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A study conducted to assess the floor vegetation shows the presence of 17 species underPopulus deltoides in comparison to 28, 29 and 35 underAlbizia lebbeck, Dalbergia sissoo and mix-culture plantations, respectively. Further, the biomass and density of floor vegetation is considerably reduced underP. deltoides compared to other plantations. In addition, the indices for species richness, evenness, dominance and diversity are also
reduced underP. deltoides showing some inhibitory mechanism being operative under these plantations. Based on available literature, allelopathy is
speculated to be responsible for this reduction. 相似文献
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依据《云南植被》编目系统,将轿子山自然保护区的植被划分为7个植被型,9个植被亚型,16个群系,20个群落,并对各植被类型的保护价值进行了数量化评价,在此基础上对保护价值较高的急尖长苞冷杉林、野八角一乳状石栎林、杜鹃矮林、杜鹃灌丛和元江栲林、高山柏灌丛等6个主要植被类型进行了评价。 相似文献
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Curtis L. VanderSchaaf James A. Moore James L. Kingery 《Forest Ecology and Management》2004,190(2-3):201-218
This study looked at the effects that multi-nutrient fertilization had on understory vegetation nutrient concentrations at four conifer forested locations in the inland Northwest. Multi-nutrient fertilization of conifer stands cannot only enhance the overstory species in the inland Northwest but also the understory vegetation. Determination of nutrient concentration response to fertilization treatments can provide managers the ability to better manipulate their forests for grazing and wildlife habitat. We grouped the understory vegetation into three general life forms: forbs, grasses and grass-likes, and shrubs. Multi-nutrient fertilization had little effect on nitrogen concentration across all life forms. Potassium and sulfur generally increased in concentration. Micronutrients as a whole showed less variability in response to multi-nutrient fertilization. Boron, copper, molybdenum, and zinc generally showed increases in concentrations across all life forms. We were able to conduct analyses on a selected number of understory vegetation species. Individual species showed variability in nutrient concentration response to multi-nutrient fertilization. Wildlife habitat and grazing quality were both increased and decreased following multi-nutrient fertilization. Increases in nutrient concentrations will provide more nutritious vegetation to these animals and vice versa for decreases in concentrations. 相似文献
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We present the results of field work and a series of interviews with Mayan beekeepers, in order to answer the following questions: (i) Which factors are relevant when establishing an apiary? (ii) How do Mayans choose the melliferous flora? (iii) How do Mayans manage the vegetation surrounding their apiaries? and (iv) What is their knowledge of flowering phenology and honey production cycle? Apiary establishment depends on: no apiaries established at a minimum distance of 3 km; water availability (i.e., “Haltunes”); direct access to roads; combination of old and young vegetation (particularly abundance of Gymnopodium floribundum). Melliferous flora is classified according to quality and quantitity of the honey produced; 34 species are considered important at different times of the year. Finest honey and arger quantities are obtained from G. floribundum, followed by Viguiera dentata; the worst honey is from Lysiloma latisiliquum. Management of vegetation is minimum, mainly cutting plants that could impede growing of important melliferous, or protecting ( = not cutting) the latter; nevertheless, some of the most important melliferous are dominant in the vegetation. Their knowledge of flowering phenology and production cycle are quite complex. We discuss the problems the beekeepers are facing in regards to forest clearing, commercialization of produces, etc. 相似文献
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乌兰布和沙漠植被及其保护 总被引:4,自引:0,他引:4
乌兰布和沙漠降雨稀少,生态环境脆弱,有种子植物49科169属312种,以蒙古种、戈壁—蒙古种、戈壁种以及古地中海区系的荒漠成分占主导地位;自然植被为亚洲中部荒漠区与草原区的分界线,主要有梭梭、柠条、白刺和油蒿、沙冬青+白刺+油蒿、白刺+红砂、白刺+霸王+油蒿、籽蒿+沙竹、芦苇、白刺+芨芨草等9类群丛。由于不合理的利用,草场植被逐年退化,正朝着极度荒漠化演变。对植被状况和平缓沙丘及半固定、半流动沙地等不同立地条件的草地,应因地制宜,造(林)封(育)飞(播)结合,开展综合治理,恢复植被,遏制沙漠化加重的趋势。 相似文献
98.
文章以乌海市平沟煤矸石山上平台和边坡两种不同小地形上的土壤为研究对象,通过野外调查取样和室内分析化验,研究煤矸石山两种小地形对土壤养分的恢复情况。结果表明,土壤有机质、全N、碱解N含量在两种不同小地形上表现为边坡>平台,土壤P素、K素含量表现为平台>边坡,总体而言,边坡上土壤养分恢复效果比平台好。平台和边坡上土壤养分含量在不同土层深度中均表现为:0~20 cm层>20~40 cm层。通过参考土壤养分分级与丰缺度标准,目前土壤养分丰缺度主要呈现出缺或极缺状态。 相似文献
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