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101.
枸杞岛海藻场大型底栖无脊椎动物摄食类群研究 总被引:1,自引:1,他引:1
随着海洋生态学研究的深入和海洋环境监测的需要,一些传统的研究方法如多样性指数等在评价大型底栖生物群落结构变化时显得说服力不足,而摄食功能群的研究越来越受到重视。本实验根据2012年8月对浙江枸杞岛海藻场大型底栖无脊椎动物的调查实验,分析该海域夏季大型底栖无脊椎动物摄食类群的组成、空间及数量分布,并进行相关生态评价。结果表明,枸杞岛海藻场夏季大型底栖无脊椎动物组成以肉食者和滤食者占较大优势,食碎屑者、植食者和食底泥者次之,杂食者最少;肉食者的优势种为布尔小笔螺、寄居蟹、扁平管帽螺、甲虫螺和四齿矶蟹等,滤食者的优势种为条纹隔贻贝、带偏顶蛤、短石蛏和布氏蚶等,植食者的优势种为钩虾、单一丽口螺和锈凹螺等;各摄食类群水平分布较均匀,垂直分布受水深和摄食饵料的限制;基于大型底栖无脊椎动物功能类群的生态参数评价结果表明,枸杞岛海藻场大型底栖无脊椎动物群落健康状态呈虚弱水平,大部分站位大型底栖无脊椎动物群落受到轻度扰动,底栖生态质量状况较好。 相似文献
102.
本文综述了水产生物基因组研究相关技术的发展历程和关键技术的应用。以二代测序技术的出现为分界点,首先回顾了早期水产养殖生物在遗传学和分子生物学方面的研究结果,以及为开展全基因组测序所做的相关基础研究,然后重点介绍了二代测序技术应用于水产生物全基因组测序和经济性状遗传基础解析的研究进展,最后展望了水产生物基因组研究发展趋势。水产生物经济性状遗传机制高度复杂,从全基因组角度阐明其遗传机制仍有很多难题,但基因决定性状是生物学法则之一,探索这一过程的奥秘引人入胜。 相似文献
103.
104.
de Mello DM da Silva V Rosas F 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2011,40(1):74-77
Background: Establishment of reference values for serum biochemical analytes is important for monitoring health and physiological status of captive animals. Objective: The purpose of this study was to measure and report ranges for serum biochemical analytes in Amazonian manatees (Trichechus inunguis). Methods: Blood samples were collected from 24 healthy captive Amazonian manatees that comprised a mixture of adults, subadults, and calves and males and females; serum analytes were measured and analyzed using a dry reagent bench‐top chemical analyzer. Comparisons were made between sexes and with previously published values of closely related species. Results: Medians and ranges (minimum–maximum) of values for the analytes were: lactate dehydrogenase (LDH), 151 (111–278) U/L (n=20); creatine kinase, 144 (76–315) U/L (n=11); alanine aminotransferase, 10 (2–28) U/L (n=18); aspartate aminotransferase, 14 (5–28) U/L (n=21); γ‐glutamyltransferase, 47 (36–73) U/L (n=21); amylase, 1428 (1010–1874) U/L (n=21); alkaline phosphatase, 73 (36–141) U/L (n=19); total protein, 6.8 (6.2–8.0) g/dL (n=24); albumin, 3.3 (2.6–4.1) g/dL (n=21); cholesterol, 188 (101–399) mg/dL (n=21); triglycerides, 126 (60–236) mg/dL (n=21); glucose, 47 (22–69) mg/dL (n=21); urea, 43 (21–69) mg/dL (n=21); uric acid, 1.1 (0.5–1.8) mg/dL (n=22); creatinine, 2.2 (1.5–3.3) mg/dL (n=22); total bilirubin, 0.2 (0.2–2.0) mg/dL (n=21); calcium, 12.7 (10.2–18.6) mg/dL (n=24); iron, 282 (207–457) μg/dL (n=13); and magnesium, 6.9 (4.3–8.9) mg/dL (n=20). With the exception of LDH, no differences were observed between sexes. Conclusions: The ranges obtained in this study provide important preliminary estimates for concentrations and activities of serum analytes in Amazonian manatees until a larger reference interval study can be conducted. 相似文献
105.
106.
农牧交错带退耕还草对土壤酶活性的影响 总被引:6,自引:8,他引:6
在中国农业大学国家草地生态系统沾源野外观测站,以马铃薯地为对照,研究了北方农牧交错带退耕地建植多年生人工草地对土壤酶活性的影响.研究结果表明,退耕地种草后土壤有机质含量提高,土壤微生物繁殖速度加快,提高了土壤的脲酶、酸、碱件磷酸酶和脱氢酶活性,且0~10 cm土层酶活性变化较10~20 cm土层显著.土壤酶活性与土壤碳、氮含量之间呈显著、极显著的正相关关系.土壤酶活性受生长季节影响较大,但无明显的规律性变化.5种人工草地(扁穗冰草、草地雀麦、无芒雀麦、羊草和紫花苜蓿草地)土壤酶活性存在差异,但因季节因素的影响,很难确定哪种人工草地对土壤酶活性的影响最大. 相似文献
107.
为探明沙漠建群种植物个体周围土壤养分和盐分空间分布及成因,对艾比湖湖区边缘三种类型沙丘下梭梭主根周围土壤含水量,电导率,全量养分和速效养分的变化进行了研究。结果表明:1固定性沙丘在表层(0~10 cm)处土壤含水量最小,流动性沙丘和半固定性沙丘在浅层(10~20 cm)处最小,以距离主根面3m处表现最为显著(P0.05)。2流动性沙丘和半固定性沙丘土壤有机质和全氮的结构性和空间自相关性均较弱,固定性沙丘养分(全量养分、速效养分)的结构性则较好。3三种沙丘土壤养分的空间分布不均,主要以条状和斑块状分布,整体上呈现出一定的集聚趋势,其中流动性沙丘和固定性沙丘集聚范围在0~2 m圈层,但纵向集聚范围中,流动性沙丘以浅层(10~20 cm),固定性沙丘以较深层(20~40cm)出现集聚,形成肥岛。4流动性沙丘土壤电导率对沙丘的影响较其他各特征因子占主导地位,半固定性沙丘和固定性沙丘养分因子占主导地位。 相似文献
108.
109.
Soil moisture is critical for vegetation growth in deserts. However, detailed dataregarding the soil moisture distribution in space and time in the Gurbantunggut Desert have not yet been reported. In this study, we conducted a series ofinsitu observation experiments in a fixed sand dune at the southern edge of the GurbantunggutDesert from February 2014 to October 2016, to explore the spatio-temporal variation of soil moisture content, investigate the impact of Haloxylonammodendron (C. A. Mey.) Bungeon soil moisture content in its root zone, and examine the factors influencing the soil moisture spatial pattern. One-way analysis of variance,least significant difference testsand correlation analysis were used to analyze the data. The results revealed that the soil moisture content exhibited annual periodicity and the temporal variation of soil moisture content throughout a year could be divided into three periods, namely, a moisture-gaining period, a moisture-losing period and a moisture-stable period.According to the temporal and spatial variability, the 0-400 cm soil profile could be divided into two layers: an active layer with moderate variability and a stable layer with weak variability.The temporal variability was larger than the spatial variability in the active layer,and the mean profile soil moisture content at different slope positions displayed the trend of decreasing with increasing relative heightand mainly followed the order of interdunearea>westand east slopes>slope top.The mean profile soil moisture content in the root zone of dead H. ammodendronindividuals was significantly higher than that in the root zones of adult and young individuals, while the soil moisture content in the root zone of adult individuals was slightly higher than that in the root zone of young individuals with no significant difference.The spatial pattern of soil moisture was attributable to the combined effects of snowfall, vegetation and soil texture, whereas the effects of rainfall and evaporation were not significant. The findings may offer a foundation for the management of sandy soil moisture and vegetation restoration in arid areas. 相似文献
110.
A HUSSNER 《Weed Research》2009,49(5):506-515
Crassula helmsii , Hydrocotyle ranunculoides , Ludwigia grandiflora and Myriophyllum aquaticum are four well known invasive aquatic plants in European waters. In this study, plant growth at different nutrient availabilities, regeneration capacity and photosynthesis were investigated. Results show high relative growth rates (RGR) of the species of up to 0.132 ± 0.008 g g−1 dry weight (dw) day−1 ( H. ranunculoides ) and a significant increase in RGR with increasing nutrient availability. All species show a high regeneration capacity and the ability to form new shoots from single nodes, even though it differs between the species. Ludwigia grandiflora and M. aquaticum also show regeneration from single leaves. Species differed in maximal amounts, and in temperature and light optima of net assimilation rates: H. ranunculoides leaves reach maximum photosynthetic rates of up to 3500 μmol CO2 × h−1 g−1 dw, L. grandiflora (leaves) up to 2200 μmol CO2 × h−1 g−1 dw, M. aquaticum (shoots) 400 μmol CO2 × h−1 g−1 dw and C. helmsii (shoots) up to 200 μmol CO2 × h−1 g−1 dw. Hydrocotyle ranunculoides , L. grandiflora and M. aquaticum preferred high light intensity and high temperatures, whilst C. helmsii was negatively affected by intense sunlight. Summarising, it can be assumed that at least H. ranunculoides , L. grandiflora and M. aquaticum can grow well under current and likely future central European climate conditions. 相似文献