湖南会同林区毛竹林地的土壤呼吸

采用CID-301PS光合分析仪(配带土壤呼吸室),对湖南会同林区毛竹林地土壤呼吸进行测定,结果表明,毛竹林地土壤总呼吸速率、异养呼吸速率、自养呼吸速率及凋落物呼吸速率的年平均值分别为2.13、1.44、0.69μmolCO2·m-2·s-1和0.31μmolCO2·m-2·s-1,并呈现明显的季节变化规律和日变化规律,季节变化曲线呈单峰型,表现为1～7月份随着气温、地温的升高呈上升的趋势,在8月达年呼吸速率的最大值,分别达4.95、3.01、1.94μmolCO2·m-2·s-1和0.80 μmolCO2·m-2·s-1,此后随温度的降低而呈逐渐递减的趋势,直到翌年的1月份或2月份,分别为0.76、0.70、 0.06μmolCO2·m-2·s-1 和 0.05μmolCO2·m-2·s-1.日变化曲线图表现为单峰形态,一般也是随着温度的升高而加大,随着温度的降低而减小.6:00～14:00,随着土壤温度的升高而增加,一般在16:00～18:00出现最高峰,此后,一直递减,直到次日4:00～8:00.由此计算出毛竹林地土壤年释放CO2量为33.94 t·hm-2·a-1,其中,林地异养呼吸、自养呼吸和凋落物呼吸分别占总呼吸的59.5%、28.3%和12.2%.     

西南丘陵区不同耕作模式下玉米田土壤呼吸及影响因素

为了探讨不同耕作模式对旱作农田土壤呼吸的影响,采用LI6400-09在重庆北碚西南大学实验农场对平作(T)、垄作(R)、平作+覆盖(TS)、垄作+覆盖(RS)、平作+覆盖+秸秆速腐剂(TSD)、垄作+覆盖+秸秆速腐剂(RSD)6种处理下的西南紫色土丘陵区小麦/玉米/大豆套作体系中玉米生长季节的土壤呼吸及其水热生物因子进行了测定和分析。结果表明,玉米整个生育期阶段农田土壤呼吸先增强后减弱,变化范围为1.011—5.575μmol m-2s-1,不同处理土壤呼吸速率差异显著,表现为RSDTSDTSRSTR。垄作降低了玉米农田土壤呼吸速率,秸秆覆盖提高土壤呼吸速率。10 cm土层的土壤温度表现为RTRSDTSDRSTS,土壤呼吸的土温敏感指标Q10值排序为TSTSDRS=RTRSD。5 cm土层的土壤含水量高低排序为TSDTSRSRSDRT。土壤呼吸的土壤水分响应阈值大小排序依次为RTRSRSDTSTSD,介于11.98%—13.11%。其中垄作下的响应阈值较低,秸秆覆盖的作用提高了土壤水分的响应阈值。干漏斗法捕获的土壤动物在玉米农田生态系统中优势类群有弹尾目、螨目和双翅目。单纯的垄作减少了土壤动物数量,秸秆覆盖下土壤动物数量明显增多,土壤动物多样性指数较高;陷阱法捕获的土壤动物与土壤呼吸存在正相关关系,地表活动的土壤动物越多,土壤呼吸作用就越强,其中R的相关系数最高,r=1.000,P=0.017,TS的相关系数r=0.915,P=0.029,而传统耕作下土壤动物数量与土壤呼吸没有明显的关系。玉米田整个生长季均表现为碳汇,净碳汇为679.244—723.764 g(C)/m2。与对照相比,垄作和秸秆覆盖有利于农田生态系统的碳汇,增汇达2.91%—6.55%。     

小兴安岭5种林型土壤呼吸时空变异

原始阔叶红松林、谷地云冷杉林、阔叶红松择伐林、次生白桦林、人工落叶松林是小兴安岭乃至东北地区的重要森林类型。采用红外气体分析法比较测定了这几种森林类型的土壤呼吸及其相关环境因子,分析探讨了这几种森林类型土壤呼吸的时空变异。结果表明:各林型土壤呼吸与5 cm深土壤温度(T5)呈显著的指数相关,并且土壤呼吸与土壤温度、土壤湿度及其相互作用的回归模型可以解释各林型土壤呼吸约71%的季节变异。生长季平均土壤呼吸速率为次生白桦林(3.59μmolCO.2m-.2s-1)>谷地云冷杉林(3.52μmolCO.2m-.2s-1)>阔叶红松择伐林(3.44μmolCO.2m-.2s-1)>原始阔叶红松林(2.58μmolCO.2m-.2s-1)>人工落叶松林(2.29μmolCO.2m-.2s-1),说明土壤呼吸对原始阔叶红松林人为干扰的响应是不同的。各林型Q10值介于1.84(人工落叶松林)—2.32(次生白桦林)之间。在整个生长季,各林型之间土壤呼吸的变异系数变化幅度为19.74%—37.39%,而各林型内土壤环间其变化幅度为32.13%—60.20%,显著大于样地间的变化幅度14.28%—35.70%(P<0.001),说明土壤呼吸在细微尺度上的差异更大。土壤湿度可以解释各林型(阔叶红松林除外)内部土壤呼吸15.8%—33.5%的空间异质性。     

不同玉米秸秆还田方式对冬小麦田土壤呼吸的影响

在连续耕作10年的保护性耕作农田进行定位试验,采用静态箱-TGC气体分析仪法田间原位观测玉米秸秆还田对冬小麦田土壤呼吸的影响.结果表明:麦田土壤呼吸与玉米秸秆留茬高度呈显著正相关关系,且在小麦整个生育期具有两个峰值;免耕不还田处理的土壤呼吸为免耕全量还田处理的72.5％,常规耕作不还田处理的土壤呼吸为常规耕作全量还田处理的76.5％.土壤呼吸与20 cm土层土壤温度和有机碳含量呈显著正相关,但与40 cm土层土壤有机碳含量相关性不显著;土壤水分与土壤呼吸的相关性显著.麦田秸秆全量还田处理的土壤日呼吸值呈单峰曲线,于18:00达到最高.20 cm土层土壤温度与土壤呼吸值的变化趋势一致.不同秸秆还田量处理中,留茬1 m的秸秆还田处理能显著减少土壤呼吸,是较合理的秸秆还田方式.     

豫南雨养区小麦-玉米周年不同耕作模式生态价值评估

以豫南雨养农业区小麦-玉米周年耕作模式为研究对象,以2007—2014年连续7年的大田定位试验数据为基础资料,利用货币归一化方法,对不同耕作模式农田生态系统服务功能价值进行估算。试验处理为两季秸秆均不还田的传统翻耕、不覆盖/不深松+覆盖/免耕、覆盖/不深松+不覆盖/免耕、不覆盖/深松+不覆盖/免耕、覆盖/深松+覆盖/免耕及不覆盖/不深松+还田/旋耕6个模式。主要估算了各模式的农产品服务价值、积累有机质功能价值、养分积累和循环功能价值、涵养水分功能价值和调节大气功能价值。结果表明,覆盖/深松+覆盖/免耕的农田生态系统各项服务价值均最高,总价值也最高,达到49326元·hm-2,其次是传统翻耕模式为45345元·hm-2,然后依次是不覆盖/深松+不覆盖/免耕、不覆盖/不深松+覆盖/免耕、覆盖/不深松+不覆盖/免耕,不覆盖/不深松+还田/旋耕模式最低,只有41440元·hm-2。两季秸秆覆盖还田+深松+免耕播种模式生态服务总价值分别比其他模式依次高8.78%、9.67%、13.46%、13.57%、19.03%,均达显著或极显著水平。说明两季秸秆粉碎覆盖还田、小麦免耕播种结合玉米季深松模式,适合豫南雨养农业区的区域生态气候特点和生产实际,适宜推广应用。     

不同耕作措施对华北地区麦田CH_4吸收通量的影响

华北地区作为我国重要的粮食产区,其农田土壤CH4的吸收与排放对我国准确合理的估算农业温室气体的排放量、制定合理的农业减排和适应措施具有重要意义。研究利用静态箱-气相色谱法研究了华北地区麦田5种不同耕作模式在不同生育时期土壤CH4通量的动态变化和日变化,试验结果表明:5种不同耕作模式在不同生育时期土壤CH4通量具有明显的动态变化。不同的耕作处理都表现为CH4的净吸收汇。整个生育期,常规耕作无秸秆还田处理≈常规耕作秸秆还田处理耙耕≈旋耕深松耕免耕。CH4吸收通量具有明显的日变化,吸收通量白天高夜晚低。处理间比较,常规耕作无秸秆还田处理常规耕作秸秆还田处理免耕。结论:常规耕作无秸秆还田处理CH4的吸收通量较高,但此种耕作方式不利于土壤耕层的保护,而耙耕、旋耕这两种保护性耕作方式使表层土壤具有较好的保墒保肥能力,对土壤扰动小,且只比常规无秸秆还田的CH4吸收值低5.35%和6.31%,较有利于农业减排,所以从环境效益和土壤保护这两个方面来看,耙耕和旋耕这两种保护性耕作处理较为理想。     

不同秸秆还田和耕作方式对夏玉米农田土壤呼吸及微生物活性的影响

采用基质诱导呼吸法和CO2释放量法,研究了冬小麦季长期不同耕作方式(常规翻耕、免耕和深松)和秸秆处理(秸秆还田和无秸秆还田)对夏玉米田土壤呼吸及微生物活性的影响.结果表明:秸秆还田和保护性耕作主要在O～ 10 cm土层起作用.秸秆还田能明显提高土壤微生物生物量碳和微生物活性,降低呼吸熵,在苗期和开花期提高土壤呼吸,而在灌浆期、腊熟期和收获期降低土壤呼吸;在相同秸秆处理条件下,深松和免耕比常规翻耕能显著降低土壤呼吸和呼吸熵,提高微生物生物量碳和微生物活性.整个生育期,秸秆还田结合保护性耕作能显著提高微生物生物量碳和微生物活性,降低呼吸熵,与常规翻耕无秸秆还田相比,深松秸秆还田和免耕秸秆还田0～10 cm土层微生物生物量碳平均提高了95.8％和74.3％,微生物活性提高了97.1％和74.2％.     

长期不同耕作与秸秆还田对土壤养分库容及重金属Cd的影响

于2005—2013年在湖南宁乡双季稻田开展免耕秸秆还田(NTS)、翻耕秸秆还田(CTS)、翻耕秸秆不还田(CT)、旋耕秸秆还田(RTS)4种不同耕作方式与秸秆还田试验,分析不同耕作方式与秸秆还田对土壤养分含量、养分库容量及重金属Cd的影响,为稻田合理耕作与重金属Cd污染修复提供理论依据.结果表明:耕作措施与秸秆还田主要影响0~10 cm耕层土壤性状;长期翻耕和旋耕提高了土壤养分含量,增强了土壤通气性,但耕层变浅,养分库容降低,土壤Cd含量显著偏高,水稻植株地上部分富集Cd能力相对较低;长期免耕增加了表层土壤容重,土壤养分含量较低,但养分库容相对较高,水稻植株地上部分富集Cd能力较强;秸秆还田显著增加了土壤养分含量和阳离子交换量,增加了耕层深度和土壤养分库容量,增强了土壤的保肥能力,但同时也将秸秆中富集的Cd重新归还到稻田土壤中,不利于土壤Cd的转移修复.因此,长期单一耕作方式和长期秸秆还田均存在一定弊端,需改进耕作和秸秆还田方式,如实行翻耕、旋耕与免耕相结合的土壤轮耕或深松耕,以及减少秸秆还田量或实行秸秆轮还,在改善土壤肥力的同时,实现土壤污染的有效修复.     

冻融交替对科尔沁沙地不同土地利用方式土壤呼吸的影响

在中高纬度和高海拔地区,冻融作用影响土壤的理化性质和微生物性状,进而影响土壤呼吸过程。研究冻融作用下土壤呼吸的变化,对准确估算全球碳循环具有重要意义。以科尔沁沙地沙质草地、樟子松疏林草地和农田为研究对象,通过冻融实验比较不同土地利用方式和冻融循环对土壤呼吸的影响。结果表明:土地利用方式对土壤呼吸有显著影响,在未发生冻融作用时沙质草地土壤呼吸速率显著大于樟子松疏林草地和农田(P0.05),3种土地利用方式的土壤呼吸平均速率分别为0.339、0.258和0.234μmolCO2.m-2.s-1;不同冻融循环对沙质草地和樟子松疏林草地土壤呼吸影响显著(P0.05)。其中,一次冻融循环条件下沙质草地、樟子松疏林草地和农田土壤呼吸平均速率分别为0.276、0.243和0.233μmolCO2.m-2.s-1,多次冻融循环条件下分别为0.314、0.274和0.259μmolCO2.m-2.s-1;沙质草地、樟子松疏林草地和农田的Q10值分别为116.0、26.2和16.4,表明冬季低温条件下土地利用方式强烈影响土壤呼吸对温度的敏感性。     

保护性耕作对土壤微生物量及活性的影响

研究保护性耕作对土壤微生物特性的影响对于土壤管理具有重要意义。试验研究了保护性耕作对麦田土壤微生物量碳、活跃微生物量、土壤呼吸、呼吸商的影响。前3项采用的方法分别是:基质诱导呼吸法、呼吸曲线数学分析法和CO2释放量法。结果表明,保护性耕作土壤微生物量碳0～10cm土层大于10～20cm土层,而常规耕作两土层间无明显差异。秸秆还田在播种前、越冬期和起身期能显著提高土壤微生物量碳,而开花期和收获期则降低土壤微生物量碳。少耕还田10～20cm土层微生物具有较强的养分调控作用。保护性耕作利于0～10cm土层活跃微生物量的提高。秸秆还田和保护性耕作在耕作作业初期(越冬期和起身期)能增强土壤呼吸速率;在耕作作业后期(开花期和收获期)能显著降低土壤呼吸速率。免耕秸秆覆盖在10～20cm土层呼吸商较高,而常规耕作无秸秆还田在0～10cm土层呼吸商较高。土壤微生物量碳和呼吸商是衡量土壤微生物特性的重要指标。     

Cropping systems for phytoremediation of phosphorus-enriched soils

Eutrophication of freshwater bodies is frequently attributed to elevated phosphorus (P) concentrations in surface runoff from P-enriched agricultural soils. Forage and grain-cropping systems were compared for their effectiveness at remediating P-enriched soils. At each of four locations, one of three forage systems (Forage I = cereal rye silage and corn silage annually; Forage II = alfalfa; Forage III = annual ryegrass and corn silage annually) and the grain system (corn, small grain, and soybean rotation) were maintained for 3 yr on soils with five distinct initial soil P concentrations that were established by using four annual applications (1994-1997) of five different rates (0, 100, 200, 300, and 400 kg total P ha(-1) y(-1)) of poultry manure, dairy manure, or commercial fertilizer. Across all manure P treatments at all locations, the forage systems had greater removal of P than the grain system. Soil P concentration changes (2001-2004) did not reflect differences in crop P removal. Few significant reductions in soil P concentration were observed for either crop system. When reductions did occur, they were for the more highly enriched soil P treatments. No significant reductions in soil P concentration have occurred for the lowest manure P treatments. Considerable variability in crop P concentrations was observed among species at locations and among years produced. However, crop P concentrations did increase uniformly as soil P concentration increased, indicating that luxury consumption of P does occur in agronomic species produced on P-enriched soils.     

旱作农田不同耕作土壤呼吸及其对水热因子的响应

为研究旱作农田春玉米生育期不同耕作土壤呼吸变化特征及其对水热因子的响应情况,在山西省寿阳县旱农试验基地采用红外气体分析法测定了传统耕作(CT)、少耕(RT)和免耕(NT)土壤呼吸速率,并同步测定了各土层土壤水分、温度.研究表明:在春玉米生育期内,土壤呼吸速率均呈单峰型变化趋势,峰值出现在8月;传统耕作与少耕土壤呼吸速率变化趋势基本一致,而免耕土壤与前两者相比波动幅度较大;土壤呼吸峰值与水分、温度之间无明显相关,其余时期土壤呼吸与水分、温度因子具有良好的相关性;双因子模型较单因子模型能更好的描述土壤呼吸与水分、温度之间关系,基于水热双因子(10-20 cm)的指数-幂模型能够解释土壤呼吸变化的81％-87％ (P＜O.01);3种耕作土壤呼吸对水热因子协同影响的敏感性表现为CT＞NT＞RT.     

不同施肥模式下稻田土壤微生物生物量磷对土壤有机碳和磷素变化的响应

通过15年的红壤稻田长期定位试验,研究了不同施肥模式下土壤微生物生物量磷(MB-P)对土壤有机碳和磷素变化的响应.结果表明红壤稻田有机碳源的长期投入和土壤有机碳的逐年升高使土壤微生物生物量碳(MB-C)维持在较高水平(＞800 mg·kg-1),是稻田土壤MB-P(＞16.0 mg·kg-1)提高的主要原因.长期不施磷肥条件下,土壤全磷含量与试验前相比显著降低(P＜0.05),而土壤有机磷含量平均提高了29.3%;土壤亏损的磷形态主要是无机磷(Al-P、Fe-P、Ca-P和O-P),其中Al-P含量处于最低水平(平均0.5 mg·kg-1).另外,长期不施磷肥土壤的MB-P远高于Olsen法提取态磷(Olsen-P)(＜7.0 mg·kg-1),而稻田土壤MB-P与Al-P呈显著相关(P＜0.05),表明土壤微生物对稻田土壤Al-P、Fe-P、Ca-P和O-P的利用是促进其向有效磷方向转化的关键途径.磷肥配合有机养分循环利用不仅提高了土壤磷库的积累,而且通过土壤微生物的活化有效地提高了土壤磷的有效性.     

Soil health in agricultural systems

Soil health is presented as an integrative property that reflects the capacity of soil to respond to agricultural intervention, so that it continues to support both the agricultural production and the provision of other ecosystem services. The major challenge within sustainable soil management is to conserve ecosystem service delivery while optimizing agricultural yields. It is proposed that soil health is dependent on the maintenance of four major functions: carbon transformations; nutrient cycles; soil structure maintenance; and the regulation of pests and diseases. Each of these functions is manifested as an aggregate of a variety of biological processes provided by a diversity of interacting soil organisms under the influence of the abiotic soil environment. Analysis of current models of the soil community under the impact of agricultural interventions (particularly those entailing substitution of biological processes with fossil fuel-derived energy or inputs) confirms the highly integrative pattern of interactions within each of these functions and leads to the conclusion that measurement of individual groups of organisms, processes or soil properties does not suffice to indicate the state of the soil health. A further conclusion is that quantifying the flow of energy and carbon between functions is an essential but non-trivial task for the assessment and management of soil health.     

坡耕地-桑树系统土壤微生物群落结构的PLFA分析

土壤微生物群落对土壤生态环境敏感,能够指示土壤质量变化,决定土壤的生态功能。利用磷脂脂肪酸(PLFA)法分析了不同配置模式的坡耕地-桑树系统对旱坡地紫色土土壤生态系统微生物群落结构的影响。结果表明,种植桑树篱能显著提高土壤Phospholipid-derived fatty acids(PLFA)含量,改善微生物群落结构:T1处理(两带等高桑)土壤微生物的PLFA总量(20.54nmol/g)显著高于CK处理(常规农作);T1处理显著提高了土壤细菌含量,T5处理(两带纵坡桑)土壤中真菌的丰富度相对较高。T1的多样性指数(H')和均匀度指数(J)最高,T2(三带等高桑)的丰富度指数(R)最高。主成分分析表明,第一主成分(PCI)主要包括a17:0、16:1ω5c和17:0等直链饱和脂肪酸和多不饱和脂肪酸,占PC1的58.15%;第二主成分(PC2)包括i12:0 3OH、20:1ω9c和cy19:0ω8c等直链单不饱和脂肪酸和环丙烷脂肪酸,占PC2的77.50%;T1与T2微生物群落结构相似,与CK差别较大。冗余分析(RDA)表明:微生物群落结构主要受全磷、p H、全氮、有机质、硝态氮含量影响;全磷、全氮对支链饱和脂肪酸、G+、细菌等影响较大,p H对G-影响较大。相关性分析表明,径流量与i16:0、10Me17:0、a17:0、18:3ω6c(6,9,12)呈显著正相关,与20:1ω9c呈极显著正相关;泥沙量与i16:0、i17:0呈显著正相关,与18:3ω6c(6,9,12)呈显著负相关,与20:1ω9c呈极显著正相关。     

Soil carbon dioxide efflux determined from large undisturbed soil cores collected in different soil management systems

The aim of this study was to evaluate a measuring technique for determining soil CO₂ efflux from large soil samples having undisturbed structure under controlled laboratory conditions. Further objectives were to use the developed measuring method for comparing soil CO₂ efflux from samples, collected in three different soil management systems at various soil water content values. The experimental technique was tested and optimised for timing of sampling by taking air samples after 1, 3 and 6 hours of incubation. Based on the results, the incubation time was set to three hours. The CO₂ efflux measured for different soil management systems was the highest in the no-till and the lowest in the ploughing treatment, which was in accordance with measurements on accessible organic carbon for microbes. An increase in CO₂ efflux with increasing soil water content was found in the studied soil water content range. Our results indicate that soil respiration rates, measured directly after tillage operations, can highly differ from those measured long after.     

Soil temperature effects from minirhizotron lighting systems

Observing root dynamics or soil fauna with minirhizotrons requires the use of incandescent or ultraviolet (UV) lighting systems. These light sources can generate heat which would be transferred to the surrounding soil adjacent to the minirhizotron observation tubes and thus may influence root growth and development or fauna activity. The objective of this study was to determine the effect of incandescent and UV light from a minirhizotron camera system on soil temperatures next to minirhizotron tubes. Temperature probes were attached next to and at 0.5 cm from the tube surface and the tubes were then placed in boxes with either a fine sand or a loamy clay soil. Incandescent light was operated stationary for 5 min or moved at 1 cm increments every 10 s down the tube for both dry and wet soils. The UV light was used in a stationary position for 10 minutes in both dry soils. Maximum temperature increases were 3.41–3.52 °C and 1.69–2.14 °C next to the tube for the dry and wet soils, respectively with 5 min of stationary incandescent light. Ultraviolet lights increased soil temperatures to a maximum of approximately 2.5 °C in the dry soil. Probes placed 0.5 cm from the tube surface also showed temperature increases up to 2.15 °C. Moving the light source every 10 s, however, resulted in lower temperature increases (<0.8 °C). Therefore short durations of light resulted in small temperature increases suggesting minimal impact on root development. Increased soil temperatures from longer durations of light, however, may alter root growth and development as well as soil fauna activity and warrants further study.     

Optimizing nutrient management for farm systems

Increasing the inputs of nutrients has played a major role in increasing the supply of food to a continually growing world population. However, focusing attention on the most important nutrients, such as nitrogen (N), has in some cases led to nutrient imbalances, some excess applications especially of N, inefficient use and large losses to the environment with impacts on air and water quality, biodiversity and human health. In contrast, food exports from the developing to the developed world are depleting soils of nutrients in some countries. Better management of all essential nutrients is required that delivers sustainable agriculture and maintains the necessary increases in food production while minimizing waste, economic loss and environmental impacts. More extensive production systems typified by 'organic farming' may prove to be sustainable. However, for most of the developed world, and in the developing world where an ever-growing population demands more food, it will be essential to increase the efficiency of nutrient use in conventional systems. Nutrient management on farms is under the control of the land manger, the most effective of whom will already use various decision supports for calculating rates of application to achieve various production targets. Increasingly, land managers will need to conform to good practice to achieve production targets and to conform to environmental targets as well.     

Soil multitrophic network complexity enhances the link between biodiversity and multifunctionality in agricultural systems

Belowground biodiversity supports multiple ecosystem functions and services that humans rely on. However, there is a dearth of studies exploring the determinants of the biodiversity–ecosystem function (BEF) relationships, particularly in intensely managed agricultural ecosystems. Here, we reported significant and positive relationships between soil biodiversity of multiple organism groups and multiple ecosystem functions in 228 agricultural fields, relating to crop yield, nutrient provisioning, element cycling, and pathogen control. The relationships were influenced by the types of organisms that soil phylotypes with larger sizes or at higher trophic levels, for example, invertebrates or protist predators, appeared to exhibit weaker or no BEF relationships when compared to those with smaller sizes or at lower trophic levels, for example, archaea, bacteria, fungi, and protist phototrophs. Particularly, we highlighted the role of soil network complexity, reflected by co-occurrence patterns among multitrophic-level organisms, in enhancing the link between soil biodiversity and ecosystem functions. Our results represent a significant advance in forecasting the impacts of belowground multitrophic organisms on ecosystem functions in agricultural systems, and suggest that soil multitrophic network complexity should be considered a key factor in enhancing ecosystem productivity and sustainability under land-use intensification.     

土壤种子库的分类系统和种子在土壤中的持久性

对国际上已经发表的10个土壤种子库分类系统的内容进行了总结和阐述,并对土壤种子库分类系统进行了评述,其中Thompson ＆ Grime在1979年提出的把土壤种子库分为短暂土壤种子库（Transient soil seed bank）和持久土壤种子库（Persistent seed bank）的二元分类系统以及Thompson等人提出的把土壤种子库分为（1）短暂土壤种子库,（2）短期持久土壤种子库（Short term persistent seed bank）,（3）长期土壤种子库（Long termp ersistent seed bank）的三元分类系统在生态学文献中已被广泛采用。在此分类的基础上产生了植物种子在土壤中的持久性（Persistence）概念,持久性是指植物的一种特性,是指植物的种子在土壤中能够存活超过1a的特性;植物种子的持久性被认为是一种对环境的进化适应,它可以在多个生长季节萌发从而分担环境震荡的风险,持久土壤种子库不仅在不稳定的环境里占有优势;即使在稳定的环境里,也被认为能够减少种内和种间的竞争;造成持久性的原因可分为环境因子和种子本身的特性比如休眠等两个方面,持久土壤种子库的出现使得土壤种子库的研究与进化生物学结合起来,使得土壤种子库的研究进入一个新的领域,更易激发人们的兴趣。关于种子的大小、形状及持久性的关系问题已经引起了相当的争论,基本上有4种格局：一是种子大小和形状与种子在土壤中的持久性有关,小而圆或扁的种子在土壤易存活持久;二是种子大小与种子在土壤中的持久性有关,小种子在土壤中易存活持久,但种子形状与持久性无关;三是种子大小、形状与种子在土壤中的持久性无关;四为较大的种子在土壤易存活持久,而种子形状与种子在土壤中的持久性无关。影响种子在土壤中的持久性因子比较复杂,总结过去的文献发现主要有以下几个因子：①种子的散布方式,②捕食,③植被的物种组成,④风,⑤土壤基质,⑥火,⑦干扰等。通过比较分析和研究,提出影响种子大小和在土壤中的持久性关系格局的关键因子是气候,特别是生态系统所在地的雨量;湿润气候下容易产生前两种格局,而干旱环境下的生境容易产生后两种格局。