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1.
Abstract. Due to the complexity of coastal barrier vegetation, it is useful to apply a functional-type approach to assess the response of barrier island vegetation to climate change. In this paper, a simple clustering analysis is applied to a group of 19 plant associations, based on six plant attributes and six environmental constraints. This analysis results in the suggestion that the main division of the vegetation types at Virginia Coast Reserve is between herbaceous and woody types, which differs from the existing classification which recognizes three groups: xeric-mesic herbaceous, woody and hydric-halophytic herbaceous. Considerations about grouping plant functional types are also addressed in this paper. At a global scale, inclusion of barrier plant functional types may not be so important for the climate-change response of vegetation, but it may be necessary to consider these important systems for spatially explicit modelling of landscape responses. 相似文献
2.
The survival of alpine species in changing climates depends on dispersal or adaptation. However, it is unclear whether trait
variability along elevation/climatic gradients is adaptive or represents stress towards lower/warmer elevations, particularly
for the endangered endemics for which protected status and plant longevity preclude experimental study. We chose one such
species, known for its phenotypic variability (Primula glaucescens, endemic to the southern Alps), and quantified key functional traits in situ throughout its range, correlating these with
elevation as a proxy for climate. Larger leaves were evident towards lower elevations, but tissue nitrogen dilution and limited
regenerative fitness were symptomatic of stress. Specific leaf area, a correlate of relative growth rate, was consistently
low: the entire species exhibits conservative leaf economy and inherently slow growth. This seemingly variable species exhibits
superficial variability around a fundamentally conservative, cold-adapted survival strategy, and thus phenotypic variability
is unlikely to facilitate the persistence of alpine endemics during rapid climate warming.
Nomenclature: Pignatti (1982). 相似文献
3.
4.
Abstract. We describe an approach for developing a Dynamic Global Vegetation Model (DGVM) that accounts for transient changes in vegetation distribution over a decadal time scale. The DGVM structure is based on a linkage between an equilibrium global vegetation model and smaller scale ecosystem dynamics modules that simulate the rate of vegetation change. Vegetation change is classified into four basic types, based largely on the projected change in above-ground biomass of the vegetation. These four types of change are: (1) dieback of forest, shrubland or grassland; (2) successional replacement within forest, shrubland or grassland; (3) invasion of forest, shrubland or grassland; (4) change in tree/grass ratio. We then propose an approach in which the appropriate ecosystem dynamics module for each type of change is applied and the grid cells of the global model updated accordingly. An approach for accounting for fire, as an example of a disturbance which may strongly influence the rate and spatial pattern of forest dieback, is incorporated. We also discuss data needs for the development, calibration and validation of the model. 相似文献
5.
Christina Skarpe 《植被学杂志》1996,7(3):397-404
Abstract. A system of easily defined plant functional types for a dry savanna is presented and related to climate data. To predict possible changes of vegetation in response to climate change, a system of functional attributes is developed. The attributes are based on both structural and functional characteristics and are chosen to be related to climatic conditions. plant functional types are defined as assemblages of plant species having similar combinations of plant functional attributes. Direct and indirect gradient analyses of a test data set show that the plant functional types as well as the vegetation described from them are strongly associated with total annual precipitation, precipitation of the wettest month and a moisture index (all related to soil moisture) and with temperature of the coldest month. 相似文献
6.
植物功能型及其生态学意义 总被引:20,自引:2,他引:20
植物功能型是近年来在全球变化研究中引入的一个新的生态学术语,综 植物功能型概念的由来、划分植物及其生态学意义,用系统生物学的理论与方法理解植物功能型,并指出了植物功能型在全球变化研究中的意义。 相似文献
7.
Growth performance of two deciduous Vaccinium species in relation to nutrient status in a subalpine heath 总被引:1,自引:1,他引:1
Renato Gerdol 《Flora》2005,200(2):168-174
Net primary production (NPP) of two Vaccinium species (V. myrtillus and V. uliginosum) was determined in three subalpine heath communities on the Northern Apennines (N. Italy). The main objective of the study was to test the hypothesis that two species sharing the same plant functional type (deciduous dwarf shrub) have similar growth performances along environmental gradients. The second objective was to assess whether, and to what extent, NPP of the two species was associated with functional and morphological traits, which can affect plant growth in relation to nutrient status. Total community NPP in the three communities was closely related to soil nutrient availability. NPP of V. uliginosum did not vary among communities, while that of V. myrtillus peaked in the most fertile habitat. The N:P ratio in the whole plant as well as in the leaves of the two shrubs exactly mirrored the among-community pattern in soil phosphate concentration. In particular, the foliar N:P ratio in both V. uliginosum and V. myrtillus was >16 in the poorer sites, which indicates P limitation. I concluded that the growth response of the two shrubs in relation to soil nutrient availability is individualistic. Growth of V. myrtillus is P-limited while that of V. uliginosum is not. 相似文献
8.
Abstract. Low temperatures exert a primary constraint on the growth of high arctic vascular plants. However, investigations into the impact of temperature on high arctic plants rarely separate out the role of air and soil temperatures, and few data exist to indicate whether soil temperatures alone can significantly influence the growth of high arctic vascular plants in a manner that might direct community composition. We examined the response of high arctic plants of three functional types (grasses, sedges/rushes and non‐graminoids) to manipulated soil temperature under common air temperature conditions. Target plants, within intact soil cores, were placed in water baths at a range of temperatures between 4.9 and 15.3 °C for one growing season. Grasses responded most rapidly to increased soil temperature, with increased total live plant mass, above‐ground live mass and total below‐ground live mass, with non‐graminoids having the lowest, and sedges/rushes an intermediate degree of response. The ratio of above‐ground live mass to total live mass increased in all growth forms. Grasses, in particular, responded to enhanced soil temperatures by increasing shoot size rather than shoot number. In all growth forms the mass of root tissue beneath the moss layer increased significantly and to a similar extent with increasing soil temperature. These results clearly indicate that different growth forms, although collected from the same plant community, respond differently to changes in soil temperature. As a consequence, factors influencing soil temperature in high arctic ecosystems, such as global climate change or herbivory (which leads to reduced moss depth and increased soil temperatures), may also direct changes in vascular plant community composition. 相似文献
9.
This study reviewed the distribution of ten common savanna trees in Namibia. Tree distributions were investigated in relation to bioclimatic, topographic and edaphic variables at a national scale. The factors of importance at these broad geographic scales appeared to be rainfall, substrate and, likely, the incidence of frost. Baikiaea plurijuga, Burkea africana, Guibourtia coleosperma and Pterocarpus angolensis seem to reach their bioclimatic limits in Namibia.At the local level, plant traits become important and contribute to explaining distribution patterns. High water and/or nitrogen use efficiency (Acacia erioloba, Colophospermum mopane), dual water obtaining strategies (Faidherbia albida), fire tolerance (e.g. Acacia species, Burkea africana and Pterocarpus angolensis) and drought tolerance (Boscia albitrunca) are some key attributes providing additional explanations for current distributions.Amongst the selected trees and at broad geographic scales, below-ground adaptations are governed by rainfall regime in combination with coarse-textured soils, whereby shallow-rooted trees prevail in the Kalahari sandveld. Deep-rooted species are found largely on non-sandy soils. Physiological performance of many trees appears to be directly linked to rainfall regime and trees may hence show varying performance throughout their distribution range. Insight into plant functional attributes of trees in Namibia is required to develop appropriate management strategies in the light of climate change. Modelling climate change impacts should consider the relative contribution of bioclimatic versus local environmental factors that explain the current distribution patterns of the selected trees. 相似文献
10.
气候变化对森林演替的影响 总被引:16,自引:2,他引:16
森林演替是森林生态动力源驱动下森林再生的生态学过程,自20世纪初建立群落演替理论以来,演替研究成为生态学研究中的热点.客观准确地认识森林演替规律,研究森林演替动力学机理及其模型,是科学管理森林生态系统的需要;对于天然林保护工程与森林植被的恢复重建,具有重要的理论与实际意义.干扰是森林循环的驱动力,导致森林生态系统时空异质性,是更新格局和生态学过程的主要影响因素.它可改变资源的有效性,干扰导致的林隙是森林循环的起点.回顾了目前演替研究的几种方法,即马尔科夫模型、林窗模型(GAP)、陆地生物圈模型(BIOME)和非线性演替模式.介绍了气候变化对森林演替的影响;并在已有成果的基础上,提出了目前研究存在的问题及未来的发展方向. 相似文献
11.
本文在扼要概述全球气候变化背景的基础上,根据近百年气候历史资料以及海温、太阳黑子活动、火山爆发、CO2浓度变化、O3浓度变化、大气环流指数特征等因子与我省气修变化的定量与定性关系,分析了各因子的综合影响,预测了我省未来十年气候变化趋势。结果表明:我省未来十年气候以温暖、干旱为主,年际间仍存有波动。虽然总的气候变化趋势与全球变化是一致的,但具有明显的区域特征。同时提出了气候变化可能对森林的影响,初步探讨了应采取的森林对策。 相似文献
12.
Spatial and temporal variability in fire occurrence within the Las Bayas Forestry Reserve, Durango, Mexico 总被引:2,自引:0,他引:2
Patterns of fire occurrence within the Las Bayas Forestry Reserve, Mexico are analyzed in relation to variability in climate, topography, and human land-use. Significantly more fires with shorter fire return intervals occurred from 1900 to 1950 than from 1950 to 2001. However, the frequency of widespread fire years (25% filter) was unchanged over time, as widespread fires were synchronized by climatic extremes. Widespread fire years occurred during dry years that lagged wet years. Widespread fire years lagged the negative El Niño phase (wet winters) of the Southern Oscillation by 1 year, but were not synchronized by the positive, La Niña phase (dry winters) of the Southern Oscillation. The smaller, localized fires that occurred more frequently during the first half of the 20th century were attributed to changes in land tenure with the introduction of the ejido system in the early 1950s. Ejido management strategies lowered fire frequencies by suppressing fires and reducing anthropogenic fires. There were likely more ignitions prior to the arrival of the ejido system as fires were ignited by lightning and indigenous people. As the movement of indigenous peoples across the landscape has been restricted by changes in land tenure, numbers of human-ignited fires subsequently decreased post 1950. After 1950, fires occurred less frequently, were more synchronized, and more restricted to years of extreme climate. 相似文献
13.
植物功能性状是指能够反映植物碳获取、水分传递、养分循环等的重要生命活动的属性,包括植物生理、形态和物候等方面的特征。通过植物功能性状探讨物种分布格局、生长策略和存活机制及其对全球变化的响应与适应,是近年来生态学研究的热点之一。然而,不同尺度下植物功能性状与环境因子的关系存在差异,并且性状之间的关系也不尽相同。从物种、种群、群落、植被区系到全球尺度,围绕植物功能性状之间的相互关系及其对气候环境变化响应的热点问题进行了综述,梳理了近年来植物功能性状研究领域的进展,并讨论了目前植物功能性状研究的局限性和该领域未来的发展趋势。 相似文献
14.
Abstract. Despite increasing temperatures since the end of the Little Ice Age (ca. 1850), wildfire frequency has decreased as shown in many field studies from North America and Europe. We believe that global warming since 1850 may have triggered decreases in fire frequency in some regions and future warming may even lead to further decreases in fire frequency. Simulations of present and future fire regimes, using daily outputs from the General Circulation Model (GCM), were in good agreement with recent trends observed in fire history studies. Daily data, rather than monthly data, were used because the weather and, consequently, fire behavior can change dramatically over time periods much shorter than a month. The simulation and fire history results suggest that the impact of global warming on northern forests through forest fires may not be disastrous and that, contrary to the expectation of an overall increase in forest fires, there may be large regions of the Northern Hemisphere with a reduced fire frequency. 相似文献
15.
为了探究退化森林的树种组成变化和生物量储量的恢复规律,该研究选取云南哀牢山不同演替阶段的常绿阔叶林为对象,比较了不同演替阶段森林群落结构、树种多样性和生物量变化。结果表明,从演替早期到演替末期,乔木的科数先减少后增多,属数和种数则逐渐增加;Margalef丰富度指数、Simpson优势度指数、Shannon-Wiener多样性指数和Pielou均匀度指数随演替进程均呈增加的趋势;乔木生物量储量随演替进程逐渐升高,演替早期和演替中期的生物量分别为演替末期生物量的9.87%和65.98%;群落水平的树种多样性指数与总生物量呈显著正相关关系(P<0.05)。树木的生长和树种多样性的提高是影响群落乔木生物量储量递增的因素,且哀牢山处于湿冷的气候条件,退化森林植被的恢复相对比较缓慢。 相似文献
16.
17.
Norway spruce is one of the economically most important tree species in Central European forestry. However, its high susceptibility to droughts poses a strong challenge to its cultivation under future conditions with likely more frequent and prolonged droughts and shifts in the seasonal climate. To compensate for expected losses of forest areas suitable for the cultivation of spruce, more drought-tolerant species are required. Silver fir and Douglas fir are two potential candidates, which promise lower drought susceptibility and equal or even higher yield when compared to Norway spruce.Using the Black Forest as a regional case study, we assessed the effects of seasonal climate change, including drought stress, on tree-ring width formation of these three economically relevant conifer species over the last 60 years. In addition, we projected potential species-specific growth changes under different climate change scenarios until 2100.Our results suggest that both silver fir and Douglas fir will possibly experience growth increases in a warmer future climate, as predicted under the 4.5 and 8.5 Representative Concentration Pathway (RCP) climate change scenarios, whereas growth of spruce is expected to decline. Moreover, drought susceptibility in silver fir and Douglas fir is lower than in spruce, as shown for past drought events, and their ability to benefit from milder winters and springs could play a major role in their capacity to compensate for drier summers in the near to mid-term future. This study highlights the need to advance our understanding of the processes that drive drought resistance and resilience in tree species to guide management strategies in the face of climate change. 相似文献
18.
Sapling growth as a function of light and landscape-level variation in soil water and foliar nitrogen in northern Michigan 总被引:3,自引:0,他引:3
Kobe RK 《Oecologia》2006,147(1):119-133
Interspecific differences in sapling growth responses to soil resources could influence species distributions across soil
resource gradients. I calibrated models of radial growth as a function of light intensity and landscape-level variation in
soil water and foliar N for saplings of four canopy tree species, which differ in adult distributions across soil resource
gradients. Model formulations, characterizing different resource effects and modes of influencing growth, were compared based
on relative empirical support using Akaike’s Information Criterion. Contrary to expectation, the radial growth of species
associated with lower fertility (Acer rubrum and Quercus rubra) was more sensitive to variation in soil resources than the high fertility species Acer saccharum. Moreover, there was no species tradeoff between growth under high foliar N versus growth under low foliar N, which would
be expected if growth responses to foliar N mediated distributions. In general, there was functional consistency among species
in growth responses to light, foliar N, and soil water availability, respectively. Foliar N influenced primarily high-light
growth in F. grandifolia, A. rubrum, and Q. rubra (but was not significant for A. saccharum). In A. saccharum and A. rubrum, for which soil water availability was a significant predictor, soil water and light availability simultaneously limited
growth (i.e., either higher light or water increased growth). Simple resource-based models explained 0.74–0.90 of growth variance,
indicating a high degree of determinism. Results suggest that nitrogen effects on forest dynamics would be strongest in high-light
early successional communities but that water availability influences growth in both early successional and understory environments. 相似文献
19.
Heavy disturbance-induced mortality can negatively impact forest biota, functions, and services by drastically altering the forest structures that create stable environmental conditions. Disturbance impacts on forest structure can be assessed using structural sustainabilitythe degree of balance between living and dead portions of a tree populations size-class distributionwhich is the basis of baseline mortality analysis. This analysis uses a conditionally calibrated reference level (i.e., baseline mortality) against which to detect significant mortality deviations without need for historical references. Recently, a structural sustainability index was developed by parameterizing results of this analysis to allow spatial and temporal comparisons within or among forested landscapes. The utility of this index as a tool for forest health monitoring programs and triage decisions has not been examined. Here, we investigated this utility by retrospectively analyzing the structural sustainability of a mountain pine beetle (Dendroctonus ponderosae)-impacted, lodgepole pine (Pinus contorta)-dominated landscape annually from 2000 to 2006 as well as among watersheds. We show that temporal patterns of structural sustainability at the landscape-level reflect accumulating beetle-induced mortality as well as beetle-lodgepole pine ecology. At the watershed-level, this sustainability spatially varied with 2006 beetle-induced mortality. Further, structural sustainability satisfies key criteria for effective indicators of ecosystem change. We conclude that structural sustainability is a viable tool upon which to base or supplement forest health monitoring and triage programs, and could potentially increase the efficacy of such programs under current and future climate change-associated disturbance patterns. 相似文献
20.
Daniel Spitale 《Journal of bryology》2017,39(2):128-140
Understanding the main factors driving bryophyte communities in forests is a worthwhile research area as it provides a framework within which to evaluate effective management options. Previous studies elucidated the role of forest structure, substrate, and climate, but their effect in a wide environmental context encompassing several types of forests is still unclear. The aim of this study was to assess the effect of climate, stand structure, substrates (tree trunks, deadwood, forest floor), and different forest types for species richness, species composition, and cover of bryophytes. Seven different types of Alpine forests dominated by spruce, larch-stone pine, silver-fir, Scots pine, oak, beech, and alder were selected. Bryophytes were sampled on tree trunks, deadwood, and forest floor. The importance of forest type, substrate, climate, and forest structure was determined by variance partitioning. Species richness and species composition were best explained by substrate (respectively 13% and 11%) and by forest type (respectively 13% and 11%). The bryophyte cover was primarily explained by the forest type (24%), and to a lesser extent by the climatic factors and stand structure. Overall, these results suggest that in this region ecologically based forest management might focus their efforts in protecting all the forest types and associated substrates. This means that forests of less economic value should also be preserved, and that acceptable silvicultural options should pay attention to the naturally available substrates. Too often, deadwood availability was a limiting substrate for bryophytes. 相似文献