河套灌区九排域农田排水沟植物物种多样性

2010年8-9月对河套灌区九排域农田排水沟植物进行了综合调查.分别在干沟、支沟、斗沟/农沟的上、中、下游布设断面,断面上设置0.5m×0.5m和5m×5m样方对草本和灌木的植物种类和数量进行调查.结果表明:河套灌区九排域农田排水沟植物由17个科、38个属、39个种组成,禾本科(n=10)、菊科(n=7)和藜科(n=4)植物种类最多,芦苇、羊草和盐地碱蓬是分布面积最广的物种.干沟、支沟和斗/农沟的多样性指数、丰富度指数、均匀度指数和优势度指数值分别为0.57、1.93、0.37和0.81,0.77、3.46、0.65和0.50,0.90、3.88、0.64和0.53.物种多样性表现为边坡的高于沟底,但排沟等级间的变化趋势不明显.水的存留时间及农业管理(清沟)是影响植物物种多样性最主要的因素.     

宁蒙引黄灌区农田排水沟渠水质特征

黄河上游农业面源污染正在变成影响黄河水质的主要污染源,威胁到下游黄河流域水资源的安全利用。通过对宁蒙引黄灌区排水沟渠土壤和水质的调查,发现宁蒙灌区排水的pH、TN、TDS和NO3--N分别受不同排水沟渠、排水沟渠级别及二者互作的影响。内蒙古九排干排水的TDS和NO3--N浓度受排水时间影响显著,TN、TP、NH4+-N和COD浓度主要受排水时间、沟道级别及二者互相的影响。宁蒙灌区沟底底泥中的全盐含量明显低于边坡,而TN和TC平均是边坡土壤的1.2倍。内蒙古河套灌区沟底底泥中TN、TP和TC的增加比例是宁夏灌区的1.6、3.8和6.3倍。内蒙古河套灌区农田排水水质明显差于同期(8月)的宁夏灵武灌区,其TDS、TN、TP、NH4+-N和COD浓度是宁夏灵武灌区的3.2、2.5、2.8、10.0和1.5倍。宁蒙引黄灌区农田排水污染以氮含量超标为主,尤其以农沟和干沟为主,而磷浓度较低,基本不造成污染。内蒙古引黄灌区各主要排水时期,以8月农沟排水中氮超标和干沟排水中氮和磷污染程度最高。     

旱区排水沟植被空间分布格局与土壤因子的关系

揭示旱区排水沟植被空间分布格局与土壤因子间的关系，可为旱区农田排水沟渠湿地的生态环境修复与生态灌区构建提供理论依据和技术指导。以陕西富平卤泊滩盐碱地的排水干沟和斗沟为例，采用野外调查、方差分析、相关性分析、典型相关分析和RDA分析方法，研究了排水沟边坡植被和土壤因子(含水率、电导率和pH)的时空分布特征以及植被和土壤因子间的相关关系。结果表明：(1)排水沟边坡植被分区明显(芦苇区、过渡区和共生区),干沟物种多样性高于斗沟、物种优势度低于斗沟；干沟和斗沟不同分区的植被Simpson优势度指数均随距排水沟距离的增大而减小，物种丰富度指数、Shannon多样性指数和Pielou均匀度指数随着距排水沟距离的增大而增大；(2)3月土壤含水率(均值23.7%)最高，9月土壤电导率(均值576.97μS·cm^-1)和pH(均值8.95)最高，但不同时期间差异不显著；干沟芦苇区的土壤含水率、电导率和pH最大，斗沟芦苇区的土壤含水率最高、过渡区的土壤电导率和pH最大，且不同分区间差异显著；(3)决定旱区排水沟植被空间分布和物种丰富度的关键土壤因子是含水率与电导率。根据研究结果，本文...     

样地面积对黔中喀斯特石漠灌丛林植物多样性的影响

在生境要素及植被发育程度相似的黔中喀斯特石漠灌丛林内,一次性完成12个200 m2样地及其中96个25 m2样方的调查,采用改进的巢式样方法研究植物多样性指数值随样地面积增加的变化规律,并为确定植物多样性研究的最小调查样地面积提供科学依据。结果表明:随着有序样地面积增大,灌木植物Patrick指数、Gleason指数及Margalef指数值增加,Shannon指数、Pielou指数及Alatalo指数值先增后减,样地间6种植物多样性指数值的差异性显著; Simpson指数及McIntosh指数值也先增后减,但样地间2种植物多样性指数值的差异性不显著。8种植物多样性指数按信息保存量≥80%划分,最小调查样地面积被划分为2种类型:100 m2样地包括Patrick指数,反映物种数量多少; 25 m2样地包括Gleason指数、Margalef指数、Simpson指数、Shannon指数、Pielou指数、Alatalo指数及McIntosh指数,反映植物多样性及均匀度。8种植物多样性指数值的ConnorMcCoy模型拟合效果较好、de Caprariis模型及Michaelis-Menton模型拟合效果较差,Patrick指数和Margalef指数的Arrhenius模型及Logistic模型拟合效果也较好。8种植物多样性指数与96个样方的灌木植物平均高度和草本植物平均盖度的相关性显著,与草本植物平均高度的相关性不显著。主成分分析表明,立地要素、林分密度及林分空间属性对石漠灌丛林灌木植物多样性的贡献率分别为4.3%～11.7%、35.4%～67.9%和20.4%～60.2%,灌木植物多样性主要受林分结构及发育程度的影响。     

方山中山丘陵区植物多样性研究

以方山地区27个样方的调查资料为基础,从物种种类组成的相似性,不同层次的物种丰富度,物种多样性等方面对方山植物多样性进行分析.结果表明,该地区乔木层物种丰富度较低,而灌木层和草本层较高;该地区物种多样性随海拔高度的升高而降低;在同一海拔高度上,北坡的物种多样性大于南坡;人类活动对该地区植物物种多样性有明显影响.     

宁夏灵武地区农田排水沟植物物种多样性

为探索宁夏灵武地区农田排水沟植物物种组成和多样性特征,选择24条农田排水沟,分别于2009和2010年8月对植物物种和群落结构进行调查,并对物种多样性特征进行分析.结果表明,排水沟植物由17科36属43种组成,分为以芦苇(Phragmites australis)为主要建群种的6种群落类型和1个沉水植物群落,其中水烛+芦苇(Typha angustifolia+Phragmites australis)群落生物量(平均鲜重达2326.2 g· m-2)显著高于其他群落,2010年排水沟植物群落生物量较2009年小;边坡较沟底的物种多样性高,其中Shannon指数、丰富度指数差异达到显著水平,且2009年沟底物种多样性高于2010年.排水沟水文条件、水质和人为干扰可能是影响农田排水沟植物分布、群落组成及多样性特征的主要因素.     

成南高速公路边坡植被恢复模式

采用样线法对成南高速公路边坡植被恢复进行调查,并分析了研究区域内植物群落的α多样性指数以及重要值参数,同时,根据坡度差异将调查所得边坡划分为斜坡(Ⅰ)、陡坡(Ⅱ)和急坡(Ⅲ)三大类.结果显示:调查所得植物属于41个科,85属,91个种;其中豆科(Leguminosae)、禾本科(Gramineae)、菊科(Asteraceae)、蔷薇科(Rosaceae)的种类最多,占全部种数的44％;不同类型坡面具有不同的适应物种,草本层和灌木层具有不同的适应性特征.同时,通过分析多样性指数和重要值筛选出了不同类型边坡的实用性物种,并根据此次调查的分析处理结果,提出了植被恢复的一些原则以及建议.     

衡山青冈栎群落结构及物种多样性研究

利用样方法进行野外群落调查,共设计了15个样方,每个样方大小为20m×5 m,对衡山青冈栎(Cyclobalanopsis glauca)群落的种类组成、外貌、结构特征及物种多样性进行了研究.结果表明:在1 500 m2样地中,共有维管束植物26科37属46种,其中优势科为壳斗科、山茶科和蔷薇科等;该群落主要是以青冈栎为主的单优种群落,生活型谱以高位芽植物占绝对优势,叶级谱以中、小型叶为优势的特点,群落季相不明显;群落分层较明显,乔木层树种很少,灌木层种类较丰富,对群落物种多样性具有较大影响;物种多样性分析显示该群落多样性指数偏低,其多样性复杂程度由高到低的顺序为灌木层、藤本层、乔木层、草本层.     

乡土植物生活型构成对川渝地区边坡植被水土保持效益的影响

乡土植物灌木化建植是高速公路边坡防护的重要生态模式。为了探讨生态恢复过程中乡土植物的生活型构成对边坡植被水土保持效益的影响,揭示乡土植物生活型-物种多样性-生态系统功能间的偶合关系,借助3个物种配置试验,于2009年4月构建了以草本、灌木或乔木为主体的草本型、灌木型、乔木型绿化配置及草-灌-乔混合型试验区。自建植次年(2010年)起,对试验区进行持续5a生态监测。结果表明:1)边坡植被的物种丰富度与乡土植物的生活型有关,呈现乔木型灌木型草-灌-乔混合型草本型趋势;2)植被的物种多样性(Shannon-Wiener指数、Pielou指数)与乡土植物生活型构成及建植年限有关:建植后第1、第2年,多样性水平呈草本型草-灌-乔混合型灌木型乔木型变化趋势;自建植后第三起(2012—2014年),呈草-灌-乔混合型草本型灌木型乔木型波动;3)植被的水土保持性能(径流系数、侵蚀模数)与群落的物种多样性密切相关:多样性水平越高,水土保持性能越强。可见,乡土植物的生活型构成对提高边坡植被的物种多样性、改善生态性能至关重要。     

恢复方式和地形对晋西黄土区退耕林分物种多样性的影响

运用样带样方调查法,对比不同恢复方式和地形条件下退耕林分的物种多样性,以期为晋西黄土区植被恢复效果评价和经营管理提供参考.结果表明: 恢复方式对退耕林分物种多样性具有显著影响.自然恢复林物种数为刺槐人工林的 1.6倍,Shannon 指数大于刺槐人工林,Pielou 指数小于刺槐人工林.物种多样性受坡位影响显著,各指数均表现为沟底>沟坡>梁峁坡>梁峁顶;坡向对退耕林分物种多样性影响不显著,各指数均表现为阴坡>阳坡.物种多样性受地形和恢复方式综合作用影响显著,在自然恢复林阴坡沟底处最高,物种均匀度在刺槐人工林阴坡沟底处最高.从提高物种多样性角度,黄土区植被恢复在遵循适地适树原则的同时,应参照自然恢复林分,在不同地形部位采用不同的造林设计.     

山西霍山灌丛空隙草本植物物种多样性与更新

采用物种重要值和物种多样性指数,分析了山西霍山灌丛空隙内主要草本组成及其多样性随灌丛空隙面积梯度的变化规律。结果表明:在自然状况下形成的10 m2的灌丛空隙最多,占51.2%。灌丛空隙内草本植物的重要值高于灌丛下草本,且以10~20 m2的空隙为最高。主要草本可分为3类:(1)对灌丛空隙更新反应不明显的草本,(2)对灌丛空隙有正更新反应的草本,(3)对灌丛空隙有负更新反应的草本。灌丛空隙内的物种丰富度、多样性指数和均匀度指数均高于灌丛下,而生态优势度均小于灌丛下,呈现"单峰型"的变化趋势,且在10~20 m2达到峰值。因此,适宜大小的灌丛空隙是森林生态系统草本层植物多样性维持的重要途径。     

Plant diversity in a water-meadow landscape: the role of irrigation ditches

Species-rich, extensively managed grasslands are among the most threatened ecosystems in Europe. The traditional technique of meadow irrigation, formerly practised in large parts of Europe, may be a viable management option that meets both ecological and economical objectives. While studies on plant diversity of the meadow matrix exist, the role of other landscape components for biodiversity conservation is unknown. We quantify the role of irrigation and drainage ditches compared with field paths, and analysed the local and landscape plant species composition and diversity in a water-meadow landscape. The meadows are located in the river Queich catchment (Upper Rhine valley, Germany). We recorded plant species cover on 18 meadows, adjacent ditches and field paths and analysed alpha, beta and gamma diversity within and among these landscape components. Irrigation and drainage ditches were more species rich than meadows and more heterogeneous in their species composition compared with meadows and paths. Ditches contributed one-third of the landscape’s plant species numbers, habitat for wetland species and refuges for high nature value grassland species. Fertilization of the adjacent meadow had no negative impact on the ditch diversity, while well-maintained ditches were more plant species rich than ditches filled with sediments. Traditional flood meadow irrigation should be taken into account when sustainable grassland management techniques are discussed that meet economical and ecological needs. A major contribution to landscape richness arises from the ditch structures as crucial part of the traditional irrigation technique.     

西双版纳热带山地常绿阔叶林蕨类植物多样性研究

基于4个50m×50m(包含400个5m×5m)样方调查,统计了蕨类植物的α多样性指数、优势度指数、相似性指数及β多样性指数。结果表明:在调查的1hm2西双版纳热带山地常绿阔叶林里,蕨类植物的物种丰富度为32种;不同样地蕨类植物丰富度指数、多样性指数、优势度指数及均匀度指数的变化趋势一致;该森林群落蕨类植物的物种多样性虽然不高,但优势种群显著;通过3个无人为干扰与1个受人为干扰样地的对比分析研究看出,该类森林遭受一定程度的人为干扰后,蕨类植物物种丰富度、多样性、优势度及相似性等均显著下降,其中物种多样性的降低尤为显著,既使群落的外貌、结构等恢复至接近原始林状态,蕨类植物丰富度及多样性也难以恢复,故此,保护原始的森林植被是保护该森林蕨类植物多样性的有效措施之一。     

白龙江干旱河谷不同坡向主要灌丛群落随海拔梯度变化的物种多样性研究

采用样方调查法,研究了白龙江干旱河谷不同坡向主要灌丛群落沿着海拔梯度的结构特征、物种多样性的变化规律,旨在了解白龙江干旱河谷不同海拔梯度植被特征和物种多样性变化,为白龙江干旱河谷区域不同海拔植被恢复提供理论依据。研究结果表明：（1）不同海拔梯度同一坡向物种数不同,同一海拔不同坡向物种数也不同,随着海拔的升高不同坡向物种数表现为先增加后减少的趋势,同一海拔梯度内不同坡向主要植被类型也不同。（2）主要灌木群落α多样性在不同坡向随着海拔梯度的升高,表现出先升高后减小的趋势。不同坡向草本群落α多样性随着海拔的升高,也表现出先升高后减小的趋势。对主要灌丛α多样性指数进行相关性分析得物种丰富度指数对物种多样性贡献率最大,表现为丰富度指数（D₁、D₂）> 生态优势度指数（SN）> 种间机遇指数（H）> 群落均匀度指数（R）。（3）不同坡向主要灌丛群落β多样性Whittaker指数沿着不同海拔梯度变化不大,最大值出现在海拔1250~1650m;Routledge和Codyβ多样性指数在海拔1450~1650m出现最大值,但是大体呈现出波形变化。草本β多样性随着海拔的升高变化较大,阳坡植物的β多样性指数在海拔1050~1250m达到最大,阴坡和半阴半阳坡在海拔区间1250~1450m达到最大,半阴半阳坡的β多样性指数均大于阳坡。白龙江干旱河谷不同坡向、不同海拔梯度物种α多样性和β多样性都不同,且不同坡向随着海拔梯度的变化物种α多样性和β多样性呈一定的相关性,说明海拔和坡向是影响生物多样性主要因子之一。     

Patterns of diversity in the strata of boreal montane forest in British Columbia

Abstract. Patterns of diversity were analyzed in a boreal coniferous forest and its strata (tree, shrub, herb and bryophyte layers): number of species per community — α-diversity, total species richness — γ-diversity, mean similarity — β-diversity, and mosaic diversity, a measure of complexity. These four measures of diversity consistently decreased from lower to upper vegetation layers. To study the effect of juveniles of larger life forms on diversity of lower layers, they were removed from the data and the measures of diversity reanalyzed. Number of species per community and mosaic diversity decreased substantially, but β-diversity did not change. So, the effect of juveniles on γ-diversity is due to the greater number of species per community. Multiple regression models revealed that the relationships between α-diversity and the environmental variables were the same for the whole forest and for the herb layer. Elevation and soil pH were the major variables explaining α-diversity in the whole community. Climate was the only environmental gradient related to species richness in all individual strata. Tree and herb richness values were negatively related to soil drainage and acidity, respectively. Species richness of the plant community was affected by environmental variability mostly through the herb layer. Various explanations of the observed diversity patterns included: environmental constraints, resource competition, generation time, and colonization processes.     

天山中段南坡巴伦台地区不同海拔植物群落物种多样性与土壤因子的关系

为探讨天山中段南坡巴伦台植物群落物种多样性随海拔梯度的分布特征及其与土壤环境因子的关系,该研究采用野外调查的方法,在和静县巴伦台地区海拔范围内设置34个样地进行了植物多样性和土壤因子的调查及室内指标的统计分析。结果表明:(1)研究区共调查到30科75属134种植物,草本层为主要优势层。不同海拔高度上土壤理化指标具有异质性,土壤含水量、全盐、有机质、全氮、全钾、有效氮和有效钾差异性显著(P<0.05),其中除全钾以外,其他土壤因子的含量均表现为中海拔大于低、高海拔区域。随海拔的升高,植物群落在低、高海拔段Pielou均匀度指数较高; 灌木层物种Patrick丰富度指数较低; 草本层物种Shannon-Wiener指数、Simpson指数随海拔升高先增加后减小。(2)RDA分析表明,影响植物群落物种多样性的主要环境因子是海拔、土壤含水量、全盐、有机质、全氮和有效氮。海拔作为主导因子,与草本层各物种多样性指数呈正相关,与灌木层各物种多样性指数呈负相关关系; 全盐是抑制植物群落总体物种Simpson指数的主要土壤因子; 氮元素一定程度上限制灌木、半灌木物种的生长。该研究结果表明土壤因子对不同生活型物种多样性的形成具有一定的筛选作用及不同物种对环境变化的适应策略不同。     

Wind and Water Dispersal of Wetland Plants Across Fragmented Landscapes

Biodiversity in wetlands is threatened by habitat loss and fragmentation, of which agricultural activities often are a cause. Dispersal of plant seeds via wind and ditches (water) may contribute to connecting remnant wetland plant populations in modern agricultural landscapes, and help to maintain and restore biodiversity. We developed a spatially explicit model to assess the relative importance of dispersal by wind and dispersal by water through drainage ditches for two wetland plant species in agricultural landscapes: a typical wind disperser and a typical water-disperser. Simulation results show that the typical wind disperser had a much higher capability to disperse by wind (90th percentile <30 m) than the typical water-disperser (90th percentile <2 m). Surprisingly, the capability to disperse via water was similar for the two species: 90th percentile dispersal distances following a combination of wind and water dispersal were between approximately 100 and 1000 m. Dispersal by water transported more seeds over long distances for both species. The main determinants for dispersal distance by water were roughness of the ditch (determined by, for example, bank vegetation) and the presence of obstructions (for example, culverts). Density or direction of the ditch network did not seem to affect water dispersal distances substantially. From a biodiversity conservation perspective, it would be most useful if areas with suitable riparian wetland habitat were intersected with a network of shallow ditches with a high roughness promoting seed deposition. These areas should then be connected to other suitable areas by a few regularly cleaned ditches with no obstructions and low seed trapping probability.     

Plant diversity patterns in the Aljibe Mountains (S. Spain): a comprehensive account

The Aljibe Mountains are located in the southern tip of the Iberian Peninsula and have a remarkable biogeographical interest. The complete plant species list (trees, climbers, shrubs, perennial and annual herbs, ferns, lichens, bryophytes and macroscopic algae) was recorded in four 0.1 ha plots from each of the most representative community types (Quercus suber woodland, Q. canariensis forest, open heathland and Q. coccifera shrubland). Up to 119 plant species were found in total in the Q. suber woodland plot. The diversity of woody plants was analysed from 44 samples of cover (100 m line), and the herbaceous layer was explored in 200 quadrats (of 0.5 × 0.5 m). Three biodiversity components (species richness, endemism, and taxonomic singularity) were evaluated in both shrub and herbaceous layers. Open heathlands showed the highest richness of endemic species, both woody and herbaceous. The highest number of woody species was found in the evergreen Q. suber woodland, and of herbaceous species in the semi-deciduous Q. canariensis woodland. Taxonomic singularity was higher in Q. canariensis woodlands and Q. coccifera shrublands for woody species, but there were no significant differences in the herbaceous layer. Local species diversity of heathlands in this region resembles that of South African heathlands (fynbos), despite the obvious geographic and floristic distance, and contrasts with the low diversity of biogeographically closer, European temperate heathlands. The Aljibe Mountains show high diversity values for different life forms (from trees to mosses) and spatial scales (from community to region), and are rich in endemic species. Thus, this area should be recognised as a relevant unit within the Mediterranean plant diversity hot spots.