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排序方式: 共有383条查询结果,搜索用时 281 毫秒
1.
王蕙 《农业图书情报学刊》2007,19(8):175-178
为了加强对红树林生态环境保护的宣传力度,增强图书馆对外服务的功能,满足对红树林海岸生物多样性信息编目、分类等资料管理需求,采用目前先进的Web技术、数据库技术、数据处理技术构建了红树林海岸生物多样性信息管理系统,较为详细地讨论了构建专项库的意义以及关键技术。 相似文献
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广州市红树林资源现状及其保护利用对策 总被引:1,自引:0,他引:1
概述了广州红树林资源现状,分析了广州市红树林资源保护工作中急需解决的主要问题,并提出解决问题的相关建议。 相似文献
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红树植物地面反射光谱特征研究 总被引:1,自引:1,他引:1
结合使用野外便携式光谱仪对九龙江口红树林保护区白骨壤、秋茄、桐花树3种红树植物的叶冠表观光谱的测量结果,系统分析比较了红树植物叶冠反射光谱特征及其差异;并在一个潮间带底质遥感信息处理平台上对研究地点进行基于表观光谱特征的白骨壤和秋茄的SPOT卫星遥感图像分类;最后讨论了红树光谱研究中存在的问题。 相似文献
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W.A. Houston 《Mangroves and Salt Marshes》1999,3(1):29-40
A hailstorm in October 1994 was found to have moderately or severely impacted on 5.3% of the mangrove forests in Port Curtis. All mangrove species showed evidence of hail damage, including the three most common species (Rhizophora stylosa, Ceriops tagal and Avicennia marina). Physical effects of hail damage included stripping of leaves from plants, holes punched through leaves, bruising to bark, divots removed from bark, branch and plant death. Speciesspecific differences in vulnerability to the effects of hail were observed with C.tagal experiencing relatively higher mortality rates than the other two common mangrove species. A delayed pattern of mortality was observed in two species _ C.tagal and A.marina. Alterations to mangrove community structure included: (1) reductions in stem density, stem diameter and basal area, (2) reductions in canopy cover (based on a photographic index of foliage projective cover) and (3) changes in relative abundance of species in mangrove zones. Recovery was observed in some stands but others had not recovered to prehail levels of canopy cover two years after the hailstorm. Recovery had occurred by regeneration of fresh leaves but no recruitment of young plants had been observed during the study. The forests in the impact area were dominated by either Ceriops tagal or Rhizophora stylosa with Avicennia marinaas a subdominant in places. C.tagal dominated forests within the impact area were relatively more severely affected (41.8% in the severe category) than R.stylosa dominated communities (only 17.4% in the severe category). This indicated that C.tagal dominated forests were more vulnerable to the effects of hail damage than R.stylosa dominated forests. In addition, hailimpacted C.tagal dominated forests represented a relatively high percentage of the area of C.tagal dominated forests in Port Curtis (44.3%). This percentage was much higher than hailimpacted R.stylosa dominated forests in Port Curtis (2.7%). These two factors – relatively severe impact on C.tagal communities and a relatively higher percentage affected within the Port Curtis area – illustrate that hailstorms, as a form of natural disturbance, are an important influence on the forest ecology of mangrove ecosystems in this region. 相似文献
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The study examines vegetation – environment relationships. Vegetation measurements included species frequency, density, diameter and tree height, while environmental measurements were soil particle size distribution, acid properties (pH, Al, SO4), nutrient cations (Ca, Na, Mg, K), organic carbon, nitrogen, phosphorus and chloride content. Nypa fruticans was the dominant species in the A stratum (> 3 m tall) while Rhizophora mangle was dominant in the B stratum (1–3 m tall). The C stratum (< 1 m tall) was dominated by mangrove, Nypa and Raphia saplings. Silt was dominant and the most variable particle size fraction. A principal components analysis of the soil data indicated the first three dominant components influencing the vegetation were salinity, nutrient and soil texture. Tree height and density correlated highly with the salinity and soil texture gradients (P < 0.01), while basal area correlated with salinity and nutrient gradients (P < 0.01). While Avicannia africana in the A stratum was influenced largely by the salinity and soil texture gradients. Nypa fruticans in the B stratum was influenced by salinity and nutrients. 相似文献
8.
Jeffrey Chow 《Journal of Sustainable Forestry》2015,34(6-7):651-681
Mangroves worldwide provide a wide range of ecosystem services utilized directly and indirectly by local peoples. Between 1966 and 2001, Bangladesh established approximately 148,000 ha of mangrove plantations in coastal areas within the Barisal and Chittagong Divisions. Though erosion and human encroachment and conversion have removed over two-thirds of these stands, the Forest Department has continued to undertake new plantation activities.To investigate how and to what degree people directly utilize these mangroves, I conducted 340 household surveys across eight coastal villages located in close proximity to established plantations. The predominant direct use of the mangrove plantations by local rural communities is the extraction of detritus and nonmain stem material (e.g., limbs, leaves) for combustible fuel. This study uses household foraging distances to estimate and map net value densities based on reported market prices of extracted goods. The average extractive value of mangrove plantations is Tk 2,300 ha?1 yr?1, ranging among the villages from 300 to Tk 27,400 ha?1 yr?1, with values concentrated closer to the village. Cost-benefit analyses suggest that direct use values alone have justified the establishment and management of previously planted stands. However, other indirect values must be taken into account if these areas are to merit additional plantations. 相似文献
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ABSTRACTThe relationship between stand attributes and biomass accumulation pattern in a mangrove forest has been intensively studied in this study. We assessed above (AGM) and belowground mass (BGM) and examined the relationship between forest attributes and aboveground mass in the Sundarbans, Bangladesh. The study was conducted with 18 plots having total area of 1.08 ha. The mean AGM and BGM of the study sites were 234.08 and 132.85 Mg ha?1 respectively. H. fomes contributed the highest amount (82.9% of total AGM and 80.53% of total BGM) of above (193.56 Mg ha?1) and belowground mass (107.09 Mg ha?1) at the study site. Our study revealed structural attributes (tree diameter, height, and basal area) positively correlated with AGM. In contrast, species richness and species diversity negatively correlated with AGM. Our study indicated that lack of positive relationship between species diversity and AGM which may be attributable to high AGM of the dominant species (H. fomes) and may have a considerable consequence in AGM of the study area. Thus, maintaining large trees (DBH and height) rather than species diversity in the Sundarbans mangrove forest might be an effective approach for increasing aboveground mass. 相似文献