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香港郊野公园森林群落结构和物种多样性 总被引:3,自引:0,他引:3
通过香港大榄郊野公园森林群落的样地调查,利用物种的丰富度、多样性指数和均匀度指数对群落的类型、结构和物种多样性进行了分析和研究。结果显示了7个主要的森林群落的物种多样性和群落结构的关系,森林群落的物种多样性顺序为:土沉香群落>台湾相思群落>红胶木群落>木荷群落>毛叶桉群落>湿地松+鸭脚木群落>柠檬桉群落。森林群落的乔、灌、草3个层次的丰富度和多样性指数普遍以灌木层最高,均匀度指数则以乔木层最高。而影响物种多样性的因素主要为造林技术和频繁的山火。
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广州市林业碳汇措施——从近10年森林碳汇动态谈起 总被引:2,自引:0,他引:2
采用材积源-生物量法和广州市1993-2006年森林资源档案数据,旨在定量评估近10年来广州市森林碳储量、碳密度的动态变化,并通过分析森林碳汇的结构和变化趋势探寻提高本区域森林碳汇能力的林业措施。
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通过对苏州市3所高中校园植物种类、数量的调查,分析了校园绿化植物的应用频率和物种丰富度。结果表明:这些高中校园共有144种植物,隶属于65科131属,其中乔木31种,占21.5%;灌木37种,占25.7%;草本73种,占50.7%;藤本3种,占2.1%。人工栽培的绿化植物92种,占植物总数的63.9%;杂草51种,占35.4%,其中狗牙根(Cynodon dactylon)、马尼拉草(Zoysia matrella)为主要杂草种。整体上校园植物资源丰富,但结构相对简单,布局不合理,建议增加植物种类,提高美化效果。 相似文献
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关帝山次生林区典型植物群落物种多样性垂直分布研究 总被引:6,自引:0,他引:6
为了分析和探讨海拔对植物多样性的影响,沿海拔梯度(1600–2600m),设定14个样地,对每个样地内对植物物种进行调查。结果表明:随海拔升高,群落优势种变化依次为:辽东栎、油松、白桦、红桦、华北落叶松和云杉。群落内乔木树种的平均树高和胸径表现为先增大后减小,最大树高和胸径表现为单峰变化。群落内不同生活型树种(针叶树和阔叶树)的最大树高表现为先增大后减小.阔叶树最大胸径无明显变化规律,针叶树最大胸径不断减小。中海拔群落内,针叶树种的最大树高和胸径高于阔叶树种。群落的Shannon-wiener指数和Margalef指数均表现为单峰变化,中海拔群落(1900–2200m)植物多样性最高,高于低海拔群落(1600–1900m)和高海拔群落(2200–2600m)。Shannon-wiener指数和Margalef指数反映出的植物α多样性变化与海拔高度显著相关。在研究地区,植物多样性变化与群落所处的海拔显著相关,此外,还与群落结构、物种组成、树种特性和人为干扰有关。图8表3参13。 相似文献
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佳木斯市杏林湖公园植物群落数量特征分析 总被引:1,自引:0,他引:1
采用分层随机抽样方法对佳木斯市杏林湖公园的植物群落进行调查,并进行群落数量特征分析。结果表明:公园内共有维管植物46科105属124种,其中蕨类植物2科2属2种,裸子植物2科3属5种,被子植物42科100属117种。多样性分析表明物种丰富度指数(S)和多样性指数(H’)表现一致,均为:草本层>乔木层>灌木层;生态优势度指数(C)表现为灌木层>乔木层>草本层;均匀度指数(J)表现相反为乔木层>草本层>灌木层。建议今后在公园维护过程中加强抚育,加大灌木种类的引进力度,促进群落物种多样性的提高。 相似文献
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Effects of diversity of tree species and size on forest basal area growth,recruitment, and mortality
Jingjing Liang Joseph Buongiorno Robert A. Monserud Eric L. Kruger Mo Zhou 《Forest Ecology and Management》2007
The objective of this study was to determine the relationship, or lack thereof, between growth and diversity of tree species and size in conifer stands of western North America. Growth was measured by net basal area growth and its components: survivor growth, recruitment, and mortality. The analysis used inventory data from permanent plots in the Douglas-fir/western hemlock forest type in Oregon and Washington, and in the mixed-conifer forest type in California. The methods consisted of generalized least square regression with spatial autocorrelation, controlling for the effect of other stand characteristics. Other things being equal, in the two forest types under study there was a strong positive relationship between net basal area growth and tree-species diversity. This effect was associated with higher recruitment in stands of higher tree-species diversity. Neither mortality nor growth of survivors was related to tree-species diversity. The relationship between growth and tree-size diversity was less clear. For Douglas-fir/western hemlock, net basal area growth was negatively correlated with tree-size diversity, essentially because recruitment was lower on plots of high tree-size diversity. For mixed conifers, net basal area growth tended also to be lower in plots of high tree-size diversity, but this was mostly because mortality was higher in plots of higher tree-size diversity. 相似文献
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Effects of species and tree size diversity on recruitment in the Alaskan boreal forest: A geospatial approach 总被引:1,自引:0,他引:1
This study empirically evaluates and maps the relationships between recruitment and species and tree size diversity, as measured with the Shannon’s index, within mixed poplar/birch and mixed spruce stands across the boreal forest of Alaska. Data were collected from 438 permanent sample plots re-measured at a 5-year interval. Significant explanatory factors of recruitment, including species and tree size diversity were first identified using hierarchical partitioning. The effects of tree diversity on recruitment were then studied using generalized linear models and universal kriging to account for non-spatial factors and for spatial autocorrelation. We found a consistent positive relationship between recruitment and species diversity and a general negative relationship between recruitment and tree size diversity, indicating a tradeoff between species diversity and tree size diversity in affecting recruitment. These relationships however were not uniform across the landscape, presumably because they were subject to strong spatial autocorrelation attributable to natural disturbances and environmental stressors. In general, diversity had least effect on recruitment in stressful environments where stress, rather than competition, most likely governed recruitment. 相似文献
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IntroductionMorerecently,Thehumanl1asshowedagreatinterestli1studiesonpatternsofchangesinspeciesdiversityduriI1gprocessofsuccession,ThedistuIbal1ceofI1umanactivitiesornaturedisastershasagreatbopactonspeciesdiversity.PlantsPeciescomprisingapost-disturbancecommunityderhefromavarietyofsources-winddispersedseed,buriedpropagulesandresproutingsurvivorsl1'l.TheirulthatecontributiontotheserialflorarenectSacomplexinteractionofinitialabundance,includingdistuthanceintCnsity,proPagatCavailability,andc… 相似文献