首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Leizhou Peninsula, located at southern end of mailand China, has 9284.3 ha mangrove distributed more than 100 sites along its inlets and open coastlines. This paper presents the surveys on mangrove area in Leizhou Peninsula during 2000 and 2008, especially the survey in the eight major mangrove areas in 2002. The flora recorded in mangrove systems includes 69 large algea species, 13 native true mangrove species, nine native semi-mangrove species, and another seven intoduced true mangrove species with Sonneratia apetala as the quickest growing exotic mangrove species dominatant in the mangrove plantations, and more than 100 land flora species, consisting of 17 main mangrove associations. The plant biodiversity habitats remained mainly small patches and diverse, and were becoming worse under the intensive disturbance of human acitivities and coastal pollutions, which decreased the value of mangrove coasts as the important sites for flying-by migrating birds in Leizhou Peninsula. The effective mangrove conservation measures should be implemented.  相似文献   

2.
雷州半岛红树林区软体动物多样性与生物量研究   总被引:6,自引:0,他引:6  
2002年7~9月对雷州半岛8个主要红树林区软体动物进行了清查,记录有37科110种软体动物,且各红树林区的软体动物区系组成存在较高的地理分布上的差异(相似度均小于61.0%)。各红树林区的软体动物平均生物量为206Ind./m^2或106g/m^2;树栖软体动物平均生物量为20Ind./m^2或14.7g/m^2,树栖贝类优势种类有黑口滨螺等;地栖平均生物量为197Ind./m^2或100.6g/m^2,以殊带拟蟹守螺等为优势种。生物量的大小主要与底质和林区群落特征有关,底质为淤泥土壤和高密度的群落生物量较低,泥沙质土壤和较低密度的群落的生物量较高,同一群落类型以林外缘带的软体动物的生物量最高。由于人为过渡采挖和环境污染严重,绝大部分软体动物种质资源趋于濒危状态,急需加强保护。  相似文献   

3.
The exoticSonneratia apetala in Leizhou Peninsula, has shown outstanding fast-growing ability in restored mangrove forests, at the middle and high tide intertidal zone, with year-round fresh water input from drainage. By setting plot and selecting standard tree, investigation and measurement on height growth, diameter growth, biomass, productivity, and so on, were made in aS. apetala plantation at age of six at Lanbel, Fucheng, Leizhou Peninsula in May 2001. The investigating results showed that the mean annual height growth of plantation was 2.03 m and mean annual growth of diameter at breast height (DBH) was 2.35 cm. There exists a significant correlation between the diameter at ground surface (DGS) and DBH. The average biomass of a single standard tree in dry weight was 95.647 kg/m2. A ratio of above-ground biomass to under-ground biomass was 1.60. The stand biomass of unit area was 22.955 kg/m2, singletree wood volume was 88.23 dm3, and the annual wood volume productivity (P A) of the same year was 0.407. The forest energy accumulation was 424.851 MJ/m2, with annual solar energy fixing rate of 40.68×10−7%. It is concluded thatS. apetala species had characteristics of outstanding high biomass accumulation and could be used as coastal planting tree species in southern China. Foundetion item: The paper was supported by the project of integrated mangrove management and coastal protection (IMMCP) in Leizhou Peninsula, Guangdong Province. Biography: Han Wei-dong (1963-), male, associate professor, in Zhanjiang Ocean University, Zhanjiang 524088, Guangdong; and presently as postdoctoral researcher in Life Science College, Xiamen University, Xiamen 361005, Fujian, P.R. China Responsible editor: Zhu Hong.  相似文献   

4.
无瓣海桑作为潮间带红树林外来树种,在有长年淡水排放条件的中高潮间带红树林生态恢复生境中具有优良速生特点。2001年5月对雷州半岛附城岚北的6年生无瓣海桑人工林进行了调查,林地样地和标准木调查结果显示,该人工林年平均树高生长为2.03 m,年平均胸径生长为2.35 cm;地径与胸径呈极显著相关性。标准木单株总生物量干重为95.647 kg,群落单位面积生物量为22.955 kg/m2;地上生物量与地下生物量之比为1.60;当年平均生物量积累为9.337 kg/m2;单株材积为88.23 dm3、当年材积的年生产力(PA)为0.407。群落单位面积热能积累为424.851×103 kJ,年太阳辐射能固定成生物量的转换率为40.68 ×10-7%。结果表明无瓣海桑在红树林树种中具有突出的高生物量生长积累特性,应作为我国南方海岸滩涂的优良速生造林树种加以推广。  相似文献   

5.
蔡俊欣 《热带林业》2008,36(1):12-15
从项目管理的角度对中荷合作雷州半岛红树林综合管理和沿海保护项目的实施和成效进行分析和小结,认为更新观念、科学设计、管理体系、合理配备人员和良好合作机制是项目取得成功的关键因素。  相似文献   

6.
Methane fluxes from sediments in different zones of a Bruguiera sexangula mangrove wetland were determined by closed static chamber techniques during one whole year period, at Changning River estuary, northeast of Hainan Island, China. Methane productions were also measured by anaerobically incubating sediment samples. Impacts of salinity, sulphate and temperature on methane production rates were studied in vitro. Great differences of annual methane fluxes were observed in three zones, with the values of 0.39, 0.20 and 0.12gm–2 in the outer zone, middle zone and inner zone, respectively, in part due to the differences of sediment water contents and crab bioturbation. The highest fluxes in each zone occurred in autumn and the lowest in winter. Large diurnal fluctuations in fluxes were caused by the changes of tidal conditions rather than the changes of air or sediment temperatures. The temporal and spatial patterns of methane production differed somewhat from those of methane flux. There was great seasonality for methane production and the highest productions were found in autumn and the lowest in spring. Different horizontal and vertical patterns occurred in different seasons and different zones, suggesting the complexity of factors controlling methane production. The in vitro control experiments indicated that salinity and sulphate had negative effects whereas temperature (20–50°C) had positive effects on methane production rates. However, there were different sensitivities for the different levels of the three factors.  相似文献   

7.
The Sanjiang Plain is a vast area of alluvial floodplains and low hills in northeast Heilongjiang Province. It is the largest tract of wetlands in China and East Asia outside of Siberia. 28 wetland nature reserves exist on the Sanjiang Plain, and three of them have been listed as wetlands of international importance to water bird conservation by the Ramsar Convention Bureau. The wetlands of Sanjiang Plain are noteworthy for its rich biodiversity, but they continue to decline in area and deteriorate in quality currently. The main threats or constrains, immediate cause, root cause and required response are analyzed in this paper, and the four aspects opinion such as improvement of watershed management, enhancement of protection and restoration of habitats and biodiversity, alternative livelihoods of rural residents living in and near natural wetland reserve, and reinforcement of capacity building of natural reserves are brought forward as the effective measures for the Sanjiang Plain wetland protection.  相似文献   

8.
东北三江平原湿地现状、面临的威胁和保护措施   总被引:1,自引:0,他引:1  
三江平原是黑龙江省东北部由冲积平原和低山组成的广袤区域,它是中国和东亚最大的一片湿地.三江平原现有28个湿地保护区,其中3个被列为Ramsar公约有重要国际影响的湿地.三江平原湿地具有丰富的生物多样性,但随着近年来开发的加剧,三江平原湿地的面积不断缩小,湿地的质量逐步恶化.本文在阐述了三江平原湿地现状的同时,对湿地面临的主要威胁、退化的主要原因以及亟待解决的问题做了深入的分析,同时提出了改善流域的管理、加强湿地生境与生物多样性的保护与恢复、改变湿地周边地区居民的生活方式及强化湿地保护的能力建设等4个方面保护三江平原湿地的有效措施.  相似文献   

9.
广东省雷州市九龙山风景区植物共记录有种子植物112科394属579种(包括变种),其中裸子植物7科9属14种,被子植物105科385属565种;其中野生81科294属423种,栽培69科162属227种;植物区系表现了我国北热带植物区系资源的典型性,植物种类丰富,广布种较多;天然植被以湿地红树林群落、次生季雨林和灌丛为优势,人工植被以坡地尾叶桉和热带作物等为优势;是一个具有极大科研价值和保存价值的地区。建议加快红树林国家级湿地公园建设,加强其自然资源保护与生态旅游开发力度。  相似文献   

10.
对紫斑牡丹在东北地区的引种情况及引种后的物候表现、品种表现及防寒措施进行了总结与分析,结果表明:紫斑牡丹引种东北地区后总体物候期延迟,花期普遍缩短,但品种间存在一定差异。应采取必要的防寒措施,以保证东北地区成功引种紫斑牡丹。  相似文献   

11.
天然油松林与人工油松林物种结构等方面存在一定差异,其群落物种丰富度和最小面积也不同。本文对河北蔚县的天然次生油松林和人工油松林的物种丰富度及木本植物群落最小面积进行了探讨。结果表明,油松天然林乔木物种丰富度较人工林高,乔木幼苗幼树差距不大,灌木物种丰富度比人工林高,草本物种丰富度比人工林低。从总的物种组成来看,天然油松林与人工油松林具有较高的相似性。用8个模型对天然林和人工林木本植物种-面积曲线分别进行了拟合,并确定各自的最优模型,得出各取样比例时的最小面积。结果表明,当所取物种比例为0.6及以下时,天然林的最小面积小于人工林;而所取比例为0.7及以上时,天然林的最小面积大于人工林。  相似文献   

12.
延边地区草坪病虫害调查初报   总被引:2,自引:0,他引:2  
2000—2002年对延边地区的草坪病虫害进行了实地调查,发现草坪病害6种,其中发病较重的是褐斑病与锈病;草坪虫害5类,其中危害较大的是粘虫和蛴螬。  相似文献   

13.
We investigated the spatial distribution (horizontal and vertical concentrations) of copper (Cu), lead (Pb), zinc (Zn), and cadmium (Cd) in five wetland types (mudflat, aquaculture wetland, water area,...  相似文献   

14.
北京八达岭植物群落多样性特征分析   总被引:5,自引:0,他引:5  
根据34个样地的调查资料,分析了该地区森林植物群落物种多样性的特征:群落内各层物种丰富度指数的大小为草本层>灌木层>乔木层;多样性指数的大小为乔木层<灌木层和草本层。灌木层与草本层的多样性指数随林分郁闭度变化而变化,在林分郁闭度为25%的侧柏黄栌混交林中,灌木层的多样性指数和丰富度指数小于草本层;在郁闭度53%的杂木林中,灌木层和草本层的多样性指数接近;在郁闭度53%以上的各个群落内,草本层的多样性指数和丰富度指数基本上都大于灌木层。人工林中的物种多样性变化多样,明显低于天然林,林分层次单一,更新不良,缺乏灌木层和地被植物,生态系统很不稳定。  相似文献   

15.
Regressive formulae to calculate the quantity of plant leaf area for 13 species of ornamental plants were set up based on investigation data of 30 species on 3 major public squares (Dongfeng square, Shengli square and Guandu square) in Kunruing City, China, which were applied to calculate quantities of plant leaf area of these 13 species. The quantities of plant leaf area for the other 17 ornamental plant species on these squares were directly measured, and the total quantity of plant leaf area of each studied square was obtained individually. The results showed that the quantity of plant leaf area on Shengli square with ornamental plants structure composed of arbor tree species, shrub tree species and turf grass was highest among the three squares. It is believed that the design model of multi-storied vertical structure and proper tending of plant community could not only increase the quantity of plant leaf area, but also play an important role in generating ecological and landscaping benefits.Some corresponding suggestions were put forward on the basis of comprehensive analyses on the plant leaf area quantity of the three representative squares in Kunming urban area.  相似文献   

16.
水是干旱区最为宝贵的自然资源之一,水量平衡在很大程度上影响着土地荒漠化过程.本文在荒漠化公约所作的荒漠化气候分区的基础上,对干旱区因水资源的不合理利用对土地荒漠化的影响如土壤盐渍化、植被退化和现有耕地的废弃加以综合分析,并据此提出了缓解这些影响的相应对策.  相似文献   

17.
Introduction Biodiversity is a popular way of describing the diversity of life on earth. It includes all life forms and the ecosystems in which they live (Menini 1998). Biodiversity plays a fundamental role in organic and sustainable food production, and …  相似文献   

18.
This paper aims to study the effects of vegetation on runoff and sediment transport at the watershed scale, and to provide a theoretical basis for afforestation in the Loess area, in the nested Caijiachuan watershed, Jixian County, Shanxi Province of west China. Forest watersheds and farmland watersheds with similar terrain features were selected through cluster analysis to study their runoff and sediment transport characteristics. Results showed that compared with farmland watersheds, runoff generation time in forest watersheds was delayed remarkably, and peak flow was reduced greatly, which indicates that vegetation played an important role in holding and absorbing rainfall. Besides, with the increase of forest coverage, the runoff amount, runoff depth and runoff coefficient decreased during the rainy seasons. The runoff depth and runoff coefficient of farmland watersheds in the rainy season were 5–20-fold as much as that of forest watersheds, and runoff and sediment yield of watersheds with low forest coverage were 2.7–2.9-fold and 3–6-fold as great as those with high coverage during rainstorms, and low forest coverage had larger variation in sediment hydrograph. For the complexity and scale dependence of the influence of forest vegetation on runoff, forest hydrological functions based on regional scale or watershed scale were worthy of further studies. __________ Translated from Science of Soil and Water Conservation, 2006, 4(3): 48–53 [译自: 中国水土保持科学]  相似文献   

19.
韩辉林  李成德 《林业研究》2007,18(2):144-146
本文报道了分布于黑龙江省塔和地区的2个中国夜蛾科新记录种:北方纬夜蛾Atrachea japonica (Leech, 1889) 和暗绿丫金翅夜蛾Autographa macrogamma (Eversmann, 1842),同时首次将以新种记述于韩国和台湾省的中文夜蛾Neustrotia rectilineata Ueda, 1987在大陆予以报道.对标本材料的外部形态特征、生殖器图片和世界性分布予以记述.所用标本材料收藏在东北林业大学林学院昆虫实验室.  相似文献   

20.
旅游开发对若尔盖自然保护区土壤养分和物理性状的影响   总被引:2,自引:0,他引:2  
对高原湿地若尔盖国家级自然保护区不同旅游开发强度下土壤养分和物理性状进行研究的结果表明:(1)不同旅游开发强度(强度等级)对若尔盖高原湿地花湖景区土壤养分含量(有机质、氮、磷、钾)有着较大差异。(2)不同旅游开发强度对土壤理化性质的影响表现为:随着放牧干扰强度的增加,样地土壤容重逐渐增大、孔隙度逐渐减小。干扰导致土壤持水量和含水量下降,重度和中度干扰下土壤持水量和含水量与无放牧干扰时相比均有显著下降(P〈0.05)。放牧压实造成土壤表层孔隙度下降,致使土壤初渗速率、稳渗速率下降,其中稳渗速率下降最为明显,轻度、中度和重度放牧干扰下土壤稳渗速率比未受放牧干扰时分别下降了49.81%,81.89%和92.34%。(3)旅游活动、过牧超载等人为干扰活动是引起生态退化的主要原因。气候寒冷造成土壤利用性能受限,植被生长缓慢且破坏后难于恢复,湿地中伴随着水的大量流失和进而引发的湿地功能的的丧失对若尔盖及附近地区乃至全球生态环境的形成与演变产生重大影响。应对若尔盖湿地自然生态环境进行保护。严禁挖沟排水和过度无序旅游,乃是保护土壤,稳定若尔盖湿地高原生态环境的重要措施。只有这样,保护土壤生态系统才有依托,才有物质基础。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号