共查询到17条相似文献，搜索用时 173 毫秒
1.
2.
为研究井陉县大青山地区野皂荚群落植物组成和多样性特征，以太行山中部井陉县低山区的野皂荚群落为研究对象，采用样方法，分析群落植物组成和多样性特征。结果表明，井陉县大青山地区野皂荚群落共有植物30种，隶属于19科28属；从植物组成来看，调查样地植物种类较多的是禾本科、豆科和菊科；植物优势种为鹅耳枥、野皂荚、荆条、中亚苔草和中华卷柏；从多样性指数来看，灌木层和草本层多样性指数、丰富度均高于乔木层；而乔木层的均匀度和优势度均高于灌木层和草本层。 相似文献
3.
4.
对藏东南地区不同坡向及海拔高度下云南松次生林中植物种类、主要物种重要值、植物物种多样性等进行了调查,以揭示云南松次生林中植物空间分布格局。结果表明:样地内共有植物20科32属41种,单科单属单种物种相对较多。云南松的重要值阳坡高于阴坡,随海拔高度的增加而增加;所有植物阴、阳坡重要值均存在一定差异,灌木中阳坡海拔2 100m处拟变缘小檗重要值最高,海拔2 300、2 500m处雅致山蚂蟥重要值最高;阴坡2 100、2 300m处拟变缘小檗重要值最高,2 500m处米饭花重要值最高;阴、阳坡不同海拔高度所有植物中,蕨的重要值阳坡随海拔高度先升高后降低,阴坡随海拔高度上升而下降。物种丰富度指数阴坡高于阳坡,阴坡海拔2 300m处最高,阳坡物种丰富度指数随海拔升高呈下降趋势;物种Pielou均匀度指数、物种Shannon-Wiener、Simpson多样性指数阴坡均高于阳坡,随海拔的上升逐渐降低。 相似文献
5.
《果树学报》2020,(4)
【目的】探索施药和田间生草对苹果园节肢动物群落多样性的影响,为提高幼龄苹果园生物防治效果和天敌利用提供参考。【方法】通过田间节肢动物群落调查,研究施药清耕、地布+行间自然生草、自然生草和非施药的清耕、地布+行间自然生草、自然生草对幼龄苹果园节肢动物群落结构及相对稳定性的影响。【结果】幼龄苹果园内节肢动物种类包括14目77科123种,植食性害虫主要为蚜科、蓟马科和飞虱科害虫,金蛛科为主要天敌,蝇科昆虫为中性种类。田间生草能显著提高物种丰富度、多样性、均匀度、相对稳定性,施药能显著减少苹果园天敌和中性物种数量,促进植食性害虫增加,降低群落结构稳定性。主成分分析表明,物种多样性指数、均匀度、物种数量、优势集中性为第一主成分,物种丰富度为第二主成分;相似性指数和聚类分析分析结果表明,节肢动物群落分成4大类:自然生草不施药和地布+行间自然生草不施药、自然生草施药和地布+行间自然生草施药、清耕施药、清耕不施药。【结论】幼龄苹果园内生草可以优化节肢动物群落结构,提高群落多样性、均匀度、相对稳定性和天敌生物数量,可以逐步达到利用生态途径控制有害生物、减少化学农药使用量的目的。 相似文献
6.
湖北保康野生蜡梅自然群落调查与研究 总被引：1，自引：0，他引：1
通过对保康县8个野生蜡梅群落样地进行调查研究。结果表明:群落以蜡梅为主要建群种,蜡梅在多度(88)、重要值(29.82)和频度(100%)方面均为蜡梅群落灌木层中最高者,蜡梅在群落中处于绝对优势的地位。刺滩沟蜡梅群落的丰富度指数(28)、Simpson指数(0.84)和Shannon-Wiener指数(1.06)为8个群落最大者。蜡梅群落灌木类植物物种的Pielou均匀度指数与多样性指数总体表现出较为相似的特征,即物种多样性高,均匀度也较高。物种丰富度、多样性、均匀度均表现出相似的变化趋势。 相似文献
7.
对贵阳阿哈湖国家湿地公园昆虫类型进行调查，结果表明：（1）昆虫种类有125种，隶属于11目70科125种，其中，优势科为凤蝶科，优势种为黑肩毛萤叶甲、中稻缘蝽。（2）公园的物种丰富度（D）为24.32;Shannon-Weiener多样性指数（H）为6.32；群落均匀度（J）为1.27。（3）根据昆虫生物学习性特点划分为植食类群、捕食类群、寄生类群及其他类群四类，其中，植食类群优势度最大，寄生类群优势度最小，植食类群中优势个体为黑肩毛萤叶甲、中稻缘蝽，捕食类群中优势个体为食虫虻。由此可知，阿哈湖国家湿地公园昆虫类型多，建议加强保护各类型昆虫资源，从食用、药用、观赏和科研价值等方面综合性开发利用昆虫资源。 相似文献
8.
通过建立城市森林群落密度梯度,对沈阳市森林群落进行抽样调查,应用spss分析各密度梯度下物种群落及群落中不同层次物种的丰富度指数（Ma）、优势度指数（C）、Simpson指数（D）、Shannon-Wiener指数（H）及Pielou指数（Jh,Jd）等响应关系。结果表明：群落的Ma指数与群落密度变化响应关系显著,群落密度对物种多样性、物种均匀度均不具有显著相关关系。 相似文献
9.
【目的】明确密闭和间伐荔枝园害虫的群落组成、多样性特征以及年度发生动态,为荔枝园害虫的绿色防控提供科学依据。【方法】2016年对广州地区的密闭和间伐荔枝园进行害虫调查,对不同荔枝园害虫的群落组成、多样性特征以及年度发生动态进行了分析。【结果】密闭荔枝园共采集到害虫7目35科61种,其中半翅目害虫在数量上占绝对优势;间伐荔枝园共采集到6目26科39种,其中鳞翅目害虫在数量上占绝对优势。多样性分析结果表明:密闭荔枝园鳞翅目害虫的Margalef物种丰度最高,其次是半翅目和鞘翅目;Shannon多样性指数从高到低依次是半翅目、鳞翅目、鞘翅目、蜱螨目、双翅目、缨翅目、等翅目;蜱螨目害虫的Pielou均匀度指数最高,其次是半翅目和鞘翅目;双翅目害虫的Simpson生态优势度指数最高,其次是蜱螨目。而间伐荔枝园鳞翅目害虫的Margalef物种丰度同样最高,其次是半翅目和鞘翅目;Shannon多样性指数从高到低依次是鳞翅目、半翅目、鞘翅目、双翅目、蜱螨目、缨翅目;半翅目害虫的Pielou均匀度指数最高,其次是双翅目;蜱螨目害虫的Simpson生态优势度指数最高,其次是双翅目。密闭荔枝园与间伐荔枝园害虫群落个体数的年度发生动态呈现"双峰"模式,分别在4月份和8月份达到最大值。而密闭荔枝园害虫群落物种数的年度发生动态呈现单峰模式,在9月份达到最大值;间伐荔枝园害虫群落物种数的年度发生动态呈现2个高峰期,分别为4—5月份和9月份。【结论】这说明对密闭荔枝园进行合理间伐对降低害虫危害具有重要意义。 相似文献
10.
越冬橘园蜘蛛群落多样性研究 总被引：2，自引：0，他引：2
通过系统调查,湖南省邵阳市越冬橘园蜘蛛群落共有12科22属28种,其中斑管巢蛛(Clubionareichlini)和美丽蚁蛛(Myrmarachaefarmicaria)为优势种。异质性大的越冬橘园蜘蛛群落的多样性指数、丰富度和个体总数均大于异质性小的越冬橘园,越冬橘园蜘蛛群落的多样性指数大小主要由群落物种丰富度和个体总数决定,与均匀度大小无关。 相似文献
11.
Urban areas have increased greatly in recent decades, which has resulted in habitat loss. However, the promotion of urban green spaces could have a profound effect on biodiversity. Traditional fruit orchards are an important land-use type with the potential to host myriad organisms. Our goal was to determine the most important factors that influence orchard biodiversity in the million city of Prague (the capital of the Czech Republic). We used a multitaxon approach to evaluate the effect of orchard restoration in a landscape context. Restoration had a positive impact on species diversity, specifically, the diversity of orthopterans and butterflies. Moreover, landscape context determined the biodiversity of orthopterans, butterflies, and birds but not that of lichens. Our study underlines the importance of both the internal and external structures of traditional fruit orchards for species richness and composition. The results of our study support the restoration of traditional fruit orchards as a suitable management practice for promoting city biodiversity. Furthermore, orchard restoration can improve the attractiveness of suburban areas. Such areas often lack sufficient urban greening. Thus, restoration in these areas can also increase future recreational value. 相似文献
12.
13.
Habitat fragmentation strongly affects insect species diversity and community composition, but few studies have examined landscape
effects on long term development of insect communities. As mobile consumers, insects should be sensitive to both local plant
community and landscape context. We tested this prediction using sweep-net transects to sample insect communities for 8 years
at an experimentally fragmented old-field site in northeastern Kansas, USA. The site included habitat patches undergoing secondary
succession, surrounded by a low turf matrix. During the first 5 years, plant richness and cover were measured in patches.
Insect species richness, total density, and trophic diversity increased over time on all transects. Cover of woody plants
and perennial forbs increased each year, adding structural complexity to successional patches and potentially contributing
to increased insect diversity. Within years, insect richness was significantly greater on transects through large successional
patches (5000 m2) than on transects through fragmented arrays of 6 medium-sized (total area 1728 m2) or 15 small (480 m2) patches. However, plant cover did not differ among patch types and was uncorrelated with insect richness within years. Insect
richness was strongly correlated with insect density, but trophic and α diversities did not differ among patch types, indicating
that patch insect communities were subsets of a common species pool. We argue that differences in insect richness resulted
from landscape effects on the size of these subsets, not patch succession rates. Greater insect richness on large patches
can be explained as a community-level consequence of population responses to resource concentration. 相似文献
14.
苹果、梨园悬挂黄色粘板诱虫的生态效应 总被引：3，自引：0，他引：3
为了探索苹果、梨园悬挂黄色粘板诱集昆虫的生态效应,对开花前悬挂的黄板,到6月底麦收后收集样本,调查诱集昆虫种类和数量,发现不同生态条件下果园诱到的昆虫种类和数量差异很大,在果园周围种植有麦田的江苏丰县地区苹果、梨园,黄板诱集到大量的蚜茧蜂,苹果园诱集到昆虫的益害比为1∶0.16,在梨园诱集到昆虫的益害比为1∶2.05;在浅山岭区的河南陕县、灵宝市地区苹果园,黄板诱集昆虫的益害比分别为1∶2.92和1∶1.46;而在河南郑州市郊区梨园黄板诱集的昆虫益害比为1∶0.24。由此看出,在果园悬挂黄板治虫,要根据环境条件,及时悬挂与摘除。 相似文献
15.
Context
Patch diversity, evenness and dominance are important metrics of landscape composition. They have been traditionally measured using indices based on Shannon’s information entropy (H) and Simpson’s concentration statistic (λ).
ObjectivesThe main objectives of this study are: (1) to show that the Lorenz curve is an appropriate framework to understand and measure patch dominance, evenness and diversity; (2) to show that Lorenz-compatible indices have better mathematical behavior than H-based and λ-based indices.
MethodsThirteen different hypothetical landscapes were created to assess landscape composition with the Lorenz curve and to compare the mathematical behavior of Lorenz-compatible indices with that of H-based and λ-based indices.
ResultsThe Lorenz curve is a suitable framework to understand and measure patch dominance, evenness and diversity due to four relevant equivalences: (1) patch dominance?=?the separation of the Lorenz curve from the 45-degree line of perfect patch evenness; (2) patch evenness?=?1 ? patch dominance; (3) patch diversity (eliminated by patch dominance)?=?patch richness?×?patch dominance; (4) patch diversity (preserved by patch evenness)?=?patch richness?×?patch evenness. Accordingly, patch diversity/patch richness?=?1???patch dominance and land-cover concentration?=?1/patch diversity.
ConclusionsLorenz-compatible indices have better mathematical behavior than H-based and λ-based indices, exhibiting greater coherence and objectivity when measuring patch dominance, evenness and diversity.
相似文献16.
云南核桃不同套种模式根际丛枝菌根真菌多样性 总被引：1，自引：0，他引：1
以云南省昌宁县5种不同套种模式的十年生核桃为试材,按照丛枝菌根形态学的研究方法,研究了不同套种模式下核桃根系中AMF侵染情况和根际AMF群落组成和多样性,以期为核桃种植园中AMF自然潜力的充分发挥以及菌根技术的应用提供科学参考依据。结果表明:5种套种模式的核桃园中,核桃均与AMF形成了典型的丛枝菌根共生体,根系中AMF的总侵染率在64.63%~91.81%;从5种处理的核桃根际土中共分离到6属15种AMF,其中近明球囊霉是共有的优势种;5种处理AMF的孢子密度介于86~1 442个·(50g)-1土。统计分析表明,5种不同处理核桃根系中AMF总侵染率和根际土壤中AMF孢子密度差异显著,其中套种茶树的种植园中AMF总侵染率和孢子密度最高,显著高于其它4种处理,而套种豌豆的种植园中AMF总侵染率和孢子密度最低。不同套种及相应的耕作方式对AMF的种类组成和多样性影响较大,该研究得出在土壤翻耕扰动较少的种植园,核桃根系中有较高的AMF定殖率,根际土壤中的孢子密度也较大。套种茶树较有利于核桃园AMF繁殖以及AMF数量和多样性的保持,是核桃林下一种较理想的种植模式。 相似文献
17.
苹果主要害虫的演变及原因分析 总被引：2，自引：0，他引：2
苹果园内植食性昆虫种群数量的上升和主要种类的变替,原因是多方面的.其主要虫害会随着农药的施用、品种的替换、不同的农事而发生变化,因此不同年代主要的虫害并不恒定,随着时间而变化.对我国苹果主要产区过去50多年重要害虫的发生及种类演替进行综述,并分析其原因.导致演替的主要原因有以下几种:不合理使用农药;新的管理措施的应用,如套袋技术、生草果园及生态苹果园的推广等;新害虫的入侵等. 相似文献