Determinants of diversity in afrotropical herbivorous insects (Lepidoptera: Geometridae): plant diversity,vegetation structure or abiotic factors?

Aim This study was conducted to investigate the potential of predicting alpha diversity and turnover rates of a highly diverse herbivorous insect family (Geometridae) based on vascular plant species richness and vegetation structure. Location The study was carried out on the south‐western slopes of Mount Kilimanjaro within a wide range of habitats between 1200 and 3150 m elevation. Methods The floristic and structural composition of the vegetation was recorded at 48 plots of 400 m². Geometrid moths were sampled manually at light sources located at the plot centres. Principal components analysis, redundancy analysis and multiple linear regression were used to explore how alpha diversity and species turnover of geometrid moths are related to vegetation structure and plant species richness. Results Alpha diversity of geometrid moths was significantly correlated with species diversity patterns in the most common vascular plant families (R² = 0.49) and with plant structural parameters (R² = 0.22), but not with overall floristic diversity. Species turnover of geometrid moths was strongly linked to diversity changes in a range of plant families (40% explained variance), less strongly to changes in vegetation physiognomy (25%), and only weakly to overall floristic diversity (5%). Changes in elevation were a better predictor of both alpha diversity and species turnover of geometrid moths than any principal component extracted from the vegetation data. Main conclusions Vegetation composition, diversity and structure all showed significant correlations with the diversity and species composition of geometrid moth assemblages. Nevertheless, in most cases relationships were indirect, via environmental parameters such as temperature and humidity, which influenced both vegetation and moth fauna. Possible direct links between geometrid diversity and potential food plants were much weaker. The lack of a significant correlation between overall plant species richness and geometrid diversity indicates that tropical geometrid moths may not be very selective in their food plant choice. Accordingly, a clear correlation between floral diversity and herbivore species richness must be regarded as overly simplistic, and the diversity of vascular plants cannot universally be used as a suitable biodiversity indicator for diverse insect taxa at higher trophic levels.     

鼎湖山人工松林生态系统蒸散力及计算方法的比较

Based on the consecutive measurement (1995-1997) of meteorology and microclimate of artificial Pinus forest in Mount Dinghu, we calculated the potential evapotranspiration by using four different methods to discuss the method which is fit for forest ecosystem. The results are given as follows.1) In terms of the enviromental conditions of forest ecosystem, we redefined some parameters in Penman equation and used it to calculate the potential evapotranspiration of artificial Pinus forest ecosystem in Mount Dinghu.Preliminary result is that Penman equation is worth spreading for calculating the potential evapotranspiration of forest ecosystem,compared with several other methods.2) The annual average potential evapotranspiration of the artificial Pinus forest in Mount Dinghu is 937.55mm,according to Penman equation. It is 50% of the rainfall in the corresponding period. The highest mean monthly potential evapotranspiration is July and the lowest mean monthly potential evapotranspiration is January. This is completely consistent with the variations of temperature.     

氮添加对武夷山亚热带常绿阔叶林植物叶片氮磷化学计量特征的影响

该文以福建武夷山亚热带常绿阔叶林为研究对象, 通过设置3个氮(N)添加梯度的野外实验, 研究了群落内乔木植物、灌木植物、草本植物、蕨类植物和苔藓植物叶片N、磷(P)化学计量特征对N沉降的响应, 以及不同功能群和物种化学计量特征对N沉降响应的差异。在已开展5年人工N添加的样地内, 3年的监测结果表明: N添加整体上提高了植物叶片N含量, 草本层植物叶片N含量对N添加的响应比乔木层和灌木层植物更加敏感, 优势种米槠(Castanopsis carlesii)、草本植物砂仁(Amomum villosum)、蕨类植物狗脊(Woodwardia japonica)的叶片N含量显著增加。N添加整体上增加了植物叶片P含量, 乔木层植物和灌木层植物叶片P含量没有显著变化, 草本层植物叶片P含量显著增加, 而苔藓植物叶片P含量显著减少。N添加促使武夷山亚热带常绿阔叶林植物叶片N:P由18.67上升至19.72, 加剧了植物生长的P限制; 乔木物种N:P的变化较灌木和草本物种更加稳定。N添加条件下, 植物叶片N:P的变化主要受到叶片P含量而非N含量变化的影响, N添加对生态系统P循环的影响显著。     

游客和居民视角下武夷山市生态系统文化服务感知比较研究

生态系统文化服务(CES)的核心是人与自然之间的情感连接,利益相关者视角下的参与式制图是感知与保护热点文化服务地区的有效方法。采用参与式制图与访谈、问卷相结合的方式调查了游客和居民2类群体对武夷山市CES的感知情况;利用空间分析、热点分析和相关性分析比较分析了游客和居民CES的感知差异特征、影响因素及其空间分布格局。结果表明：(1)除了居民月收入对感知有影响外,游客和居民对武夷山市CES认知基本不受人口学特征(性别、年龄、职业和文化程度)的影响(P>0.05);(2)居民的CES价值人均支付保护意愿较游客高。文化遗产、游憩与生态旅游、教育、美学价值是游客和居民都重视的4类子文化服务。游客对文化遗产价值服务的支付意愿最高,而居民则对教育价值服务支付意愿最高。(3)居民对CES价值感知分布空间范围较广,几乎涵盖了武夷山市大部分乡镇;而游客则相对集中,主要位于旅游点密集区域,对其他地区的感知程度较低。CES价值冷热感知程度与旅游点分布呈现相同的空间分布格局,游客和居民对CES价值热点区的感知强度从南向北逐渐降低。(4)从不同文化服务类型权衡/协同关系上看,除了“精神与宗教价值”和“游憩...     

五台山亚高山土壤真菌海拔分布格局与构建机制

生物多样性的海拔分布格局与维持机制是生物多样性与生态系统功能研究的热点领域。尽管微生物驱动着地球上许多重要的生物地球化学循环,但与大型生物体相比,对微生物多样性海拔梯度分布格局知之甚少。运用Illumina Miseq高通量测序技术,全面分析了五台山亚高山生态系统（海拔2000-3058 m范围内）土壤真菌群落组成和多样性变化特征。结果表明,子囊菌门（Ascomycota）、担子菌门（Basidiomycota）、接合菌门（Zygomycota）、壶菌门（Chytridimycota）为主要的优势菌门。非度量多维尺度分析（NMDS）和相似性分析（ANOSIM）表明真菌群落组成和结构在海拔梯度上存在显著的差异（P<0.05）。典范对应分析（CCA）显示pH、植物丰富度、总碳含量与土壤真菌群落结构存在显著相关性（P<0.05）。局域海拔尺度上,土壤真菌多样性与植物多样性（α和β多样性）呈显著正相关关系（P<0.05）。方差分解分析（VPA）和偏Mantel分析表明土壤真菌群落构建过程中,环境因子和空间变量都起作用,并且环境因子占绝对的优势。土壤真菌群落之间的Bray-Curtis距离与海拔距离呈显著正相关关系（P<0.05）,说明环境选择是亚高山土壤真菌海拔分布格局的决定因素。总之,五台山亚高山沿海拔梯度土壤真菌群落结构和多样性产生明显的变化,群落构建主要由确定性过程和随机过程驱动,但确定性过程占主导地位。土壤pH、植物丰富度、总碳含量是影响土壤真菌群落结构的重要因素。     

山西五台山种子植物区系分析

五台山有种子植物865种,隶属于392属92科,其中裸子植物3科, 6属, 7种,被子植物89科, 386属, 858种(双子叶植物76科, 294属, 699种,单子叶植物13科, 92属, 159种)。五台山种子植物属的区系成分类型多样,具有明显的温带色彩。突出特征是温带成分占绝对优势,达255属,占总属数的73.48%(其中北温带成分156属,占总属数的为44.96%),在植物区系的组成中具有重要作用。在五台山种子植物种的区系成分中,中国特有种占绝对优势,达286种,占总种数的33.41%,它们是构成五台山优势植被类型的建群种和优势种的主要成分,如华北落叶松、油松、青木千、黄刺玫、虎榛子、蚂蚱腿子等。类平均聚类结果表明,五台山种子植物区系成分与北京东灵山、百花山关系最为密切,与长白山关系次之,与关帝山、大青山有一定差异,与太岳山、太行山和中条山差异较大,与太白山差异最明显,这主要由它们的生态地理条件、区系成分的组成及植被建群种和优势种等差异所决定。     

Application of cryopreservation techniques to islet cell allotransplantation

This study continues our investigations in the area of canine islet cell cryopreservation. Islet cell allografts were frozen using a simple method to ?196 °C with rapid freezing rates and dimethyl sulfoxide as the cryoprotectant. Good in vitro viability was observed using trypan blue dye exclusion. After intrasplenic transplantation, grafts which did not reject were able to maintain normoglycemia for periods of greater than 60 days. The use of either Cy A as an immunosuppressant or ALG as a graft pretreatment contributed to prolongation of allograft survival in these long-term surviving recipients. These results encourage further studies in this area for potential future clinical application of this technique to human pancreas.     

Properties of selected mutations and genotypic landscapes under Fisher's geometric model

The fitness landscape—the mapping between genotypes and fitness—determines properties of the process of adaptation. Several small genotypic fitness landscapes have recently been built by selecting a handful of beneficial mutations and measuring fitness of all combinations of these mutations. Here, we generate several testable predictions for the properties of these small genotypic landscapes under Fisher's geometric model of adaptation. When the ancestral strain is far from the fitness optimum, we analytically compute the fitness effect of selected mutations and their epistatic interactions. Epistasis may be negative or positive on average depending on the distance of the ancestral genotype to the optimum and whether mutations were independently selected, or coselected in an adaptive walk. Simulations show that genotypic landscapes built from Fisher's model are very close to an additive landscape when the ancestral strain is far from the optimum. However, when it is close to the optimum, a large diversity of landscape with substantial roughness and sign epistasis emerged. Strikingly, small genotypic landscapes built from several replicate adaptive walks on the same underlying landscape were highly variable, suggesting that several realizations of small genotypic landscapes are needed to gain information about the underlying architecture of the fitness landscape.     

Microbial community structure in moraine lakes and glacial meltwaters, Mount Everest

The bacterial diversity and abundance in two moraine lakes and two glacial meltwaters (5140, 5152, 5800 and 6350 m above sea level, respectively) in the remote Mount Everest region were examined through 16S rRNA gene clone library and flow cytometry approaches. In total, 247 clones were screened by RFLP and 60 16S rRNA gene sequences were obtained, belonging to the following groups: Proteobacteria (8% alpha subdivision, 21% beta subdivision, and 1% gamma subdivision), Cytophaga-Flavobacteria-Bacteroides (CFB) (54%), Actinobacteria (4%), Planctomycetes (2%), Verrucomicrobia (2%), Fibrobacteres (1%) and Eukaryotic chroloplast (3%), respectively. The high dominance of CFB distinguished the Mount Everest waters from other mountain lakes. The highest bacterial abundance and diversity occurred in the open moraine lake at 5152 m, and the lowest in the glacial meltwater at 6350 m. Low temperature at high altitude is considered to be critical for component dominancy. At the same altitude, nutrient availability plays a role in regulating population structure. Our results also show that the bacteria in Mount Everest may be derived from different sources.