共查询到20条相似文献，搜索用时 218 毫秒
1.
The phenology of figs(Ficus spp.Moraceae) is being monitored in the dry forests of Mudumalai, southern India and individuals belonging to the genus are marked with unique tag numbers and their vegetative and reproductive phenologies have been monitored since August2000 on a monthly basis.The influence of abiotic factors on fig phenology and the differences between fig and nonfig phenologies are being examined.The seasonality of different phenophases of fig phenology is also being examined.The maximum intensity of leaf flush occurred in drier months.Fig and non-fig species showed significant differences with expansion and senescence phenophases of leafing.Flowering also occurred in drier months.There were significant differences between fig and non-fig species with reproductive phenophases.As with non-fig species,leafing was influenced by maximum temperatures.Both vegetative and reproductive phenophases were significantly seasonal. 相似文献
2.
以深圳坝光湿地园银叶树（Heritiera littoralis）群落为研究对象,分析了深圳坝光湿地园银叶树群落 8 种优势树种叶片碳、氮、磷含量及其化学计量关系,以及 3 种生境（沼泽、山地、临海）土壤和不同土壤深度（0~10 cm、10~20 cm、20~40 cm）有机质、全氮、碱解氮、全磷、有效磷含量及其化学计量关系。结果表明：不同优势树种叶片的碳、氮、磷含量及其计量特征具有显著差异,显示出明显的种间差异性;不同生境（临海、山地、沼泽）之间的土壤差异主要表现为氮及碳氮比,其他如有机质、磷等差异不明显;不同土层则表现为有机质和氮差异明显,浅层土壤元素含量最高,其他指标在各土层中差异不显著。研究表明,除银叶树生长可能受到氮限制外,其他优势树种元素限制现象不明显。 相似文献
3.
Fabio Orlandi Tommaso Bonofiglio Luigia Ruga Carlo Sgromo Bruno Romano Marco Fornaciari 《Annals of Forest Science》2007,64(5):557-568
Phenological stages are the result of biorhythms and environmental factors, these last are probably the same ones that caused, during evolution, adjustments of the species to different climate. The present study was carried out in a Phenological Garden located in central Italy (Perugia, Umbria Region) which contains indicator species, common to all International Phenological Gardens. The aim of this study was to determine and analyse the average trends of development of eight plant species and their phenological adjustment to the Mediterranean environment, over a nine-year period (1997–2005). The results of the statistical analyses show a strong relationship between the temperature trends and vegetative seasonal evolutions interpreted by phenological data for all the species considered. Moreover, it was demonstrated that the plants studied may approach or close completely the timing gaps eventually created during the first phenological phases, adjusting thus the beginning of subsequent phenophases. 相似文献
4.
Deciduous trees with high-density wood that occur in dry seasonal tropical regions respond to rainfall seasonality with synchrony in phenophases. However, they may exhibit interannual differences in sy... 相似文献
5.
6.
Through 5 years of phenological observations onLarix principis-rupprechtii Mayr. in primary seed orchard and studies on population and individuals of clones, the annual periodic phenological laws
were revealed and the annual phenological periodic table was drawn up. The correlation between various phenophases, the air
temperature and active accumulated temperature were analyzed and expounded. The authors also analyzed the similarities and
differences of phenophases among clonal individuals as well as the blooming properties of male and female flowers at the same
time. This study could provide theoretical reference for working out the production plan of improved varieties and other management
measures in seed orchard ofLarix principis-rupprechtii.
Biography: ZHANG Xin-bo (1956-), male, senior engineer in Shanxi Academy of Forestry Science and Northern Research Institute of Forestry
of China, Taiyuan 030012, P. R. China.
Responsible editor: Zhu Hong 相似文献
7.
8.
Tracer gas studies and oxygen uptake measurements have shown that pressurized gas transport improves oxygen supply to roots in the wetland tree species Taxodium distichum L. Rich. (Taxodiaceae), Betula pubescens J.F. Ehrh. (Betulaceae), and Populus tremula L. (Salicaceae), but not in Acer pseudoplatanus L. and Ilex aquifolium L., which are found in drier habitats. In the deciduous tree species Betula pubescens and Populus tremula, pressurized gas transport was most evident during the resting period, which is characterized by soil anoxia following waterlogging of the natural habitat. Because pressurized gas transport is found in species of distantly related families, we hypothesize that it helps wetland species survive the initial period of soil flooding before acclimation to waterlogging cccurs. 相似文献
9.
根据中国物候观测网武汉观测站的物候和气温、降水资料,分析了武汉市25种木本植物春季展叶期、始花期和盛花期,秋季落叶期等4个关键物候期的变化趋势、对气候变化的阶段响应特点及气温、降水变化的关系。结果表明:1963年以来,武汉地区气温呈显著上升趋势。春季物候期的早晚主要受春季气温的影响,特别是春季物候期发生当月和上1月的平均气温对物候期的影响很大。秋季物候期受秋季气温的影响,特别是物候发生当月的温度。叶子的物候期与前1月的降水量有较为明显的关系,但是花的物候期和降水的关系不明显。 相似文献
10.
《Forest Ecology and Management》2006,221(1-3):42-51
We studied two pairs of congeneric species (Dipterocarpus hispidus, Dipterocarpus zeylanicus, Mesua ferrea, and Mesua nagassarium). These species are canopy trees of rain forest in south-west Sri Lanka that exhibit differing topographic affinities. We hypothesized that topographic affinity is related to successional status and species ability to endure drought. We tested for these changes by measuring morphology of seedlings growing with each other in differing combinations of light and water. We constructed shade houses with a range of photosynthetic photon flux densities (PFD) and red:far red (R:FR) ratios. Two watering regimes within shade treatments created soil conditions that were either evermoist or periodically dry. Seedlings of the four species were inter-planted at equal spacing within large flats. They were allowed to grow amongst each other for a 2-year period. The more shade-intolerant Dipterocarpus spp. exhibited greater morphological responsiveness to increases in irradiance than the more shade-tolerant Mesua spp. We also demonstrate that all four species differ substantially from each other when morphological attributes (height, dry mass, leaf area) are compared together. Differences among these four species can be logically explained by their sequential competitive exclusion in relation to increasingly limited resources of light and soil water. In high light and evermoist soil conditions D. zeylanicus performs best. Under deep shade Mesua spp. have greater height than Dipterocarpus spp. When soil water is limiting, and the level of shade intermittent, M. nagassarium has greater height than the other three species. These results conform to species observed topographic distribution in the forest. Further studies are needed of wild populations growing across a range of forest sites to confirm whether these four species differ when grown under natural field conditions. 相似文献
11.
Tree plantations are increasingly common in tropical landscapes due to their multiple uses. Plantations vary in structure and composition, and these variations may alter soil fauna communities. Recent studies have demonstrated the important role of soil fauna in the regulation of plant litter decomposition in the tropics. However, little is known about how plantation species affect soil fauna populations, which may in turn affect the biogeochemistry of the plantation system. We measured soil macroinvertebrate abundance and biomass in 9-year-old N2-fixing Leucaena leucocephala, Casuarina equisetifolia, and non-N2-fixing Eucalyptus robusta plantations on a degraded site in Puerto Rico. Nutrient concentrations and standing stocks of forest floor litter were also determined to examine the relationship between litter chemistry and soil macroinvertebrates. Leucaena plantations had significantly higher abundances and biomass of millipede species than Casuarina and Eucalyptus. Earthworm biomass did not differ among plantation treatments. Nitrogen, P, and K concentrations were generally higher in Leucaena litter, which resulted in higher standing stocks of these nutrients in fragmented, moderately decomposed litter (Oe horizon). Millipede biomass was highly correlated to N concentration and C/N ratio in the Oi litter horizon. These results suggest that plantation species differ in their influence on soil fauna, and the biomass and abundance of soil fauna can be regulated through careful selection of plantation species in degraded tropical lands. 相似文献
12.
以广西银杉林不同生境的样地作为不同资源的综合体(资源位),以各物种的重要值作为资源位上的状态指标,定量分析银杉林各主要树种种群的生态位宽度、生态位相似性比例和生态位重叠。结果表明:1)银杉、变色杜鹃、华南五针松、五列木、绣球茜草具有较大的重要值和较宽的生态位宽度值,占据群落中的重要资源,在所调查的生境中具有更强适应能力,在银杉林中具有重要的地位。而含笑、大头茶、小花桤叶树等种群数量相对较少,分布范围较窄,生态位宽度较小,对资源的利用能力比较弱。2)银杉林中各种物种之间的相似性比例值多数较大,多数物种间的生态学特性较相似或他们利用资源的相似性程度较大。生态位宽度大的物种和其他物种间的生态位相似性比例值大,生态位宽度小的物种与其他物种间的生态位相似性比例值较小。3)银杉林中各主要树种间的生态位重叠值较低,各主要树种之间的相互竞争不高。生态位宽度大的物种具有较大生态位重叠值,与其他物种利用或占有同一资源的概率大;生态位宽度小的物种具有的生态位重叠值较小,与其他物种的占有或利用同一资源的概率小。4)银杉在各个样方中都占据较大重要值,具有较大的生态位宽度值,是银杉林的优势种和群落的建群种。 相似文献
13.
浅谈城市湿地生态功能退化的原因及其恢复与保护 总被引：4，自引：0，他引：4
湿地在调节全球气候和维持区域生态平衡以及提供野生动植物的栖息地方面具有重要作用。城市湿地是城市重要的生态基础设施,是城市可持续发展依赖的重要自然系统,具有众多的生态及社会服务功能。本文阐述了城市湿地生态系统的特点,较全面地分析了系统的生态功能、当前城市湿地功能退化的原因,在此基础上提出了恢复和保护的措施。 相似文献
14.
Artificial drainage is widely used to increase timber production and improve its quality in northern boreal and temperate forests, but its impact on biodiversity remains largely unexplored. Amphibians are particularly dependent on forest wetland qualities to complete their complex life cycles. We explored the supply of water bodies, their occupancy by amphibians, and persistence during the larval period comparatively in drained and natural forest plots in two years in Estonia. The water bodies in drained plots were more abundant but less diverse and of generally lower quality than in natural plots; however, the drainage ditches were favoured by newts. In the dry spring of 2009, water bodies were used more frequently in natural than in drained plots, while in the typical spring of 2010, several natural depressions appeared in drained plots and the frequency of use of water bodies did not differ between natural and drained plots. However, most natural depressions used for breeding in drained plots dried out before tadpole metamorphosis; such drying was not observed in natural plots. Thus, by profoundly changing natural hydrology, intensive large-scale forest drainage reduces the variety of water bodies and the quantity and quality of amphibian breeding sites. Moreover, we suspect that, at least in some years, temporary water bodies in drained areas function as ecological traps for amphibians. We suggest that, where possible, intact wet-forest areas with remaining natural hydrology should stay undrained. In areas already drained, breeding sites for amphibians can be provided by creating depression-like enlargements to some ditches. 相似文献
15.
Although key factors for vegetation composition and structure, site and soil condition have received little attention as predictors of habitat suitability in wildlife ecology to date. Using the example of capercaillie (Tetrao urogallus), an indicator species for open, well-structured forest habitats, we evaluated the potential use of ecological forest site mapping for the identification of areas where the preferred vegetation structures are supported by the prevailing soil conditions. These are sites that we, therefore, expected to be of long-term relevance to the species. 相似文献
16.
17.
调查了天津滨海新区湿地野生植物群落,计算出各群落中优势种的重要值,并应用典范对应分析法对湿地植被群落类型及其分布与主要环境因子之间的关系进行了研究。结果表明:1)土壤含盐量、土壤pH值以及滨水距离的差异是形成滨海新区湿地植物分布格局的三个主要环境因素。2)三个主要环境因素之间存在相关关系,滨水距离能够对土壤理化因子的数量和强度进行再分配,间接影响了物种生存状态。三个主要环境因素不仅决定了群落在排序空间中的位置,也决定了群落物种组成。3)优势种的分布与样方的分布格局极其相似,优势种的分布格局在一定程度上决定了群落类型的分布格局。 相似文献
18.
湖北省水鸟的多样性及其保护对策 总被引：1，自引：0，他引：1
湖北省位于长江中游,地处我国南北过渡地带。境内河流纵横、湖泊众多,湿地资源丰富,享有“千湖之省”、“鱼米之乡”的美誉。湿地类型既有平原湿地,又有亚高山湿地,湿地总面积在161.7万hm2以上。复杂的湿地环境和丰富的湿地生物资源,使湖北成为水鸟重要的繁殖地、迁徙停歇地和越冬地。在我国的231种水鸟中,湖北省有126种,隶属7目19科58属。其中,属于国家重点保护的有20种,属于湖北省省级重点保护的有18种。笔者对湖北省水鸟的物种多样性、种群数量、生态分布规律进行阐述,并提出了相应的保护对策。 相似文献
19.
珠海淇澳红树林湿地生物多样性现状及保护 总被引：4，自引：0，他引：4
红树林湿地是珠海淇澳岛生态系统的主体,为湿地生物的生长、栖息和繁殖提供了良好生境,孕育了丰富的生物资源。文章以野外调查结果和资料统计为根据,从红树林植被与湿地植物、动物等方面概述淇澳岛的红树林湿地生物多样性现状,继而分析了淇澳岛的红树林湿地资源保护中存在的问题,如人为干扰、水污染、资源过度利用、大面积纯林营造等。最后,就淇澳岛未来的红树林湿地生物多样性保护提出了建议：①加强自然保护区建设;②开展生物多样性保护的科学研究;③加强滩涂治理;④进行红树林湿地恢复和定位监测等。 相似文献
20.
文中总结了目前盐城大丰区湿地保护与修复工作的现状，及其在湿地保护体系的初步建立、内陆河道的生态建设、退居还湿的生态修复等方面的成效，分析当前保护与修复中存在的问题，包括小微湿地生态退化、针对重要湿地尚无预警机制、科研监测能力不足。在此基础上，提出相应对策:加快小微湿地保护修复，优化生境；积极开展湿地科研监测，完善生物档案及监测数据，并建立应对生态突发事件的预警机制；加强区域内生态系统的联系互补，提高生态服务能力；采取生态经济发展模式，推动湿地生态环境与经济协调发展。探索加强大丰区湿地保护修复，对于维护湿地生态良性循环、促进经济社会可持续发展具有重要的意义。 相似文献