Assessment of anadromous salmon resources in the diet of the Alexander Archipelago wolf using stable isotope analysis

The Alexander Archipelago wolf (Canis lupus ligoni) is unique to southeast Alaska, occurring on islands south of Frederick Sound and along the mainland between Dixon Entrance and Yakutat Bay. Sitka black-tailed deer (Odocoileus hemionus sitkensis) are an important prey species for wolves across the southern part of the region. Spawning salmon (Onchorynchus sp.) are seasonally available but their presence in wolf diets has not previously been quantified. We examined the range of bone collagen δ¹³C and δ¹⁵N values for wolves throughout southeast (n = 163) and interior (n = 50) Alaska and used a dual-isotope mixing model to determine the relative contribution of salmon-derived marine protein in the diet. Southeast Alaska wolves consumed significantly more salmon (mean ± SE: 18.3 ± 1.2%) than did wolves from interior Alaska (9.1 ± 0.6%, P<0.001). Wolves on the southeast Alaska mainland appeared to have higher marine isotopic signatures than island wolves, although this difference was not significant. Variation among individual wolf diets was higher for southeast than for interior Alaska wolves, and variation was highest in coastal mainland wolf diets (P<0.001). Marine resources may augment the diet of southeast Alaska wolves during seasonal or annual fluctuations in the availability of deer, particularly in those areas on the mainland where densities of terrestrial ungulates are relatively low. Received: 1 July 1998 / Accepted: 23 February 1999     

长山列岛邻近海域沉积环境微塑料的分布特征

长山列岛(长岛)属于典型的海岛生态系统,随着海洋微塑料污染日益加剧,其周边海域沉积环境中的微塑料分布现状值得深入探究。文章以长岛养殖区和航道沉积物为研究对象,利用显微镜观察和傅里叶变换红外光谱测定等方法对沉积物中的微塑料进行分析。结果表明,长岛邻近海域沉积物中微塑料的丰度为133.14—499.82个/kg,平均丰度为252.59个/kg。微塑料的尺寸以<500μm为主,占微塑料总丰度的70%以上;微塑料的形状以颗粒状为主,其次为碎片状、纤维状和小球状;微塑料的颜色以透明色为主;微塑料的聚合物类型以玻璃纸为主,其次为聚乙烯、聚对苯二甲酸乙二酯和纤维素等。由于长岛地处黄渤海交汇处,整体水动力交换能力较好。虽然长岛南部水域水体流动性弱于北部,且南部水域距离入海河流更近,受陆源输入的影响更大,但是长岛南部水域沉积物中微塑料的丰度并未显著高于北部。研究为长岛海洋生态环境中微塑料污染的科学评估与管理提供科学依据。     

Diatoms in surface sediments of the Indonesian Archipelago and their relation to hydrography

Diatoms from 53 surface sediments (water depth 350–7200 m) of the Indonesian Archipelago were studied to determine the recent distribution of important assemblages. Three significant assemblages were distinguished, each related to hydrographic parameter(s) of the overlying water mass. The first assemblage is related to the warm saline surface waters of Pacific and Indian Ocean origin; the second assemblage reflects the low-salinity lobe in Makassar Strait; and the third corresponds to major seasonal upwelling areas in the Arafura Sea and south of Java.The normalized ratio of typically Pacific Ocean and Indian Ocean species reflects the fluctuations of the Pacific versus Indian Ocean inflow during the Late Quaternary.Absolute diatom abundances (ADA; in valves g^–1 carbonate-free dry wt) and diatom accumulation rates (DAR; in valves CM^–2 ka^–1) of autochthonous species did not correspond to daily rates of primary production in the photic zone and consequently cannot be used for paleoproductivity estimates.Besides vertical transport some lateral transport of diatoms occurs, as was demonstrated by the presence of three groups of allochthonous species. They are indicators of productivity in the littoral environment, bottom currents and river outflow.     

Periphyton growth as an indicator of eutrophication; an experimental approach

Growth of periphyton was studied in the Archipelago Sea (Finland) during summer 1994 as a part of the annual monitoring control of fish farms. Experimental growth plates (Whatman GF/C filters) were incubated (two weeks) at 213 sites in different parts of the Archipelago Sea and in the coastal area north of the Archipelago Sea. At each site incubations were repeated two or three times during the summer (July 4- -September 1). The growth of periphyton was measured as the amount of chlorophyll a (mg m-2) extracted from the incubation plates. The growth varied significantly among different parts of the study area. The strongest growth was observed in the inner archipelago and in areas with high fish production and relatively slow water exchange. In the outer archipelago, rapid water exchange ensured good mixing of nutrients from fish farms and other sources into relatively large water volumes. The local impacts of nutrient loading thus remained too low to be detected by measuring nutrient concentrations or periphyton growth. Periphyton growth was positively correlated with concentrations of total nitrogen, total phosphorus and chlorophyll a in the productivity layer (approximately 2 × Secchi depth). A significant inverse correlation was also shown between periphyton growth and Secchi depth. Archipelago areas with different levels of eutrophication could satisfactorily be distinguished in this study. The results were consequent with previous classifications of the eutrophication levels in the Archipelago Sea. Periphyton studies thus are a useful addition to conventional monitoring programs. This revised version was published online in July 2006 with corrections to the Cover Date.     

基于能值生态足迹的长山群岛人地关系分析

为探究长山群岛人地关系变化特征以及人类活动对海岛资源环境的影响,利用改进能值生态足迹模型,分析了1996—2016年长山群岛人地关系供需平衡变化情况,并利用脱钩效应模型探讨了海岛经济发展与能值生态足迹之间的关系。结果表明:(1)经济发展速度和海岛居民生活水平的提高使长山群岛能值生态足迹增长,经济发展和城镇扩张导致能值生态承载力不断下降;(2)长山群岛人地关系始终处于生态赤字状态并呈扩大趋势,但各账户生态赤字表征涵义不同,应区别对待;(3)长山群岛能值生态足迹与GDP之间经历了"扩张连接-弱脱钩-扩张连接-弱脱钩-强脱钩"的转变过程,经济发展速度、产业结构和增长方式是脱钩状态变化的重要因素。(4)随着产业重心的转移,长山群岛能值生态足迹的影响从海洋转向岛陆。     

Orthoptera, a new order of pollinator

Background and Aims

Pollinator-mediated selection and evolution of floral traits have long fascinated evolutionary ecologists. No other plant family shows as wide a range of pollinator-linked floral forms as Orchidaceae. In spite of the large size of this model family and a long history of orchid pollination biology, the identity and specificity of most orchid pollinators remains inadequately studied, especially in the tropics where the family has undergone extensive diversification. Angraecum (Vandeae, Epidendroideae), a large genus of tropical Old World orchids renowned for their floral morphology specialized for hawkmoth pollination, has been a model system since the time of Darwin.

Methods

The pollination biology of A. cadetii, an endemic species of the islands of Mauritius and Reunion (Mascarene Islands, Indian Ocean) displaying atypical flowers for the genus (white and medium-size, but short-spurred) was investigated. Natural pollinators were observed by means of hard-disk camcorders. Pollinator-linked floral traits, namely spur length, nectar volume and concentration and scent production were also investigated. Pollinator efficiency (pollen removal and deposition) and reproductive success (fruit set) were quantified in natural field conditions weekly during the 2003, 2004 and 2005 flowering seasons (January to March).

Key Results

Angraecum cadetii is self-compatible but requires a pollinator to achieve fruit set. Only one pollinator species was observed, an undescribed species of raspy cricket (Gryllacrididae, Orthoptera). These crickets, which are nocturnal foragers, reached flowers by climbing up leaves of the orchid or jumping across from neighbouring plants and probed the most ‘fresh-looking’ flowers on each plant. Visits to flowers were relatively long (if compared with the behaviour of birds or hawkmoths), averaging 16·5 s with a maximum of 41·0 s. At the study site of La Plaine des Palmistes (Pandanus forest), 46·5 % of flowers had pollen removed and 27·5 % had pollinia deposited on stigmas. The proportion of flowers that set fruit ranged from 11·9 % to 43·4 %, depending of the sites sampled across the island.

Conclusions

Although orthopterans are well known for herbivory, this represents the first clearly supported case of orthopteran-mediated pollination in flowering plants.     

Phytogeography of upwelling areas in the Arabian Sea

Aim The identification of the marine plant communities of two islands from different upwelling areas of the Arabian Sea, with a similar diversity in biotopes. A comparison of the species composition of these macroalgal communities and their biogeographical affinities within the Indian Ocean should give insight into the biogeographical position of the Arabian Sea within the larger Indian Ocean. The incorporation of environmental parameters in the analysis is instructive in understanding their importance in shaping the diverse marine assemblages of the Arabian Sea. Location Arabian Sea: (1) the Socotra Archipelago (Yemen; 12.47° N, 53.87° E) in the Somali upwelling area, (2) Masirah Island (Oman; 20.42° N, 58.79° E) in the upwelling area of the southern Arabian Peninsula. Methods The marine flora of different biotopes around both islands were examined by means of qualitative assessments. Ordination analysis [detrended correspondence analysis (DCA)] was used to identify the different plant communities and to correlate these with environmental parameters. The species composition of the identified communities were compared (tripartite similarity index) and their biogeographical affinity with nations bordering the Indian Ocean was determined. Indicator species analyses were performed to identify the characteristic species of the different plant communities and their biotopes. Results The DCA analysis shows a clustering of sites (plant communities) corresponding with their geographical position, linked in turn to the prevailing environmental conditions of the different coastal areas. The combined interpretation of the ordination, similarity and biogeographical analyses results in the aggregation of similar plant communities of both upwelling areas into four biotopes. Main conclusions The north coast communities of Socotra and the west coast communities of Masirah can be grouped into three biotopes related to the degree of exposure (to upwelling) and sedimentation. These biotopes are typified by indicator species, characteristic for specific substrata, and have a high biogeographical affinity with the East African coast. The plant communities of Socotra's south coast and Masirah's east coast constitute a fourth biotope, being diverse and species rich, typified by a large proportion of red macroalgae including the characteristic species of the unique Arabian Sea flora. This biotope has a pronounced biogeographical affinity with distant regions (disjunctly distributed taxa) as South Africa's East Coast and Western Australia. Within the different biotopes, the communities of Masirah are more divergent from an East African flora in comparison to Socotra, the latter being a stepping stone between the East African and Arabian Sea flora.     

舟山群岛四个养殖獐种群遗传多样性和遗传结构

基于ISSR分子标记技术,对来自舟山群岛4个獐(Hydropotes inermis)养殖种群的遗传多样性和遗传结构进行了分析.26条ISSR引物共扩增出286个可分析位点,多态位点百分比(PPL)为64.34％.獐物种水平上的Nei's遗传多样性指数(H)为0.210,Shannon's多态信息指数(Ⅰ)为0.318,各种群的H介于0.157-0.190之间,I在0.228-0.278之间,与已报道的ISSR标记在其它动物物种中的应用结果相比,其遗传多样性较为丰富.Structure软件分析结果显示,所有个体根据遗传信息的不同可以被分为4个组群,每个养殖场内的个体基本上都在各自独立的组群中,这与地理区域的划分相似.另外发现各养殖场獐种群间已表现出了较大的遗传分化(Gst=0.163).同时,为了解各种群间的遗传关系,计算了各种群间的Nei's遗传距离,结果显示舟山种群(ZS)和秀山种群(XS)之间的遗传距离最近,为0.045,而岱山种群(DS)和朱家尖种群(ZJJ)间的遗传距离最大,为0.066.基于以上结果,建议加强不同岛屿种群间的个体交流,特别是朱家尖种群(ZJJ)与其它种群间的交流.     

The genus Myrmarachne (Araneae,Salticidae) in?Flores,Indonesia

Two new species of the genus Myrmarachne are described (Myrmarachne acutidens sp. n., Myrmarachne epigealis sp. n.), and Myrmarachne macrognatha and Myrmarachne melanocephala are redescribed from Flores specimens. The females of Myrmarachne macrognatha are recorded for the first time.     

Molecular survey of morphological subspecies reveals new mitochondrial lineages in Podarcis muralis (Squamata: Lacertidae) from the Tuscan Archipelago (Italy)

Recent analyses of molecular markers have significantly revised the traditional taxonomy of Podarcis species (Squamata: Lacertidae), leading to critically reconsider the taxonomic value of several subspecies described only on morphological bases. In fact, lizards often exhibit high morphological plasticity both at the intra‐specific and the intra‐population level, especially on islands, where phenotypic divergences are mainly due to local adaptation, rather than to evolutionary differentiation. The Common wall lizard Podarcis muralis exhibits high morphological variability in biometry, pholidosis values and colour pattern. Molecular analyses have confirmed the key role played by the Italian Peninsula as a multi‐glacial refuge for P. muralis, pointing out the lack of congruence between mitochondrial lineages and the four peninsular subspecies currently recognized. Here, we analyse a portion of the protein‐encoding cytochrome b gene in the seven subspecies described for the Tuscan Archipelago (Italy), in order to test whether the mitochondrial haplotypes match the morphologically based taxonomy proposed for Common wall lizard. We also compare our haplotypes with all the others from the Italian Peninsula to investigate the presence of unique genetic lineages in insular populations. Our results do not agree completely with the subspecific division based on morphology. In particular, the phylogenetic analyses show that at least four subspecies are characterized by very similar haplotypes and fall into the same monophyletic clade, whereas the other three subspecies are closer to peninsular populations from central Italy. From these results, we conclude that at least some subspecies could be better regarded as simple eco‐phenotypes; in addition, we provide an explanation for the distinctiveness of exclusive lineages found in the archipelago, which constituted a refuge for this species during last glacial periods.