基于DNA条形码的白斑切叶蜂粉源植物种类及多样性分析

利用人工蜂巢收集白斑切叶蜂(Megachile strupigera)蜂粮样本,并通过克隆测序方法,比较分析了新余市水北镇(XYSB)、吉安市戈坪乡(JAGP)、赣州市沙地镇(GZSD)和赣州市齐云山自然保护区(GZQYS)的4种不同林地类型的白斑切叶蜂粉源植物组成及多样性。共鉴定出粉源植物9科10属15种。其中黄荆Vitex negundo和山牡荆Vitex quinata为优势种。Chao1指数、Shannon-wiener指数和Simpson指数分析结果表明,4个样地粉源植物的丰富度和多样性依次为GZQYSGZSDXYSBJAGP。并且,4个样地七月上旬的物种丰富度均明显高于八月中旬。同一时期的粉源植物种类及多样性存在显著差异,表明不同林地利用方式对白斑切叶蜂粉源植物多样性的影响非常明显,并随人为干扰程度的增高而降低。相同样地中2个不同时期均呈现出粉源植物多样性随花期变化而降低的趋势,但其主要粉源植物种类没有发生改变,表明该蜂主要粉源植物没有受到花期变化的影响。因此,黄荆和山牡荆是白斑切叶蜂的主要粉源植物,对维持白斑切叶蜂种群的稳定具有重要作用。     

不同植被类型植物物种多样性

为了评价大面积人工种植杜仲对当地植物多样性的影响,以河南省汝阳县不同植被类型为研究对象,通过群落学调查,运用重要值、Shannon-Wiener物种多样性指数(H)、Simpson物种多样性指数(D)和均匀度指数(JH')等指标,统计分析杜仲人工林、温带落叶阔叶林(以下简称次生林)和撂荒地3种不同植被类型的植物物种多样性,探讨杜仲种植对植物多样性的影响。调查发现,杜仲林样地中出现植物82种,隶属39科63属,草本层为最发达的一层;次生林样地中出现植物70种,隶属32科62属,乔木层为最发达层;撂荒地样地中出现植物84种,隶属35科69属,无乔木层。杜仲林物种丰富度和多度均不亚于次生林和撂荒地,且杜仲林草本层物种丰富度和植株总数均高于次生林。统计分析显示,杜仲林乔木层、灌木层和草本层多样性指数H和D值、均匀度指数JH'值与其它两种植被类型相比无显著性差异(P0.05)。因此,种植杜仲过程中采用合理密度,适当管理,不仅能提供叶、花、果等资源,而且能够丰富草本植物的种类和数量,增加植物物种多样性。     

带状采伐对毛竹林林下植被物种多样性的影响

成本上升、利润下降严重影响毛竹林经济效益及竹农生产积极性,研究毛竹林新型经营管理技术、方法势在必行。本研究通过控制采伐宽度及采伐面积,观测一年恢复期后江苏宜兴国有林场内五种宽度(3 m、5 m、8 m、12 m、15 m)毛竹林带状样地郁闭状态及林下植被物种多样性特征,分析物种多样性对毛竹林采伐宽度及恢复状态的响应机制,研究表明:(1)研究区毛竹林下物种53科95属110种(灌木计37科64属76种,草本计18科30属34种),以蔷薇科、菊科、大戟科、茜草科、百合科、唇形科、禾本科、马鞭草科等为主。(2)物种丰富度随着毛竹郁闭度增加而降低,且人为采伐对物种丰富度(特别是木本植物)有显著促进作用,以8 m和15 m宽度带状样地物种增加最多。(3)带状采伐促进林下植被物种多样性,但降低了林下植被物种均匀度;8 m和15 m宽度带状样地Shannon-Wiener指数、Simpson指数及Gleason物种丰富度表现优于参考样地毛竹林;五种宽度带状样地林下植被物种均匀度小于参考样地,在相同宽度样地类型中,保留样地比采伐样地物种均匀度高。(4)带状采伐对8 m和15 m宽度采伐样地林下植被生物量有明显促进作用,对其余带状样地无明显影响。因此,带状采伐对8 m、15 m毛竹林带状样地林下植被的促进作用显著。     

井冈山云锦杜鹃群落特征研究

以井冈山云锦杜鹃群落10个样地调查资料为基础,对该群落的物种组成、区系成分、群落结构和物种多样性进行研究。结果表明：该群落有维管植物44科67属83种,其中蕨类植物有6科6属6种,裸子植物4科4属5种,被子植物34科57属72种;区系分析显示,该群落植物区系地理成分复杂,热带性成分和温带成分均占较大比例;群落为复层异龄结构,云锦杜鹃、交让木和猴头杜鹃是组成该群落的建群种;物种多样性分析显示,群落Simpson指数和Pielou指数较高,Shannon-Wiener指数和物种丰富度指数较低,物种多样性指数在样地间有一定差异,在群落不同层次未表现出一致的变化规律。     

千岛湖岛屿小型兽类群落的多样性

2007 年秋季和2008 年春季,选取千岛湖地区14 个岛屿和2 个半岛作为样地,采用夹夜法进行小型兽类群落组成调查。两季度共布夹20 400 个,捕获小型兽类1 141 只,隶属2 目3 科9 属13 种,啮齿目(Rodentia)鼠科(Muridae)10 种和仓鼠科(Cricetidae)1 种,食虫目(Insectivora)鼩鼱科(Soricidae)2 种。利用以上结果分析其群落多样性,结果显示:14 个岛屿小型兽类群落春、秋两季的多样性指数、均匀度指数和优势度指数均呈现极显著差异且优势种发生变化;对可能影响岛屿小型兽类群落多样性的岛屿面积、距最近陆地距离、距最近大岛距离和植物丰富度等因素进行逐步回归分析,发现只有植物丰富度对小型兽类群落的物种丰富度有显著影响;对16 个样地按照物种组成比进行聚类,许源半岛样地与14 个岛屿聚为一类,姚家半岛样地单独归为一类,相似性指数比较结果亦显示姚家半岛样地与其它样地的相似性指数偏低。结论:景观破碎化导致千岛湖岛屿小型兽类群落的稳定性下降,物种多样性季节变化强烈;随岛屿面积的增加,小型兽类物种丰富度并非总是增加的,而是出现反复,呈现明显的小岛效应;14 个岛屿的物种与许源半岛样地物种构成比接近,推断在水库未形成前属同一生境。     

太行山山地森林群落植物区系与地理格局——基于植物群落清查数据

太行山区位于黄土高原与华北平原之间,是我国生物多样性保护的重要优先区之一.本文以广义太行山涉及的108个行政县域为研究区域,基于太行山山地森林群落植物清查数据,系统分析了太行山山地森林群落的科属特征、区系组成、植物多样性地理格局及其丰富度热点地区.结果表明: 调查的778个样地得到太行山山地森林群落种子植物共计100科447属963种,其中,裸子植物3科7属12种,被子植物97科440属951种,生活型以草本植物占优势(71.1%);科的分布区类型以热带分布(38%)和温带分布(24%)为主,属的分布区类型以温带成分占主导(68.7%);太行山山地森林群落植物多样性的水平分布格局呈由西南向东北逐渐递增的趋势,群落物种多样性与经纬度均呈正相关关系,但不同生活型植物的多样性格局不相一致,草本植物多样性与经纬度呈正相关,而木本植物多样性与经纬度则无明显相关性;在垂直梯度上,太行山山地森林群落植物丰富度呈单峰分布,集中分布在400~1800 m的低中海拔地带,在1000~1200 m丰富度最高;基于群落清查数据绘制太行山山地森林群落植物丰富度分布图,鉴别出小五台山、云台山、太岳山、王屋山、中条山等山地为植物丰富度热点地区,应列入太行山优先保护的重点规划区域.     

陕南秦巴山区药用植物群落物种多样性研究

采用样方法对陕南秦巴山区药用植物群落物种多样性进行了研究。结果显示,该地区药用植物共计105科268属361种,其中药用裸子植物5科6属7种,药用被子植物92科254属344种,药用蕨类植物7科8属10种;含1属的科、含2~5属的科和含1种的属的药用植物数量较多,所占比例较高;该地区各植被类型的物种多样性变化各具特点,其中,物种丰富度指数(S)、Shannon-Wiener多样性指数(H)及Simpson多样性指数(D)表现为:乔木层最小、灌木层较大、草本层最大,但Pielou物种均匀度指数(J)的变化较为复杂;药用植物群落总的物种丰富度、乔木层物种丰富度和草本层物种丰富度均随海拔的升高表现出先升高后下降的趋势,且物种丰富度最大值出现在海拔1000~1200 m的山地常绿落叶阔叶林和温性针阔混交林的过渡区域,但灌木层物种丰富度与海拔之间无相关关系。本研究结果为阐明山地物种多样性的分布格局提供了基础资料,也为该区域药用植物的保护和管理提供参考。     

亚热带不同树种组成森林中土壤甲螨群落结构特征: 以江西新岗山为例

在全球环境变化的大背景下, 生物多样性丧失日益加剧。土壤动物作为生物多样性重要组成之一, 受到广泛的关注。位于我国江西省新岗山的亚热带森林生物多样性与生态系统功能实验样地(BEF-China)是全世界25个森林生物多样性控制实验样地之一。本研究自2019年9月至2022年4月在BEF-China两个不同树种组成的样地(A样地和B样地)内采样, 共获得甲螨23,704头, 隶属于34科50属61种。本文分析和对比了两个样地内甲螨群落结构的差异, 及其多度、物种丰富度、Shannon多样性指数的季节性差异; 通过Pearson检验探讨了甲螨多度与环境因子的关系。结果表明: 在A、B两个不同树种组成的森林生态系统内, 土壤甲螨群落结构及其季节动态具有显著差异。具体表现在: A样地奥甲螨科、罗甲螨科、若甲螨科和尖棱甲螨科的相对多度高于B样地; B样地菌甲螨科、盖头甲螨科和礼服甲螨科的相对多度高于A样地。A样地中夏季和秋季甲螨多度、物种丰富度和Shannon多样性指数显著低于春季和冬季; 而B样地中秋季甲螨多度和物种丰富度与春季差异不显著。Pearson检验结果显示, 凋落物木质素含量与单翼甲螨科和菌甲螨科多度呈负相关关系, 而与奥甲螨科多度呈正相关关系。菌甲螨科多度与土壤和凋落物同一理化因子的相关性基本相同(碳氮比除外), 但与凋落物碳氮比呈正相关关系而与土壤碳氮比呈负相关关系。     

苦槛蓝的开发利用

苦槛蓝属(Myoporum)是隶属于苦槛蓝科的双子叶植物。此属植物共约32种,主要分布于亚洲(例如我国和日本)、大洋洲(例如澳大利亚和新西兰)、太平洋的夏威夷群岛和印度洋的毛里求斯等地。我国只有苦槛蓝(M.bonti-oides)一种,产两广、福建和台湾的海边。在澳大利亚南部和东部的温带地区和半干旱地区,该属植物分布很广,少数还分布于干旱地区或北部的热带地区。     

内蒙古典型草原不同围封年限样地访花昆虫多样性

本文对内蒙古锡林郭勒退化典型草原围封样地,1983年围封禁牧区域(A样地)、1996年围封禁牧区域(B样地)和未围封的自由放牧区(C样地)的访花昆虫群落多样性及时序特征、访花频率进行了研究。结果表明:在3个样地共采集到访花昆虫成虫标本2131头,隶属7目71科,共183种;其中,A样地有7目60科154种1133头,B样地有6目59科158种847头,C样地有3目13科21种151头;A样地访花昆虫的数量最多,B样地访花昆虫的种类最多,C样地访花昆虫的种类与数量均最少;B样地7月份的访花昆虫Shannon多样性指数(3.12)、Pielou均匀度指数(0.86)和Margalef丰富度指数(7.16)均最高;C样地6月份的访花昆虫Berger-Parker优势度指数(0.15)最高。访花昆虫的Shannon多样性指数与Pielou均匀度指数随月份的变化趋势一致,而与Berger-Parker优势度指数相反;通过Jaccard群落相似性系数计算可知,A样地与B样地的访花昆虫Jaccard群落相似性系数(0.25)最高;A样地与C样地的访花昆虫群落相似性系数(0.16)最低;不同样地各月份的优势开花植物的优势访花昆虫不同,访花频率也不同。     

First pollen record for Ancyloscelis apiformes (Apidae: Emphorini) in Central Amazon

Abstract

The first pollen study for the solitary bee Ancyloscelis apiformes (Emphorini) in a nest aggregation in the Central Amazon was made in October 2012 at the Sucupira apiary in east Manaus, Amazonas, at 03° 00? 05″ S, 59° 51? 05″ W. A total of 15 samples/nests (N1–N15) were analysed, including intact pollen loads (stored inside the nest) and post-emergence residues, which were acetolysed and mounted in glycerine gelatin. From each sample, 500 pollen grains were counted to determine the pollen frequencies and diversity (H′) and evenness (J′) indices. The most representative pollen types were Bonamia ferruginea (N1 = 95.6% and N2 = 96.00%) and the Ipomoea (N3 = 96.40%), both of which belong to the Convolvulaceae. In addition, Byrsonima crispa (N10 = 93.40%) and Malpighia glabra (N7 = 90.20% and N9 = 97.60%), representatives of the Malpighiaceae, were classified as temporary specialisation events with frequencies above 90%. In this study, A. apiformes, which is considered an oligolectic bee species, presented a polylectic tendency since it collected large percentages of pollen types from plants in distinct families that were not phylogenetically related.     

Pollination of Campanula rapunculus L. (Campanulaceae): How much pollen flows into pollination and into reproduction of oligolectic pollinators?

We studied an isolated population of Campanula rapunculus and two oligolectic bee species of Chelostoma (Megachilidae), their main pollinators. The population of C. rapunculus consisted of 2808 plants. Measurements of pollen flow showed that 3.7% of the pollen produced by a flower contribute to pollination, 95.5% was collected by bees for their offspring and 0.8% remained on the styles. Pollen analyses of brood cells of Chelostoma rapunculi revealed that females collected on average 4.9 million Campanula pollen to rear one bee. We calculated that approximately 1588 bees of this species could have been reared at the study site during the studied season. The amount of potentially viable pollen deposited on stigmas was 3.6 to 10.7 times higher than the number of ovules. We discuss morphological features of the flowers which may lower the pollen removal rate per bee visit and consequently cause a high visitation and pollination rate.The study was supported by a joint project CAPES / DAAD (Probral 112/00). We thank NaBu (Naturschutzbund) Bonn and the Untere Landschaftsbehörde Siegburg for the permission to work at the Natural Reserve Dünstekoven.     

Melissopalynology in an area of Atlantic Forest (northeast region,Brazil)

Apis mellifera is a bee that was introduced to Brazil and has adapted very well to the climate conditions and vast diversity of plants that exist in the country. In the northeast region of Brazil, beekeepers make use of the association between bees and plants by selling various bee products, notably honey. One way to identify species visited by bees in an area is by the pollen in its products. Based on this, 16 samples of honey were analysed, which were collected over a period of two years and obtained from an apiary in the Atlantic Forest biome in the municipality of Entre Rios (Bahia). In addition, climatic data (precipitation and temperature) of the region were obtained for the months sampled. The average temperature of the region during the collection months varied from 22 to 28 °C. The highest precipitation recorded in the region was 133.7 mm³ and the lowest was 0.3 mm³. Seventy pollen types were found. The family Fabaceae was notable, with ten pollen types, of which Mimosa pudica was the most important with a high frequency of occurrence and distribution. The Eucalyptus (Myrtaceae) pollen type also had a high frequency of occurrence and distribution. In addition, pollen types corresponding to species that supply nectar to bees were identified, which contributes to the large diversity of bee plants for Apis mellifera in the study area.     

Dioecy in the endemic genusDendrocacalia (Compositae) on the Bonin (Ogasawara) Islands

Dendrocacalia crepidifolia Nakai (Compositae, Senecioneae), the only species of this arboreal genus endemic to Haha Island in the Bonin Islands, was found to be dioecious. Male flowers differ from female ones in having a stunted style (style in female exserted from corolla and deeply bifurcating) and anthers filled with fertile pollen (anthers in the female lacking pollen). The size of the corolla and number of florets per head were similar between male and female flowers. The crown area of this arboreal species was also similar in male and female plants. The sex ratio was 0.55 male, not significantly different from 0.5. Both sexes produced nectar of similar sugar concentration (ca. 50%). The flowers are pollinated by feral honeybees (Apis mellifera), but they are thought to have been pollinated by small, lesshairy, endemic solitary bees before honeybees were introduced and subsequently became the dominant bee species on the island. The evolution of dioecy ofDendrocacalia on the island is thought to stem from the deleterious effects of inbreeding that are inherent in plants with geitonogamy. The increased geitonogamy on the island has resulted from increased woodiness (i.e., increased number of flowers per plant) and the original dependence on endemic bee pollinators, which are now endangered.     

Bee diversity on nectarful and nectarless honey mesquites

Nectar production has been proposed as an adaptation to attract pollinators that benefit from this resource. Energetic investments may be expensive, so some species such as Prosopis glandulosa have developed a dimorphic system of nectar production, which is expected to affect floral visitor behaviour and then plant fitness. We quantified bee diversity during a 2 year period in a population of the honey mesquite in order to determine changes in bee diversity due to the presence of nectar, bee preferences to collect either nectar of pollen, and to determine between year variations of bee faunas. Floral visitors were captured at three different times of the day during the flowering seasons of 1994 and 1995, in a population of Prosopis glandulosa which has a 1:1 proportion of nectar: nectarless individuals. Pollinators were clearly distinct between nectar morphs, bee species diversity and relative abundance of visits were significantly greater on nectarful than on nectarless plants, with species on nectarless individuals being a subset of those in the nectarful morph. Our results suggest differences in the function of floral rewards (i.e., nectar and pollen) to attract floral visitors. For the Chihuahuan arid environment, mesquite provides floral rewards with ease, quantity and quality for close to 10% of all bee fauna making them important components of these communities.     

Arecaceae potential for production of monofloral bee pollen

Bees often collect pollen from plants that are near their colonies or apiaries. Arecaceae are characterised by having species that flower throughout the year and produce large quantities of pollen. Pollen grains of Arecaceae have two main forms, namely monosulcate and trichotomosulcate. The study area is located in the coastal region of the state of Sergipe, Brazil, where large amounts of bee pollen are produced by Apis mellifera. This study aims to evaluate how Arecaceae contribute to the production of monofloral bee pollen. Samples of bee pollen loads were collected each month for two years (totalling 24 samples), acetolysed, and mounted on permanent slides. At least 500 grains of pollen were counted for each sample, the data was analysed, and figures were made using the Tilia software. The pollen grains of Cocos nucifera were present in 23 samples (96%), and concentrations of this pollen type varied between 1.1 and 46.8% (but were commonly above 20%). The concentration of Arecaceae pollen grains is the result of the large-scale production of coconuts along the coastline. However, the presence of other pollen types, such as Mimosa arenosa, Mimosa pudica, Mikania and Myrcia, compliments the diets of bees in the region. The results show that even when in low frequency, Cocos nucifera pollen grains represent a large proportion of pollen content compared with other pollen types, because of the large size of Arecaceae pollen grains.     

Suitability of pollen sources for the development and reproduction of Coleomegilla maculata (Coleoptera: Coccinellidae) under simulated drought conditions

Laboratory experiments compared the nutritive value of various pollen sources for the development of Coleomegilla maculata DeGeer under conditions of continuous water availability and simulated drought. When water was continuously available, larval survival was not different from 100% on diets of frozen eggs of Ephestia kuehniella Zeller, corn pollen, sorghum pollen, or pulverized bee pollen, whereas survival of larvae was significantly reduced on the latter three diets in the simulated drought treatment. Pollen of cultivated sunflower, Helianthus annus L., proved fatal to both larvae and adults; its surface structure caused clumping and accumulation on the insect cuticle that led to death from exhaustion/desiccation in petri dishes. The Ephestia egg diet yielded shorter developmental times and heavier adult weights than any pollen diet in both treatments. The drought treatment increased developmental time on all diets with a significant treatment–diet interaction. Drought reduced the adult weight of females on the sorghum pollen diet, and that of both sexes on the bee pollen diet, again with a significant treatment–diet interaction. Initial water content was highest in corn pollen (36.8%), followed by Ephestia eggs (29.2%), sorghum pollen (25.3%), sunflower pollen (8.7%), and bee pollen (4.6%), but did not appear correlated with C. maculata larval survival on pollen sources under drought conditions. Reproductive adult females that received corn or sorghum pollen as a supplement to Ephestia eggs did not differ in fecundity or fertility from those fed only Ephestia eggs.     

Inflorescence Height Affects Visitation Behavior of Bees–A Case Study of an Aquatic Plant Community in Bolivia1

We studied the bee fauna visiting a plant community of 10 species of flowering aquatic plants in an inundated savanna region in Bolivia. In total we observed 36 bee species in 17 genera at the flowers. Cluster analysis of the similarities among the plant species in terms of their visitor spectra showed a division into two groups: plants with inflorescence heights shorter than the grass height and plants with inflorescences projecting out of the surrounding vegetation. Larger bees of the genera Apis, Melipona, Bombus, and Xylocopa were observed only at flowers above the surrounding vegetation. Smaller, mainly solitary bees (e.g., Augochlorella, Ancyloscelis) visited flowers in the dense vegetation near the water surface. Analyses of the pollen loads revealed that most individuals were highly flower constant. When bees carried different pollen types, it was generally pollen from flowers within a single stratum. We discuss specialization, flower constancy, competition, and different foraging strategies as possible reasons for stratum fidelity.     

The diversity of interspecific pollen-pistil incongruity in Nicotiana

Nicotiana tabacum was used as a pistillate parent and crossed with three self-compatible species, N. rustica, N. repanda and N. trigonophylla, which were previously reported to have pollen tubes unilaterally inhibited by N. tabacum pistil. Temporal and morphological observations revealed distinct differences of pollen tube behavior among these incongruous crosses. Pollen tubes of N. repanda were arrested in stigma and those of N. rustica in the middle of the style. On the other hand, pollen tubes of N. trigonophylla continued growing at a slow rate. Tubes of N. repanda and N. rustica showed morphological abnormalities such as swelling, thick wall, and irregular callose deposition. In addition, tubes of N. rustica often elongated in reverse direction and wound about in the middle of the style. Although the tubes of N. trigonophylla were apparently normal in morphology, they were distributed throughout the transmitting tissue, differing from the self-pollination of N. tabacum in which they were confined to the peripheral region of it. The diversity of pollen tube behavior indicates that physiological causes of incongruity are different among the three crosses. Bud pollination enabled pollen tubes to reach the ovary in all crosses, indicating that the N. tabacum pistil acquired its ability to inhibit foreign pollen tube elongation with its development. When interspecific hybrids between N. tabacum and the other three species were pollinated by parental species, tubes reached the ovary in all crosses, but the elongation rate of tubes slowed down and morphology was abnormal.