可提高蔬菜产量5.3%~11.6%,增产效果和商品有机肥无显著差异。餐厨有机肥可提高设施菜地土壤有机质含量25.5%~31.8%、土壤速效氮含量8.6%~11.3%、土壤有效磷含量3.1%~12.6%、土壤速效钾含量6.5%~8.2%,但餐厨有机肥和商品有机肥处理间土壤有机质、速效氮、有效磷和速效钾含量均未出现显著差异;餐厨有机肥处理的菜地土壤可溶性总盐含量提高4.0%~5.8%,但餐厨有机肥和商品有机肥处理间无显著差异;餐厨有机肥可以提高土壤水稳性大团聚体(R0.25)含量9.9~14.5百分点,餐厨有机肥和商品有机肥处理之间无显著差异。总的来看,餐厨有机肥料和普通商品有机肥的肥效基本类似;餐厨有机肥可提高设施菜地土壤有机质、速效养分和土壤水稳性大团聚体(R0.25)含量,其效果和商品有机肥料基本相似;餐厨有机肥料可导致土壤可溶性总盐含量小幅上升,但上升幅度和商品有机肥料无明显差异。

RUSLE模型对黄土高原退耕植被恢复坡面土壤侵蚀的模拟效果分析

[目的]为了探究RUSLE模型对黄土高原退耕植被恢复坡面土壤侵蚀模拟的效果。[方法]基于陕北安塞区坊塌小流域内10个径流小区2016-2022年的降雨产流产沙监测资料,通过RUSLE模型中各因子在黄土高原的不同常用算法之间的变换组合,模拟144种因子组合下各退耕植被恢复坡面的土壤侵蚀量,采用纳什效率系数(NSE)和均方根误差(RMSE)评价模型模拟结果的有效性。[结果]利用RUSLE模型144种因子组合模拟的退耕植被恢复坡面土壤侵蚀量,NSE范围为-38.47~0.19,RMSE范围为1.92~12.65 t/(hm 2·a),模拟效果较差,所选各因子算法难以适应退耕植被恢复坡面上的土壤流失量的评估,还需要对RUSLE模型各因子进一步改进。运用RUSLE模型对黄土高原退耕植被恢复坡面土壤侵蚀模拟时,建议尽可能采用时间分辨率高的数据减小对R因子的计算误差,综合考虑土壤有机质含量、土壤粒径与团粒结构组成和容重等土壤理化性质对K因子的影响,以及植被覆盖度、植被高度、枯落物、生物结皮等对C因子的影响,充分考虑10°以上的坡度,细化其LS因子的算法。[结论]RUSLE模型无法很好地适用于黄土高原退耕植被恢复坡面土壤侵蚀的模拟。研究结果为土壤侵蚀模型的研发及RUSLE模型在黄土高原植被恢复坡面的应用提供一定参考依据。

Preliminary Experimental Study on Effectiveness of Vegetative Filter Strip to Pollutants in Surface Runoff

Vegetative filter strip (VFS) is a main kind of Best Management Practices for the control of non-point source pollution. The goal of this paper is to evaluate the effectiveness of VFS in Chinese northwest regions. Three VFSs with natural grass and Hippophae rhamnoides/grass patterns have been constructed in the bank slope of Xiaohuashan reservoir, Huaxian County, Shannxi Province. The removal effects of VFS and influencing factors have been analyzed based on field experiment data. The result reveals a positive effect on reducing the transportation of suspended solids, phosphorus and nitrogen in surface runoff, and it is more efficient on suspended solids removal. The experiment also shows that most of the suspended particles and pollutants bound to them were entrapped in the first 10 m of VFS. The main factors influencing effectiveness of VFS include vegetation patterns and inflow rate. In addition, inflow pollutant concentration has a larger impact on reducing total nitrogen and total phosphorus by VFS, but the reduction effect on SS has no significant difference.

Influence of vegetation cover and other sources of variability on sediment and runoff response in a burned forest in South Korea

Post-fire field measurements of sediment and run off yield were undertaken in natural rainfall event-basis during five rainy months in Korea on a total of 15 small plots: four replica burned unseeded plots, six replica burned seeded plots, and five replica unburned plots. The main aim was to evaluate the effects of vegetation recovery and spatial distribution patterns on sediment and runoff response between and within the treatment replica erosion plots. Sixyears after the wildfire, total sediment and runoff yield in the burned unseeded plots with 20%-30%vegetation cover was still 120.8 and 20.6 times higher than in the unburned treatment plots with 100%ground cover, 8.3 and 6.7 times higher than in the burned seeded plots with 70%-80% vegetation cover,while only 1.6 and 2.0 times higher than in the burned seeded plots with 50%-60% vegetation cover,respectively. The differences in sediment and runoff yield between the treatment plots was proportional to total vegetation cover, distance of bare soil to vegetation cover, magnitude of rainfall characteristics and changes in soil properties, but not slope gradient.Three out of the six within-treatment pairs of two replica plots showed large differences in sediment and runoff yield of up to 6.0 and 4.2 times and mean CV of up to 99.1% and 62.2%, respectively. This was due to differences in the spatial distribution patterns of surface cover features, including aggregation of vegetation and litter covers, the distance of bare soil exposed to vegetation cover closer to the plot sediment collector and micro topographic mounds and sinks between pairs of replica plots. Small differences in sediment and runoff of only 0.9-1.4folds and mean CV of 8.6%-25% were observed where the within-treatment pairs of replica plots had similar slope, total surface cover components and comparable spatial distribution pattern of vegetation and bare soil exposed surface covers. The results indicated that post-fire hillslopes undergoing effective vegetation recovery have the potential to reduce sediment and runoff production nearer to unburned levels within 6-years after burning while wildfire impacts could last more than 6-years on burned unseeded ridge slopes undergoing slow vegetation recovery.

A Technique to Analyse Succession Data from Permanent Plots

Data from vegetation succession study is usually a matrix of plot × species × time.It is difficult to analyse this kind of data at present.A simple technique,clustercentering ordination is described in this paper,which can be used to analyse such a matrix directly.The data of 5 permanent plots in 7 years of inlands and grasslands in Kootwijki,the Netherlands,is analysed using this method as an application example.The results obviously illustrate the trend,direction and speedof community succession and can be easily interbrated.This suggests that clustercentering ordination is an effective and time-saving technique in study of vegetation succession.

Assessment of the State of Forests Based on Joint Statistical Processing of Sentinel-2B Remote Sensing Data and the Data from Network of Ground-Based ICP-Forests Sample Plots

The research was carried out on the territory of the Karelian Isthmus of the Leningrad Region using Sentinel-2B images and data from a network of ground sample plots. The ground sample plots are located in the studied territory mainly in a regular manner, laid and surveyed according to the ICP-Forests methodology with some additions. The total area of the sample plots is a small part of the entire study area. One of the objectives of the study was to determine the possibility of using the k-NN (nearest neighbor method) to assess the state of forests throughout the whole studied territory by joint statistical processing of data from ground sample plots and Sentinel-2B imagery. The data of the ground-based sample plots were divided into 2 equal parts, one for the application of the k-NN method, the second for checking the results of the method application. The systematic error in determining the mean damage class of the tree stands on sample plots by the k-NN method turned out to be zero, the random error is equal to one point. These results offer a possibility to determine the state of the forest in the entire study area. The second objective of the study was to examine the possibility of using the short-wave vegetation index (SWVI) to assess the state of forests. As a result, a close statistically reliable dependence of the average score of the state of plantations and the value of the SWVI index was established, which makes it possible to use the established relationship to determine the state of forests throughout the studied territory. The joint use and statistical processing of remotely sensed data and ground-based test areas by the two studied methods make it possible to assess the state of forests throughout the large studied area within the image. The results obtained can be used to monitor the state of forests in large areas and design appropriate forestry protective measures.

基于站点观测的河南土壤侵蚀因子变化分析

土壤侵蚀产生水土流失是影响生态环境的重要因素,土壤侵蚀因子是开展水土保持综合治理与生态保护的依据。基于河南水土保持观测站实测资料,选择土壤侵蚀因子量化方程,计算河南土壤侵蚀降雨、地形、土壤、植被、水土保持因子,并分析其变化特征。结果表明:降雨侵蚀力R呈增大趋势,自东南向西北R呈减小趋势;土壤可蚀性K整体呈减小趋势;地形LS南召站高于陕州站和罗山站,当坡度超过20°时,土壤侵蚀加剧;不同植被类型植被覆盖C存在差异性,乔灌植被C较小,空地C较大;水土保持P整体呈减小趋势,水土保持措施发挥了良好的防护效果。

广西壮族自治区草原综合植被盖度监测研究

通过草原综合植被盖度监测,主要调查草原样地基本特征、地理位置(经纬度)、主要植物种类、样地综合植被盖度等要素,综合测算广西草原综合植被盖度。结果表明,本次调查广西共布设监测样地812个,测算出草原综合植被盖度为82.76%,较2019年提高0.93%,其中,热性草丛类、热性灌草丛类、暖性灌草丛类植物的综合植被盖度分别为84.11%、82.88%、89.00%。同时对关系草原综合植被盖度变化原因及存在问题进行分析,提出相关建议,以期为广西全面建成小康社会统计监测指标体系和广西绿色发展指标体系提供重要基础指标数据。

不同使用功能区土壤酸碱性的对比分析研究

本文对长沙市某大学校园内外的耕地、林地以及景观园林等不同功能区的土壤pH值进行了测定。结果显示:土壤pH值整体偏酸性。耕地、林地和景观园林的pH值大小排序为:景观园林>林地>耕地;下层土壤(10~20 cm)pH值低于表层土壤(0~10 cm)pH值;靠近公路的功能区土壤pH值均低于远离交通区域的土壤pH值。

太湖典型地区蔬菜地土壤磷素淋失风险

以太湖典型地区宜兴市大浦镇湖滨公路以东沿太湖50hm2老蔬菜基地为研究对象,采用网格法(50m×50m)采集表层(0～20cm)土壤样品156个.地统计学分析表明:土壤P(全P、Bray P、CaCl2浸提水溶P)呈明显空间变异,土壤高P区出现在朱渎港、林庄港两村庄附近.土壤Bray P低于60mg·kg-1,几乎没有检测到CaCl2浸提水溶P,而当土壤速效P大于60mg·kg-1后,CaCl2浸提水溶P随Bray P增加而直线增加.以土壤Bray P含量60mg·kg-1为研究地土壤发生P淋溶的临界值,研究范围内土壤发生P淋溶面积占总调查面积28%.针对目前土壤状况,提出控制蔬菜地P淋溶对策.

珠江三角洲地区典型菜地土壤与蔬菜重金属分布特征研究

通过对珠江三角洲地区的广州市、佛山市、江门市和惠州市典型菜地土壤和蔬菜中重金属(Pb、Cr、Cd、As和Hg)含量及其土壤中有效态(Pb、Cr、Cd)含量的调查,分析蔬菜重金属污染状况与土壤重金属含量的相关性,探讨了土壤重金属含量、有效态含量与土壤理化性质的相关性。结果表明,菜地土壤主要受Pb、Cd、Hg污染。Pb、Cd主要以轻度污染为主;而Hg污染在广州市菜地土壤以轻度污染和重度污染为主,佛山市菜地土壤以中度污染和重度污染为主,江门市和惠州市菜地土壤以轻度污染为主。蔬菜主要受Pb、Cd、Hg污染,少数蔬菜受到Cr污染,但并未检测出蔬菜受As污染。蔬菜中重金属含量与土壤中Pb、Cr、Cd的总量、有效态含量之间呈显著正相关关系,与土壤中As、Hg的总量无显著相关性。土壤中Pb、Cr含量与土壤有机质含量、黏粒含量、粉粒含量均达到显著相关。土壤中有效Pb与有效锰含量呈显著负相关关系,土壤中有效Cr含量与土壤粘粒含量、有效铁含量呈极显著正相关关系。

太湖流域典型蔬菜地土壤氮及pH空间变异特征

以太湖典型地区宜兴市大浦镇湖滨公路以东50hm2蔬菜地为研究对象,网格法(50m×50m)采集表层(0～20cm)土壤156个,采用传统统计和地统计学相结合的方法,研究了土壤氮素及pH的空间变异特征。结果表明:土壤全N和NH4+-N有明显的空间变异结构。全N符合指数模型,NH4+-N变异函数符合线性模型,全N有强烈的空间相关性,NH4+-N有中等的空间相关性。土壤pH普遍偏低,pH变异函数符合指数模型,在小范围内具有强烈的空间相关性。土壤碱解N与pH呈显著负相关,表明施用氮肥是导致土壤pH下降的主要原因。通过研究土壤氮的空间变异性,获取田间土壤氮的连续分布图,为氮素分区管理、氮素重点控制区设置及生态拦截草带的建立提供科学依据。

滨河湿地不同植被对农业非点源氮污染的控制效果

滨河湿地作为连接河流水体和陆地的一个功能过渡界面区,是河流生态系统与陆地生态系统进行物质、能量、信息交换的一个重要过渡带,也是保护河流水体的最后一道屏障,对水质净化和农业非点源污染控制起着非常重要的作用。以黄河湿地国家自然保护区孟津扣马段为研究对象,采取野外定位观测试验和稳定同位素示踪(人工富集15N源的同位素稀释法)相结合的方法,研究了滨河湿地土壤对农业非点源氮的持留作用、渗漏到地下水中的农业非点源氮和湿地不同植被对滞留在土壤中的农业非点源氮的吸收作用。结果显示:通过地表径流进入滨河湿地的农业非点源氮在3个实验样方的垂向和侧向都发生了渗漏。滨河湿地土壤对农业非点源氮的滞留作用主要发生在0—10cm,相当于一个过滤器的功能。3种受试植被土壤表层的滞留量为芦苇(0.045mg/g)>藨草(0.036mg/g)>水烛(0.032mg/g),分别占到土壤滞留氮的59.2%、56.3%和56.1%。滞留在土壤中的农业非点源氮污染存在一个相对较长的效应。滨河湿地特殊的氧化还原条件导致强烈的土壤微生物反硝化作用以及滨河湿地植被对氮素的吸收作用,使得0-10cm土层土壤外源氮变化速度最快,1个月后,滞留芦苇、水烛、藨草样方中15N下降了77.8%、68.8%和8.3%;3个月后,芦苇、藨草、水烛样方中的15N下降了93.3%、72.2%和37.5%。滨河湿地复杂的水文过程,使得滞留在土壤表层的农业非点源氮迁移转化更为复杂多变。监测数据显示,在实验设计的浓度和强度范围内农业非点源氮没有对地下水造成影响。不同植被和同一植物的不同生长时期对滞留在土壤中氮的吸收能力差别较大,吸收量依次为芦苇嫩芽(9.731mg/g)>老芦苇(4.939mg/g)>藨草(0.620mg/g)>水烛(0.186mg/g)。通过对生物量计算得出滨河湿地芦苇、水烛和藨草对农业非点源氮的吸收能力分别为氮吸收量96.11、3.76、0.32kg/hm2。可见,滨河湿地作为连接河流与陆地的缓冲带,通过截留、过滤、植物吸收等过程能有效的削减农业非点源氮对临近地表水体污染,对农业非点源氮污染控制起着非常重要的作用。合理的滨河湿地保护与利用模式对河流水环境保护具有重要的意义。

安徽沿江城郊蔬菜地土壤动物群落生态学研究

对沿江蔬菜地土壤动物群落的研究表明 ,1 82 2 2个标本分隶于 6门 1 4纲 2 9目72科 ,其中以弹尾目、螨目和线虫纲动物数量最多 .同种青菜地土壤动物群落组成丰富性( S)、多样性、均匀性指数值以 7月最大 ,1 2月最小 ;个体数、密度和优势性值以 1月最大 .在不同品种菜菜地 ,8月以青菜和韭菜 S值最大 ,豇豆、毛豆次之 ,萝卜最小 .但随着不同品种生长周期的变化 ,土壤动物群落结构也发生变化 .肥力高的黑砂土 。

植被过滤带对地表径流中污染物的净化效果

植被过滤带是控制非点源污染的"最佳管理措施"之一。为了探讨植被过滤带在中国西北地区的实际应用,该文作者在陕西小华山水库岸坡地建设了3条不同配置方式的植被过滤带,通过试验测定了植被过滤带对地表径流中几种污染物的净化效果,并分析其影响因素。结果表明,植被过滤带对地表径流中的颗粒态氮、颗粒态磷、总氮、总磷和化学需氧量浓度削减率分别达到82.02%、77.13%、46.05%、73.28%和60.48%以上,负荷削减率分别达到89.98%、87.25%、69.93%、85.11%和77.97%以上,并能有效地削减溶解态氮和溶解态磷的负荷量;自然草地过滤带和沙棘-草本过滤带对地表径流中这几种污染物的削减主要发生在前10m。过滤带内的植被条件、入流流量和入流污染物浓度是影响过滤带净化效果的重要因素。

坡面产流过程及产沙临界对立地条件的响应关系

利用人工模拟降雨试验,以黄土高原黄土丘陵沟壑区第三副区黄土为模拟对象,依据45、90和130mm/h降雨强度下共计18个试验组次观测资料,定量研究了裸地、草地和灌木地3种立地条件20°陡坡产流过程及其产沙临界的响应关系。研究表明,高强度降雨条件下,草地和灌木地的减流作用会降低;裸地径流过程具有明显的起涨阶段,而草地和灌木地的起涨阶段不明显,对径流过程具有消波调控作用,同时草地产流量受下渗率的影响比灌木地的大;裸地下渗率比草地和灌木地的明显为小,且其过程波动性强;3种立地条件的初渗率与稳渗率之差以裸地的最大,草地的最小,而且,产流与入渗的关系对降雨的响应是非线性的;断面比能参数可表征为产沙的主导因子,裸地、草地和灌木地的临界断面比能分别为0.074、0.11和0.13cm。该研究对于揭示植被调控坡面产流产沙机理,为生态修复工程建设提供科学依据具有重要科学意义。

南京市郊蔬菜地土壤肥力的时空变化规律

本文以南京市城市化进程中蔬菜地土壤肥力的时空变化为例,分析了蔬菜地土壤肥力的空间变化和时间变化的规律,并对肥力的时空变化原因进行了剖析。结果表明:城市化促进了蔬菜地土壤肥力的空间变异,城区全P、有机质和全N较郊区和农区偏高,这与菜地耕作时间和熟化程度有关。pH值从城区到农区依次降低,与城市建筑废弃物的碱性输出有关。1999年与1980年比较,全N、有机质和有效K含量增加,pH值增加,总P含量降低。

园地植被覆盖度的无人机遥感监测研究

设计构建了基于无人直升机平台的遥感系统,以北京地区园地的板栗为研究对象,对其主要生育期进行监测。基于植被、土壤自身光谱特征差异,提出了一种无人机遥感影像植被覆盖度快速计算方法,利用多时相无人机遥感影像实现了板栗植被覆盖度年变化监测。采用计算机模拟的方式构建模拟场景,对板栗植被覆盖度统计尺度特征进行分析,进一步验证了无人机遥感影像植被覆盖度计算结果的有效性。