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1.
Despite their socio-economic and ecological role, many studies have shown that the parklands are degrading very rapidly. Therefore,
there is a need to undertake restoration actions for both production and environmental services. To do so, there is a need
to identify factors that are affecting the dynamics of parkland systems. The present study aimed at characterizing and quantifying
tree diversity of parkland systems taking into consideration the household’s wealth status, land uses, market access and the
type of farming system (cereal based on the “Plateau Central” and cotton based in “Boucle du Mouhoun”). Six villages (Kienfangué,
Ipelcé, and Kuizili with easy access to the market and, Karang-Tanghin, Nionsna and Targho with poor access to the market)
in the “Plateau Central” and six villages (Bondoukuy, Ouahabou and Yaho with easy access to the market and, Dora, Fakéna and
Mamou with poor access to the market) in “Boucle du Mouhoun” were studied. In each village, the Participatory Analysis of
Poverty and Livelihood Dynamics method was used by rural farmers to rank farmer households of their communities and that gave
three groups of wealth status that are poor, fairly well-off and well-off. Five households representing each of the three
wealth groups in each village, giving a total of 15 households per village, were randomly selected by wealth group. Tree/shrub
inventories were conducted in all land use types (house fields, village fields and bush fields) of the 180 selected households
for the 12 studied sites. The number of species in the different land use types ranged from 96 to 102, but the majority of
species were represented by less than 10 individuals. This indicates the selection effect made by the farmers to the parklands.
Land use and farming system showed a clear effect on tree diversity in parklands. The effect of accessibility to market was
evident in some cases whereas wealth status did not show any effect. Despite the statistical significant effect of farming
system and land use type, the ANOVA models accounted for relatively little variation, indicating that other factors may contribute
to tree diversity in parkland systems. The most threatened species were Adansonia digitata, Afzelia africana, Bombax costatum,
Celtis integrifolia,
Ficus asperifolia, Ficus iteophylla, Lannea velutina, and Parkia biglobosa. These species were represented in the largest diameter class (≥80 cm) or showed very few individuals in the different diameter
classes. Due to the increasing degradation of the parklands, a domestication and conservation strategy of key threatened species
needs to be developed and implemented with the participation of local communities. 相似文献
2.
Weston F. Mwase Åsmund Bjørnstad James M. Bokosi Moses B. Kwapata Brita Stedje 《New Forests》2007,33(3):297-307
Biodiversity is declining throughout southern African miombo woodlands due to poor land use practices that are detrimental
to soil, vegetation and habitat. We aimed at examining tree and shrub species diversity and distribution in Uapaca kirkiana-dominated woodlands under three land tenure types; forest reserves, customary and leasehold land. The study was conducted
at different forest sites within similar agroecological zone in southern Malawi. Study sites were located at a range of altitudes
between 900 and 1,200 m a.s.l. Three circular plots each with 32.60 m radius were established at each study site to sample
tree and shrub species composition, structure and distribution under three land tenure types. We found that forest reserves
had higher species diversity with an average of 16 tree families, 27 genera and 34 species as compared to only 10 tree families,
6 genera and 6 species on customary forest lands. Comparisons of diameter at breast height size class distributions showed
that customary land had significantly low numbers of small (5.0–10.0 cm) and very large (≥30 cm) diameter classes suggesting
lower levels of regeneration and high rate of anthropogenic activities. The high species diversity and richness in forest
reserves and leasehold land indicate high potential for protected lands to restore tree species diversity. It is concluded
that levels of human activities as influenced by land tenure type reduce tree species diversity, composition and distribution
at the different sites, and this confirms the hypothesis that open access lands are not compatible with conservation of tree
and shrub species diversity because of high anthropogenic activities. 相似文献
3.
Side Sadat Ebrahimi Hassan Pourbabaei David Potheir Ali Omidi Javad Torkaman 《林业研究》2014,25(2):455-462
Plant diversity plays key ecological roles in forest ecosystems, including influencing succession, resilience and nutrient cycling. This study was conducted to investigate the effect of livestock grazing and human uses on herbaceous species diversity. We surveyed 50 ha of protected area and 50 ha of unprotected area to evaluate herbaceous species diversity in oriental beech (Fagus orientalis Lipsky) forests in northern Iran. We calculated and compared three indices each of diversity and evenness, and species richness between the two areas. Herbaceous cover was higher in the unprotected area while leaf litter depth and tree canopy cover were higher in the protected area. The diversity indices, H (Shan- non-Wiener index ), N~ (McArthur index), N2 (Hill's index), EQ (Modified Nee index), E,ar (Smith-Wilson index), E5 (modified index of Hill) and R=S (species richness) and species richness R=S were greater in the protected area than in the unprotected area, suggesting that protection from grazing results in increased numbers of plants and species. The effect of land protection on plant diversity was more pronounced for evenness than for species richness and the positive correlation between diversity and evenness indices was higher than that between diversity and richness. 相似文献
4.
Anders Ræbild Hanne H. Hansen Joachim Dartell J.-M. Kiléa Ky Lassina Sanou 《Agroforestry Systems》2007,70(2):157-167
Woody vegetation in cultivated landscapes in Burkina Faso is influenced by agricultural activities that are in turn influenced
by institutional arrangements. Research was undertaken in a village in south-west Burkina Faso to investigate the relationship
between species composition, diversity, density, species accumulation and land use category. Additionally the relationship
between number of trees, size of farmed land and farmer ethnicity was investigated. Indigenous Tiéfo farmers had on average
more than double the number of large (>4 m) trees of Vitellaria paradoxa Gaertn. f., Parkia biglobosa (Jacq.) R. Br. Ex G. Don and Anacardium occidentale L. than farmers belonging to other ethnic groups, but this was partly explained by a larger area being available. Differences
between ethnic groups were not significant when expressed per ha. Botanical inventories of fallows more than 4 years old,
cultivated parklands and plantations of Mangifera indica L. and A. occidentale showed that tree density and Simpson’s index of diversity for trees were highest in the fallow. Simpson’s index was not significantly
different for regeneration, but sample-based species accumulation curves indicated that species accumulation in parklands
was faster than in plantations when expressed per individual. The average regeneration density was 12,605, 1,995 and 6,772
seedlings ha-1 for fallow, parklands and plantations, respectively. This low density for parklands means that species accumulation is slow
compared to the other land uses when expressed per unit area. Fallow seems the most efficient way of keeping tree diversity
in the agricultural landscape. 相似文献
5.
The population status and regeneration of a data-deficient tree species were examined in both protected and unprotected areas. The target species was found in six habitat types, seven aspects between 2,100- to 3,300-m altitude, and sites dominated by different species. The species was best represented in a shady moist habitat, north and northwest aspects, altitudinal range >2,700 m, and sites dominated by Acer caesium in both protected and unprotected sites; but the generalized linear model indicated nonsignificant effect of sites, habitat, altitude, and dominance except for aspects. Difference in sapling and seedling density among aspects and sites only was significant. Probability of use and resource use index indicated poor preference and less pressure as fuel. It can be concluded that the species is not under any significant threat in the study area. But, further studies on population status, regeneration, and relationship with environmental factors in a wider geographic region are suggested to evaluate species and place under suitable priority category. 相似文献
6.
Javier Guitián Pablo Guitián Ainhoa Magrach Carmen Docampo Paula Domínguez Luis Guitián 《Journal of Forest Research》2012,17(1):98-104
This paper analyzes the effect of the spatial characteristics and intensity of land use on vascular plant species richness
in Castanea (Chestnut) woodlots of the northwestern Iberian Peninsula included in the category “9260 Castanea sativa woodland” (Annex I, DC 92/43 European Community). Digital maps were used to characterize 30 woodlots for which land use intensity
was estimated and all plants found were inventoried. The results show that woodlot shape and land use intensity have a significant
effect on vascular plant richness and indicator species number. However, an analysis of the interaction between woodlot characteristics
and land use intensity suggests that the response of vascular plant species to land use intensity does not exhibit a uniform
pattern and that it is modulated by the shape of the woodlots. We conclude that restricting the use of these types of woods
to traditional practices must be determined in keeping with the specific characteristics of each woodlot, since the moderate
management of Castanea sativa woodlots of the northwest Iberian Peninsula may continue to play an important role to maintaining plant species diversity
in this area. 相似文献
7.
Variation in floristic composition of recovering Baikiaea–Guibourtia–Pterocarpus woodlands was studied in different development stages (from early regrowth to mature woodland) under different land-use systems (protected areas, timber harvesting, pole and firewood collection, and abandoned crop fields), in the Gwayi and Tsholotsho areas in north-western Zimbabwe. A total of 150 nested circular plots were sampled representatively in four different development stages related to the land-use systems. The DBH (stem diameter at 1.3 m above ground level) and tree height were recorded by species for all stems of tree species with DBH ≥ 15 cm in a 30-m-radius plot (0.283 ha) and for trees with DBH 5.0–14.9 cm in a 11.3-m-radius plot (0.04 ha) (both centred around the same midpoint). Stems with DBH < 5 cm were counted by species in an inner sub-plot of 5.65 m (0.01 ha) radius. Tree data (stem DBH ≥ 5 cm) and regeneration data (stem DBH < 5 cm) by stem counts per species per plot, were used separately to run TWINSPAN (TWo-way INdicator SPecies ANalysis) classifications of species assemblages. Importance values were calculated for all tree species per community. Shannon–Wiener diversity indices were calculated for each community and tested for differences using one-way ANOVA in SPSS version 21. Detrended correspondence analysis (DCA) implemented in the CANOCO ordination software was used to determine the extent of variation amongst the identified communities. The classification identified 12 tree communities and 13 regeneration communities, clustering plots from different land uses together. Baikiaea plurijuga was the most important tree species in all tree communities, except where Combretum collinum, C. apiculatum, Commiphora mossambicensis and Pterocarpus angolensis were dominant. Pterocarpus angolensis showed low importance in most communities, except for communities from undisturbed sites (mostly mature trees) and abandoned fields (mostly young trees). Baikiaea plurijuga was most important in most regeneration communities, except in communities dominated by Baphia massaiensis, C. collinum, C. apiculatum and P. angolensis. Species diversity differed significantly (p < 0.05) amongst tree communities. The DCA ordination showed little variation amongst the communities. The cumulative contribution of environmental factors explaining variation in species composition was 22.6% for tree communities and 26.1% for regeneration communities, suggesting that recovery from disturbance after different land uses may explain more of such variation. 相似文献
8.
Soil properties under an exotic plantation (Pinus caribaea) and an indigenous plantation (Podocarpus imbricatus) were compared with adjacent secondary forests and abandoned land in the tropical forest areas of Jianfengling National Nature
Reserve in Hainan province, southern China. The surface soil (0–0.2 m) under Pi. caribaea has higher bulk density, lower soil organic carbon, total N, total K, available N, microbial biomass carbon, and smaller
soil microbial communities (as indicated by soil Biolog profiles) than under Po. imbricatus. Both land use types showed negative cumulative soil deterioration index (DI) compared to secondary forests. However, compared
to abandoned land (DI = –262), the soil quality of Po. imbricatus showed improvement (DI = –194) while that of Pi. caribaea showed deterioration (DI = –358). These results demonstrated that these exotic pine plantations can significantly and negatively
influence soil properties. By contrast, our results showed that adoption of indigenous species in plantations, or natural
regeneration, can improve soil quality. 相似文献
9.
关帝山次生林区典型植物群落物种多样性垂直分布研究 总被引:6,自引:0,他引:6
为了分析和探讨海拔对植物多样性的影响,沿海拔梯度(1600–2600m),设定14个样地,对每个样地内对植物物种进行调查。结果表明:随海拔升高,群落优势种变化依次为:辽东栎、油松、白桦、红桦、华北落叶松和云杉。群落内乔木树种的平均树高和胸径表现为先增大后减小,最大树高和胸径表现为单峰变化。群落内不同生活型树种(针叶树和阔叶树)的最大树高表现为先增大后减小.阔叶树最大胸径无明显变化规律,针叶树最大胸径不断减小。中海拔群落内,针叶树种的最大树高和胸径高于阔叶树种。群落的Shannon-wiener指数和Margalef指数均表现为单峰变化,中海拔群落(1900–2200m)植物多样性最高,高于低海拔群落(1600–1900m)和高海拔群落(2200–2600m)。Shannon-wiener指数和Margalef指数反映出的植物α多样性变化与海拔高度显著相关。在研究地区,植物多样性变化与群落所处的海拔显著相关,此外,还与群落结构、物种组成、树种特性和人为干扰有关。图8表3参13。 相似文献
10.
埃塞俄比亚东南部Dello Menna森林植被的植物区系和结构分析(英文) 总被引:2,自引:0,他引:2
描述了埃塞俄比亚东南部Dello Menna森林植被的植物区系组成和植被结构。鉴定和描述了50个20m×20m的样方的植物群落类型、物种多样性、丰富度和均匀性,分析了已鉴定植物群落类型与环境因子的相关性,还描述了木本植物种群结构。每个样方内,均记录木本植物的物种、丰富度、高度和胸径以及海拔、坡度。利用PC-ORD软件对植被进行分类。用Sorensen相似性系数探测群落之间的差异性。计算Shannon-Wiener多样性指数、物种丰富度、Shannon均匀性来描述各种植物群落的物种多样性。共记录了53个科的171个维管植物种。豆科植物是主要的优势植物科系,包括13个属26种(1 5%),其次依次是菊科、唇形科和槭树科,各包括8个物种(4.6%)。根据植物分类结果,识别并描述了3个植物群落(Dalbergia microphylla群落、Grewia bicolar-Acaciabrevispica群落、Combretum molle-Combretum collinum群落)。植物区系之间的物种丰富度、多样性和均匀性存在差异。物种丰富度和多样性随海拔变化呈现出贝尔型分布。群落间植物随海拔梯度有一定的变化,表明海拔是决定植物群落分布的重要因素之一。Dalbergia microphylla群落物种丰富度和多样性均最高。优势种群落结构呈现出各种模型。植被可持续利用是今后的研究方向。 相似文献
11.
Jiaojun Zhu Zhihong Mao Caihong Zhang Qiaoling Yan Zugen Liu 《Frontiers of Forestry in China》2008,3(4):422-428
The effects of thinning on plant species diversity and composition of understory herbs in a larch plantation were investigated.
The relationships between plant species diversity and composition of understory herbs and light conditions were established.
Twenty-five 1 m × 1 m plots and fifteen 13 m × 1 m transects were set up in unthinned and thinned stands, respectively. All
the transects in the thinned stands were set across the thinned rows and unthinned rows, and each of them was divided into
nine 1 m × 1 m sub-plots. The herb diversity and light conditions were observed in each plot and sub-plot. The results show
that there was a significant difference in herb diversity between the thinned and unthinned stands. All biodiversity indices
except for evenness index in the thinned stand were higher than those of the unthinned stand, i.e., the herb diversity increased
after thinning. According to the changes in herb densities and whether one species could be found in a stand or not before
and after thinning, all herb species were classed into three types: positive, neutral and negative species, which referred
to a species newly appeared and having an obviously increased density after thinning, with no obvious changes in its appearance
and density after thinning, and disappeared and having an obviously decreased density after thinning, respectively. Many new
species were found in the thinned stand like Corydalis pallida, Prenanthes tatarinowii, Vicia unijuga and Sonchus brachyotus etc. However, most species found in both the thinned and unthinned stands were negative species. In all nine subplots, only
11 and 10 species were found in spring and in autumn respectively, accounting for 17.74% and 15.15% of all the species in
the thinned stand, respectively. All biodiversity indices were the highest in the center sub-plots and most of them tended
to reduce from middle to side sub-plots. There was a close correlation between most of the three types of species and light
conditions which was similar to each other in the thinned and unthinned stands.
__________
Translated from Chinese Journal of Ecology, 2006, 25(10): 1201–1207 [译自: 生态学杂志] 相似文献
12.
Plant diversity of secondary forests in response to anthropogenic disturbance levels in montane regions of northeastern China 总被引:4,自引:0,他引:4
The effects of anthropogenic disturbances on forest structure and plant diversity of secondary forest ecosystems were evaluated
based on the classification by site factors in the montane regions of northeastern China. Forty-five sample plots containing
720 sub-plots of overstory species (8 m × 8 m), 1,440 quadrats of understory species (2 m × 2 m), and 1,440 quadrats of herbaceous
layer species (1 m × 1 m) were clustered into five groups (G1, G2, G3, G4 and G5) by site variables with Hierarchical Cluster
Analysis. Meanwhile, the disturbance levels corresponding to the five groups were determined according to the factors influencing
human disturbances (D0-G2, D1-G1, D2-G3, D3-G5, and D4-G4). Species diversities of overstory, understory, herbaceous layer
and overall species were evaluated using species number, Margalef index, Pielou index, Shannon–Wiener index, and Simpson index;
and β-diversities (Whittaker index, Cody index). Basal area of stands exhibited a decreasing trend along the disturbance level
due to a gradual increase in the extraction of timber by the human disturbances. The indices of species diversity suggested
that overstory and understory species were distributed evenly among the groups or disturbance levels. There were no absolutely
dominant tree species in the secondary forest ecosystems. The differences in site factors and the current disturbance intensities
were not intense enough to lead to loose changes in overstory and understory species. The species diversity indices exhibited
the maximum values at D3 (G5) for herbaceous layer species; this may suggest that the current disturbance intensities were
intense enough to lead the changes of herbaceous layer species. Three rare and endangered species (Juglans mandshurica, Fraxinus mandshurica and Acanthopanax senticosus) were found within the secondary forests. These rare and endangered species appeared in each clustered group or disturbance
level, which suggested that the current disturbance intensity in the study area was not strong enough to influence the distribution
of rare and endangered species. The current disturbances in the secondary forests may not lead to a decrease in stability
and complexity of the overstory and understory species, but the higher disturbance level may be intense enough to change the
habitat fitness for the herbaceous species.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized authors. 相似文献
13.
Structure and species diversity of subtropical evergreen broad-leaved forest in northern Okinawa Island, Japan 总被引:4,自引:0,他引:4
Xiaoniu Xu Eiji Hirata Yoshihiro Tokashiki Takeo Shinohara 《Journal of Forest Research》2001,6(3):203-210
The structure and tree species diversity of a subtropical evergreen broad-leaved forest in northern Okinawa Island, Japan,
were studied. Enumeration of the six sampling plots revealed an average density of 5,580 individuals with DBH≧3.0 cm/ha, having
an average basal area of 55 m2. The large-size trees of DBH≧20 cm contributed 10% of the total individuals, and 49% of the total basal area. The forest
showed a high diversity of tree species, which is comparable to some tropical rain forests. A total of 54 over-story species
of 24 families and a total of 63 understory species of 26 families were identified in the six sampling plots. Fagaceae and
Theaceae were the most important families;Castanopsis sieboldii, Schima wallichii andDistylium racemosum were the most important species. The diversity index and equitability index of species were 4.15 and 0.72 for the overstory
plots, and 4.72 and 0.79 for the understory subplots, respectively. The diversity index for the overstory was significantly
correlated to the total basal area of trees over 20 cm DBH (p<0.05) and the importance value ofC. sieboldii (p<0.001), while for understory, the diversity index was not correlated to the structural parameters (allp>0.16). The size distribution pattern and age structure indicated differences in regeneration strategies for canopy dominants.
In population dynamics of the succession process,C. sieboldii andD. racemosum were self-maintaining types, andS. wallichii was a gap- or opening-dependent type.
This study was made possible by support from the Japanese Ministry of Education, Sciences, Sports and Culture, which provided
a Monbusho scholarship to X.N. Xu. 相似文献
14.
Zhenhong Wang Chengbo Yang Limei Yang Zizong Zhou Jing Rao Li Yuan Ju Li 《Frontiers of Forestry in China》2007,2(1):18-27
In recent years, the relationship between biodiversity and ecosystem stability, productivity, and other ecosystem functions
has been extensively studied by using theoretical approaches, experimental investigations, and observations in natural ecosystems;
however, results are controversial. For example, simple systems were more stable than complex systems in theoretical studies,
and higher productivity was observed in human-made ecosystems with poorer species composition, etc. The role of biodiversity
in the ecosystem, such as its influence on sustainability, stability, and productivity, is still not understood. Because accelerated
soil-erosion in various ecosystems has caused a decrease of primary productivity, a logical way used in the study of the relationship
between biodiversity and ecosystem function can be used to study the relationship between plant species diversity and soil
conservation. In addition, biodiversity is a product of evolutionary history, and soil erosion is a key factor controlling
the evolution of modern environment on the surface of the Earth. A study on the relationship between biodiversity and soil-erosion
processes could help us understand the environmental evolution of Earth.
Fifteen 10 m × 40 m standard runoff plots were established to measure surface runoff, soil erosion, and total P loss in different
secondary communities of semi-humid evergreen broad-leaved forests that varied in composition, diversity, and level of disturbance
and soil erosion. The following five communities were studied: AEI (Ass. Elsholtzia fruticosa + Imperata cylindrical), APMO (Ass. Pinus yunnanensis + Myrsine africana + Oplismenus compsitus), APLO (Ass. Pinus yunnanensis + Lithocarpus confines + Oplismenus compsitus), AEME (Ass. Eucalyptus smith + Myrsine africana + Eupatorium adenophorum), and ACKV (Ass. Cyclobalanopsis glaucoides + Keteleeria evelyniana + Viola duelouxii). Tree density, the diameter of the tree at breast height, and the hygroscopic volume of plant leaves were determined in
each plot.
Results indicated that surface runoff, soil erosion, and total P loss decreased as a power function with increase in plant
species diversity. Their average values for three years were 960.20 m3/(hm2 · year), 11.4 t/(hm2 · year), and 127.69 kg/(hm2 · year) in the plot with the lowest species diversity, and 75.55 m3/(hm2 · year), 0.28 t/(hm2 · year), and 4.71 kg/(hm2 · year) in the plot with the highest species diversity, 12, 50, and 25 times respectively lower compared with the lowest
species diversity plots. The coefficients of variation of surface runoff, soil erosion, and total P loss also followed a power
function with the increase of plant species diversity, and were 287.6, 534.21, and 315.47 respectively in the lowest species
diversity plot and 57.93, 187.94, and 59.2 in the highest species diversity plot. Enhanced soil conservation maintained greater
stability with increased plant species diversity. Plant individual density increased linearly and the canopy density and cross
section at breast height increased logarithmically with the increase of plant species diversity. The hydrological function
enhanced as the plant species diversity increased. There were obviously relationships between plant species diversity and
rainfall interception, coverage, and plant individual density, which was related to soil conservation functions in the five
forest communities.
The complex relationships between plant species diversity and the above-mentioned ecological processes indicated that plant
species diversity was an important factor influencing the interception of rainfall, reducing soil erosion and enhancing the
stability of soil conservation, but its mechanism is not known. This experiment showed that plant species diversity promoted
soil and nutrient conservation and ultimately lead to the increase of the primary productivity of the ecosystem, and was thus
a good way to study the relationship between biodiversity and ecosystem stability. Rainfall interception could be assessed
easily using the hygroscopic volume of plant leaves. Because there were strong correlations between plant species diversity
and soil conservation functions, the patterns of plant species diversity will show a certain level of predictability on the
interactions of life systems with surface processes of the Earth.
__________
Translated from Journal of Plant Ecology, 2006, 30(3): 392–403 [译自: 植物生态学报 相似文献
15.
Yuanguang Wen Fang Chen Shirong Liu Hongwen Liang Chang’an Yuan Hongguang Zhu 《Frontiers of Forestry in China》2009,4(2):146-152
To reveal the relationship between species diversity and biomass in a eucalyptus (Eucalyptus urophylla × E. grandis) plantation located in the Dongmen State Forestry Farm of Guangxi, south China, 18 sample plots were established and the
total biomass, arbor layer biomass and undergrowth biomass of communities were subsequently harvested. The results were as
follows: 1) Species richness in eucalypt plantation had remarkable positive correlation with biomass of arbor layer, undergrowth
and community (α = 0.001), its correlation coefficients were 0.6935, 0.7028 and 0.7106 respectively. 2) Leaf area index (LAI) had remarkable
positive correlation with species richness and undergrowth biomass (α = 0.001). Its correlation coefficients were 0.7310 and 0.6856, respectively. 3) Arbor layer biomass had remarkable correlation
with soil organic matter and hydrolysable N, its correlation coefficients was 0.6416 and 0.6203 respectively. Species richness
had remarkable correlation with soil organic matter and correlation coefficient was 0.6359. Among them, the correlation was
significant at the 0.1 level. Undergrowth biomass had little correlation with nine soil nutrients and correlation coefficients
were under 0.4. To sum up, species diversity was advantageous to the promotion of the biomass of the eucalyptus plantation,
and the variation of LAI and soil nutrient in small-scales could result in the difference of species diversity and biomass
in different sample plots.
Translater from Scientia Silvae Sinicae, 2008, 44(4): 14–19 [译自: 林业科学] 相似文献
16.
Juan Shi Youqing Luo Jiying Song Xiaosu Yan Ping Jiang Yijiao Wang 《Frontiers of Forestry in China》2007,2(4):466-473
Reported in this paper are our findings of the study on changes in species diversity of different Masson pine communities
after the invasion of Bursaphelenchus xylophilus (Steiner and Buhren) Nickle and subsequent and different removal disturbance management approaches. Based on the results,
the species diversity indices for the arbor layers of the different communities can be arranged in the following order (from
high to low): 1) broad-leaved stand after the removal of all infected pine trees in the pure pine stand in Fuyang; 2) lightly
infected Masson pine and Schima superba mixed stand in Fuyang; 3) uninfected stand mixture of Masson pine and Castanopsis fargesii as a control; 4) lightly infested pure Masson pine stand in Fuyang; 5) Quercus variables stand formed following the selective removal of infected pine trees from a mixed Masson pine and Q. variables stand in Zhoushan Islands; 6) pure young Masson pine stand formed following the removal of all infected pine trees from a
pure Masson pine stand; 7) pure Liquidambar formosana stand after the removal of infected pine trees from a pure pine stand in Zhoushan Islands; 8) a mixed stand consisting of
Pinus thunbergii and the Masson pine in Zhoushan Island; and 9) moderately infected Masson pine stand in Zhoushan Islands.
All the three diversity indices (R
0 = richness, H′ = Shannon-Wiener index, and E = evenness) for the shrub layer did not show any significant differences among the various communities except for the pure
pine stand in Zhoushan Island, which had the lowest diversity. The three indices for the herb layer of the pure young Masson
pine, Q. variables stand, and L. formosana stand were higher than that of other stands.
The integrated analysis showed that the Masson pine forest in different geographical situations and extent of damage had distinct
disparity, just as in different disturbance degrees and restoring manners.
We created the “index of disturbing intensity of stump and fallen woods” (IDISFW) to represent the degree of disturbance of
tree removal to plant diversity. We found that the relationship between the species diversity index and the IDISFW shows both
a lower and higher degree of removal disturbance that follows the “mid-altitude bulge” theory. Specifically, both excessive
and insufficient removal of infected trees will cause a decline of plant species diversity to a certain degree. Covariance
analysis indicated that different IDISFW had no significant effects on the species diversity of the arbor layer, but had different
impacts on that of the shrub and herb layers, and therefore can be used to assess changes in species diversity of different
Masson pine communities after the invasion of pine wood nematode.
__________
Translated from Chinese Journal of Applied Ecology, 2006, 17(7): 1,157–1,163 [译自: 应用生态学报] 相似文献
17.
Edwin Tambara Amon Murwira Shakie Kativu Emmanuel Torquebiau 《Agroforestry Systems》2012,84(2):299-309
We tested whether cultivation and fallowing have any significant effect on tree species diversity and dominance in semi-arid
Zimbabwe. To this end, we quantified tree species diversity and physiognomy on two soil types (mutapo and bandati) stratified into three land-use categories, i.e., cultivated land, fallow land and woodland. Results showed that tree species
diversity was significantly different on the two soil types. Tree species diversity was high on bandati soil and low on mutapo soil. Results also showed that there was significant difference in tree species diversity among the three land-use categories
on mutapo soil but no differences on bandati soil. Pairwise comparisons revealed significant differences in species diversity between paired categories on mutapo soil but no significant differences on bandati soil. Tree physiognomy was significantly different among all three land use categories. Colophospermum mopane and Diospyros kirkii were the dominant species within woodlands, while Acacia tortilis subsp. spirocarpa replaced them as the dominant species within the fallow land category. These results indicate that woodland conversion for
cultivation purposes has no immediate significant effect on tree species diversity on bandati soil, while it has a pronounced effect on mutapo soil, at least in the short term. 相似文献
18.
Simultaneous flowering caused a gregarious dieback of umbrella bamboo (Fargesia murielae) all over the world in 1993–2000. Mountain Shennongjia in Central China’s Hubei Province is the only native home of umbrella
bamboo, where it dominates the understorey of the farges fir (Abies fargesii) forest between 2 400 and 3 100 m, covering the ground for more than one century before a periodically flowering death. Data
from 20 quadrats along a vegetation sequence revealed that the density, coverage, and height of umbrella bamboo negatively
affected the species richness, diversity, and evenness of vascular plants in the forest. Local climax community of fir-bamboo
was the poorest in species diversity, while the bamboo-free communities (i.e. shrubs and meadows) were bearing a higher species
diversity. The simultaneous dieback of umbrella bamboo is an ecological release, which can periodically promote the plant
diversity in the fir forest. 相似文献
19.
Composition and structure of the main forest types, as well as the species changes under disturbance, were described as the
representation of the forest vegetation in the north slope of Changbai mountain, northeast China. There were 3 forest zones
from 600 m to 2,000 m asl, (1) broad-leaved-conifer mixed forest zone, 600–1,100 m asl, dominated byPinus koraiensis, Tilia amurensis, Acer mono, Ulmus japonica, (2) coniferous forest zone, 1,100–1,700 m asl, dominated byPicea jezoensis var.komarovii, P. koraiensis, Abies nephrolepis, and (3)Betula ermanii forest zone, 1,700–2,000 m asl, dominated byBetula ermanii, except for the east slope which was occupied byLarix olgensis. The evergreen component increased with elevation up to the upper limit of the coniferous forest zone (1,700 m), but disappeared
in theB. ermanii zone. Species richness was significantly related to elevation. Towards higher elevation, the lapse rate of species-number
was 1.6 species per 100 m, and it was only one species near the timberline. Species richness was reduced sharply under intensive
disturbance, such as clear cutting, windfalletc. The species diversity was very low in the early stage of succession, and high in the later. 相似文献
20.
W. Bonou R. Gll Kakaï A.E. Assogbadjo H.N. Fonton B. Sinsin 《Forest Ecology and Management》2009,258(7):1084-1092
A study was carried out in the Lama forest reserve of Benin to characterize the habitat of Afzelia africana Sm., an endangered multipurpose tree species (found in African humid, dry forests and woodlands), in order to define a sustainable management strategy for its conservation. An estimation of species density was done on 100 square plots of 1 ha each, while tree height and dbh of all the species were measured on subplots of 50 m × 30 m within the 1 ha plots. The regenerations of A. africana (dbh < 10 cm) were counted in the diagonal quadrats of the principal plots. Presence–absence data of the species was subjected to multidimensional scaling and results showed four vegetation communities including: young fallow, old fallow, typical dense forest and degraded dense forest. Significant differences were noted between the four communities with respect to dendrometric parameters of the species. High values of these parameters were noted for the species in typical dense forest (5.2 stems/ha, 66.7 cm, 17.9 m, 7.9 m2/ha and 38.8% for the tree-density, the mean diameter, the mean height, basal area and basal area contribution of the species, respectively) whereas the lowest values were obtained for the old preforest fallow as far as the mean diameter (59.7 cm), the mean height (15.7 m) and the basal area contribution (27.7%) of the species were concerned. In general, the basal area of A. africana in the over vegetation types was less than 3 m2/ha. No A. africana tree was found in the young preforest fallow while more than 80% of A. africana trees were found in the typical dense forest community. Stem diameter and height structures of the species in all the four communities showed a left dissymmetric Gaussian shape and were well adjusted to Weibull distribution. 相似文献