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1.
Impact of groundwater abstraction on a Banksia woodland, Swan Coastal Plain, Western Australia 总被引:1,自引:0,他引:1
By Philip K. Groom Ray H. Froend Elizabeth M. Mattiske 《Ecological Management & Restoration》2000,1(2):117-124
Summary The Gnangara Groundwater Mound, centred 38 km north of Perth, Western Australia, is a large, shallow unconfined aquifer that is currently under abstraction as part of the public metropolitan water supply. To investigate the impact of lowering groundwater levels on a Banksia woodland on the Mound, vegetation monitoring near a groundwater abstraction bore (known as P50) began 1 year before becoming operational. In February 1991, 2 years after abstraction commenced, extensive death of the Banksia overstorey was observed within close proximity of the bore, following a short period of high summer temperatures. The site was subsequently revisited and the understorey floristic composition, abundance and vigour of overstorey species resurveyed, and compared with data collected from a site under long‐term monitoring and not currently influenced by abstraction. A lowering of groundwater level by 2.2 m at P50 between the summers of 1990 and 1991, resulting from the cumulative effects of abstraction and below average annual rainfall (low groundwater recharge), coincided with a loss of between 20 and 80% of adults of overstorey species and up to 64% of adults of understorey species within 200 m of the bore. Over a similar time period no significant decreases in the abundance of overstorey or understorey species were recorded in the monitored site not influenced by groundwater abstraction. Of the overstorey species, Holly‐leaf Banksia (Banksia ilicifolia) displayed the greatest susceptibility and lowest net recovery following the abstraction event at P50. The negative impact of groundwater drawdown on Holly‐leaf Banksia populations makes this overstorey species an important indicator of decreasing groundwater levels on the Gnangara Groundwater Mound. Water stress may have been the primary cause of vegetation death in close proximity to the P50 bore, although this would have been exacerbated by extreme summer temperatures (> 45°C) recorded during February 1991. The P50 scenario represents a localized response to an acute drawdown event, in association with other environmental factors, and provides invaluable information on the assessment of groundwater abstraction and poor groundwater recharge events on a Banksia woodland community. However, there are limitations in using the community response at P50 to manage the impact of drawdown events on other plant communities occurring on sandy, shallow aquifers. 相似文献
2.
Abstract Diurnal and seasonal water relations were measured in selected species of a Banksia woodland at a site with groundwater at a depth of 6–7 m. The canopy co-dominants Banksia attenuata and Banksia menziesii exhibited similar patterns of variation in water relations, both diurnally and seasonally. Stomatal conductance was usually 0.4–0.5 cm s?1 diurnally and seasonally and, generally, did not respond to water deficit and other factors. Transpiration was correlated positively with factors indicative of atmospheric evaporative demand, especially total global radiation and pan evaporation, and was highest in summer when canopy water use reached 2.1 mm d?1. Xylem pressure potential at dawn averaged ?0.25 MPa in both species throughout the year. Minimum xylem pressure potential varied seasonally and was negatively correlated with transpiration. Seasonal means of minimum xylem pressure potential varied from ?1.0 MPa in winter to ?1.5 MPa in early summer. Both Banksia species appeared to function as phreatophytes, utilizing groundwater which enabled them to maintain high rates of water use in late summer. Water use over a 12 month period totalled 635 mm, of which the canopy and understorey contributed 61% and 39%, respectively. Water use in the woodland was dominated by the canopy in late summer and the understorey at other times. 相似文献
3.
植被志(vegegraphy)是基于植被调查资料, 全面记叙植被的群落外貌、种类组成、结构和功能、生境条件, 以及地理分布等特征, 并对同类植被进行归纳和总结的志书。“植被志”的英文译为“vegegraphy”, 是本文的新造词, 它是由“vegetation”的词头“vege-”和英文后缀“-graphy” (记叙之意)组成的合成词。《中国植被志》的研编是一项时间紧迫、内容复杂、工作量浩繁的重大科学工程。它的完成将极大提升中国植被科学和生态学的研究水平, 并为中国植被资源的合理利用、生物多样性保护及生态环境治理等提供不可或缺的基础资料。本文首先简述了植被的基本特征(主要包括外貌特征、种类组成、群落结构以及动态变化等)和国内外植被调查的进展情况, 简要回顾了中国植被分类系统的研究历史, 并对以往的分类系统进行了若干修订。在此基础上, 着重讨论并提出了《中国植被志》卷册编排体系和用于《中国植被志》研编的植被类型划分方案。在对植被分类系统的修订方面, 主要对高级分类单位及相对应的英文名称进行了讨论和修订。按照本文修订的分类系统, 中国植被的分类单位及其对应的英文名称分别是: 植被型组(Vegetation Formation Group)、植被型(Vegetation Formation)和植被亚型(Vegetation Subformation)、群系组(Alliance Group)、群系(Alliance)和亚群系(Suballiance)、群丛组(Association Group)以及群丛(Association)。在植被型组中, 划分为9类: 森林、灌丛、草本植被、荒漠、高山冻原与稀疏植被、沼泽与水生植被、农业植被、城市植被及无植被地段。关于《中国植被志》的卷册编排和“植被类型”划分, 首先按高级分类单位——植被型划分相应的“卷”; 在此框架下, 模糊“植被亚型”、“群系组”和“群系”的概念, 确定“植被类型” (Vegetation type), 并将其作为植被志各卷中的“册”。这样处理不仅保证了研编工作的可操作性, 也保持了同一卷册中特定植被类型的完整性。《中国植被志》编排体系中的“植被类型”的划分很重要, 它是指具有相同建群种及相同优势类群(如种、属)的植被组合, 但它不是严格意义上的植被分类单位。“植被类型”的划分遵循“优势类群及生活型的同一性, 生境条件的相对重要性, 植被特征及用途的差异性, 以及突出植被志的应用性”等原则。按该编排体系, 《中国植被志》将由48卷约110册组成。 相似文献
4.
Colin J. Yates David J. Coates Carole Elliott Margaret Byrne 《Biodiversity and Conservation》2007,16(5):1379-1395
In this study we investigate the composition of the potential honeyeater pollinator community, patterns of honeyeater visitation,
pollination and the mating system in a range of population fragments for the bird-pollinated mixed mating system shrub Calothamnus quadrifidus R.Br. Specifically, we aimed to answer the following questions. For smaller and more isolated population fragments are honeyeater
species lost from the pollinator community, patterns of visitation different, levels of pollination lower and rates of selfing,
biparental inbreeding and correlated paternity higher. The composition of the honeyeater community was similar across population
fragments and there was no relationship between the abundance of birds and population fragment size. Honeyeaters were most
commonly observed visiting numerous inflorescences within single plants in all populations, but as population fragments became
larger movements between plants were more commonly observed. Our observations of honeyeater visitation were generally consistent
with our measurements of pollination and patterns in the mating system across population fragments. We found no significant
relationship between population fragment size and levels of pollination. Mating system studies showed outcrossing rates (t
m) comparable to those found in other bird-pollinated Myrtaceae, and ranged from 0.54 to 0.90 across populations. Outcrossing
rates were not significantly correlated with log population size, but correlations of outcrossed paternity indicate a clear
trend from low correlated paternity in larger populations to significantly higher correlated paternities in smaller populations.
As a consequence mating in small populations will occur between much smaller groups of plants, and this may affect population
fitness in subsequent generations. 相似文献
5.
Management of wetlands influenced by the Gnangara groundwater mound, Western Australia, is becoming increasingly challenging
due to an ongoing decline in the regional groundwater table. A number of these groundwater-dependent wetlands have acidified
(with adverse effects on the extant macroinvertebrate fauna) due to the oxidation of pyritic sediments. One management option
in such cases is artificial augmentation of surface water in order to maintain or reinstate anaerobia in the sediments. This
paper documents cycles of macroinvertebrate decline and recovery over 12 years of monitoring in three Gnangara mound wetlands
affected by drought-induced acidification, one of which is being artificially augmented. Acidification did not result in a
reduction of the total number of macroinvertebrate families present, however, there were clearly identifiable groups of acid-sensitive
taxa (amphipods and isopods, ostracods, chydorid and daphnid cladocerans, mayflies, oligochaetes, clams and snails) and acid-tolerant
taxa (sandfly larvae, macrothricid cladocerans and water boatmen). In the artificially augmented wetland, the effects of acidification
were reversed: acid-sensitive taxa reappeared and acid-tolerant taxa decreased in numbers. Moreover, there were a number of
taxa that appeared for the first time since augmentation, and summer family richness increased markedly. This study has shown
that artificial augmentation of wetland water levels can be a successful recovery strategy for recently acidified systems,
but this will depend on a number of factors, and the ‘recovered’ state will be at least slightly different from the original
state.
Handling editor: R. Bailey 相似文献
6.
Long-term change in the floristic composition and vegetation structure of Carnac Island, Western Australia 总被引:1,自引:0,他引:1
Aim To document changes in the floristic composition and vegetation structure of Carnac Island during a period of 40 years. This paper presents a synthesis of all available floristic and vegetational information. Location Carnac Island is 8 km offshore from Fremantle, south‐west Western Australia. Methods Comparison of lists of plant species for 1951, 1958/9, 1966/7, 1975/6 and 1995–6. Comparison of vegetation, based on structural and floristic elements, for 1951, 1965, 1972, 1984 and 1995. Results Floristic composition (both native and exotic species) changed most dramatically in the period 1975/6–1995/6, with a 37% reduction in number of plant species. The number of annual and perennial native species present in 1995/6 was most similar to that in 1951. The most remarkable change in the flora has been the increase in annual exotic species since 1951. Immigration and extinction rates were greatest in the periods 1951–58/9 and 1958/9–1966/7, respectively. Vegetation structure has also altered, involving a reduction in height of dominant species from 3–4 m to 1 m as Acacia rostellifera and Olearia axillaris have declined in distribution. The weed species Mesembryanthemum crystallinum (first recorded 1975) and Malva parviflora (1958) now dominate the vegetation of half the island. Main conclusions Five factors are considered to have contributed to botanical change: nesting seabird populations, eradication of the rabbit in 1969, drought, increased saltload from occasional cyclones in summer or autumn, and competition from increasing dominance of several weed species. Several of these factors have operated in opposing ways with respect to plant species richness and vegetation cover. Experimental studies are required to determine the strength of these interactions. Two weed species, Zantedeschia aethiopica (first recorded 1966) and Lycium ferocissimum (1992) have the potential to dominate the vegetation of the island. 相似文献
7.
高寒湿地植物群落的物种多样性保护及生态恢复对策 总被引:23,自引:0,他引:23
以物种组成较为复杂的青藏高原东部地区玛曲县高寒湿地为背景.从恢复生态学角度,系统地探讨了影响湿地植物群落物种多样性与生产力变化的主要因素,从不同的时间和空间尺度研究了典型样区植物群落中物种多样性与生产力的恢复机理与过程,以及生境异质性对其的影响。结果表明:在导致湿地植被退化的人类干扰诸因素中.超载放牧是主要因素。该地区超载量高达24%;其次.气候变化对湿地物种多样性与生产力也有较大影响。典型样区的恢复试验结果表明:实行围栏轮牧、控制载畜量、鼠虫害防治和建植人工草地等人工综合措施,能使样区植被得以卓有成效的恢复与保护。其中.黄河滩地的植物群落中.物种丰富度从23种/m^2上升到29种/m^2;Shannon多样性指数从3.82上升到4.62;草场生产力(地上生物量)从729.2g/m^2上升到935.38g/m^2。阳坡和阴坡样地植被也有类同的恢复效果。在以上三类样地中.以滩地的生态恢复效果最为显著。据此,我们提出了相应的湿地物种多样性保护和生态恢复对策.即:加强自然保护区建设、协调人类活动与物种多样性保护的关系、严格控制载畜量、发展人工草地等主要措施与建设。 相似文献
8.
草地退化是中国北方草原面临的主要生态问题。该文以1984和2004年草原植被群落调查数据为主要依据, 以优势种、建群种和群落类型及其比例的变化作为主要指标, 并与20世纪80年代的植被类型图比较, 分析了内蒙古锡林河流域草地的退化趋势及其空间分布。根据流域内草地退化的实际情况, 将其分为未退化、轻度退化、中度退化、重度退化和极度退化5种退化类型。另外, 根据近20年前后草地植被变化的实际情况, 又划分了恢复和盐化两个类型。结果表明: 草地退化呈现明显的空间分布, 以锡林河为标志, 总体上从上游到下游退化程度逐渐加剧, 表现为浑善达克沙地进入锡林河的部分及沿河地区为重度退化, 锡林浩特市以北的区域, 尤其是流域的西北部, 已经达到了极度退化; 流域中部的白音锡勒牧场主要是中度退化; 轻度退化则均匀地分布于整个流域; 未退化类型多分布于锡林河的西部, 锡林河中下游地区由于农田退耕、草地围封出现了一定程度的恢复; 锡林浩特市以北沿锡林河植被的盐化程度较重。不同的植被类型退化程度也不同, 沙地灌丛植被轻度退化比例较高, 占植被的43%; 羊茅(Festuca ovina)草原和榆树(Ulmus pumila)疏林沙地中度退化草地的比重较高, 超过50%; 贝加尔针茅(Stipa baicalensis)草原和无芒雀麦(Bromus inermis)杂类草草甸的重度退化面积达50%以上; 极度退化比例较大的有克氏针茅(S. krylovii)草原和小叶锦鸡儿(Caragana microphylla)灌丛化草原。对于羊草(Leymus chinensis)草原, 以轻度和中度退化为主。导致不同区域和不同植被类型草地退化的原因也不尽相同, 从近20年的时间尺度来看, 过度放牧、不合理的居民点布局, 以及道路等是草地退化的主要人为驱动因子。研究结果还显示, 仅以生物量的变化来划分草地退化存在一定的局限性, 因此, 该文以群落优势种和建群种来表征草地的退化类型更具有客观性和实际的应用价值。 相似文献
9.
Understanding the relative importance of factors driving savanna–forest dynamics is vital as changes in the extent of tropical forests can have major impacts on global climate and carbon balance, biodiversity, and human well-being. Comparison of aerial photographs for 50 rainforest patches in Kakadu National Park had previously revealed a landscape wide expansion of rainforest boundaries between 1964 and 2004. Here, we used generalized linear and mixed effects models to assess the role of fire, buffalo impact, and patch characteristics in determining the rate of boundary change. The analysis was conducted at both the patch scale, and within-patch (plot) scale, to capture the different processes operating. At the patch scale, the rate of change was best explained by rainforest type and historical buffalo impact. Fire activity, patch size, and fragmentation were not important predictors of the rate of change. At the plot scale, distance from rainforest edge was the most important predictor of the probability of change, while the fragmentation and aspect of the boundary were unimportant. Rainforest expansion has occurred through a process of margin extension rather than eruption of new patches. The rainforest expansion is consistent with having been driven primarily by shifts in global change phenomena, such as increased rainfall and atmospheric CO2 , rather than changes in disturbance regime. It appears that the current fire regimes are not sufficiently destructive to limit the overall expansion of the rainforest patches. Rainforest type and historical buffalo impact have mediated the rate of change at the patch scale. 相似文献
10.
山西岚县皇姑梁小流域人工植物群落生态 总被引:7,自引:0,他引:7
应用双向指示种分析法(TWINSPAN)和除趋势对应分析(DCA)等数量分析方法,对山西岚县皇姑梁小流域人工植物群落生态关系进行研究,将该人工植被划分为12个群丛,分别位于不同的海拔高度和坡向。分类结果很好地反映了人工植物群落类型及优势种的分布与环境因子的关系,并在DCA二维排序图上得到了较好的验证。DCA排序轴反映了群落土壤含水量、坡向、海拔高度、人工植被恢复时间和物种多样性的梯度变化,表明土壤含水量、坡向、海拔高度、物种类型及其配置模式是影响人工植物群落分布和变化的主要环境因子,不同物种配置模式对群落演替和物种多样性变化有重要影响,油松+华北落叶松.沙棘、小叶杨+油松、油松-沙棘、油松-柠条锦鸡儿等组成的乔灌混交林的物种多样性高于柠条锦鸡儿灌木纯林,并且油松+华北落叶松-沙棘混交林的物种多样性高于小叶杨+油松混交林,混交林的生态恢复效果优于纯林,并且对该小流域的生态恢复作用明显。华北落叶松适合在该小流域海拔较高的梁坡顶、半阳坡、半阴坡和阴坡生长,小叶杨适合在其海拔较低的沟底、半阳坡和半阴坡生长,而油松、沙棘、柠条锦鸡儿的生态适应性强,可在其不同海拔和坡向生长。人工植物群落的演替进程,遵循地带性植物群落演替规律。随着群落演替,野生植物不断侵入,油松、华北落叶松、小叶杨等人工林郁闭度增加,沙棘、柠条锦鸡儿等逐渐退化,油松、华北落叶松、小叶杨等出现枯枝、死株现象,这是自然稀疏的结果,亟待加强管理。 相似文献
11.
Isabella C. Richmond Shawn J. Leroux Travis R. Heckford Eric Vander Wal Matteo Rizzuto Juliana Balluffi-Fry Joanie L. Kennah Yolanda F. Wiersma 《Journal of Plant Ecology》2021,14(3):398
4种北方植物元素性状的时间变化及其驱动因素
植物种内性状的变异对个体适合度和草食动物的觅食有重要影响。对于植物来说,在空间维度上的性状变异已经得到了很好的证明。然而,对性状变异的时间维度仍知之甚少,但其可能受生长度日、温度和降水季节差异的影响。本研究的目的是量化4种常见的北方植物物种性状的种内时间变异及其变异的驱动因素。我们对4种常见树种的叶片进行了为期两年的元素和化学计量性状采样(%C, %N, %P, C:N, C:P, N:P)。本研究分两个步骤进行,首先将广义线性模型(GzLM, n = 24)与我们研究的物种的元素和化学计量性状拟合,以测试它们是否随年份而变化。当我们获得时间变异性的证据时,我们拟合第二组GzLMs (n = 8),将温度、生产力和湿度作为解释变量。研究结果显示,除了两个例外,4种北方植物的大部分元素和化学计量性状都没有时间变异性。年份是所有4种植物的碳百分比(R2 = 0.47–0.67)以及香脂冷杉(Abies balsamea)中多种元素和化学计量性状(5/8, R2 = 0.29–0.67)的重要预测因子。因此,碳百分比的变化与年际差异有关,而与限制北方森林养分的氮和磷关系更大。这些研究结果还表明,由于生活史的差异,针叶树的化学计量比落叶植物的化学计量的年际差异更大。生长度日是第二轮模型中最频繁出现的变量(8/8 次,R2 = 0.21–0.41),表明温度是这些性状时间变异的重要驱动因素。 相似文献
12.
广州城区生态安全岛典型植物群落的结构及物种多样性研究 总被引:1,自引:0,他引:1
以广州城区生态安全岛典型的自然和半自然型植物群落为研究对象,通过样方调查,对物种组成、区系成分、群落结构、珍稀濒危种、物种丰富度和多样性等要素进行了研究,结果表明:广州城区6处生态安全岛3.238hm2的调查样方中,共记录到维管束植物145科342属495种,热带亚热带区系特征明显。不同保护级别的珍稀濒危植物6科7属7种;群落垂直结构复杂,乔木层一般都能划分亚层。物种丰富度Partrick指数值在22-100之间变化、Shannon-Wiener多样性指数值在0.3861-3.0901之间变化、Simpson优势度指数值在0.1380-0.9261之间变化以及Pielou均匀度指数值Jsw在0.1289-0.9427之间变化,相似性系数S和Bray-Curtis指数存在一定差异。目前广州城区生态安全岛的植物群落随着正向演替的进行,物种多样性在不断增加。在区系上,生态安全岛与具有南亚热带地带性典型植被的鼎湖山联系较密切,虽然在物种多样性方面尚有一定差距,但演替时间较长的生态安全岛植物群落的物种多样性已相当于鼎湖山南亚热带地带性植被演替的后期阶段。植被之间的空间距离、与城市中心距离的远近等生境条件差异、人为干扰均对群落的物种多样性产生影响。因此,需加强保护,才能在高度城市化的区域保存这样一些具有地带性顶级群落的结构和物种多样性特征的植物群落。 相似文献
13.
辽西大黑山北坡植物群落组成及多样性研究 总被引:2,自引:3,他引:2
在辽西大黑山自然保护区北坡,沿海拔400~1000m,选择典型地段设置3条垂直样带,样带间隔100m,每条样带垂直梯度上隔100m设置一个样地,共21个样地森林群落,进行了群落组成、群落多样性等随海拔上升变化情况的研究。结果表明,森林群落的郁闭度、平均胸径和胸高断面积等随海拔上升有较明显的增加,海拔800m以上主要是分布于核心区内的山地原生植被,700m以下主要为山地疏林和部分人工林;群落的优势种组成随海拔升高表现出由复杂多样逐渐向简单单一过渡的变化趋势;乔木种和灌木种的Shannon多样性指数随着海拔的增加而呈现近似于线性的降低趋势,二者的优势度随着海拔的增加有较明显的上升;草本植物和乔灌层相比优势度较高,多样性指数较低,而且随着海拔的变化幅度也较小,表明群落中草本植物随海拔并没有明显的变化;群落的水平β多样性随海拔增加呈明显的下降趋势,说明在本研究的空间范围内,森林组成在较低海拔更加斑块化。 相似文献
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Abstract. We studied the effects of neighbours on the biomass of seven randomly chosen species in species‐rich sub‐alpine meadows in the central Caucasus Mountains by comparing the performance of plants with neighbours removed experimentally to that of paired plants with their neighbours left intact. In most cases the removal of neighbours led to significant increases in vegetative and total above‐ground biomass implying the species were limited by competition. However, the neighbour removal led also to an increased leaf wilting for target plants, as well as to strong decline in reproductive effort for some species. We hypothesise that competition may be the prevailing type of interaction in species‐rich sub‐alpine meadow communities, but competitive effects on vegetative production may be balanced, if not outweighed, by facilitation, at least for some species. Such a balance may enhance species coexistence in communities. 相似文献
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Comparing ecological restoration in South Africa and Western Australia: the benefits of a ‘travelling workshop’
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Peter J. Carrick Todd E. Erickson Carina H. Becker C. Ellery Mayence Amanda R. Bourne 《Ecological Management & Restoration》2015,16(2):86-94
Researchers and practitioners of ecological restoration from South Africa and Western Australia recently undertook a travelling workshop across several South African biomes to discuss and evaluate the various approaches currently being utilised in the field. Key findings from the workshop highlighted the contrasting nature of ecological restoration undertaken in these two ecologically similar, but socially and politically different regions. 相似文献
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Hussein M. Sulieman 《African Journal of Ecology》2014,52(2):217-227
The present study seeks to provide a contribution to the understanding of vegetation regrowth on abandoned agricultural land by investigating the impacts of the previous cultivation period and the duration of the fallow on the subsequent natural regeneration in terms of vegetation composition, structure and diversity. The results of the study show that both factors have significant effects on the subsequent regeneration of plant species and thus the vegetation development in the southern Gadarif Region, Sudan. The oldest abandoned farmlands were recolonized by tree/shrub species, whereas recently abandoned ones are covered with herbaceous vegetation. There is a general tendency regarding the number of species to decrease with an increase in the period of cultivation. The plant species diversity pattern shows domination of herbaceous species with some scattered woody species. Vegetation changes due to land abandonment may have implications for the conservation of plant species diversity and composition of fauna harboured in the region. Although natural regeneration could be recommended as means of restoring natural vegetation that previously dominated that region, the current regeneration capacity might not be sufficient to reach the climax vegetation except for some pockets, which received more regenerative resources. 相似文献
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Manipulating plant order of arrival, a process that creates priority effects, may be an unexplored powerful tool to hinder the establishment of invasive non‐native plants in sites under restoration. Knowledge and experimental studies on priority effects in the neotropics are scarce. Here, we propose a research agenda that investigates whether manipulating plant order of arrival can create priority effects in the neotropics, and if this strategy can be used to avoid the spread of undesired species in restoration projects. We also describe our view on expanding existing knowledge on priority effects to the neotropics and identifying key questions for future research. 相似文献
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浙江省生态公益林植被恢复过程中物种组成及多样性的变化 总被引:6,自引:3,他引:3
在浙江省生态公益林区域的现状植被中分析了6种主要群落类型的物种组成和多样性的变化格局,包括演替系列中的2种灌丛、松优势林、2种混交林和常绿阔叶林。结果表明含松较多的灌丛和松优势林常分布在环境退化较严重(土层瘠薄)的生境中,其中灌木层主要由阳性的映山红、木、白栎等组成,常绿阔叶林优势种木荷、青冈、苦槠、甜槠等在其中偶见,因此推断其自然恢复为常绿林的速度慢;含常绿阔叶树较多的灌丛及含松较少的混交林分布在土层较厚处,木荷、青冈、苦槠、甜槠等的频度和重要值都较大,较容易自然恢复为常绿阔叶林。各种群落中物种多样性指数——Gleason、Shannon-Wiener、Simpson指数基本上以常绿阔叶林为最高,其次是含松较少的混交林,含松较多的灌丛和松优势林各种多样性指数最低。本研究显示我国中亚热带东部森林植被恢复途径有3条:(1)灌草丛→针叶林(松)→针(松)阔混交林→常绿阔叶林;(2)灌草丛→针(松)阔混交林→常绿阔叶林;(3)灌草丛→常绿阔叶林。这意味着本区域的常绿阔叶林恢复可以不必经历松林阶段,在生境条件较好的地方通过人工干预、补种常绿阔叶树可以加速常绿阔叶林恢复。 相似文献
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该文调查了新疆奇台荒漠类草地自然保护区的主要植被类型, 通过对65个样地的样方数据分析, 量化描述了该保护区的主要植物群落特征。该保护区内主要包括梭梭荒漠(Haloxylon ammodendron Semi-Arbor and Shrub Desert Alliance)、膜果麻黄荒漠(Ephedra przewalskii Simi-Arbor and Shrub Desert Alliance)、裸果木荒漠(Gymnocarpos przewalskii Simi-Arbor and Shrub Desert Alliance)、红砂荒漠(Reaumuria soongarica Simi-Arbor and Shrub Desert Alliance)、戈壁藜荒漠(Iljinia regelii Semi-Shrub and Herb Desert Alliance)、短叶假木贼荒漠(Anabasis brevifolia Semi-Shrub and Herb Desert Alliance)、短穗柽柳落叶阔叶灌丛(Tamarix laxa Deciduous Broadleaf Shrubland Alliance)、盐爪爪荒漠(Kalidium foliatum Semi-Shrub and Herb Desert Alliance)、灌木亚菊荒漠(Ajania fruticulosa Semi-Shrub and Herb Desert Alliance)、芨芨草草地(Achnatherum splendens Tussock Grassland Alliance)、窄颖赖草草地(Leymus angustus Rhizome Grassland Alliance)和芦苇草地(Phragmites australis Rhizome Grassland Alliance)共12个主要群系, 并进一步划分出15个群丛。 相似文献