浑善达克沙地丘间低地植物群落的分类与排序

对浑善达克沙地中部丘间低地的草本植物群落进行TWINSPAN分类和DCA排序的研究结果表明,这些植物群落可分为4组：第1组为大针茅(Stipa grandis) 糙隐子草(Clistogenes squarrosa)群落,固定时间长,比较稳定,土壤全氮和有机质含量在四组群落中最高;第2组为冰草(Agropyron cristatum)群落,主要物种有冰草、冷蒿(Artemisia frigida)、苔草(Carex sp．)和糙隐子草,土壤全氮和有机质含量比第一组的低;第3组为羊草(Leymus chinensis) 赖草(Leymus secalinus)群落,群落物种少且主要为1年生种,有过严重的干扰,土壤全氮和有机质含量在4组群落中最低;第4组为西伯利亚剪股颖(Agrostis sibirica)群落,属于草甸性质的群落,土壤可溶性钠和可溶性钾含量高。群落DCA排序及排序轴与土壤因素的相关分析表明,土壤可溶性钠和pH值对群落的分布有显著影响,但群落在可溶性钠的梯度上分异更明显,说明盐分是影响浑善达克沙地中部丘间低地草本植物群落分布的主要因素。     

辽东山区天然次生林的数量分类

结合DCA排序和TW IN SPAN分类结果,将辽东山区天然次生林划分为5个群落类型:花曲柳林、蒙古栎林、阔叶混交林、水曲柳林、胡桃楸林。DCA排序与TW IN SPAN分类产生了较一致的分类结果。DCA第一轴代表的环境意义为坡向。花曲柳林多分布于阳坡的中坡及中上坡,蒙古栎林多分布在中上坡。花曲柳与蒙古栎常混生在一起,随着坡位上升,花曲柳优势度下降,而蒙古栎优势度增加。阔叶混交林多位于阴坡,乔木层没有稳定和绝对优势种,多以假色槭、风桦、色木槭为优势种,但假色槭分布于乔木层第2亚层。水曲柳林多分布在中下坡。胡桃楸分布在山下部,喜潮湿生境。色木槭在辽东山区分布广泛,重要值较高,且更新良好,很可能是群落演替顶级物种。辽东山区天然次生林林下藤本植株数量多,以五味子、软枣猕猴桃、狗枣猕猴桃为主。     

Classification and ordination of macroinvertebrate assemblages to predict stream acidity in upland Wales

Macroinvertebrates were collected from riffles at 104 sites in upland Wales during April and July 1984. Species assemblages were ordinated by DECORANA, classified by TWINSPAN and related to stream chemistry and other environmental factors using correlation and multiple discriminant analysis. DECORANA axis 1 was most strongly correlated with pH and aluminium concentration whilst axis 2 correlated with stream gradient and flow. Four TWINSPAN site groups established in each season were also principally related to pH and aluminium concentration, and reflected overall taxon-richness; differences between groups were most apparent during spring, when catchment forest cover and taxon-richness were also related. A dichotomous key based on indicator species was established for each season with the coleopteran Hydraena gracilis Germar and the Ephemeroptera, including Baetis rhodani Pictet, important indicators at Level 1. We propose that these indicator systems may be used for the rapid detection and assessment of acid waters throughout Wales, and that the methodology is applicable generally.     

苹果园噻虫嗪表土残留及其对地表节肢动物的影响

为了进一步评估苹果园施用噻虫嗪的生态风险,本研究利用QuEChERS技术改进前处理方法检测噻虫嗪在苹果园土壤中的残留,并监测了其对蜘蛛目、鞘翅目、双翅目和弹尾目等节肢动物种群数量及多样性特征的影响。结果表明,噻虫嗪在土壤中的添加回收率为90.11%~95.03%,变异系数为3.4%~6.63%,最小检出量均为0.1 ng,最低检出质量浓度均为0.02 mg/L。该方法缩小取样体积、节约试剂,提高了工作效率,适用于苹果园土壤噻虫嗪残留分析。噻虫嗪施用后在苹果园土壤中能够快速消解,消解动态满足一级动力学方程C=2.3421e-0.11t,其半衰期为6.36 d。苹果园施用噻虫嗪防治苹果蚜虫类害虫,表土节肢动物代表类群的生物多样性指数短期内会受到影响而降低,28 d后趋于恢复;对土壤蜘蛛类、甲虫的种群数量在5 d内有显著抑制作用,对地表双翅目、弹尾目的种群数量抑制作用较小。     

Soil arthropods as indicators of water stress in Antarctic terrestrial habitats?

Abiotic features of Antarctic terrestrial habitats, particularly low temperatures and limited availability of liquid water, strongly influence the ecophysiology and life histories of resident biota. However, while temperature regimes of a range of land microhabitats are reasonably well characterized, much less is known of patterns of soil water stress, as current technology does not allow measurement at the required scale. An alternative approach is to use the water status of individual organisms as a proxy for habitat water status and to sample over several years from a population to identify seasonal or long‐term patterns. This broad generalization for terrestrial invertebrates was tested on arthropods in the maritime Antarctic. We present analyses of a long‐term data set of body water content generated by monthly sampling for 8–11 years of seven species of soil arthropods (four species of Acari, two Collembola and one Diptera) on maritime Antarctic Signy Island, South Orkney Islands. In all species, there was considerable within‐ and between‐sample variability. Despite this, clear seasonal patterns were present in five species, particularly the two collembolans and a prostigmatid mite. Analyses of monthly water content trends across the entire study period identified several statistically significant trends of either increase or decrease in body water content, which we interpret in the context of regional climate change. The data further support the separation of the species into two groups as follows: firstly, the soft‐bodied Collembola and Prostigmata, with limited cuticular sclerotization, which are sensitive to changes in soil moisture and are potentially rapid sensors of microhabitat water status, secondly, more heavily sclerotized forms such as Cryptostigmata (=Oribatida) and Mesostigmata mites, which are much less sensitive and responsive to short‐term fluctuations in soil water availability. The significance of these findings is discussed and it is concluded that annual cycles of water content were driven by temperature, mediated via radiation and precipitation, and constituted reliable indicators of habitat moisture regimes. However, detailed ecophysiological studies are required on particular species before such information can be used to predict over long timescales.     

广西英罗港红树植物群落的非线性排序

采用主分量分析 (PCA)、无偏主分量 (DPC)和非度量多维调节 (NMDS)等方法对广西英罗港 2 2个红树植物群落样地进行了排序。PCA和 DPC分析结果表明 ,取样数据具有明显的非线性结构。通过 NMDS分析 ,得到二维 NMDS排序格局 ,它能较好地反映了红树植物群落与环境因子之间的相互关系。     

不同类型城市森林对土壤肥力的影响

以东北林业大学城市林业示范研究基地中9种人工林(兴安落叶松林、樟子松林、黑皮油松林、黄波罗林、胡桃楸林、水曲柳林、白桦林、蒙古栎林、针阔混交林)及附近的农耕地和撂荒地土壤为研究对象,通过对林地土壤不同层次pH值、有机质及主要养分含量的测定分析,研究了不同林型对土壤肥力的影响.结果表明：阔叶林(除蒙古栎林)的土壤趋于中性,针阔混交林、兴安落叶松林、樟子松林和黑皮油松林的土壤呈微酸性,蒙古栎林的土壤呈酸性;随土壤深度增加,土壤有机质、水解氮、速效钾、有效磷、全氮、全磷含量均呈下降趋势.不同林地土壤同一层次化学指标整体差异显著(P＜0.05).土壤肥力优劣为：水曲柳林>黄波罗林>针阔混交林>胡桃楸林>白桦林>撂荒地>农耕地>樟子松林>兴安落叶松林>蒙古栎林>黑皮油松林,说明阔叶林(除蒙古栎林)和针阔混交林中的土壤肥力增加,而针叶林的土壤肥力趋于下降.     

常绿阔叶林片段中木荷凋落叶分解速率及中小型土壤节肢动物群落的结构动态

2004年6月-2006年4月,选择浙、闽、赣交界山地的4个森林片段作为研究地点,并以浙西的古田山国家级自然保护区作为连续森林对照,采用尼龙网袋法,研究了不同常绿阔叶林群落优势种木荷凋落叶的分解速率及土壤节肢动物群落的结构和动态.结果表明：5个研究地共获土壤节肢动物1050个,分属8纲23目,其中鳞翅目、膜翅目、弹尾目和双翅目占个体总数的10%以上,为该地区的优势类群.片段化对群落物种组成的影响主要体现在稀有类群的差异上.不同分解阶段各种土壤节肢动物类群优势度因其功能的不同而各异.经过2年的分解,各研究地木荷凋落叶损失量为60%～70%,研究地凋落物中土壤节肢动物的各项多样性指标均有一定的变化,且与连续森林的变化规律不一致.     

拉萨河谷草地群落的数量分类与排序

采用TWINSPAN数量分类和DCA、CCA排序的方法,对拉萨河谷草地23个样点进行统计分析。结果显示:(1)TWINSPAN数量分类将拉萨河谷草地群落划分成8种类型,拉萨河谷的草地群落分布呈现明显的垂直地带性分布格局。(2)TWINSPAN分类所划分的各群落在DCA排序图上都有各自的分布范围和界限,说明DCA排序能较好的反应各群落与其环境资源之间的关系,同时,TWINSPAN的分类结果也在排序图上得到较好的印证。(3)样点DCA排序的第一轴基本反映了海拔高度的变化梯度,第二轴基本反映了坡向的变化。(4)样点CCA排序表明,影响群落分布的主要环境因子是海拔,其次是坡向。CCA排序进一步阐明了拉萨河谷草地群落分布决定于海拔和坡向等环境因子,并间接验证了TWINSPAN的分类结果。(5)物种CCA排序和TWINSPAN分类结果表明:植物群落中物种的分布格局与植物群落类型的分布格局存在一定的相似性,物种的分布格局在很大程度上影响着群落的分布格局。     

秸秆还田对中国农田土壤节肢动物数量及多样性影响的整合分析

秸秆还田是提高土壤生物数量和多样性的有效手段,但土壤节肢动物对秸秆还田的响应尚未明确。搜集2005到2020年国内有关秸秆还田对农田土壤节肢动物数量及多样性影响的25篇田间试验文献,分别获得230对土壤节肢动物数量数据和112对土壤节肢动物多样性数据,并采用整合分析方法探究不同气候类型、土层深度、种植制度、秸秆还田量、还田方式及还田时间下秸秆还田对农田土壤节肢动物数量及多样性的影响。结果表明,与不还田相比,秸秆还田总体上显著增加了农田土壤节肢动物的数量,但在亚热带季风气候区或还田时间大于5 a时,秸秆还田对节肢动物数量的增加效应则不显著;此外,秸秆还田对土壤节肢动物数量的促进作用还受到节肢动物体型的影响,秸秆还田显著增加土壤中小型节肢动物的数量,特别是蜱螨目类土壤节肢动物,但是对大型土壤节肢动物的促进作用并不显著。秸秆还田总体上也提高了农田土壤节肢动物的多样性,特别是在温带季风气候、年均温小于5℃、年均降水量小于600 mm、秸秆还田量大于10000 kg/hm²、轮作以及还田时间大于5 a这些条件下,秸秆还田能显著提高土壤节肢动物的多样性。回归分析结果显示随着秸...     

小陇山国家级自然保护区次生林分类、排序及演替

在野外调查基础上,采用TWINSPAN和DCA对小陇山林区次生林群落进行了数量分类和排序,从植物群系组成、植物群落与环境的生态关系方面,研究小陇山植被群落的分布格局,用以确定该区次生林演替,并给予合理的环境解释。结果表明:采用TWINSPAN数量分类方法,将植被划分为12个群落类型;DCA排序图明显反映出排序轴的生态意义,第一轴基本上突出反映了湿度变化,沿第一轴从左到右,湿度逐渐增大;第二轴主要表现了温度梯度,沿第二轴从下到上,温度逐渐降低;次生林的演替序列为山杨林→山杨+白桦林→锐齿栎混交林及锐齿栎纯林,其自然恢复演替以锐齿栎林为顶极群落。     

沼液施用对海岸带围垦麦田土壤中小型节肢动物群落的影响

土壤节肢动物群落结构是反映土壤动物多样性及土壤质量的重要指标。沼液施用对土壤结构与肥力的改变,可能对土壤节肢动物群落的特征产生显著影响。以江苏东台海岸带连续施用沼液5年的围垦麦田为例,研究沼液不同用量(0、100、200、300 m~3/hm~2)及沼液替代(0%、33%、66%、100%)化肥对土壤中小型节肢动物群落结构的影响。结果表明:各施肥管理下麦田土壤中小型节肢动物的优势类群均为前气门亚目、甲螨亚目和弹尾目,平均分别占总捕获量的52.09%—53.33%、22.42%—23.86%和13.14%—16.51%。当沼液用量从0增加到300 m~3/hm~2时,土壤动物密度增加了94%,类群数增加约2个,优势度指数增加9.4%(P<0.05)。沼液66%替代化肥时,土壤动物密度、类群数和优势度指数最高。因此,施用沼液显著增加了土壤中小型节肢动物的密度、类群数与优势度指数。当沼液替代化肥的比例为66%时,促进效应最佳。主成分分析表明,无论单施沼液还是沼液替代化肥,弹尾目、前气门亚目与甲螨亚目的响应最为敏感,可将其作为土壤中小型节肢动物对施肥响应的指示指标。     

浙江金华不同城市绿地大型土壤动物群落结构与多样性

2004年10-11月对金华市市区8种城市绿地生境中的大型土壤动物群落进行了调查,共获得大型土壤动物1231只,隶属3门8纲20目。其中优势类群为近孔寡毛目、膜翅目、双尾目和蜘蛛目,常见类群为正蚓目、等足目、柄眼目、鞘翅目、鳞翅目、双翅目和同翅目,其余类群为稀有类群。不同城市绿地生境中的土壤动物的类群组成以及个体数不同。在土壤动物研究中,群落复杂性指数(C)比Shannon-Wiener指数(H′)更能体现群落的复杂性与多样性,且能修正不同类群个体数对多样性的影响。大型土壤动物显示了明显的表聚现象,垂直分布有明显差异,类群数和个体数随深度增加而减少。群落聚类以及排序的结果显示,8种城市绿地生境中的大型土壤动物群落可以分为6大类:草坪类、草地类、新植草坪类、无草本层的人工林类、有草本层的人工林类和灌木林类。     

农林复合生态系统防护林斑块边缘效应对节肢动物的影响

于2008和2009年在黄淮海平原典型地区商丘民权林场(34°31'-34°52'N, 115°00'-115°28'E)进行。选择杨树林、槐树林和杨槐混交林3种人工林模式,调查节肢动物群落构成、生物多样性及边缘效应对节肢动物群落结构的影响。结果显示,节肢动物科级水平上不同年份间的类群数和个体数差异都不显著(P>0.05),防护林不同模式间个体数(df=2, F=59.48, P<0.001)和类群数(df=2, F=15.44, P<0.001)差异均显著。3种防护林中以杨树林物种丰富度指数较高,S_杨树林(9.65)>S_{杨槐混交林}(8.78)>S_槐树林(7.47);生物多样性指数H'_杨树林(1.78)>H'_{杨槐混交林}(1.65)>H'_槐树林(1.46),其中杨树与槐树林的S和H'差异显著(P<0.05)。杨树林和槐树林边缘效应对节肢动物群落的影响大于杨槐混交林,林地边缘节肢动物的类群数和个体数均较高。节肢动物类群组成表现为林地边缘的偶见种和农田种多于林内。杨树林和槐树林边缘节肢动物多样性指数较高,向林内40m显著下降;而杨槐混交林边缘效应对节肢动物多样性指数的影响较小。综合分析认为,杨树林和槐树林边缘效应对节肢动物群落结构和多样性的影响距离为40m,杨槐混交林距离为20m。单一树种农田防护林斑块不小于80m宽,混交林斑块不小于40m宽,可以保护林内物种生存,维持农田生态系统生物多样性。     

Habitat and species identity,not diversity,predict the extent of refuse consumption by urban arthropods

Urban green spaces provide ecosystem services to city residents, but their management is hindered by a poor understanding of their ecology. We examined a novel ecosystem service relevant to urban public health and esthetics: the consumption of littered food waste by arthropods. Theory and data from natural systems suggest that the magnitude and resilience of this service should increase with biological diversity. We measured food removal by presenting known quantities of cookies, potato chips, and hot dogs in street medians (24 sites) and parks (21 sites) in New York City, USA. At the same sites, we assessed ground‐arthropod diversity and abiotic conditions, including history of flooding during Hurricane Sandy 7 months prior to the study. Arthropod diversity was greater in parks (on average 11 hexapod families and 4.7 ant species per site), than in medians (nine hexapod families and 2.7 ant species per site). However, counter to our diversity‐based prediction, arthropods in medians removed 2–3 times more food per day than did those in parks. We detected no effect of flooding (at 19 sites) on this service. Instead, greater food removal was associated with the presence of the introduced pavement ant (Tetramorium sp. E) and with hotter, drier conditions that may have increased arthropod metabolism. When vertebrates also had access to food, more was removed, indicating that arthropods and vertebrates compete for littered food. We estimate that arthropods alone could remove 4–6.5 kg of food per year in a single street median, reducing its availability to less desirable fauna such as rats. Our results suggest that species identity and habitat may be more relevant than diversity for predicting urban ecosystem services. Even small green spaces such as street medians provide ecosystem services that may complement those of larger habitat patches across the urban landscape.     

藏北高原草地群落的数量分类与排序

采用TWINSPAN数量分类和DCA、CCA排序的方法,对藏北高原草地29个样点进行统计分析。结果显示:(1)TWINSPAN数量分类将藏北高寒草地群落划分成10种类型。(2)样点DCA排序第一轴基本反映了水分环境梯度,第二轴基本反映了热量梯度。(3)TWINSPAN分类所划分的各群落在DCA排序图上都有各自的分布范围和界限,说明DCA排序能较好的反应各优势群落与其环境资源之间的关系。(4)样点CCA排序表明,影响群落分布的首要环境因子是水分因子(年均降水量)和空间因子(经度),其次是热量因子(年均温度),CCA排序进一步阐明了群落分布决定于水分和温度等环境因子,并间接验证了TWINSPAN的分类结果。(5)物种CCA排序和TWINSPAN分类结果表明:植物群落中物种的分布格局与植物群落类型的分布格局存在一定的相似性。     

Recognition of successional pathways in forest communities using size-class ordination

Certain of the problems associated with the use of size-class ordinations to identify successional pathways are explored. Examples of such ordinations, where it was attempted to minimize a number of the interpretational dangers noted by Austin (1977), are presented for two tropical rainforest types from Papua New Guinea. By limiting the analysis to groups of sites which show a high degree of homogeneity, and by using the non-linear ordination method Continuity Analysis (Noy-Meir 1974) a simple successional interpretation of the species-in-size-class data was possible. As heterogeneity increases so does the number of possible interpretations of the resultant size-class-in-space pattern.Nomenclature follows Paijmans, K. (ed.) 1976. New Guinea Vegetation. A.N.U. Press, Canberra.I would like to thank Dr. T. Meredith and Dr. J. Ogden for reading and commenting on a draft of this paper. The research was conducted whilst the author was a Ph.D. scholar in the Department of Biogeography and Geomorphology, R.S.Pac.S., Australian National University, Canberra, Australia.     

Non-target impact of deltamethrin on soil arthropods of maize fields under conventional and no-tillage cultivation

Abstract:  Deltamethrin is a commonly used insecticide for controlling its key maize pest, the fall armyworm Spodoptera frugiperda (Lep., Noctuidae). Its toxicological profile is well known, but its impact on arthropods widely reported as bioindicators, mainly springtails (Collembola) and mites (Oribatida), is yet to be assessed in tropical maize fields. The treatments used to circumvent this shortcoming were conventional cultivation and no-tillage cultivation (with a pre-sowing application of 2,4-D and glyphosate) systems with or without deltamethrin spraying. The deltamethrin residue analysis of soil samples by gas chromatography did not detect the insecticide 24 h after it was sprayed on the maize fields. There was no significant overall effect of deltamethrin based on principal component analysis. However, repeated-measures analyses of variance detected significant impact of deltamethrin in a species of Nitidulidae (Coleoptera). The cultivation system also provided significant impact on Oribatida and Gamasida soil mites and on the same Nitidulidae species referred above, which were more abundant in the conventional cultivation system. Springtails were also significantly affected by the cultivation system showing greater abundance in the conventional system, except Podumorpha. Analyses using only high taxonomic levels did not allow the detection of impact in the ant assemblage assessed. The results suggest that the impact of deltamethrin on soil arthropods from tropical fields varies among species and is lower than expected. The cultivation system imposes more drastic effects on arthropod assemblage.