Functional diversity research of forest communities in the Xiaowutai Mountain National Nature Reserve,Hebei

Plant functional traits are the plant physiological characteristics which can response to the changes of the living environment and have a certain impact on the ecosystem structure and function. The objective of our study was to explore characters of present functional diversity indices, the relationships between functional diversity and environmental variables, the relevance of species diversity and functional diversity. In this paper, habitat type, seed dispersal, pollination method, life cycle, life form, leaf form, leaf hair type, flowering period and flowering time were chosen as functional traits, and the research were done in the typical forest communities in the Xiaowutai Mountain National Nature Reserve, Hebei. One hundred and forty-eight quadrats (10 m × 10 m) of forest communities were established along altitude gradients, at the same time, species composition, functional traits, and environmental variables were measured in each quadrat. The results showed that functional diversity indices in forest communities that were calculated by functional distances varied greatly. Functional diversity indices (FAD, MFAD, FDp, FDc, FRic, Rao and FDis) had highly significantly positive correlation with Patrick index and showed a linear increasing trend. All the nine functional diversity indices (FAD, MFAD, FDp, FDc, FRic, Rao, FEve, FDiv, FDis) had significantly correlation with Shannon-Wiener index and Pielou index. Only FDiv showed significantly negative correlation, and the other eight functional diversity indices showed positive correlation. Environmental filtering was important to functional diversity pattern, and functional diversity indices showed correlation with environmental variables. Altitude was a significant factor to functional diversity in forest communities. Except for FDiv, other functional diversity indices displayed a decreasing trend along altitude gradients. Among all the functional diversity indices, only Rao and FDis showed significantly positive correlation with aspect. The functional diversity indices (FAD, MFAD, FDp, FDc, FRic, Rao and FDdis) showed a negative correlation with slope, slope position, litter layer thickness, soil thickness, while, they showed a positive correlation with soil temperature and disturbance. All the nine indices were proved successful in the analysis of functional diversity in forest communities with different effectiveness. They were divided into three categories, functional richness (FAD, MFAD, FDp, FDc, FRic), functional divergence (Rao, FDis), functional evenness (FEve, FDis). Meanwhile, each category was highly inter-correlated and each category was relatively independent with other categories. The study of functional diversity provides a number of ecological indication and monitoring methods for the forest, and it can address a wide range of important ecological questions that links species and ecosystems through mechanisms in biodiversity research.     

Woody vegetation composition and diversity in woodlands inside and outside a Forest Reserve in Jos,Nigeria

Protected areas such as forest reserves are often assumed to be best ways to conserve biodiversity and maintain intact ecosystems. We examined woody plant composition and diversity in the gallery forest and savannah woodland habitats of Amurum Forest Reserve and areas immediately surrounding it in Jos, Nigeria. A total of 100 10 × 10 m sample plots were established inside and outside the reserve. All woody plants ≥1 cm diameter at breast height (dbh) were identified and measured. A total of 7,564 individual plants categorized as 134 species from 44 families were recorded. Overall species diversity was significantly higher in the Forest Reserve than outside the reserve, although more species were encountered outside the reserve. Our findings suggest that, protected areas and the areas surrounding them are important for the conservation of biodiversity as the areas outside protected areas also contain species of conservation value. The continuous degrading areas outside protected areas isolates them and poses a serious threat to the long‐term viability of wildlife populations, so it is important that biodiversity in protected areas and their surrounding areas be conserved.     

砂仁生产对西双版纳自然保护区的影响

调查研究表明 ,西双版纳砂仁种植主要在沟谷季节性雨林林下 ,它造成局部雨林垂直结构层次简单化 ,使中层乔木部分树种和几乎全部下层乔木、灌木和草本植物种类流失 .种植砂仁只能在试验区内一般地段进行 ,严格保护核心区 .在试验区确定保护植物相对集中的敏感地段和村民共同管理 ,在核心区最适宜发展砂仁的沟谷地段重点巡护有利于提高保护区的管理水平 .砂仁高产与环境保护关系密切 ,有利于提高当地村民参与自然保护的自觉性 .     

Woody Debris in the Mangrove Forests of South Florida1

Woody debris is abundant in hurricane‐impacted forests. With a major hurricane affecting South Florida mangroves approximately every 20 yr, carbon storage and nutrient retention may be influenced greatly by woody debris dynamics. In addition, woody debris can influence seedling regeneration in mangrove swamps by trapping propagules and enhancing seedling growth potential. Here, we report on line‐intercept woody debris surveys conducted in mangrove wetlands of South Florida 9–10 yr after the passage of Hurricane Andrew. The total volume of woody debris for all sites combined was estimated at 67 m³/ha and varied from 13 to 181 m³/ha depending upon differences in forest height, proximity to the storm, and maximum estimated wind velocities. Large volumes of woody debris were found in the eyewall region of the hurricane, with a volume of 132 m³/ha and a projected woody debris biomass of approximately 36 t/ha. Approximately half of the woody debris biomass averaged across all sites was associated as small twigs and branches (fine woody debris), since coarse woody debris >7.5 cm felled during Hurricane Andrew was fairly well decomposed. Much of the small debris is likely to be associated with post‐hurricane forest dynamics. Hurricanes are responsible for large amounts of damage to mangrove ecosystems, and components of associated downed wood may provide a relative index of disturbance for mangrove forests. Here, we suggest that a fine:coarse woody debris ratio ≤0.5 is suggestive of a recent disturbance in mangrove wetlands, although additional research is needed to corroborate such findings.     

Protein composition of human submandibular secretions

The protein composition of human submandibular saliva obtained from a single donor has been investigated, and 21 proteins have been resolved. On Sephadex G-100, submandibular secretions (unstimulated) separated into four fractions, I, II, III, and IV. Each fraction was analyzed further by isoelectric focusing and disc gel electrophoresis. The major components detected in each fraction along with their isoelectric point (pI) are as follows: I, blood group specific substance (2.3), immunoglobulin A (5.0–6.0), and immunoglobulin G (4.5–6.5); II, albumin (4.9), two glycoproteins (5.0), and acid phosphatase (5.2); III, three phosphoproteins (4.3–4.4), isoamylase 1A (5.9), isoamylase 1B (6.4), unidentified protein (7.1), lysozyme (>10), and a basic protein (>10); and IV, isoamylase 2A (5.9) and isoamylase 2B (6.4). Isoamylase 1A and IB are glycoproteins. Stimulated submandibular secretions were also resolved into four protein fractions by gel filtration. Fraction III, compared with unstimulated secretions, showed the greatest percent increase in protein. Analysis of this fraction by disc gel electrophoresis demonstrated the presence of four protein bands which were not detected in the unstimulated secretion. One of these proteins is tentatively identified as a phosphoprotein and two as basic proteins (pI > 10). The protein composition of submandibular, parotid, and sublingual secretions is compared.     

Cat preantral follicle survival after prolonged cooled storage followed by vitrification

The aim of this study was to investigate the impact of prolonged storage at 4 °C on survival of cat preantral follicles (PAFs) pre- and post-vitrification. Ovaries were obtained from 12 queens and transported at 4 ºC within 2–6 h. Parts of the ovaries were stored for an additional 24 h or 72 h. The ovarian cortex was dissected, analyzed for viability (neutral red - NR) and morphology (histology - HE and ultrastructural analysis by TEM) and vitrified. We used 2 mm biopsy punches to obtain equal size pieces as the experimental units. After NR assessment, each sample was fixed and embedded in paraffin for HE staining to determine the number of morphologically intact follicles. Another 2 mm piece of ovary was subjected to TEM. NR viability assessment and HE results showed a similar tendency with PAF survival postvitrification even after prolonged cooling at 24 h and 72 h. With TEM, integrity of mitochondria, plasma and basal membranes as well as the presence of pre-granulose cells of PAFs were documented postvitrification for the control group and 24 h prolonged storage group, but not after 72 h storage. Our results showed that cat PAFs can survive prolonged storage followed by vitrification. The described set of techniques are applicable towards creating a gamete bank for endangered feline species.     

Insect outbreaks alter nutrient dynamics in a southern African savanna: patchy defoliation of Colophospermum mopane savanna by Imbrasia belina larvae

Invertebrate herbivore outbreaks have important impacts on system biogeochemical cycling, but these effects have been poorly documented in African savanna ecosystems. In semi‐arid African savannas, outbreaks of the lepidopteran Imbrasia belina (mopane worm) affect discrete patches of the dominant Colophospermum mopane trees; larvae may completely defoliate trees for up to six weeks during each of the early and late growing seasons. We studied the impact of mopane worm outbreaks on the availability of nitrogen (N), phosphorus (P), and potassium (K) within mopane savanna by quantifying major nutrient pools in defoliated and non‐defoliated savanna patches, including leaves, leaf litter, worm frass, and the soil beneath trees. Within an outbreak area, approximately 44 percent of trees were infested, supporting ~29,000 worms/ha, leading to ~640 kg/ha dry weight frass deposition at 1.4 g of frass/day‐individual (fourth or fifth instar), compared with an average 1645 kg/ha dry weight of leaf on trees most of which should be deposited by litterfall at the end of the growing season. Frass had twofold higher P, 10 percent higher K, but equivalent N content than litter. Taking frass and litter deposition together, the N, P, and K contents added due to the outbreak event at our study site were 0.88, 5.8, and 2.8 times those measured in non‐outbreak patches, a pattern which was reflected in the nutrient contents of soil surfaces beneath defoliated trees. Invertebrate herbivory appears to be an important driver for mopane savanna but has been largely neglected.     

Diversity at two genetic loci associated with the major histocompatibility complex in the golden snub-nosed monkey (Rhinopithecus roxellana)

Habitat loss via human activity has fragmented populations of the golden snub-nosed monkey (Rhinopithecus roxellana), and thus affected patterns of gene flow. We investigated in-depth a single troop in the Qinling Mountains, central China, two major histocompatibility complex (MHC) class II loci, DQA1 and DQB1, and compared the resulting data with data from troops from the wider Qinling Mountains region. We found that a novel DQB1 allele was only present in the study troop and relatively few divergent alleles at the DQA1 and DQB1 loci were present compared with the wider population. The inbreeding coefficient (F_is) at the MHC region was lower than previous measurements, which may have reflected different sampling strategies. However, R. roxellana has relatively high diversity in MHC genes, even though it has probably experienced serious past population bottlenecks and reduced gene flow between populations. We also found that some alleles present in the wider population had been lost in the study troop, and suggest that conservation management strategies be implemented to increase gene flow between troops in order to increase genetic variation.     

Agricultural sustainability does not imply biocenotic sustainability

Abstract. Sustainability is an important quality of the types of agriculture nowadays promoted in central Europe, notably ‘biological agriculture’ and ‘integrated production’. Agronomists, decision-makers and the public generally assume that this agricultural sustainability implies the maintenance of species diversity. However, this assumption often does not hold true. This is shown in a case study of moderately ferti-lized Arrhenatheretum meadows in northern Switzerland. Earlier and more frequent mowing, simultaneous harvesting of all the grasslands in a region, and ecological changes in surrounding arable fields, hedges and other ecosystems often cause a decline in plant and animal species richness, while agricultural yield does not noticeably change. To emphasize the distinction the concept of biocenotic sustainability is proposed for describing the capability of a community to maintain its species composition and structure. For maintaining or attaining biocenotic sustainability. results of modern ecology have to be taken into account, e.g. the theories of island biogeography, minimum viable populations, dispersal, and metapopulations. There is evidence that biocenotic sustainability always implies sustainability of agricultural yield.