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A total of 41,099 insect specimens of 133 families and 492 morphospecies were collected from 31 trees of six species of Acacia in north-east Tanzania, representing one of the largest insect samples ever analysed from a tropical savannah habitat. Herbivores (sapsuckers and chewers) and parasitoids had the highest diversity shares, whereas the highest biomass shares were obtained by phytophagous chewers, ants and predators. The percentage biomass of ants was correlated positively with the diversity share of sapsuckers and negatively with the diversity share of tourists. A positive correlation was found with the residual biomass share of phytophagous sapsuckers, indicating a protective function of ants for this guild. Diversity and abundance share was much higher in egg and coccoid parasitoids compared to larval parasitoids, probably due to predation by ants on larval parasitoids. Their low diversity supports the hypothesis of a decline towards the equator in ichneumonid diversity.  相似文献   

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The spatial monitoring and reporting tool (SMART) is being implemented in Tanzania's protected areas to help improve the efficiency of ranger patrols. Unfortunately, there has been no attempt to understand users' perspectives regarding site‐specific factors likely to affect its use. In this study, we investigated the perspectives of staff in Ugalla Game Reserve, a protected area in western Tanzania, to understand the challenges that affect the use of SMART in the reserve. The main challenges included a lack of motivation to use SMART, limited knowledge of SMART among game scouts, insufficient ranger capacity, difficulty collecting data during night patrols, limited resources for patrolling, and difficulty accessing some remote sections of Ugalla. The presence of trophy hunting company patrol teams has led Ugalla rangers to concentrate their effort in less‐patrolled areas. We recommend introducing incentives to encourage game rangers to use SMART alongside improving patrol coverage in wet seasons. Advanced and regular refresher trainings in SMART should be conducted to enhance data collection. Furthermore, game scouts should be trained and equipped to participate effectively in the SMART process. Although SMART is now becoming increasingly popular in Tanzania, understanding local factors that influence its implementation will be important to improve uptake.  相似文献   

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There are numerous incidences of impoverishment and livelihood change in pastoral societies following transformations in land use, and land and livestock ownership. Opinion is divided over the effect of these changes on women. This paper considers the case of the former residents of the Mkomazi Game Reserve. Pastoralists were evicted from the Reserve in the late 1980s and their livelihoods have changed as a result. I show that women from poorer households now have to sell milk, firewood, or medicine frequently to meet daily family needs, but I argue that increased income-earning activity by women is not only the result of impoverishment. Selling goods is useful for women as it provides an income that they control and some choose to earn their own money. The income resulting is also subject to intrahousehold power dynamics. Women may have to sell more goods more often and may be less free to use the money as they wish because men sometimes withdraw normal provisions for day-to-day needs in the expectation that women's income will meet the deficit. Debates over the changing status of women in pastoral society need to be cognizant of these intrahousehold contests.  相似文献   

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Little consideration has been given to the genetic composition of populations associated with marine reserves, as reserve designation is generally to protect specific species, communities or habitats. Nevertheless, it is important to conserve genetic diversity since it provides the raw material for the maintenance of species diversity over longer, evolutionary time-scales and may also confer the basis for adaptation to environmental change. Many current marine reserves are small in size and isolated to some degree (e.g. sea loughs and offshore islands). While such features enable easier management, they may have important implications for the genetic structure of protected populations, the ability of populations to recover from local catastrophes and the potential for marine reserves to act as sources of propagules for surrounding areas. Here, we present a case study demonstrating genetic differentiation, isolation, inbreeding and reduced genetic diversity in populations of the dogwhelk Nucella lapillus in Lough Hyne Marine Nature Reserve (an isolated sea lough in southern Ireland), compared with populations on the local adjacent open coast and populations in England, Wales and France. Our study demonstrates that this sea lough is isolated from open coast populations, and highlights that there may be long-term genetic consequences of selecting reserves on the basis of isolation and ease of protection.  相似文献   

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高洁  李巧明 《生物多样性》2008,16(3):271-278
羽叶金合欢(Acacia pennata)是一种重要的经济植物。本研究使用微卫星(SSR)分子标记技术对分布于云南西双版纳地区的7个羽叶金合欢自然居群进行了遗传多样性和居群遗传结构的研究,旨在从分子水平探讨其自然居群的遗传多样性,制定科学的保护策略,为今后的持续利用提供科学依据。我们用筛选出的6对SSR引物对采自7个自然居群的124个个体进行了扩增,共检测到23个等位基因。平均观察等位基因数(Na)为3.381,有效等位基因数(Ne)为2.460,平均期望杂合度(He)为0.573,Nei’s多样性指数(h)为0.567。其中景洪居群具有较高的遗传多样性,曼腊居群遗传多样性相对较低。遗传分化系数FST仅为0.113。结果表明羽叶金合欢的自然居群具有较高的遗传多样性水平,居群间分化较小,遗传变异主要来源于居群内。羽叶金合欢为多年生植物,分布范围广泛,这可能是其具有较高水平遗传多样性的原因;同时其繁育系统可能为异交,种子可远距离传播,这些特性也可能导致其较高的遗传多样性水平和较低的居群遗传分化。我们建议在对羽叶金合欢进行迁地保护时,要在遗传多样性较高的居群内进行大量取样,同时也要对不同居群进行取样。  相似文献   

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Ethnozoological research was conducted to gather information on the hunting activities and their relevance for the subsistence of local people in 8 villages around the game reserve of Gile, Mozambique. Two series of data were gathered by questionnaires to: (a) 510 householders from eight villages located in the outskirts of the Reserve; (b) 10 hunters from the village of Gile, the main centre of the study area. Several hunting techniques were recorded: spears, nets, traps (including gin-traps) and wildfires, while the use of guns did not appear relevant. The importance of subsistence hunting for local people was underlined by the high percentage of respondents who declared that they usually conduct this activity and sell bushmeat. The proportion of hunters per village was related to the village size but not to its geographical location of villages and the household composition. A positive relationship existed between the proportion of hunters, crop production and fishing activities, indicating that hunting is part of an integrated system of subsistence activities. Most animals harvested were mammals (89.5%, of which 46.7% were ungulates) and most were captured within the Reserve (96%). A higher percentage of animals was sold (56%), representing a relevant income source for the villagers. Small animals were mainly captured by traps during solitary hunting, medium-sized animals in collective net hunting; larger prey were captured by gin-traps adopted by both solitary and collective hunting. In the diet of the local people wild animals represented a higher protein source than domestic animals.  相似文献   

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Dieback of Acacia xanthophloea (Benth.) has opened up the once densely forested Lerai area in Ngorongoro Caldera, Tanzania. Soil samples were taken from profiles in the Ngorongoro Conservation Area and Lake Manyara National Park at sites of dieback and at sites with healthy A. xanthophloea trees. Dieback sites had significantly greater electrical conductivity (EC), water‐soluble Na+, K+, Cl?, SO and sodium adsorption ratios (SAR) than healthy sites. The following mean values were recorded: EC (179 versus 70 mS m?1; P < 0.001, Student's t‐test, n = 8 and 10, respectively; 40–60 cm); Na+ (99 versus 30 mmolc kg?1, P < 0.001, n = 7 and 8 respectively); K+ (11 versus 3 mmolc kg?1, P < 0.05); Cl? (36 versus 7 mmolc kg?1, P < 0.01); SO (31 versus 5 mmolc kg?1, P < 0.01); and SAR (28 versus 8 mmol l?1/2, P < 0.01). Water‐soluble Na+, Cl? and SO concentrations in the Lerai profiles have probably resulted in toxicity and osmotic stress which contributed to dieback. Accumulation of salts may have occurred because of reduced flow of freshwater through Lerai and/or flow of water from Lake Magadi into Lerai. Forest recovery may be possible if salinity is reduced. Management strategies for reducing salinity have been implemented and included re‐establishing streams that flow through Lerai. Exclusion of elephants (Loxodonta africana) from Lerai is another management strategy presently under consideration.  相似文献   

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The diversity of easy-to-study organisms (e.g. vascular plants) is often used as a proxy for the diversity of other organisms whose investigation needs more effort, time and specialist knowledge. Some previous studies have found positive relationships between plant and macrofungal diversity and thus support this approach, while others question this practice. Our aim was to explore the possibility of using plant diversity as surrogate for macrofungal diversity in the forests of the Pannonian ecoregion. A total of 19 permanent plots in north-east Hungary were sampled for vascular plants and macrofungi. The effect on macrofungal abundance and diversity, as well as degradation level, of plant evenness and richness was tested using generalized linear models. Species richness of macrofungi assemblages proved to be independent of the diversity and naturalness of vascular plant communities; however, there was congruence in the composition of the two communities. In contrast to diversity, macrofungi abundance was significantly negatively correlated to plant species richness. There was a hump-backed relationship between the abundance of terricolous macrofungi and the degradation level estimated on the basis of the occurrence of vascular plants, although degradation did not influence the abundance of lignicolous macrofungi. Our results question the reliability of decisions on nature conservation actions based on a few groups of easy-to-observe organisms, and underline the necessity of studying as wide a range of taxonomic groups as possible.  相似文献   

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Biologists are still trying to grasp the global dimensions of the phylum Arthropoda and its major class the Insecta, in spite of the fact that over a million species of arthropods have been described. The canopy of rain forest trees is believed by many to hold the key to the immense diversity of insects. In recent years the use of knock-down insecticides to sample insects from rain forest canopy has revealed information on the canopy's arthropod inhabitants and community structure. The sampling techniques involved are outlined and data reviewed on taxonomic and guild structure, species abundance, body size and biomass of insects, and the faunal similarity of trees. Calculations by Erwin (1982), based on knock-down insecticide studies of the beetle fauna of one species of Central American tree, suggest there may be 30 million species of tropical forest arthropods. Reanalysis of these calculations, using additional data, produces a range of possible estimates from about 10 to 80 million. The unknown range of plant host-specificities of tropical insects is the main weakness of this method of calculation. Assessment of the faunal importance of the canopy in relation to that of other rain forest biotopes requires comparative quantitative studies. The preliminary results of one such simple study suggest that over 42 million arthropods may be found in a hectare of Seram rain forest (at the time of study), and that 70% occur in the soil and leaf litter and 14% in the canopy. They also suggest that Collembola and Acarina are the dominant groups in this hectare, and that there are as many ants as all the other insects (excluding Collembola).  相似文献   

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濒危植物四合木(Tetraena mongolica)为我国特有的蒺藜科单种属落叶小灌木.对四合木林地昆虫群落进行了调查,共得昆虫标本11363号,263种.隶属于67个科(或总科)11个目.同翅目的个体数量和优势度指数最高;膜翅目的物种丰富度和多样性指数最大;双翅目的均匀度最大.数量优势类群(>10%)为木虱和叶蝉类,常见类群(1%~10%)是象甲、小蜂、粒脉蜡蝉、拟步甲、蚂蚁、蝽科、皮蝽、盲蝽、斑翅蝗科昆虫.营养结构中植食性类群在种类和数量上占绝对优势,其中的吸食类昆虫优势度最大;天敌昆虫以寄生性类群为主,多样性最高;捕食性和中性昆虫的种类和数量相对较少,但捕食者的均匀度最高.灌木层与草本层相比,灌木层昆虫群落的物种丰富度和个体数量明显占优;优势种的优势度大.而草本层昆虫群落的多样性和均匀度高.2层整体的相似性低.膜翅目的共有种最多.  相似文献   

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The Cape Floristic Region (CFR) is characterized by exceptionally high plant species richness and it is yet to be determined whether this is matched by an equally high diversity of insect fauna associated with these plants. In an attempt to do this, data from the literature on the number of insects for various taxa found at different sites in the CFR were compared with equivalent data from other areas in South Africa and elsewhere. Results indicate that the herbivorous insect fauna of the CFR is not particularly rich in species, perhaps except for the small guild of endophagous insects. It is speculated that this is the result of CFR vegetation being a poor food source for herbivores, particularly in view of its sclerophyllous nature. Plant defence mechanisms, such as a pronounced cyanogenic ability of the leaves coupled with the relatively simple architecture of the plants are possible contributing factors.  相似文献   

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Genetic diversity of north-east Asian cattle based on microsatellite data   总被引:3,自引:0,他引:3  
Kim KS  Yeo JS  Choi CB 《Animal genetics》2002,33(3):201-204
In order to assess the genetic variability and population structure of north-east Asian cattle, 13 microsatellite loci were analysed for a total of 200 individuals including Korean, Chinese, Japanese Black and European Holstein cattle. Observed and expected heterozygosity, two estimators (F(ST) and G(ST)) of gene differentiation, and Nei's DA distance were evaluated. Based on expected mean heterozygosity, the lowest genetic diversity was exhibited in Japanese Black cattle (H(E)=0.471), and the highest in Chinese cattle (H(E)=0.744). Korean cattle revealed a relatively high degree of genetic diversity (H(E)=0.728). Average proportion of genetic variation because of interpopulation subdivision among north-east Asian cattle varied between 10.9 and 9.9%, depending on the estimator used. N-J tree based on Nei's DA genetic distance showed that Korean and Chinese cattle are closely related, whereas Japanese Black cattle are clearly distinct from the other two populations, forming a north-east Asian outgroup.  相似文献   

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This study investigated pollinator assemblage diversity and richness in four forested ecosystems of southern Punjab, Pakistan, with different landscape types. Pirowal is situated in the plains of irrigated Punjab, Lal Suhanra is part of a sandy desert ecosystem, Ghazi Ghat is part of the Indus River delta, and Fort Munro is located in dry hilly mountains. A yearlong survey of pollinator populations was carried out in these four forested ecosystems from January to December of 2010. Fortnightly hand netting was performed for collecting flower-visiting insects whereas, pan traps of three colors (white, blue, and yellow) were deployed for collecting the data. A total of 8,812 individuals from two orders (Lepidoptera and Diptera) were observed, including 22 families and 154 species. Bees were the most abundant, with 4,502 individuals, and the most species-rich taxa, with 70 species in five families, followed by flies having 2,509 individuals and 51species in 10 families. Wasps were the least abundant with 1,801 individuals and 33 species in seven families. The assemblage structure of pollinator communities as visualized through rank abundance curves showed that there were many species with low abundance and only a few species with a much higher abundance. The most abundant species among the bees, in order, were Nomia sp.3, Megachile bicolor, and Colletes sp.3; among flies, Syrphus sp.2, Calliphoridae sp.1, and Empididae sp.4; and among wasps, Tiphiidae sp.1, Myzininae sp.2, and Scelionidae sp.1.  相似文献   

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扎龙湿地不同生境的昆虫多样性   总被引:4,自引:0,他引:4  
Gu W  Ma L  Ding XH  Zhang J  Han ZW 《应用生态学报》2011,22(9):2405-2412
为了探讨湿地不同生境对昆虫物种多样性的影响,对扎龙湿地8种生境的昆虫进行了系统调查.共捕获昆虫5822只,分属11目58科143种,其中直翅目、双翅目、蜻蜒目为扎龙湿地的优势类群.不同生境中,草原草甸昆虫多样性最高,湖边生境多样性指数和均匀度指数均较高,杂草甸均最低.聚类分析和主分量分析结果表明,不同生境的昆虫群落相似性与水资源状况和植被类型有关,捕食性类群种类数和个体数量对昆虫群落稳定性具有重要的调控作用.湖边生境昆虫群落稳定性最强,湿草甸稳定性最弱.湿地水资源状况能影响昆虫生存生境,进而影响昆虫群落的组成和分布格局.  相似文献   

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