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31.
Treatment of turtle-breeding wastewater and domestic fecal sewage with soil cultivating system 总被引:2,自引:0,他引:2
LAO Shan-gen 《环境科学学报(英文版)》2001,13(3):342-345
IntroductionLandtreatmentsystemfortreatingmunicipalsewagehasbeenfairlydevelopedathomeandabroad ,whichisalowcostandhighefficiencysewagetreatmentmethodoncertainconditions.InthepastafewyearsartificialaquaticproductsbreedingindustryhadrapiddevelopedinChin… 相似文献
32.
Connectivity in an Agricultural Landscape as Reflected by Interpond Movements of a Freshwater Turtle 总被引:2,自引:0,他引:2
Abstract: Connectivity is a measure of how landscape features facilitate movement and thus is an important factor in species persistence in a fragmented landscape. The scarcity of empirical studies that directly quantify species movement and determine subsequent effects on population density have, however, limited the utility of connectivity measures in conservation planning. We undertook a 4-year study to calculate connectivity based on observed movement rates and movement probabilities for five age-sex classes of painted turtles ( Chrysemys picta ) inhabiting a pond complex in an agricultural landscape in northern Virginia (U.S.A.). We determined which variables influenced connectivity and the relationship between connectivity and subpopulation density. Interpatch distance and quality of habitat patches influenced connectivity but characteristics of the intervening matrix did not. Adult female turtles were more influenced by the habitat quality of recipient ponds than other age-sex classes. The importance of connectivity on spatial population dynamics was most apparent during a drought. Population density and connectivity were low for one pond in a wet year but dramatically increased as other ponds dried. Connectivity is an important component of species persistence in a heterogeneous landscape and is strongly dependent on the movement behavior of the species. Connectivity may reflect active selection or avoidance of particular habitat patches. The influence of habitat quality on connectivity has often been ignored, but our findings highlight its importance. Conservation planners seeking to incorporate connectivity measures into reserve design should not ignore behavior in favor of purely structural estimates of connectivity. 相似文献
33.
Abstract: Road mortality has the potential to alter the structure of turtle populations because turtle populations are highly sensitive to additive sources of adult mortality. To address the issue, we captured painted turtles ( Chrysemys picta ; n = 174) and snapping turtles ( Chelydra serpentina ; n = 56) in 18 wetlands surrounded by low road density (≤1.5 km roads/km2 of landscape) and 17 wetlands surrounded by high road density (>1.5 km/km2 ) in central New York in 2002. High road density was associated with male-biased sex ratios in painted turtles (74% vs. 54% males; p = 0.01) and snapping turtles (95% vs. 74% males; p = 0.08), whereas turtle morphology and abundance were not associated with road density. Disproportionate road mortality of females on nesting migrations is the most likely cause of skewed sex ratios. 相似文献
34.
对山西省境内野生鳖资源的分布区域和范围、品种类型和生物学特性等进行了全面调查研究,分析了野生鳖资源的状况和消长原因,对现存资源量进行了估算。在此基础上,提出了野生鳖资源的繁殖保护措施。 相似文献
35.
温室有砂育鳖的水质恶化是育鳖中经常遇到的棘手问题。采用光合细菌 (PSB)、硝化细菌 (NB)、玉垒菌 (S30 )等有益微生物进行温室有砂育鳖 ,结果表明 ,有益微生物联合使用可以有效分解底泥中污染物 ,去除水体中的有机物、氨氮、亚硝态氮 ,减少换水次数 ,节约用水量 ,并起到保护环境的作用 相似文献
36.
Pike DA 《Environmental management》2008,41(4):461-464
Individual sea turtle nests have an extremely low probability of producting adult turtles; thus the practice of moving nests
away from the ocean (where they will not be inundated by seawater) is a questionable conservation strategy. Recently in Environmental Management, Mrosovosky used the repeatability of nesting female turtles to place their eggs in certain locations to infer that some
females may consistently nest in areas which will be flooded, lowering the chance that any eggs will hatch. This information
was used to hypothesize that saving “doomed” sea turtle nests may then alter the genetic composition of the population, ultimately
resulting in turtles that nest in poor habitats. Here I question Mrosovosky’s argument by focusing on several weaknesses inherent
in the original article, namely that at present there is no evidence to suggest that nest-site selection is a heritable trait
with an underlying genetic basis. 相似文献
37.
Street lighting on coastal roadways is often visible at sea turtle nesting beaches, and disrupts the nocturnal orientation
of hatchlings as they crawl toward the sea. Our objective was to determine whether an alternative lighting system (light-emitting
diodes, embedded in the roadway pavement) prevented orientation disruption. Hatchlings at the beach oriented normally when
only the embedded lights were on, or when all lighting was switched off. However, turtles showed poor orientation when street
lighting was on. Measurements confirmed that street lighting was scattered to the beach, whereas embedded lighting was not.
We conclude that embedded lighting keeps the beach dark and thus protects sea turtles. However, on two overcast evenings,
lighting (“skyglow”) from nearby development, reflected by cloud cover to the beach, weakened hatchling orientation. Thus,
both indirect (reflected) and direct sources of lighting negatively impact the turtles. 相似文献