黄土旱塬麦田生态系统物质平衡及评价

根据长武试区 1986～ 1995年的统计资料并结合田间试验 ,对黄土旱塬麦田生态系统的主要物质 (氮、磷、钾 )循环及平衡特征进行了较为系统的分析。结果表明 ,农田中养分的流动量大 ,流通途径少 ,养分循环的开放性大 ,外循环规模大 ,内循环率小 ;系统养分平衡中 N基本保持收支平衡 ,K2 O入不敷出 ,P2 O5 输入大于输出 ;养分输入中 ,人工投入的化肥与有机肥是养分的主要来源 ,输出中 N主要集中于籽粒 ,K2 O主要集中于秸秆 ,P2 O5 主要残留于土壤中。指出在农业生产中 ,应采用秸秆还田以增加钾的投入 ,同时要增加氮肥投入尤其是有机肥的投入 ,而磷应以提高其有效性为主。

黄土高原地区土壤可蚀性及其应用研究

通过回顾已有的成果 ,分析评价了我国土壤可蚀性研究的进展及存在的问题 ,提出我国土壤可蚀性研究中的标准小区定义。运用野外观测资料 ,研究计算了黄土高原地区土壤可蚀性指标值。结果表明 ,陕北和晋西北一带黄土可蚀性 K值变化于 0 .3～ 0 .7之间 ,并且有以陕西子洲、绥德一带为最大 ,以此为中心 ,向南、向北和向东都减少的变化趋势。

基于GIS的小流域坡耕地调查方法探讨

坡耕地研究是水土流失治理及水土保持规划的核心内容 ,GIS的发展及其在多领域的成功应用为坡耕地研究提供了新的技术手段。用矢量基础图件叠加来获取单元图斑的方法是GIS的基本功能 ,但叠加多边形的不确定性成为影响GIS数据质量的灾难性因素。以MapGIS作为基础平台 ,以DOM作为控制底图更新信息 ,采取矢栅叠加的方法获得单元图斑 ,用操作属性表获取专题属性 ,进行小流域坡耕地快速调查的研究 ,展示了矢栅叠加方法在信息复合过程中的显著优势。

基于RS和GIS的纸坊沟流域土地利用动态监测及分析

以纸坊沟流域多年土地利用监测数据为基础 ,对其结果进行分析和讨论。结果表明 ,到 1 999年底 ,农业、林业、牧业用地面积比例分别为 1 6.9%、34.0 %、36.8%。人均基本农田由 1 975年 0 .0 5 4 7hm2 ,增到 1 999年的 0 .2 0 33hm2 ,坡耕地大幅度减少 ,粮食平均产量也由 1 975年的 5 61 kg/hm2 ,增到 1 999年的 2 31 9kg/hm2 ,流域林草有效覆盖率达到 5 7.4% ,植物种类和数量得到增加。走上了农林牧协调发展和生态环境良性循环的轨道

黄土旱塬麦田生态系统能流特征及评价

根据长武试区 1 986年～ 1 995年连续 1 0年的统计资料并结合田间试验 ,对黄土旱塬典型农田生态系统——冬小麦农田系统能量的投入产出、流向、流量与转化效率进行了较为系统的研究。结果表明 ,能量平衡中人工辅助能的投入逐渐增加 ,化肥能投入比例逐渐超过有机肥能 ;该区农业已发展到无机—有机复合阶段 ,农业生产中机械化程度有所提高。通过统计分析 ,得出提高无机能的投入比例可提高能量的产投比 ,增加化肥能投入水平则可提高能量的总产出 ,指出应在机械化条件下实行秸秆还田和多途径增加有机肥投入 ,调整能量投入结构 ,提高能量转化效率 ,提高光能利用率

黄土区渭北旱塬苹果基地对区域水循环的影响

通过对苹果地、农田和其他塬面主要土地利用方式的比较研究 ,发现苹果地土壤入渗速率大、降雨产流率低和存在生物利用型土壤干层。这些水文学性质将增强土壤 -植物 -大气间垂直水分交换 ,削弱降雨转化为地表径流和地下水的比例 ,最终影响区域地表和地下水资源的数量。另外土壤干层的出现还削弱了土壤水库对年际和季节性干旱的调节作用 ,导致苹果产量随降雨量的自然变化呈现较大波动

半湿润区农田生态系统氮肥对不同基因型冬小麦产量构成的影响

施N对“NR9405”、“9430”、“偃师9号”、“小偃6号”、“陕229”、“西农2208”、“矮丰3号”和“商188”这8种不同基因型冬小麦产量构成影响的田间试验结果表明,单株分蘖成穗数、单位面积粒数和单位面积株数的差异同时受基因和N素营养水平控制。“矮丰3号”和“小偃6号”单株分蘖成穗数最多,分别为2.00分蘖穗/株和1.72分蘖穗/株,“9430”最少,为0.85分蘖穗/株。从不同基因型看,施N比不施N处理增加0.74穗/株,每穗粒数在不同基因型间存在极显著差异,以“西农2208”最多,为36.73粒/穗,“NR9405”最少,为24.35粒/穗,施N对每穗粒数无显著影响。单位面积株数主要受施N影响,基因型间差异相对较小。基因型和施N同时显著影响单位面积粒数和千粒重,但基因型对千粒重的影响程度大于N肥。从2个施N水平看,单位面积籽粒产量存在显著差异,“矮丰3号”、“西农2208”、“偃师9号”、“陕229”、“9430”、“小偃6号”、“商188”和“NR9405”依次减小,“矮丰3号”为435g/m2,“NR9405”为316g/m2,相差119g/m2。施N可极显著增加单位面积籽粒产量,不同基因...

施氮与基因型对半湿润区冬小麦灌浆期籽粒氮、磷累积的影响

在年均降水量632mm的黄土高原南部半湿润区红油土上以“9430”、“小偃6号”和“商188”为供试材料,研究了不施N和施N(90kg/hm2)条件下不同基因型冬小麦灌浆期间籽粒中N、P累积特性。结果表明,不同基因型冬小麦灌浆期间籽粒含N量呈现出“高-低-高”的时间变化趋势,而籽粒含P量基本呈直线下降趋势。不同基因型小麦籽粒最终含N量的高低与灌浆进程中籽粒含N量的高低一致,“小偃6号”籽粒含N量始终高于“商188”和“9430”。在整个灌浆期间,籽粒中N累积速率显著高于P累积速率,灌浆末期表现更为明显。籽粒N的活跃累积期与千粒重呈显著正相关,提高籽粒中N累积速率有利于增加籽粒蛋白质含量。基因型是控制籽粒中N活跃累积期和N活跃平均累积速率的主要因子,而基因型对籽粒P活跃累积期和平均累积P速率无显著影响。施N虽然对灌浆期间籽粒N、P累积参数无显著影响,但在一定程度上可以提高灌浆进程中籽粒含N量,对最终籽粒N累积具有一定的促进作用。

Impacts of LUCC processes on potential land productivity in China in the 1990s

Using meteorological data and RS dynamic land-use observation data set, the potential land productivity that is limited by solar radiation and temperature is estimated and the impacts of recent LUCC processes on it are analyzed in this paper. The results show that the influence of LUCC processes on potential land productivity change has extensive and unbalanced characteristics. It generally reduces the productivity in South China and increases it in North China, and the overall effect is increasing the total productivity by 26.22 million tons. The farmland reclamation and original farmlands losses are the primary causes that led potential land productivity to change. The reclamation mostly distributed in arable-pasture and arable-forest transitional zones and oasises in northwestern China has made total productivity increase by 83.35 million tons, accounting for 3.50% of the overall output. The losses of original farmlands driven by built-up areas invading and occupying arable land are mostly distributed in the regions which have rapid economic development, e.g. Huang-Huai-Hai plain, Yangtze River delta, Zhujiang delta, central part of Gansu, southeast coastal region, southeast of Sichuan Basin and Urumqi-Shihezi. It has led the total productivity to decrease 57.13 million tons, which is 2.40% of the overall output.

Industrial development and land use/cover change and their effects on local environment: a case study of Changshu in eastern coastal China

The interactions among industrial development, land use/cover change (LUCC), and environmental effects in Changshu in the eastern coastal China were analyzed using high-resolution Landsat TM data in 1990, 1995, 2000, and 2006, socio-economic data and water environmental quality monitoring data from research institutes and governmental departments. Three phases of industrial development in Changshu were examined (i.e., the three periods of 1990 to 1995, 1995 to 2000, and 2000 to 2006). Besides industrial development and rapid urbanization, land use/cover in Changshu had changed drastically from 1990 to 2006. This change was characterized by major replacements of farmland by urban and rural settlements, artificial ponds, forested and constructed land. Industrialization, urbanization, agricultural structure adjustment, and rural housing construction were the major socio-economic driving forces of LUCC in Changshu. In addition, the annual value of ecosystem services in Changshu decreased slightly during 1990-2000, but increased significantly during 2000-2006. Nevertheless, the local environmental quality in Changshu, especially in rural areas, has not yet been improved significantly. Thus, this paper suggests an increased attention to fully realize the role of land supply in adjustment of environment-friendly industrial structure and urban-rural spatial restructuring, and translating the land management and environmental protection policies into an optimized industrial distribution and land-use pattern.

Land use and water quality response in the northern region of Changxing County

In this paper, taking the northern region of Changxing County for example, with ammonia nitrogen as a pollution assessment index, we used an improved export coefficient method for estimate polluting load of non-point source pollution (NSP) and the social pollution survey data in the study area to estimate point source pollution. By comparing the total pollution output and the national surface water environmental quality standards find that the whole study area achieves the second water quality standard. However, Jiapu Township exceeds the water quality standards seriously because of the superfluous point source pollution. The water quality of other Townships is good. Further analysis showed that different types of land use and proportions in the northern region of Changxing County have a significant impact on the non-point source pollution, the general law is farmland contributes the largest share of the non-point source pollution output, followed by residential area and bare land, besides, with the increase in the proportion of forest and the decrease of farmland and residential area, the non-point source pollution reduces gradually. © 2010 IEEE.

热察绥地区过去300年土地利用覆被变化

The historical land use and land cover changes is one of the key issues in LUCC research. However, the achievement of China in this field doesn't match her position in the world yet. And the reliability of the quantitive records in Chinese historical literature, the basic data for historical land use research, has been doubted. This research focuses on Re-Cha-Sui, a typical area for the farming-pastoral region in the north of China, to make a detailed case study in this field. Based on a deep mining and calibration on the data from massive historical documents and land-use surveys, the author gives a detailed analysis on the administrative region evolution, historical population dynamics, reclamation policy, and the land statistic system. According to textual researches, parallel validation and physical geographical analysis, a unified land use series for recent 300 years, which founded on the results of modern land-use surveys, is constructed. And the thematic maps on the cultivation index for different counties in several temporal sections are plotted. Based on the endeavor above, the dynamic of forest and steppe is reconstructed as well. The temporal-spatial patterns of land use/land cover changes in the area is analyzed. And the influence of different driving forces are discussed. The main conclusions of the research are as followed: 1. The quantitive records in literatures on Re-Cha-Sui area are reflection of real amounts of croplands. It is practical to reconstruct a result comparable with the modern land-use surveys, based of a deep mining and considerate validation on historical documents. The unexceptional negative attitude towards the numerical records in historical documents is unnecessary. 2. In recent 300 years, 3 climax of reclamation appeared in Re-Cha-Sui area and altered the pure pastoral area into a farming-pastoral region. The interval were respectively the early time till mid time of the Qing dynasty, the end of the Qing dynasty till early time of the Republic of China(ROC), and the time after A.D. 1949. After the first expansion, the area of cropland in this region reached 2.0 million ha. Among them, Guisui area, which was most densely cultivated, had a cultivation index over 30%, which is similar with modern situation. The second expansion covered broader area, and the amount of cropland reached 3.5 million ha. The increase of farming area after 1949 is due to the recultivation of abandoned farmland. The current area of cropland in this region is 5.6 million ha. In the southern area where the land was reclaimed early, the amount on of the cropland has some fluctuation in 300 years. While in the new reclaimed area in the north, the area of cropland has kept the trend of increasing. 3. Due to the different natural conditions, most forests in Re-Cha-Sui area distribute in the mountain area of North Hebei province, and the upland of West Liaoning province, especially the former, which has a forest coverage near 70%. However, most of these forests were destroyed before the end of the Qing dynasty. In 1949, the natural forest near Chengde was nearly cleared up. They were partly renewed after 1949 due to plantation. 4. In the steppe zone such as northern Rehe, Suiyuan and Chahar, the area of steppe has a negative correlation with that of cropland. With the expansion of cropland, the percentage of steppe has shrunk from over 80% to 53%. In the mountain area of North Hebei province, steppe expanded with the shrinkage of forest, though cropland was expanding. The percentage once reached 60%, and then fell with the renew of forest. However, in the upland of West Liaoning province, the steppe shrink slowly from original 50% to current 26%, with the expansion of cropland. 5. The land use and land cover change in Re-Cha-Sui area in recent 300 years is driven by various factors, including human dimensions such as population, policy of the government, disorder of the society, cultural tradition, and natural factors such as climate change and natural disasters. Among them, pressure from surplus population is the basic driving force.

The ecology of the song thrush, Turdus philomelos Br., in Ireland

Over the last 30 years, western European Song Thrush populations have declined with the steepest decline recorded on British farmland. Changes in agricultural practices have been implicated in these population declines. Ireland is an agriculturally dominated landscape but changes in agriculture here have occurred on a relatively slower rate and scale. Little is known about the ecology of the Song Thrush in Ireland, even though it is not classified as a species of conservation concern here. Some decline is thought to have occurred but the current breeding population appears to be stable and widespread. In light of these facts, this study investigated various aspects of Song Thrush ecology in relation to the Irish landscape from 2001-2003. The breeding season extended from mid March to late June, where mean clutch size was 4.1 and number of fledglings was 3.7. There were very few third broods. Daily nest survival rates were calculated for egg stage 0.9362, incubation stage 0.9505 and nestling stage 0.6909. Most nest failures were due to avian predation at both egg and chick stages. Most nests were located 1.3 -2.4m from the ground at trees, bushes or hedgerow. Clutch size was significantly higher on farmland than garden & parkland and woodland, and the number of fledglings was significantly lower in nests in trees than hedgerow and bush sites. Daily nest fail rates were significantly higher at tree sites and partly concealed nests. Nesting areas had significantly denser vertical vegetation than non-nesting areas. Mercury and the organochlorine HEOD were the most common contaminants in Song Thrush eggs and livers. However concentrations and occurrence were low and of no apparent biological or ecological concern. The presence of breeding Song Thrushes was influenced by mixed surrounding farmland, the absence of grass surrounding farmland, ditches especially wet ones, tall dense vegetation and trimmed boundaries. Song Thrush winter densities were predicted by ditches, with wet or dry, low thin vegetation and untrimmed boundaries. Winter densities were almost double that of the breeding season, probably due to the arrival and passage of migrating Song Thrushes through the country, especially in November. Changes in Irish agriculture did not differ significantly in areas of Song Thrush breeding population stability and apparent decline during 1970 1990. Even though the current breeding population heavily uses farmland, woodland, human and scrub habitats are more preferred. Nevertheless no farmland habitat was avoided, highlighting a positive relationship between breeding Song Thrushes and Irish agriculture. This appears to be in contrast with findings between breeding Song Thrushes and British agriculture. Theses findings are compared with other studies and possible influences by agricultural intensification, climate, latitude and insular syndrome are discussed. Implications for conservation measures are considered, especially for areas of decline. Even though Song Thrushes are currently widespread and stable here, future environmental consequences of longer-term changes in Irish agriculture and perhaps climate change remain to be seen.

Comparing impacts of new cropping systems on biodiversity in traditional rural China

This study selected six geographically-similar villages with traditional and alternative cultivation methods (two groups of three, one traditional and two alternatives) in two counties of Henan Province, China—a representative area of the Huang-huai-hai Plain representing traditional rural China. Soil heavy metal concentrations, floral and faunal biodiversity, and socio-economic data were recorded. Heavy metal concentrations of surface soils from three sites in each village were analysed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS, chromium, nickel, copper, cadmium, and lead) and Atomic Absorption Spectrophotometer (AAS, zinc). The floral biodiversity of four land-use types was recorded following the Braun-Blanquet coverage-abundance method using 0.5×0.5m quadrats. The faunal biodiversity of two representative farmland plots was recorded using 0.3×0.3m quadrats at four 0.1m layers. The socio-economic data were recorded through face-to-face interviews of one hundred randomly selected households at each village. Results demonstrate different cultivation methods lead to different impact on above variables. Traditional cultivation led to lower heavy metal concentrations; both alternative managements were associated with massive agrochemical input causing heavy metal pollution in farmlands. Floral distribution was significantly affected by village factors. Diverse cultivation supported high floral biodiversity through multi-scale heterogeneous landscapes containing niches and habitats. Faunal distribution was also significantly affected by village factor nested within soil depth. Different faunal groups responded differently, with Acari being taxonomically diverse and Collembola high in densities. Increase in manual labour and crop number in villages using alternative cultivation may positively affect biodiversity. The results point to the conservation potential of diverse cultivation methods in traditional rural China and other regions under social and political reforms, where traditional agriculture is changing to unified, large-scale mechanized agriculture. This study serves as a baseline for conservation in small-holding agricultural areas of China, and points to the necessity of further studies at larger and longer scales.

Seasonal patterns in activity and habitat use by bats (Pipistrellus spp. and Nyctalus leisleri) in Northern Ireland, determined using a driven transect

The seasonal activity of Leisler's bat Nyctalus leisleri and pipistrelle bats Pipistrellus spp. with respect to minimum bat numbers and habitat use were investigated in County Down, Northern Ireland using a driven transect from April 1998 to October 1998. Data were collected in lowland farmland near Belfast, Northern Ireland using two BatBox III bat detectors tuned to detect both species and species groups simultaneously. The number of bats/km increased during April, May and June, peaking in July and tailed off after this period. The main peak in July is assumed to reflect the occurrence of newly volant young. An increase in the number of pipistrelle social calls during August and September probably represented mating activity. Bat activity correlated with temperature in both N. leisleri and Pipistrellus spp., although bat numbers were independent of temperature after the middle of June. There was significant variation in habitat use by pipistrelle bats along roads over the study period. Pipistrelle bats were observed in greater numbers in areas of tree-line, cut hedge (