SPATIAL VARIABILITY IN SELECTED PHYSICAL CHARACTERISTICS AND PROCESSES IN CROSS LAKE,NEW YORK1

ABSTRACT: Short-circuiting of the inflow occurs from the Seneca River across the southern portion of Cross Lake, New York. Spatial differences in thermal stratification, transparency and light attenuation, and net sedimentation are documented for the lake. The depth of the epilimnion was generally deeper, and the temperature gradient in the metalimnion was at times lower, at a deep-water location proximate to the short-circuiting zone, than at a position more remote from the inflow. Transparency was generally lower, and light attenuation greater, proximate to the short-circuiting zone, indicating the contribution of attenuating components from the river. The net sedimentation rate in the short-circuiting zone was greater and temporally more irregular than for a deep-water position remote from the river inflow. The spatial differences in the physical characteristics and processes in Cross Lake are attributable to the magnitude and position of the inflow from the Seneca River.     

A Proposed Aquatic Plant Community Biotic Index for Wisconsin Lakes

The Aquatic Macrophyte Community Index (AMCI) is a multipurpose tool developed to assess the biological quality of aquatic plant communities in lakes. It can be used to specifically analyze aquatic plant communities or as part of a multimetric system to assess overall lake quality for regulatory, planning, management, educational, or research purposes. The components of the index are maximum depth of plant growth; percentage of the littoral zone vegetated; Simpson's diversity index; the relative frequencies of submersed, sensitive, and exotic species; and taxa number. Each parameter was scaled based on data distributions from a statewide database, and scaled values were totaled for the AMCI value. AMCI values were grouped and tested by ecoregion and lake type (natural lakes and impoundments) to define quality on a regional basis. This analysis suggested that aquatic plant communities are divided into four groups: (1) Northern Lakes and Forests lakes and impoundments, (2) North-Central Hardwood Forests lakes and impoundments, (3) Southeastern Wisconsin Till Plains lakes, and (4) Southeastern Wisconsin Till Plains impoundments, Driftless Area Lakes, and Mississippi River Backwater lakes. AMCI values decline from group 1 to group 4 and reflect general water quality and human use trends in Wisconsin. The upper quartile of AMCI values in any region are the highest quality or benchmark plant communities. The interquartile range consists of normally impacted communities for the region and the lower quartile contains severely impacted or degraded plant communities. When AMCI values were applied to case studies, the values reflected known impacts to the lakes. However, quality criteria cannot be used uncritically, especially in lakes that initially have low nutrient levels.     

Sex identification in female crayfish is bimodal

Sex identification has been studied in several species of crustacean decapods but only seldom was the role of multimodality investigated in a systematic fashion. Here, we analyse the effect of single/combined chemical and visual stimuli on the ability of the crayfish Procambarus clarkii to identify the sex of a conspecific during mating interactions. Our results show that crayfish respond to the offered stimuli depending on their sex. While males rely on olfaction alone for sex identification, females require the combination of olfaction and vision to do so. In the latter, chemical and visual stimuli act as non-redundant signal components that possibly enhance the female ability to discriminate potential mates in the crowded social context experienced during mating period. This is one of the few clear examples in invertebrates of non-redundancy in a bimodal communication system.     

Does the mechanism of sex determination constrain the potential for sex manipulation? A test in geckos with contrasting sex-determining systems

The concentration of yolk steroids was suggested to influence offspring gender in oviparous animals subject to both temperature-dependent sex determination (TSD) and genotypic sex determination (GSD). However, the proposed mechanisms of steroid effects are thought to differ between TSD and GSD: a direct effect of oestrogens on gonad feminisation in TSD species vs a differential induction of male-producing or female-producing gametes in GSD species. Geckos offer an ideal opportunity for testing these suggested mechanisms. Closely related gecko species differ in their modes of sex determination. They lay clutches of two synchronously formed eggs; both eggs share equal steroid levels. If identical hormonal composition and environment during vitellogenesis, gravidity and incubation determine the sex of the progeny, siblings should share the same gender in both TSD and GSD geckos. We found strong support for this prediction in a TSD gecko species. Among clutches that were incubated at the temperature that produced both sexes, there were no clutches with siblings of the opposite sex. On the other hand, about half of the clutches yielded siblings of the opposite sex in four GSD species. These results suggest that sex-determining systems constrain the ability of the female to produce single-sex siblings and, hence, it seems that the GSD mechanism constrains the opportunities for sex ratio manipulation in geckos via yolk steroid manipulation.     

Source profiles of particulate organic matters emitted from cereal straw burnings

Cereal straw is one of the most abundant biomass burned in China but its contribution to fine particulates is not adequately understood. In this study, three main kinds of cereal straws were collected from five grain producing areas in China. Fine particulate matters （PMzs） from the cereal straws subjected to control burnings, both under smoldering and flaming status, were sampled by using a custom made dilution chamber and sampling system in the laboratory. Element carbon （EC） and organic carbon （OC） was analyzed. 141 compounds of organic matters were measured by gas chromatography-mass spectrum （GC-MS）. Source profiles of particulate organic matters emitted from cereal straw burnings were obtained. The results indicated that organic matters contribute a large fraction in fine particulate matters. Levoglucosan had the highest contributions with averagely 4.5% in mass of fine particulates and can be considered as the tracer of biomass burnings. Methyloxylated phenols from lignin degradation also had high concentrations in PM2.5, and contained approximately equal amounts of guaiacyl and syringyl compounds. 13-Sitostrol also made up relatively a large fraction of PMz5 compared with the other sterols （0.18%-0.63% of the total fine particle mass）. Normal alkanes, PAHs, fatty acids, as well as normal alkanols had relatively lower concentrations compared with the compounds mentioned above. Carbon preference index （CPI） of normal alkanes and alkanoic acids showed characteristics of biogenic fuel burnings. Burning status significantly influenced the formations of EC and PAHs. The differences between the emission profiles of straw and wood combustions were displayed by the fingerprint compounds, which may be used to identify the contributions between wood and straw burnings in source apportionment researches.     

1986～2008年中国区域环境质量变化差异研究

从污染物排放量、污染物处理能力和单位土地面积的污染物排放量等方面选取中国28个省市区的18项环境指标数据,运用主成分分析、标准差、Mann-Kendall和聚类分析法,研究1986～2008年间中国区域环境质量差异及格局变化.研究表明,这期间中国区域环境质量差异呈现波动缓慢上升,分为1986～2000、2000～200...     

Research on Methods of Ecological Security Assessment of the Middle and Lower Reaches of Liaohe River Based on GIS

1INTRODUCTIONResources and environment crisis are accompanied byincreasing economic development pressures and rapidpopulation growth in many countries of the world(RobSwart,1996).Ecological security is a hotspot.Majorityof scholars have taken in the hot discussions of ecologicalsecurity of different regions,most of which is differentfrom their background of subjects(Alex F.Mc Calla,1999;Xiao Duning,Chen Wenbo and Guo Fuliang,2002).With the development of GIS,GPS,RS and modeltechno…     

Time budgets and foraging in a Malagasy primate: do sex differences reflect reproductive condition and female dominance?

Female mammals commonly employ behavioral tactics of modulating activity levels and foraging behavior to counter the energetic burden of reproduction; these behavioral changes are reflected as intersexual differences. Traditional views of Malagasy primates posit that high reproductive costs select for female dominance which guarantees to energetically stressed females priority of resource access. I tested predictions regarding reproductive influences on sex differences in time budgets and foraging behavior using two groups of Milne-Edwards' sifaka (Propithecus diadema edwardsi) in southeastern Madagascar. Compared to males, females increased neither feeding nor resting time during gestation or lactation. Sex differences were essentially absent in all foraging time variables examined (time, duration, rate). In contrast, dietary composition diverged between the sexes in some months. The possibility that females selected particular food items to boost nutrient and energetic intake to meet increased requirements during reproduction must be further clarified with nutritional analyses. Sex differences in plant part choices coincided with lactation in one of the two study groups. Thus, the timing of sex differences in feeding patterns of P. d. edwardsi only partially supports the prediction that sex differences are most pronounced during the period of greatest female energetic demand. A comparative review indicated no tight association between female dominance and sex differences in foraging among Malagasy primates. Traditional female dominance theory falls short of explaining the observed patterns. The results of my study coupled with recent evidence suggest that non-behavioral tactics involving energy conservation and storage require further attention as mechanisms by which female lemurs cope with reproductive costs. Received: 12 June 1998 / Accepted after revision: 10 October 1998     

Bibliometric investigation of the integration of animal personality in conservation contexts

Consistent individual differences in behavior, commonly termed animal personality, are a widespread phenomenon across taxa that have important consequences for fitness, natural selection, and trophic interactions. Animal personality research may prove useful in several conservation contexts, but which contexts remains to be determined. We conducted a structured literature review of 654 studies identified by combining search terms for animal personality and various conservation subfields. We scored the relevance of personality and conservation issues for each study to identify which studies meaningfully integrated the 2 fields as opposed to surface-level connections or vague allusions. We found a taxonomic bias toward mammals (29% of all studies). Very few amphibian or reptile studies applied personality research to conservation issues (6% each). Climate change (21%), invasive species (15%), and captive breeding and reintroduction (13%) were the most abundant conservation subfields that occurred in our search, though a substantial proportion of these papers weakly integrated conservation and animal personality (climate change 54%, invasive species 51%, captive breeding and reintroduction 40%). Based on our results, we recommend that researchers strive for consistent and broadly applicable terminology when describing consistent behavioral differences to minimize confusion and improve the searchability of research. We identify several gaps in the literature that appear to be promising and fruitful avenues for future research, such as disease transmission as a function of sociability or exploration as a driver of space use in protected areas. Practitioners can begin informing future conservation efforts with knowledge gained from animal personality research.     

1982—2022年黄土高原归一化植被指数变化的时空特征

长时间地表植被指数变化序列构建与分析是生态环境监测领域的重要内容。以我国生态工程建设重点地区——黄土高原为研究区，采用时间序列的方差匹配方法，融合了2套卫星遥感的归一化植被指数(NDVI)数据产品(GIMMS 3g和MODIS),建立了覆盖1982—2022年的黄土高原暖季(5—9月)NDVI数据集，揭示了其间黄土高原植被覆盖变化的时空特征。研究发现：黄土高原暖季NDVI呈现“先慢后快”的增加趋势，转折点大致出现在2002年，1982—2002年暖季NDVI增速仅为0.01/(10 a),2003—2022年增速高达0.06/(10 a),其中十八大以来增速尤为显著；暖季NDVI快速增加区域主要位于黄土高原中部，并向东北、西南方向延展，与“退耕还林(草)”重点区域范围基本一致；在黄土高原南部、东部和青海省东部一带，暖季NDVI呈缓慢下降趋势。过去40年间黄土高原NDVI增加与生态工程建设关系密切。