Isolation and characterization of microsatellite loci in the beaver (Castor canadensis)

We have isolated and characterized 10 microsatellite loci in the beaver (Castor canadensis). Sixty individuals from southern and central Illinois were screened at each locus. All loci exhibited moderate levels of polymorphism, ranging from five to 13 alleles per locus with average heterozygosity ranging from 0.317 to 0.867. Locus Cca5 deviated significantly from HWE (P < 0.001). The locus pair Cca4/Cca5 was shown to be in linkage disequilibrium in southern Illinois, but not in the central Illinois population. The remaining eight loci will be useful in investigations of mating and kinship patterns in beaver populations in Illinois.     

Beavers (Castor canadensis) facilitate early access by Canada geese (Branta canadensis) to nesting habitat and areas of open water in Canada's boreal wetlands

Several studies demonstrate how beavers influence waterfowl habitat availability, ultimately improving waterfowl breeding success; however, no current research links beavers to early season nesting activities of Canada geese (Branta canadensis) in northern climates. We examined how beavers facilitate early access to open water for geese at Miquelon Lake Provincial Park (MLPP), Canada. We surveyed 32 active and 39 inactive beaver ponds to examine whether beavers facilitate early access to open water. Open water occurred 10.7 days earlier at active beaver ponds (mean ice-off day = 87.54, s = 13.88) than inactive ponds (mean ice-off day = 98.19, s = 9.07), especially adjacent to main lodge entrances and winter food caches. Snowpack was on average 5.9 cm shallower at active ponds. Prior to availability of open water, Canada geese exhibited intraspecific territoriality over beaver lodges as nest sites and once water was present, preferred island lodges over bank lodges. These findings support other studies that examined island nesting as protection from terrestrial predators and highlight the importance of beavers in creating open water areas earlier in the season.     

Habitat and diet of young grouse broods: resource partitioning between Capercaillie (Tetrao urogallus) and Black Grouse (Tetrao tetrix) in boreal forests

We compared habitat use and diets of young Capercaillie and Black Grouse broods in a boreal forest in southeast Norway. We used pointing dogs to search for broods (N = 83) in mature “natural” forest types and examined the crop content of 66 chicks 1–9 weeks old. We also measured the abundance of insects in the habitats where broods were found. Although overlapping substantially in both habitat and diets, there were notable differences: Capercaillie broods were more frequently recorded in bilberry-dominated forest types, whereas Black Grouse preferentially used pine bog forest, a more open habitat with little bilberry. Capercaillie chicks ate proportionally more insects, particularly lepidopteran larvae, and insects dominated their diet for a longer period of time (until age 28–29 days) than in Black Grouse (14–15 days). After reaching their peaks, the quantity of insects in the crops declined rapidly especially in Capercaillie, and in one of 2 years this occurred at a time when insects, including larvae, were still abundant in the habitats. Among plant foods, both species ate large amounts of Bilberry (Vaccinium myrtillus) and Bog Whortleberry (V. uliginosum). The main difference between species was a large proportion of both over-wintered and new, not yet ripe, berries of Cranberry (Oxycoccus quadripetalus) in Black Grouse, and a higher proportion of the forb Melampyrum sylvaticum in Capercaillie. The difference in diets reflected their differential use of habitats; the Vaccinium-preferred habitats of Capercaillie were richer in insects, particularly larvae, than the pine bog habitat preferred by Black Grouse. Because insects, especially larvae, comprised a larger proportion of the diet of Capercaillie chicks and chicks of this species need more food to sustain their rapid growth, Capercaillie is likely to be more sensitive to variation in insect food than Black Grouse. Also, by reducing the abundance of bilberry, the main host plant of larvae chick food, clearcutting forestry has negative effects on the brood habitat quality of both species.     

Ecological factors explaining the location of the boundary between the mixedwood and coniferous bioclimatic zones in the boreal biome of eastern North America

Aim Climate is often regarded as the primary control determining the location of an ecotone between two vegetation zones. However, other ecological factors may also be important, especially when the northern limit of the dominant species of a vegetation zone extends further than the limit of the zone itself. This study aimed to identify the ecological variables explaining the transition between two zones within the boreal biome in Quebec (eastern Canada): the southern mixedwood forests dominated by balsam fir (Abies balsamea) and white birch (Betula papyrifera), and the northern coniferous forests dominated by black spruce (Picea mariana). Location Quebec (eastern Canada). Methods Data from 5023 sampling plots from the ecological inventory of the Québec Ministry of Natural Resources distributed throughout the two bioclimatic zones were used in logistic regressions to determine the relationships between the presence or absence of balsam fir stands and different abiotic and biotic variables, at both stand and landscape scales. Results The presence of balsam fir stands was negatively related to the thick organic horizons, coarse xeric deposits and low positions on the slope, whereas stands were favoured by high elevations, steep slopes and moderate drainage. These results defined the suitable conditions for the development of balsam fir stands. In the coniferous zone these suitable conditions were less abundant. Furthermore, the saturation level of suitable sites was lower, as well as the incidence of balsam fir stands in unsuitable sites (overflow). Balsam fir stands were mostly located near lakes and rivers. All significant variables at both the stand and landscape scales explained between 34 and 42% of the location of the potential northern distribution limit of the mixedwood zone. Main conclusions Our results suggest the important role of historical factors related to post‐glacial vegetation and past disturbances in determining the relative abundance of balsam fir in both zones of the boreal biome.     

Vegetation analysis and tree population structure of tropical wet evergreen forests in and around Namdapha National Park,northeast India

Species composition, diversity and tree population structure were studied in three stands of the tropical wet evergreen forest in and around Namdapha National Park, Arunachal Pradesh, India. Three study stands exposed to different intensities of disturbances were identified, viz., undisturbed (2.4 ha) in the core zone of the park, moderately disturbed (2.1 ha) in the periphery of the park and highly disturbed (2.7 ha) outside the park area. In total 200 plant species belonging to 73 families were recorded in three stands. Tree density and basal area showed a declining trend with the increase in disturbance intensity. The densities of tree saplings and seedlings were lower in the disturbed stands than in the undisturbed stand. Species like Altingia excelsa, Olea dioica, Terminalia chebula, Mesua ferrea and Shorea assamica in the undisturbed stand and Albizia procera alone in the moderately disturbed stand contributed more than 50% of the total tree density in respective stands. The undisturbed stand contained young tree population. In the highly disturbed stand, the tree density was scarce, but had uncut trees of higher girth class (>210 cm GBH). Low shrub density was recorded in both disturbed stands due to frequent human disturbances; the broken canopy and direct sunlight enhanced the abundance of herbs in these stands. With a species rarity (species having <2 individuals) of ca. 50%, the tropical wet evergreenforests of the Namdapha National Park and its adjacent areas warrant more protection from human intervention and also eco-development to meet the livelihood requirements of the local inhabitants in the peripheral areas of the Namdapha National Park in order to reduce the anthropogenic pressure on the natural resources of the park.     

苏州工业园区湖泊后生浮游动物群落结构及影响因子

苏州工业园区地处长江流域下游,随着城市化进程的不断推进,园区水生态系统结构与功能的稳定面临严峻考验。浮游动物作为水生态系统的重要组成部分,探究其群落结构的形成机制对生物多样性保护及生态系统健康发展具有重要意义。为深入了解苏州工业园区五个主要湖泊后生浮游动物群落结构的动态变化及影响因子,于2018年7月至2019年6月进行4次调查。研究共检出后生浮游动物112种（轮虫65种、枝角类29种、桡足类18种）,其中优势种12种（轮虫10种、枝角类和桡足类各1种）。Jaccard相似性分析表明,湖泊间后生浮游动物物种组成整体处于中等相似水平。后生浮游动物密度呈现出显著的季节和湖泊差异,而生物量、Shannon-Wiener多样性指数、Pielou均匀度指数以及Margalef丰富度指数仅存在显著的季节差异。聚类分析结果表明,夏季和秋季后生浮游动物群落结构最为相似。RDA分析表明,水温、溶解氧和pH是影响园区湖泊后生浮游动物群落结构的主要环境因子。Pearson相关性分析表明,湖泊面积与后生浮游动物群落结构无显著相关关系,样点近岸距离与生物量具有显著的正相关关系。基于水质评价标准和物种多样性指数可知,园区湖泊水质整体处于轻-中度污染水平。研究表明苏州工业园区五大湖泊后生浮游动物群落结构表现出同质化趋势;季节变化、环境因子以及样点近岸距离是调控群落结构形成的主要因素。     

Canopy gaps and establishment patterns of spruce (Picea abies (L.) Karst.) in two old-growth coniferous forests in central Sweden

The spatial pattern of seedlings, saplings and canopy trees was studied in two spruce (Picea abies (L.) Karst.) forests in central Sweden. Canopy and forest structure were determined in five 0.25 ha plots. Life stage classes were distinguished on the basis of age and size distributions. Ripley's K-function (1977) was used to analyze the spatial patterns within each class. A random distribution of seedlings gave way to a more aggregated pattern on a small scale during the establishment phase. Saplings and sub-canopy trees were strongly aggregated and canopy trees were again randomly distributed within the plots. The proportion of individuals growing in gaps was used as an index of association between the spatial pattern in saplings and sub-canopy trees and the occurrence of small (50–350 m²) canopy gaps. Under the null hypothesis of independence the expected value of this statistic would equal the canopy gap ratio for the stand. Monte Carlo simulation of this statistic, using fixed sapling positions and randomly repositioned canopy gaps, confirmed the importance of canopy gaps for the final success of establishment of spruce. The association of understorey trees with gaps suggest that small gaps are typically closed by recruitment of new saplings from a sapling bank rather than by the release of larger suppressed trees.     

Microarthropod community structures (Oribatei and Collembola) in Tam Dao National Park, Vietnam

A study on the microarthropod community with special reference to species diversity of Oribatid and Collembola communities (Microarthropoda: Oribatei and Collembola) in Tam Dao National Park of Vietnam, a subtropical evergreen broad leaf alpine forest, was undertaken with the aim to explain how they are related to forest decline, and whether they can be used as bioindicators of forest plant succession. The results have shown that microarthropod community structures, particularly species diversity of oribatid and collembolan communities, are related to forest decline. Therefore they can be used as bioindicators of forest plant succession. In Tam Dao National Park, there was an inverse relation between species diversity of the oribatid and collembola communities. The species diversity of the oribatid community gradually decreased with forest decline whereas the species diversity of the collembola community gradually increased.     

An international network to monitor the structure,composition and dynamics of Amazonian forests (RAINFOR)

Abstract. The Amazon basin is likely to be increasingly affected by environmental changes: higher temperatures, changes in precipitation, CO₂ fertilization and habitat fragmentation. To examine the important ecological and biogeochemical consequences of these changes, we are developing an international network, RAINFOR, which aims to monitor forest biomass and dynamics across Amazonia in a co‐ordinated fashion in order to understand their relationship to soil and climate. The network will focus on sample plots established by independent researchers, some providing data extending back several decades. We will also conduct rapid transect studies of poorly monitored regions. Field expeditions analysed local soil and plant properties in the first phase (2001–2002). Initial results suggest that the network has the potential to reveal much information on the continental‐scale relations between forest and environment. The network will also serve as a forum for discussion between researchers, with the aim of standardising sampling techniques and methodologies that will enable Amazonian forests to be monitored in a coherent manner in the coming decades.     

Occurrence of epibenthic dinoflagellates in relation to biotic substrates and to environmental factors in Southern Mediterranean (Bizerte Bay and Lagoon,Tunisia): An emphasis on the harmful Ostreopsis spp., Prorocentrum lima and Coolia monotis

Harmful events associated with epibenthic dinoflagellates, have been reported more frequently over the last decades. Occurrence of potentially toxic benthic dinoflagellates, on the leaves of two magnoliophytes (Cymodocea nodosa and Zostera noltei) and thalli of the macroalgae (Ulva rigida), was monitored over one year (From May 2015 to April 2016) in the Bizerte Bay and Lagoon (North of Tunisia, Southern Mediterranean Sea). The investigated lagoon is known to be highly anthropized. This is the first report on the seasonal distribution of epibenthic dinoflagellates hosted by natural substrates, from two contrasted, adjacent coastal Mediterranean ecosystems. The environmental factors promoting the development of the harmful epibenthic dinoflagellates Ostreopsis spp., Prorocentrum lima and Coolia monotis were investigated. The highest cell densities were reached by Ostreopsis spp. (1.9 × 10³ cells g⁻¹ FW, in October 2015), P. lima (1.6 × 10³ cells g⁻¹ FW, in June 2015) and C. monotis (1.1 × 10³ cells g⁻¹ FW, in May 2015). C. nodosa and Z. noltei were the most favorable host macrophytes for C. monotis (in station L2) and Ostreopsis spp. (in station L3), respectively. Positive correlations were recorded between Ostreopsis spp. and temperature. Densities of the epibenthic dinoflagellates varied according to the collection site, and a great disparity was observed between the Bay and the Lagoon. Maximum concentrations were recorded on C. nodosa leaves from the Bizerte Bay, while low epiphytic cell abundances were associated with macrophytes sampled from the Bizerte Lagoon. The observed differences in dinoflagellate abundances between the two ecosystems (Bay-Lagoon) seemed not related to the nutrients, but rather to the poor environmental conditions in the lagoon.     

Frugivory and Seed Fate in Bursera inversa (Burseraceae) at Tinigua Park,Colombia: Implications for Primate Conservation1

The large ateline primates are efficient seed dispersers in Neotropical forests and hunting is driving their populations to extinction, but we do not know whether other frugivores could substitute primates in their ecological role as seed dispersers. In this study we test this possibility using a potential keystone species (Bursera inversa) at Tinigua Park, Colombia. This plant species allows us to compare seed removal rates between emergent, isolated trees, without primate visitors and trees with connected crowns. We used traps to estimate fruit production and seed removal rates in six different trees, and fruiting trees were observed during 2 yr to quantify the number of seeds manipulated by different animal species. We carried out seed predation experiments to test if seed removal by predators was affected by distance or density effects. We found that the most productive trees attracted more visiting species and seed removal rates differed among trees, the lowest corresponding to trees without primate access. Seed removal rates from the ground by predators were not higher below parental trees than away from them, but the distribution of saplings in the forest suggests that seed dispersal is advantageous. Although it is likely that the effect of primate extinctions will vary depending on tree species traits, conserving the populations of primate seed dispersers is critical to maintain the ecological processes in this forest.     

The relative contribution of environmental and genetic factors to phenotypic variation in familial Mediterranean fever (FMF)

Introduction

Familial Mediterranean fever (FMF) is an autosomal recessive disease, caused by mutations in the FMF gene MEFV (MEditerranean FeVer). It has a large phenotypic diversity even in patients with similar genotypes. Despite evidence that environmental factors (EFs) and genetic factors, including MEFV mutations (such as M694V, E148Q) and background modifier genes (MGs), affect the clinical manifestations of FMF, the relative contribution of each remains unknown.

Methods

To investigate the relative contribution of environmental and genetic factors to the phenotype of FMF, we compared the intra-pair clinical concordance of 10 mono and 7 dizygotic twins with FMF. The part played by EFs was determined by the phenotypic discordance of the monozygous twins, and the MGs effect was determined by deducing the environmental effect, computed for MZ twins, from the phenotypic discordance of the dizygous twins.

Results

The mean ± SD of intra-pair concordance was higher in the MZ than in DZ twin group (88.1 ± 13.2 vs. 70.7 ± 14.1 respectively, P value < 0.05). Based on the concordance in clinical manifestations in MZ and DZ twins, the environmental effect on the phenotype of FMF is estimated as 11.9% ± 6.6% and the MGs effect as 17.4% ± 15.5% in average.

Conclusions

In FMF the phenotype is affected by MEFV mutations, MGs and EFs in an estimated ratio of about 6:1.5:1 respectively.     

Vegetation ecology of phytogenic hillocks (nabkhas) in coastal habitats of Jal Az-Zor National Park,Kuwait: Role of patches and edaphic factors

Phytogenic sandy hillocks (Arab. ‘nabkha’) are very frequently occurring aeolian deposits along the coastal plain of Kuwait. We investigated the vegetation of 42 nabkhas in a coastal habitat of Jal Az-Zor National Park, Kuwait. Sixty-two species were recorded (47 annuals and 15 perennials) in the studied nabkhas. Four vegetation types were recognized after classifying the vegetation of the nabkhas by TWINSPAN. They were named after their dominating host species which are Nitraria retusa, Zygophyllum qatarense, Haloxylon salicornicum and Panicum turgidum. Using Detrended Correspondence Analysis (DCA) and Canonical Correspondence Analysis (CCA), we assessed the relationships between environmental gradients, floristic composition, species diversity, and geomorphology aspects of the studied habitats. Notable environmental variables affecting the distribution of the vegetation types in the study area were: geomorphological aspect, size of plants forming the core of the nabkha, moisture and nutrients contents, salinity, sand and silt components, and pH.     

Temperature niche conservatism and strong genetic structure are involved in the trans-Panamanian colonization of Matudaea (Hamamelidaceae) to Andean forests

Matudaea is the only genus of the Hamamelidaceae found in South America. The genus is composed by two extant species, M. trinervia, from Mexico and Costa Rica, and Matudaea colombiana, from the Colombian Andes; additional fossil records are present in Central Europe. Population genetics, molecular phylogenetics and niche modelling approaches were applied to explain processes related with the trans-Panamanian M. trinervia/M. colombiana split and the putative colonization of the latter to the northern Andes. The split between the two Matudaea species was estimated during Middle Miocene. The colonization of Matudaea into South America could have been facilitated by the closure of the Isthmus of Panama and the global decreasing of temperature during Miocene. Five haplotypes of M. colombiana were identified, which show an eastwards decline of genetic diversity and suggest a founder effect in the colonization of Eastern cordillera of the Colombian Andes. We detected a niche conservatism signal between the two Matudaea species related with Temperature of Coldest Month and Mean Temperature of Driest Quarter bioclimatic variables; this signal might be related to the narrow altitudinal range occupied by the two species.     

祁连山国家公园牧民对雪豹(Panthera Unica)保护的态度认知及其影响因素

祁连山地区是中国乃至全球雪豹(Panthera Unica)分布最集中、种群密度最高的地区之一，该地区的雪豹科学保护对于全球雪豹种群具有重要意义。了解祁连山国家公园牧民对雪豹保护的态度认知、探究影响牧民对雪豹保护态度的主要因素，对于保护国家公园生态系统的原真性、促进人与野生动物和谐共处具有重要意义。基于半结构式访谈对祁连山国家公园牧民进行了随机抽样调查，结果表明：(1)受访者认为狼(n=34, 91.89%)和雪豹(n=16, 43.24%)是最重要的两种致害野生动物；(2)所有受访者对雪豹保护均持积极态度；(3)受访者认为野生动物捕杀(n=14, 50.00%)和草场退化(n=9, 32.14%)是家畜面临的两大威胁因素；(4)“雪豹捕杀家畜”和“为家畜购买商业保险”是影响牧民对雪豹保护态度的关键因素(P<0.05)。为促进人与野生动物长期共存，需要各级政府以国家公园体制建设为契机，进一步加强科学研究，制定更加科学合理的野生动物保护与管理措施。     

Growth of Halimium halimifolium under simulated and natural browsing in the Doñana National Park (SW Spain)

Abstract. The annual cycle of vegetative growth in the Mediterranean shrub Halimium halimifolium (Cistaceae) subjected to simulated and natural browsing on the stabilized sands of Doñana National Park (SW Spain) is described. In a drier area without herbivory (Monte Intermedio) plants were subjected to different intensities of clipping. In a more humid area with high herbivory pressure (Monte Negro) plants were isolated by cages. Plants were monitored monthly from February to November 1994. Vegetative growth starts in March and ends in June or July, according to temperature and water availability. Plants intensely clipped and plants subjected to natural browsing responded maximally regarding shoot length, and number of leaves on main shoots and branches. Clipped plants, however, did not reach the height and cover of controls.     

The influence of temperature, relative humidity and host factors on the attachment and survival of Boophilus microplus (Canestrini) larvae to skin slices

Attachment of B. microplus larvae was examined using slices (0.5 mm) of bovine skin stretched over a suitable medium. Optimal temperature for attachment lay between 31 and 38°C. At 38°C, 70 to 80% had attached by 4 h but this was followed 6–7 h after the release of the larvae by a significant decrease in the percentage attached. By 8 h, the percentage attached had risen again and remained at 70–80% for the subsequent 16 h. Attachment was not influenced by ambient relative humidity within the range 20–75 % on the time scale studied (16 h). Most larvae denied access to the skin surface at 20 or 45 % R.H. (38°C) died within 24 h. Those allowed to feed survived at 45% but most died at 20% R.H. There was no difference in attachment when bovine or rabbit serum or phosphate buffered saline was used, nor when skin was taken from Zebu × European cattle or Herefords. Attachment was no different when skin was taken from neck, rib or rump, or from cattle with different levels of resistance to B. microplus but there was reduced attachment with mouse skin. Attachment was reduced on skin which had been stored at ? 15°C for 1 day but storage at 10°C for 16 h had no effect. These results are related to problems of tick water balance, host specificity and stimuli for tick attachment.