中国东部森林样带典型森林水源涵养功能

通过对我国东部森林样带四个森林生态系统定位研究站（长白山站、北京站、会同站和鼎湖山站）的九种森林类型水源涵养监测数据的分析,研究了水热梯度下不同森林生态系统水源涵养功能。结果表明：在生长季的5-10月份,各森林类型的水源涵养特性表现出较大差异。林冠截留率的大小依次为：阔叶红松林＞杉木林＞常绿阔叶林＞针阔混交林＞季风常绿阔叶林＞落叶阔叶混交林＞马尾松林＞落叶松林＞油松林,最高的长白山站阔叶红松林的截留率是最低的北京站油松林的2.2倍。森林降雨截留量与林外降雨量呈显著的正相关,林冠截留率与降雨量呈显著负相关。枯落物最大持水深（5-10月份）以北京站落叶阔叶林最大,为6.0mm;鼎湖山站的季风常绿阔叶林最小,为1.0mm。0-60cm土层蓄水量最大的是会同站的人工杉木林,为247mm;最小的是北京站的落叶松林,仅为45.5mm;林分总持水量依次为：杉木林＞阔叶红松林＞常绿阔叶林＞针阔混交林＞季风常绿阔叶林＞落叶阔叶混交林＞马尾松林＞落叶松林＞油松林。各林分总持水量主要集中在土壤层,占总比例的90%以上。     

Gash模型在黄土区人工刺槐林冠降雨截留研究中的应用

为了验证Gash林冠截留解析模型在黄土高原人工林中的适用性,基于2009年黄土丘陵沟壑区吕梁市王家沟小流域刺槐林样地降雨观测数据,采用Gash模型对林冠截留进行了模拟。所选刺槐林分为人工纯林,林龄约30a,阴坡,坡度24°,密度为990株/hm2,平均树高10.8 m,平均胸径12.4 cm,郁闭度0.76。根据回归方法确定了Gash模型中的主要参数,包括饱和林冠的平均蒸发速率(E珔)、林冠枝叶部分的持水能力(S)、自由穿透降雨系数(p)、树干持水能力(St)和树干茎流系数(Pt)。结果显示,2009年5月至10月人工刺槐林样地实测降雨量为366.9 mm,穿透降雨量为317.5 mm,树干茎流为10.2 mm,林冠截留量为39.2 mm。模型模拟的林冠截留量为42.4 mm,高于实测值3.2 mm,相对误差为8.2%。敏感性分析表明,S、E珔、St和pt每增加10%,林冠截留量分别增加4.7%,3.1%,1.7%和0.5%;p增加10%,林冠截留量则减少2.6%。说明树干持水能力(St)和树干茎流系数(pt)两个参数对黄土高原人工刺槐林冠截留量的预测值影响程度较小。模拟值与实测值有较好的一致性,显示Gash模型适用于黄土高原人工刺槐林冠的截留计算。     

应用修正的Gash解析模型对岷江上游亚高山川滇 高山栎林林冠截留的模拟

修正的Gash解析模型具有较好的物理基础,是目前估算和预测林冠截留的有效工具。基于2007年6月到9月的降雨数据、气象和林分结构资料,采用修正的Gash解析模型对岷江上游川滇高山栎林冠截留进行了模拟。结果表明,林冠持水能力为0.23mm,树干持水能力为0.041mm,树干茎流系数为0.013,使林冠饱和的降雨为0.3mm;研究期间实测的林冠截留量为80.2mm,占总降雨量的16.5%,应用模型模拟的林冠截留总量为81.8mm,高于实测值1.6mm(高于实测值2.0%),林冠截留和树干茎流周累积量模拟值均与实测值有很好的一致性,敏感性分析结果显示,应用修正的Gash解析模型进行岷江上游川滇高山栎林冠截留模拟研究中,模型最易受林冠持水能力影响,其次为郁闭度、树干持水能力,影响最小的林分参数为树干茎流系数。     

滇中常绿阔叶林及云南松林水文作用的初步研究

 本文研究了滇中地区山地常绿阔叶林及云南松林的林冠截留量,冠流和茎流量,地表水土流失量,林地枯枝落叶层持水量,土壤含水量以及雨水、冠流、茎流和地表迳流中营养元素(N、P、K、Ca和Mg)的含量,并分析比较了针、阔两类森林调节和涵养水分的作用和降水中林冠养分的淋溶、迁移特点,对了解滇中亚热带山地森林生态系统的功能和生产力的研究,对本区森林资源的保护,林业的合理经营,均有重要意义。     

土地利用变化对海南土壤水源涵养功能的影响

热带地区已有大量原始林转变为其他土地利用类型,影响了陆地生态系统的水源涵养功能.为了明确热带原始林转变为其他土地类型对土壤水源涵养功能的影响,在海南中部山区选择4种典型土地利用类型,包括林龄大于100年的原始林(VF)、10年生次生林(SF)、12年生槟榔林(AF)和35年生橡胶林(RF),评估土地利用变化对土壤持水性能和水源涵养功能指数(SWI)的影响.结果表明: 与原始林相比,表层土壤(0～10 cm)中,其他土地类型土壤持水性能指标均降低,12年槟榔林各土层指标均最低.土壤含水量和最大持水量与植被郁闭度、土壤有机质和土壤容重显著相关,表明郁闭度、土壤有机质和紧实度的改变是土壤持水性能变化的重要原因.与原始林相比,次生林、槟榔林和橡胶林土壤水源涵养功能分别减少27.7%、54.3%和11.5%,不同土层的差异各异,橡胶林仅表层土壤水源涵养功能显著降低.植被郁闭度、土壤有机质和土壤容重可解释土壤水源涵养功能变量的83.3%.土地利用转变显著改变了土壤持水性能和土壤水源涵养功能,相比12年槟榔林,35年橡胶林能更好地保持土壤水分,土地管理中增加土壤有机质和减少土壤紧实度可改善土壤持水性能及水源涵养功能.     

“双季稻-鸭”共生生态系统稻季磷循环

稻鸭共生是对中国传统农业稻田养鸭的继承与发展。在长江流域双季稻主产区湖南布置了稻田养鸭田间对比试验,以常规稻作为对照,采用投入产出法,分析"稻鸭共生"生态系统P的输入输出及循环情况。结果表明:"早稻-鸭"共生生态系统P输出为52.28kg·hm-2,其中鸭产品P为1.71kg·hm-2;"晚稻-鸭"共生生态系统P输出为83.24kg·hm-2,其中鸭产品P为6.17kg·hm-2;在早、晚稻两季,"稻鸭共生"系统在目前的P养分投入水平下,降低了土壤P的亏缺量;鸭子系统P输入主要来自系统外投入的饲料P;鸭粪P在系统内循环利用,两季循环率分别为12.5%和13.5%;两季稻作后,"稻鸭共生"土壤截存的P量为195.41kg·hm-2,比常规稻作显著提高了36.9%;"稻鸭共生"可对稻田土壤增加鸭粪P为17.75kg·hm-2。     

基于修正的Gash模型对南亚热带季风常绿阔叶林林冠截留的模拟

Gash解析模型及其修正的模型是估算和预测林冠截留的有效工具,探讨其在南亚热带森林植被冠层截留模拟中的适用性,是认识该区域结构相对复杂的自然林分冠层的降雨截留能力及其相关科学问题的重要基础。基于2009年鼎湖山国家级保护区内季风常绿阔叶林样地降雨及其他气象因子的观测数据,采用修正的Gash模型对南亚热带地带性顶极群落季风常绿阔叶林的冠层截留量及其组分进行了模拟量化。结果表明:2009年,季风常绿阔叶林林内穿透雨量、树干径流量和林冠截留量分别为1310.9、85.5和498.9 mm,分别占林外总降雨量的69.2%、4.5%和26.3%。基于修正的Gash模型对林冠降雨截留量的同期模拟值为473.0 mm,模拟截留量比实测值低25.9 mm,相对误差为5.2%。对干季降雨截留模拟的相对误差较小(1.8%),湿季稍大(6.8%)。从林冠截留量的构成来看,降雨停止后的林冠蒸发(231.4 mm)是林冠截留的主要组成部分,占总截留量的48.9%。整体上,国内基于Gash及其修正模型对森林冠层截留的模拟相对误差在0.2%~35.0%。林冠持水能力被视为模型准确估算林冠截留量的先决条件,国内运用不同方法估算的不同林分林冠持水能力大致处于0.23~2.86 mm。修正的Gash模型适用于南亚热带季风常绿阔叶林林冠截留的模拟应用。     

甘肃兴隆山主要森林类型凋落物累积量及持水特性

2010年,采用野外实地观测与室内浸水法,对甘肃兴隆山6种主要森林类型(青杆林、青杆-白桦林、山杨-白桦林、灌丛林、落叶松林、油松林)林下凋落物的累积量、持水量、持水率和吸水速率进行了研究.结果表明:不同森林类型凋落物层累积量在13.40～46.32 t·hm-2,为油松林＞青杆-白桦林＞落叶松林＞青杆林＞灌丛林＞山杨-白桦林,且针叶林累积量高于阔叶林;半分解层累积量所占比例均高于未分解层.凋落物最大持水率为185.5％～303.6％,落叶松林最大,油松林最小,持水率与浸水时间呈对数关系;针叶林未分解层持水率均小于半分解层,而阔叶林则相反.凋落物最大持水量在3.94～8.59 mm,为油松林＞落叶松林＞青杆-白桦林＞青杆林＞灌丛林＞山杨-白桦林;持水量与浸水时间存在对数关系;半分解层持水量均大于未分解层.凋落物吸水速率与浸水时间存在幂函数关系,在浸水前1h内,吸水速率均直线下降,而浸水1.0h后吸水速率较小,且不同时段间变化较小;半分解层吸水速率高于未分解层.凋落物有效拦蓄量(深)为青杆-白桦林(5.97 mm)＞油松林(5.59 mm)＞落叶松林(5.46 mm)＞青杆林(4.30 mm)＞灌丛林(3.03 mm)＞山杨-白桦林(2.13 mm).     

川西亚高山不同暗针叶林群落类型的冠层降水截留特征

在林分和小流域尺度上,应用模型研究了四川卧龙亚高山暗针叶林冠层的降水截留特征.结果表明:生长季节(5—10月),箭竹-岷江冷杉原始林冠层截留系数在33%～72%之间,平均48%;冠层截留量与降水量之间呈显著的线性关系,截留系数与降水量之间呈负指数函数关系;试验小流域内,植被冠层最大截留量的平均值为1.74mm,不同林分间的差异显著,其顺序为藓类-箭竹-岷江冷杉林>草类-箭竹-岷江冷杉林>藓类-杜鹃-岷江冷杉林>草类-杜鹃-岷江冷杉林>杜鹃灌丛;冠层最大截留量与叶面积指数(LAI)之间呈极显著的线性关系;冠层截留量、冠层最大截留量、附加截留量分别占同期降水量的39%、25%和14%.所选模型对整个生长季平均截留量的模拟效果较好,相对误差为9%～14%.     

长白山阔叶红松林能量平衡和蒸散

利用开路涡动相关系统的连续观测结果,分析了长白山阔叶红松林2008年能量平衡各分量和蒸散量的特征,并对生长季和非生长季能量各分量和蒸散量的差异进行了比较.结果表明:该观测系统能量闭合度为72%,处于国际同类观测的中等水平;能量各分量日、季差异显著,生长季森林生态系统最主要的能量支出项为潜热通量,约占可用能量的66%,非生长季最主要的能量支出项为感热通量,约占可用能量的63%.长白山阔叶红松林2008年蒸散量为484.7 mm,占同期降水量(558.9 mm)的87%,证实森林蒸散耗水是我国北方温带森林最主要的水分支出项.     

Benthic macroinvertebrate biodiversity improved with irrigation ponds linked to a rice paddy field

Traditionally, many irrigation ponds supplied water to paddy fields, but most of these ponds have disappeared through improvements in irrigation systems. The aim of this study was to assess the ecological functions (especially biodiversity conservation) of irrigation ponds by using benthic macroinvertebrates that inhabit paddy fields. This study was conducted in Hwaseong‐si, Yesan‐gun, Hongseong‐gun, Uljin‐gun and Damyang‐gun, Korea. Benthic macroinvertebrates were collected using a quadrat sampler from August to September for three years (2010–2012) in paddy fields with and without an irrigation pond. In the comparisons between two paddy field types (paddy fields with and without an irrigation pond) for species richness and densities of benthic macroinvertebrates, the species richness and densities were higher in the paddy fields with a pond than in the paddy fields without a pond (P < 0.001). Biodiversity enhancement effect degree (BEED) of the irrigation pond showed positive values in all survey regions. There were no significant differences among the survey regions. BEED showed positive values in all taxonomic groups (excluding Crustacea) and were not significantly different among taxonomic groups. The BEED values for non‐insects, passive dispersers, were relatively higher than for insects, active dispersers. The results indicate that BEED is related to the dispersal abilities of each taxonomic group and an irrigation pond increases biodiversity in a paddy field in all regions. Therefore, the irrigation pond is one method that can be immediately applied in paddy fields in order to improve the biodiversity of agricultural ecosystems.     

崇明东滩冬季不同管理模式下水稻田水鸟群落特征及其生境分析

崇明东滩是亚太地区候鸟迁徙路线的重要中转站,也是上海地区促淤圈围的重点区域。水稻(Oryza sativa)田作为当地分布广泛且重点改造的人工湿地,研究其是否具有水鸟招引效果具有重要意义。本研究于2013和2014年冬季采用样方法对崇明东滩两种不同管理模式的水稻田,即2013年开始改造的传统模式水稻田和改造多年的机械化模式水稻田,进行了水鸟群落及生境因子调查,以探究不同管理模式下水稻田内生境差异,水鸟对不同生境的利用程度及其不同生境中的关键因子对水鸟分布的影响。调查期间共记录到水鸟5目7科18种1 795只次,其中传统模式水稻田记录到水鸟5目6科17种1 756只次,优势种为绿翅鸭(Anas crecca)、斑嘴鸭(A.poecilorhyncha)、鹤鹬(Tringa erythropus);机械化模式水稻田录到水鸟4目5科6种39只次,优势种为小??(Tachybaptus ruficollis)和凤头麦鸡(Vanellus vanellus)。T检验结果显示,传统模式水稻田对水鸟的招引效果(即多度和物种丰富度)显著优于机械化模式水稻田,2014年改造后传统模式水稻田的水鸟招引效果显著优于2013改造初期。多元回归分析显示,明水面面积比例是影响水稻田水鸟种类、数量分布的最重要因子。结果表明,明水面面积和适合的水位高度是影响冬季水稻田水鸟招引效果的主要因素,为提高冬季水稻田水鸟保育效果,应注重营造、维护冬季水稻田中水文条件。     

Effects of cultivars,water regimes,and growth stages on cadmium accumulation in rice with different radial oxygen loss

Plant and Soil - Large areas of paddy fields have been contaminated by cadmium (Cd) in both China and worldwide, resulting in excessive Cd accumulation in rice grains. Here, we investigated the...     

植物防御素调控水稻镉积累的新机制

镉是我国农产品的主要重金属污染物之一。随着我国土壤重金属污染问题日益突出, 包括稻米在内的农产品重金属超标时常发生。如何防控重金属在作物可食部位的积累, 在保证农产品安全的同时将农田重金属进行移除修复, 已成为我国农业生产急需解决的问题。最近, 中科院上海生命科学院植物生理生态所龚继明研究组和中国水稻所钱前研究组克隆到1个特异调控镉在水稻(Oryza sativa)叶片中积累的主效QTL基因CAL1。CAL1编码1个植物防御素类似蛋白, 通过与镉进行螯合, 将镉从维管束木质部薄壁细胞中分泌出来, 进入木质部参与长距离转运, 从而定向调控镉在水稻叶片等营养器官的积累而不影响籽粒镉的积累。该研究加深了人们对重金属镉在植物体内的转运和再分配机理的认识, 同时也为培育秸秆镉高积累而籽粒镉含量达标的“修复型”水稻品种提供有价值的新基因。研究成果具有重要的理论意义和应用价值。     

稻作系统对淡水养殖池塘富营养化的修复效应及应用前景

养殖池塘富营养化是目前制约我国淡水养殖业可持续发展的关键因素。稻作系统具有显著的净化水质能力,如何将稻作系统和淡水养殖系统进行生态耦合实现氮、磷养分的循环利用,是淡水养殖池塘富营养化生态修复的一个重要研究方向。通过文献调研和实地考察,综合分析了浮床种稻-原位修复、稻田湿地-异位修复、稻鱼生态种养3种耦合方式对养殖池塘富营养化的修复效应,以及氮、磷养分综合利用效率,归纳总结了不同模式的技术特点以及应用中存在的问题,并就修复技术研究和生态补偿提出了培育生态修复专用水稻品种,加强稻作系统生态修复理论研究和技术推广,建立养殖池塘富营养化修复的生态补偿机制等建议。     

Microbial electricity generation in rice paddy fields: recent advances and perspectives in rhizosphere microbial fuel cells

Microbial fuel cells (MFCs) are devices that use living microbes for the conversion of organic matter into electricity. MFC systems can be applied to the generation of electricity at water/sediment interfaces in the environment, such as bay areas, wetlands, and rice paddy fields. Using these systems, electricity generation in paddy fields as high as ～80 mW m^?2 (based on the projected anode area) has been demonstrated, and evidence suggests that rhizosphere microbes preferentially utilize organic exudates from rice roots for generating electricity. Phylogenetic and metagenomic analyses have been conducted to identify the microbial species and catabolic pathways that are involved in the conversion of root exudates into electricity, suggesting the importance of syntrophic interactions. In parallel, pot cultures of rice and other aquatic plants have been used for rhizosphere MFC experiments under controlled laboratory conditions. The findings from these studies have demonstrated the potential of electricity generation for mitigating methane emission from the rhizosphere. Notably, however, the presence of large amounts of organics in the rhizosphere drastically reduces the effect of electricity generation on methane production. Further studies are necessary to evaluate the potential of these systems for mitigating methane emission from rice paddy fields. We suggest that paddy-field MFCs represent a promising approach for harvesting latent energy of the natural world.     

Landscape and stand structures in a hilly agricultural area in Fenghua City,Zhejiang Province,China: impact of fuelwood collection

Paddy fields surrounded by forests are characteristic of the rural landscapes in East Asia. These characteristic landscapes are maintained by agricultural activities; recently, however, local and regional changes in economic and social systems have resulted in their deterioration. In order to conserve these landscapes, the diversity of land-use systems should be documented, and the human impact on landscape structure should be analyzed. In this study, landscape structure, stand structure, and influence of human activity on the landscape were examined for a hilly agricultural area in Fenghua City, Zhejiang Province, China. Eleven types of landscape elements were recognized that include evergreen broad-leaved forests, evergreen coniferous (Pinus massoniana) forests, tall bamboo (Phyllostachys pubescens) forests, small bamboo (Phyllostachys praecox f. prevernalis) plantations, tea gardens, grasslands, dry arable fields, paddy fields, residential areas, bare ground, and open water. In the study plots, which were established in the main forest types, the species name, cover abundance, and sociability of vascular plants were recorded, and tree height and diameter at breast height were measured. In addition, the amount of fuelwood collected from the forests was determined. There were many component species common to both secondary and natural forests, but the stand structure for these forests was considerably different. Cyclobalanopsis (Quercus) glauca, which had adapted to being frequently cut, was found to be the preferred species for fuelwood.     

华南丘陵区冬闲稻田二氧化碳、甲烷和氧化亚氮的排放特征

采用静态箱 气相色谱法对收获后冬闲稻田CO₂、CH₄和N₂O排放进行了田间原位测定,探讨了越冬稻田3种温室气体的排放规律.结果表明,残茬稻田和裸田的CO₂的排放峰值分别出现在18:00和16:00左右.日间CH₄排放为净值,夜间表现为弱吸收.残茬稻田和裸田N₂O夜间排放分别为日间平均的1.79和1.58倍.残茬稻田的昼夜CO₂平均排放通量显著高于裸田(P＜0.05).在测定期间,残茬稻田CO₂排放随温度升高而增高.相关分析表明,CO₂排放与土温、地表温度和气温均呈显著相关,表明温度是影响收获后稻田CO₂排放的主要因素.在11月10日至翌年1月18日测定期间,残茬稻田的CO₂和CH₄平均排放通量分别为(180.69±21.21) mg·m^-2·h^-1和(-0.04±0.01) mg·m^-2·h^-1,CO₂排放通量较裸田高13.06％,CH₄吸收增高50%.残茬稻田的N₂O排放通量为(21.26±19.31) μg·m^-2·h^-1,较裸田低60.75％.由此说明华南丘陵区冬闲稻田是大气CO₂和N₂O的源,CH₄的汇.     

Expression in Arabidopsis and cellular localization reveal involvement of rice NRAMP,OsNRAMP1, in arsenic transport and tolerance

Irrigation of paddy fields to arsenic (As) containing groundwater leads to As accumulation in rice grains and causes serious health risk to the people worldwide. To reduce As intake via consumption of contaminated rice grain, identification of the mechanisms for As accumulation and detoxification in rice is a prerequisite. Herein, we report involvement of a member of rice NRAMP (Natural Resistance‐Associated Macrophage Protein) transporter, OsNRAMP1, in As, in addition to cadmium (Cd), accumulation through expression in yeast and Arabidopsis. Expression of OsNRAMP1 in yeast mutant (fet3fet4) rescued iron (Fe) uptake and exhibited enhanced accumulation of As and Cd. Expression of OsNRAMP1 in Arabidopsis provided tolerance with enhanced As and Cd accumulation in root and shoot. Cellular localization revealed that OsNRAMP1 resides on plasma membrane of endodermis and pericycle cells and may assist in xylem loading for root to shoot mobilization. This is the first report demonstrating role of NRAMP in xylem mediated loading and enhanced accumulation of As and Cd in plants. We propose that genetic modification of OsNRAMP1 in rice might be helpful in developing rice with low As and Cd content in grain and minimize the risk of food chain contamination to these toxic metals.     

红壤丘陵区生态农业模式研究

根据不同坡位上红壤的理化性质分异,建议在红壤丘陵上推行“顶林、谷农、塘渔”生态农业模式。并在塘边建造猪场,以养猪为纽带,实行种养结合,建立饲草－猪－沼、菇－果、粮－果、珍珠的食物链,再定量调控种养结合链环的饲料配置,粪尿投放、制沼育菇和塘淤返田,以提高系统生产力,达到农业可持续发展。