Movement of the fluvial form of masu salmon, <Emphasis Type="Italic">Oncorhynchus masou masou</Emphasis>, in a mountain stream in Kyushu,Japan

Using mark-recapture methods, the movements of the fluvial form of masu salmon (Oncorhynchus masou masou) in a mountain stream on the island of Kyushu, Japan, were studied. Most (78%) of the masu salmon were recaptured in the pool in which they had been originally caught and tagged. Of those that moved between pools, the proportion of individuals that moved during the breeding period was not significantly higher than the proportion that moved during the non-breeding period. However, during the breeding period, a higher proportion of larger salmon moved than did smaller fish. The proportion of mobile large males during breeding period was higher than that for small males. Also, it was found that a few individuals showed long-range movement in the autumn. As a long-term movement, 78 individual fish (65%) that were recaptured more than three times showed high sedentary tendencies. Sixteen individual mobile fish (13%) moved and returned to the original pool. Fluvial form of masu salmon in Kyushu show a high sedentary nature; however, large mature males seem to actively move in search of female during breeding period.     

大别山区板栗林地水土流失特性研究

[目的]研究大别山区板栗林地水土流失特性,为该区水土流失综合防治和生态安全保障工作提供科学支持。[方法]以“全国板栗第一县”湖北省罗田县为典型,通过对10°,15°,20°共3种坡度板栗林及对照10°,15°撂荒小区2014—2018年的降雨、径流、泥沙、植被覆盖度进行观测分析,研究大别山区板栗林下水土流失特性。[结果](1)在同等坡度和降雨条件下,虽然板栗林植被覆盖度更高,但其土壤侵蚀程度较撂荒地更加严重,说明板栗林存在较明显的林下水土流失;(2)植被覆盖度越低土壤侵蚀越严重,但植被覆盖度最高时土壤侵蚀程度并不一定最弱,说明由于林分结构的复杂性,即使在相同降雨、土壤、坡度条件下,植被覆盖度也不能作为反映土壤侵蚀程度的唯一指标;(3)板栗林水土流失程度并非随坡度的增大而增大,其侵蚀峰值(临界坡度)在15°左右。[结论]大别山区板栗分布广泛,其林下水土流失现象需要引起科研和管理部门的进一步关注。     

The Estimation of Soil Trace Elements Distribution and Soil-Plant-Animal Continuum in Relation to Trace Elements Status of Sheep in Huangcheng Area of Qilian Mountain Grassland,China

The purpose of the present study was to survey contents of trace elements of Cu, Mn, Fe, and Zn in the surface layer （0-20 cm） in the soil, pasture and serum of sheep in Huangcheng area of Qilian mountain grassland, China. Also the soil-plantanimal continuum was analyzed. Soil （n=300）, pasture （n=60）, and blood serum samples from sheep （n=480） were collected from Huangcheng area of Qilian mountain grassland, China. The contents of trace element in the samples were analyzed by atomic absorption spectrophotometer after digestion. The soil trace elements density distribution shows a ladder-like pattern distribution. Equations developed in the present study for prediction of Fe （R2=0.943） and Zn （R2=0.882） had significant R2 values.     

陕西省商州山区城乡建设的SWOT分析

述了南水北调（中线）水源地陕西商洛商州区城乡规划建设现状,基于SWOT法分析了城乡规划建设环境.结果表明：商州区城乡规划建设拥有诸多机遇和优势,也面临着一定的劣势和不足.政府应借助机遇和优势,创建西安后花园,发展特色产业,努力提高城镇化率;同时,政府也要认真审视自身劣势,努力变劣势为优势,战胜威胁,积极打造精品山水城市.     

城区山岳型森林公园发展策略研究——以广东省云浮东山森林公园为例

以广东云浮东山森林公园为例,分析城区山岳型森林公园的特点,运用SWOT分析法分析其发展中存在的优势和劣势及面临的机遇和挑战,并提出相应的发展策略.     

不同坡度及坡向条件下的土壤侵蚀特征研究——以淮河北部支流低山丘陵区为例

借助RS和GIS技术获取研究区土壤侵蚀的相关影响因子,运用RUSLE土壤侵蚀模型,计算研究区土壤侵蚀模数,进行侵蚀强度分级,并探讨不同坡度和坡向条件下的土壤侵蚀特征。结果表明,研究区平均土壤侵蚀模数为1 173.755 t/(km2·a),年侵蚀总量约9.56×107t;约96%的区域为微度侵蚀;轻度以上侵蚀主要发生在西部和北部的低山丘陵区,侵蚀土壤面积占总面积的3.32%,但泥沙流失量的比重为72.024%,是防治水土流失的关键区域;随着坡度的增加,侵蚀面积呈先减小后增大而后又减小的趋势,8°~15°坡度带是土壤侵蚀状况的转折点;不同坡向条件下,土壤侵蚀面积由大到小的顺序为半阳坡、阳坡、阴坡和平地,半阳坡侵蚀面积约占总侵蚀面积的50%。     

南方山地森林小班蓄积量调查方法的对比分析

以南方山地森林为研究对象,选取有代表性的4个小班,分别采用角规抽样调查法、中心样圆法、样圆群法、六株木法、垂直样带法、标准地法共6种方法对小班蓄积量进行测定,并从6种方法的调查精度、误差大小、工作量及工具和仪器的难易程度等方面对小班蓄积量进行了对比分析,认为角规抽样调查法是最适合南方山地森林小班蓄积量的调查方法。     

高海拔山地引种栽培中华圣桃技术

通过对湖南省桑植县引种栽培的中华圣桃,进行环境适应能力和产量及品质的调查,总结出中华圣桃的引种栽培技术。中华圣桃在高海拔山地生长发育情况正常,产量稳定,经济价值高,完全适宜推广栽培。     

喀斯特山区玉米抗旱栽培技术探讨

2012年以来,广西大化县大力推广玉米地膜覆盖、秸秆覆盖、集雨灌溉、适时套播等关键技术,使春、秋2季玉米在干旱少雨的条件下,仍能获得较高的产量。笔者通过近年来对该县玉米抗旱技术的应用调查,分析总结该县玉米抗旱生产的关键措施,以供山区玉米抗旱栽培参考。     

鼎湖山冬青属“生观赏植物资源 及其园林应用研究

冬青属是冬青科植物在我国分布的唯一属,有较突出的观赏价值,但在乡土植物园林应用研究方面却 一直未得到足够的重视。鼎湖山境内冬青属植物种质资源丰富,多数至今尚未得到开发利用。通过对该区25 种“生 冬青属植物资源的实地调查,分析其种质资源、生境贮量、观赏特性,就加强鼎湖山冬青属植物的引种应用、生物学 研究和乡土园林景观应用研究,发挥园林绿化潜力,提升园林应用品质,服务生态园林城市建设及综合性利用提出 了指导性建议。