Secondary Evergreen Broad-leaved Forest Research Articles

Decreased P Cycling Rate and Increased P-Use Efficiency after Phyllostachys edulis (Carrière) J. Houz. Expansion into Adjacent Secondary Evergreen Broadleaved Forest

Decreased P Cycling Rate and Increased P-Use Efficiency after Phyllostachys edulis (Carrière) J. Houz. Expansion into Adjacent Secondary Evergreen Broadleaved Forest

Differences in Response of Tree Species at Different Succession Stages to Neighborhood Competition

Neighborhood competition influences tree growth, which can affect species composition and community succession. However, there is a lack of understanding regarding how dominant tree species at different successional stages of forest communities respond in terms of crown architecture and functional traits during their growth process to neighborhood competition. In this study, we analyzed the responses of average annual basal area increment (BAI), crown architecture, and leaf functional traits of early-successional species (Cunninghamia lanceolata and Pinus massoniana), transitional species (Alniphyllum fortunei and Choerospondias axillaris), and late-successional species (Elaeocarpus duclouxii and Castanopsis carlesii) to neighbor competition in a secondary evergreen broad-leaved forest. We found that the BAI of all species is negatively correlated with competition intensity. Notably, early-successional and transitional species exhibited a more rapid decline in growth rates compared to late-successional species in response to increased competition. Among these tree species, the response of crown structure to neighbor competition exhibited variation. Early-successional and transitional species displayed a negative correlation between the competition index and crown area (CA)/diameter, while a positive correlation emerged between the lowest branch height (LBH)/height. Conversely, late-successional species followed the opposite trend. In terms of leaf functional traits, specific leaf area (SLA) showed heightened sensitivity to neighborhood competition, with a positive correlation between SLA of all tree species and the competition index. Furthermore, water use efficiency (WUE) demonstrated negative correlations with the competition index in early-successional and transitional trees, while a positive correlation emerged with late-successional trees. These findings suggest that early-successional and transitional trees prioritize vertical canopy growth, whereas late-successional trees tend to favor horizontal canopy expansion in response to neighboring competition. Additionally, early-successional and transitional trees experience more significant suppression of radial growth rate. Our research contributes to a deeper understanding of the underlying mechanisms driving changes in species composition and community succession.

Woody plant species richness and productivity relationship in a subtropical forest: The predominant role of common species.

A long-standing key issue for examining the relationships between biodiversity and ecosystem functioning (BEF), such as forest productivity, is whether ecosystem functions are influenced by the total number of species or the properties of a few key species. Compared with controlled ecosystem experiments, the BEF relationships in secondary forest remain unclear, as do the effects of common species richness and rare species richness on the variation in ecosystem functions. To address this issue, we conducted field surveys at five sampling sites (1 ha each) with subtropical secondary evergreen broad-leaved forest vegetation. We found (1) a positive correlation between species richness and standing aboveground biomass (AGB); (2) that common species were primarily responsible for the distribution patterns of species abundance and dominance; although they accounted for approximately 25% of the total species richness on average, they represented 86-91% of species abundance and 88-97% of species dominance; and (3) that common species richness could explain much more of the variation in AGB than total species richness (common species plus rare species) at both the site and plot scales. Because rare species and common species were not equivalent in their ability to predict productivity in the biodiversity-ecosystem productivity model, redundant information should be eliminated to obtain more accurate results. Our study suggested that woody plant species richness and productivity relationship in subtropical forest ecosystem can be explained and predicted by a few common species.

Environmental Filtering and Dispersal Limitations Driving the Beta Diversity Patterns at Different Scales of Secondary Evergreen Broadleaved Forests in the Suburbs of Hangzhou.

Subtropical suburban secondary evergreen broadleaved forests are essential in regulating the ecological environment's quality and promoting urban sustainable development. In the suburbs of Hangzhou City, well-preserved secondary evergreen broadleaved forest communities were selected to establish a 6 ha forest dynamic monitoring plot. Community surveys and environmental factor measurements were conducted in this area. This study investigated the beta diversity patterns at different scales by considering the environmental and spatial factors to explore the driving beta diversity. Using a similar paired-site beta diversity decomposition method, the study aimed to investigate the differences in species composition and the mechanisms of multiple species coexistence within the secondary evergreen broadleaved forest communities. The results showed that the beta diversity of the suburban secondary evergreen broadleaved forest communities decreased with the increasing spatial scale. Both the dispersal limitation and the environmental filtering were found to drive the formation of beta diversity patterns in these subtropical suburban forests. At relatively smaller scales (<100 m), species turnover was found to determine the beta diversity patterns of the suburban secondary evergreen broadleaved forests. Dispersal limitation had a dominant influence at more minor scales, while the effect of environmental filtering gradually increased with scale, and the impact of the dispersal limitation decreased. The partitioning of the beta diversity in subtropical secondary evergreen broadleaved forests in China provides critical scientific insights into the spatial distribution patterns and changes in biodiversity. It offers valuable knowledge for the conservation and understanding of biodiversity maintenance in the region.

Negative Density Restricts the Coexistence and Spatial Distribution of Dominant Species in Subtropical Evergreen Broad-Leaved Forests in China

Negative densification affects the spatial distribution of species in secondary evergreen broad-leaved forests and is a key mechanism governing species coexistence. We investigated the effects of habitat heterogeneity and density on the spatial distribution of populations of dominant woody species in a secondary evergreen broad-leaved forest in Wuchaoshan using spatial univariate point pattern analyses. This 6 ha forest dynamic monitoring sample area in Hangzhou, China is a typical secondary subtropical evergreen broad-leaved forest. We found (1) a strong effect of habitat heterogeneity that led to the spatial aggregation of dominant species in the plot. Habitat heterogeneity had a strong impact on mature individuals at different life history stages and of different species on a large scale. (2) Negative density dependence (NDD) generally affected spatial distributions of most dominant species and decreased in magnitude with age class. Therefore, different species of subtropical evergreen broad-leaved forests in China have formed unique spatial structures due to their habitat preferences but are generally subjected to density-dependent effects.

Assessment of Species Composition and Community Structure of the Suburban Forest in Hangzhou, Eastern China

The forest community structure and dynamic structure provide basic data for in-depth study of the community maintenance mechanisms and succession processes of urban forest ecosystems. Moreover, the study on the dynamics of suburban forest communities can provide a reference for the succession process of forest communities under severe human disturbance. In this context, this study analyzes the species composition and community structure of a 6 ha subtropical secondary evergreen broad-leaved forest plot in Wuchaoshan National Forest Park, Hangzhou, Eastern China. There are 36,757 existing woody plants (with DBH ≥ 1 cm), belonging to 94 species (45 evergreen species, and 48 deciduous species) in 63 genera of 34 families, with a plant density of 6126 plants/ha. The overall size–class distribution shows an obvious inverted “J” shape. Species with the top-five important values in the sample are Schima superba, Camellia fraternal, Symplocos anomala, Cyclobalanopsis glauca, Eurya rubiginosa, accounting for 57.3% of all individuals within the sample. In addition, different species have different habitat preferences and different distribution areas. The Wuchaoshan forest is in the middle and late stages of the succession. Different interference histories in the community succession process are demonstrated through studies of secondary evergreen broad-leaved forests. Long-term community monitoring contributes to indicating the direction and potential of the secondary forest succession.

Responses of terrestrial bryophytes to simulated climate change in a secondary evergreen broad-leaved forest in southern China

Responses of terrestrial bryophytes to simulated climate change in a secondary evergreen broad-leaved forest in southern China

Soil biochemical responses to nitrogen addition in a secondary evergreen broad-leaved forest ecosystem

In order to investigate the effects of N deposition on soil biochemistry in secondary forests, one N addition experiment was conducted in a secondary evergreen broad-leaved forest in the western edge of Sichuan Basin, with the highest level of background N deposition (about 95 kg N ha−1 yr−1) in China. Three N treatment levels (+0, +50, +150 kg N ha−1 yr−1) were monthly added to soil surface in this forest beginning in April 2013. Soil biochemistry and root biomass of the 0–10 cm soil horizon were measured from May 2014 to April 2015. Soil respiration was measured for two years (September 2013 to August 2015). It was showed that N additions were correlated to significantly lower soil pH, microbial biomass C (MBC) concentration, MBC/microbial biomass N (MBN) ratio, root biomass, and soil respiration rate, and significantly higher concentrations of ammonium (NH4+) and nitrate (NO3−). These results indicate that N additions had a significant effect on the size of soil microbial community. In addition, soil C storage may potentially increase due to the dropped soil C release under N addition.

Typhoon disturbance and tree replacement pattern in a secondary evergreen broad-leaved forest, JIBP Special Research Area at Minamata, southwestern Japan

Typhoon disturbance and tree replacement pattern in a secondary evergreen broad-leaved forest, JIBP Special Research Area at Minamata, southwestern Japan

Effects of the expansion of Phyllostachys edulis on species composition, structure and diversity of the secondary evergreen broad-leaved forests

The expansion of Phyllostachys edulis into the adjacent secondary evergreen broad-leaved forest (EBF) is obvious and greatly affects its ecological function. Little research has examined its effects on community structure and biodiversity. We comparatively analyzed the characteristics of species composition, community structure and diversity before and after the expansion of P. edulis forest (PEF), P. edulis–broad-leaved mixed forest (PBMF) and EBF along a gradient of P. edulis expansion in the Jinggangshan National Nature Reserve in Jiangxi Province using a space for time substitution method. Results indicated that: (1) The Bray-Curtis similarity index values of the tree layer, shrub layer and herb layer between PEF and EBF were 0.003, 0.046 and 0.030, respectively. (2) The PEF vertical structure showed a “>” type and the abundance percentage was 33.3% in 12–14 m interval, its diameter at breast height (DBH) class structure concentrated distribution in 5–10 cm interval, whose percentage was as high as 90.0%; while the EBF vertical structure showed a “L” type and the abundance percentages was 54.3% in 2–4 m interval, its DBH class distribution range was relatively wide, the average percentage of four larger diameter grades was 10.3%. (3) The Shannon-Wiener index value in the tree layer declined from 2.56 in EBF to 0.06 in PEF, with a reduction of 98%. In the shrub layer, the index value dropped from 2.58 to 2.03, declining 21%. We suggest that the expansion of P. edulis simplified the community composition and structure of the secondary evergreen broad-leaved forest and reduced species diversity, which can cause adverse impacts on forest ecosystem functioning. ·研究报告· 650 生 物 多 样 性 Biodiversity Science 第 24 卷

White-cheeked macaque (Macaca leucogenys): A new macaque species from Medog, southeastern Tibet.

We describe a newly discovered Macaca species from the Medog, in southeastern Tibet, China, Macaca leucogenys sp. nov or the "white-cheeked macaque". Based on 738 photos taken during direct observations and captured by camera traps this new species appears to be distinct from the Macaca sinica species group. Moreover, the species is distinguished from all potential sympatric macaque species (M. mulatta, M. thibetana, M. assamensis, and M. munzala) in exhibiting a suite of pelage characteristics including relatively uniform dorsal hair pattern, hairy ventral pelage, relative hairless short tail, prominent pale to white side- and chin-whiskers creating a white cheek and round facial appearance, dark facial skin on the muzzle, long and thick hairs on its neck, and a round rather than arrow-shaped male genitalia. This new macaque species was found to exploit a diverse set of habitat types from tropical forest at 1395 m, to primary and secondary evergreen broad-leaved forest at 2000 m, as well as mixed broadleaf-conifer forest at 2700 m. Its range may extend to neighboring counties in Tibet and the part of southeastern Tibet controlled by India. The white-cheeked macaque is threatened by illegal hunting and the construction of hydropower stations. Discovery of this new primate species further highlights the high value for biodiversity conservation of southeastern Tibet and calls for more intensive surveys, studies, and environmental protection in this area.

Research on landscape ecological security pattern in a Eucalyptus introduced region based on biodiversity conservation

Landscape fragmentation and habitat loss are one of the important factors resulting in biodiversity decrease and species extinction. A large amount of Eucalyptus have been introduced into Yunnan Province in China since 2003, replaced the native forest, farmland, wasteland and other ecosystems, leading to natural habitat loss and landscape fragmentation. In order to protect habitat and the biodiversity, the secondary evergreen broad-leaved forest were selected as “protection source”, land cover types, altitude, slope and soil texture were selected as resistance factors, to construct a medium-security and high-security level landscape eco-security patterns for Eucalyptus introduction regions by using the minimum cumulative resistance model and GIS technology. The patterns were composed of the eco-security pattern compositions and ecological function zones. The eco-security pattern compositions were composed of corridor, radiating routes and strategic point etc. The ecological function zones were composed of key eco-protection zone, eco-buffer zone, eco-transition zone, Eucalyptus planting zone, Eucalyptus banned zones, farming zone, living zone etc.

瓦屋山扁刺栲-中华木荷常绿阔叶次生林土壤有机碳组分特征

PDF HTML阅读 XML下载 导出引用 引用提醒 瓦屋山扁刺栲-中华木荷常绿阔叶次生林土壤有机碳组分特征 DOI: 10.5846/stxb201401010005 作者: 作者单位: 四川农业大学,四川农业大学,四川农业大学,重庆金佛山国家级自然保护区管理局,四川农业大学,四川农业大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目(31300522);教育部高等学校博士学科点专项科研基金项目(20125103120018);四川省教育厅重点项目(12ZA118,13ZA0246) Characteristics of soil organic carbon components in a secondary Castanopsis platyacantha-Schima sinensis evergreen broad-leaved forest, Wawushan Mountain Author: Affiliation: Sichuan Agricultural University,Sichuan Agricultural University,Sichuan Agricultural University,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:次生林在全球碳循环中占有重要地位,为了研究中国中亚热带次生林土壤有机碳组分特征,以四川瓦屋山中山段扁刺栲-中华木荷常绿阔叶次生林为对象,通过挖取土壤剖面分层(0-10、10-40、40-70 cm和70-100 cm)取样方式,研究土壤各有机碳组分特征。结果表明:土壤有机碳、微生物生物量碳、可浸提溶解性有机碳和易氧化碳含量均随土层深度增加而减小,0-10 cm土层有机碳含量为121.89 g/kg,高于已报道的亚热带其他常绿阔叶林和四川各类森林;0-10 cm层微生物生物量碳含量为1931.82 mg/kg,可浸提溶解性有机碳含量为697.42 mg/kg,易氧化碳含量为20.98 g/kg,高于已报道的许多相似天然林和人工林活性碳含量。土壤有机碳储量为154.87 t/hm2,在四川省各类森林中处于中等水平。研究表明瓦屋山扁刺栲-中华木荷常绿阔叶次生林活性碳含量较大,微生物活动和养分流动较为活跃,凋落物层转化为土壤碳的潜力较大,这类生态系统可能会在区域碳循环过程中扮演更为重要的角色。 Abstract:Secondary forests are one of the most important fast-growth forest types, with a large distribution area and high potential carbon sequestration capacity. In order to investigate the component characteristics of soil organic carbon in a subtropical secondary evergreen broad-leaved forest, an experiment was conducted in a typical evergreen broad-leaved secondary forest (Castanopsis platyacantha-Schima sinensis) in the middle section of Wawushan Mountain, southwest China. The physical soil properties and soil carbon fractions were studied, with the soil profile divided (0-10, 10-40, 40-70 cm and 70-100 cm) and sampled. Results showed that the soil at each level was acidic. Soil potential acidity was between 3.2 and 4.0, field moisture capacity was 63%-190%, and total porosity and bulk density were 63.0%-83.3% and 0.41-0.99 g/cm3 respectively. Soil pH value and bulk density increased with increased soil depth, while the field moisture capacity and total porosity showed the opposite trend. The organic carbon content of litter was 443 g/kg, and the litter stock and litter carbon stock were 10.4 t/hm2 and 4.5 t/hm2, respectively. Litter organic C stock in the studied forest was higher than in the majority of the plantations and natural forests in Sichuan Province. Soil organic carbon, microbial biomass carbon, extractable dissolved organic carbon, and readily oxidizable carbon decreased with an increase in soil depth. The soil organic carbon content in the 0-10 cm layer was 121.9 g/kg, which was higher than reported in other subtropical evergreen broad-leaved forests and in all types of forests in Sichuan (3.6, 8.6, and 14.6 times the soil organic content of the soil layers at 10-40 cm, 40-70 cm, and 70-100 cm respectively). The content of microbial biomass carbon in the 0-10 cm layer was 1931.82 mg/kg, which was 2.6, 5.7, and 7.8 times that in the following three layers. The contents of extractable dissolved organic carbon and readily oxidizable carbon in the 0-10 cm layer were 697.42 mg/kg and 20.98 g/kg, respectively. The contents of labile organic carbon in the 0-10 cm layer were higher than in many other reported similar natural forests and plantations. The density of soil organic carbon, microbial biomass carbon, extractable dissolved organic carbon, and readily oxidizable carbon were 7.5-48, 0.20-0.81, 0.25-0.37, and 0.8-8.4 kg/m3, respectively. The density of soil organic carbon, extractable dissolved carbon, and readily oxidizable carbon decreased with an increase in soil depth, while the microbial biomass carbon first increased and then decreased and peaked at the horizon, 10-40 cm. Soil organic carbon stock was 154.9 t/hm2, which was at the mid-level in Sichuan Province. The stocks of microbial biomass carbon, extractable dissolved organic carbon, and readily oxidizable carbon were 3.1, 3.0 and 21.0 t/hm2, respectively. This study suggests that (1) the content of the soil labile organic carbon was relatively high, (2) the activity of microorganisms and the flow of nutrients were relatively active, and (3) there is a huge amount of forest litter in the C. platyacantha-S. sinensis evergreen broad-leaved secondary forest that can be transformed into soil carbon in the future. These ecosystems will play a more important role in regional carbon cycles in the future. 参考文献 相似文献 引证文献

Community structure and species composition of the secondary evergreen broad-leaved forest: the analyses for a 9 ha forest dynamics plot in Wuyanling Nature Reserve, Zhejiang Province, East China

The zonal vegetation type of subtropical China is evergreen broad-leaved forest (EBLF). However, due to long term anthropogenic disturbance, primary EBLF is now scarce in this region; most of the EBLFs exist as secondary forests. Therefore, to preserve the regional forest biodiversity, it is important to understand the mechanisms underlying biodiversity maintenance of the regional secondary EBLF. One method for ex- amining the mechanisms of forest biodiversity maintenance is to investigate the species composition and community structure on the basis of a large forest dynamics plot (FDP). According to protocols of Center for ·森林动态监测样地专题·

珠江三角洲不同污染梯度下森林优势种叶片和枝条S含量比较

PDF HTML阅读 XML下载 导出引用 引用提醒 珠江三角洲不同污染梯度下森林优势种叶片和枝条S含量比较 DOI: 10.5846/stxb201306031300 作者: 作者单位: 中国林业科学研究院热带林业研究所,中国林业科学研究院热带林业研究所,中国林业科学研究院热带林业研究所,中国林业科学研究院热带林业研究所,中国林业科学研究院热带林业研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金资助(31200471);中国林科院热林所基本科研业务费专项资金项目(RITFYWZX201208);国家"十二五"农村领域科技计划(2011BAD38B0305) Sulfur contents in leaves and branches of dominant species among the three forest types in the Pearl River Delta Author: Affiliation: Research Institute of Tropical Forestry,Chinese Academy of Forestry,Forest Ecosystem Station of the Pearl River Delta,State Forestry Administration,Research Institute of Tropical Forestry,Chinese Academy of Forestry,Forest Ecosystem Station of the Pearl River Delta,State Forestry Administration,Research Institute of Tropical Forestry,Chinese Academy of Forestry,Forest Ecosystem Station of the Pearl River Delta,State Forestry Administration,Research Institute of Tropical Forestry,Chinese Academy of Forestry,Forest Ecosystem Station of the Pearl River Delta,State Forestry Administration,Research Institute of Tropical Forestry,Chinese Academy of Forestry,Forest Ecosystem Station of the Pearl River Delta,State Forestry Administration Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:植物的吸储作用对降低环境中含硫污染物浓度有积极意义。筛选珠江三角洲地区具有不同污染程度的3处森林类型,检测了32个树种叶片和枝条中的总S含量(其中广州市白云区帽峰山次生常绿阔叶林16个树种,广州市南沙区海岸防护人工林11个树种,佛山市顺德区龙凤山人工改造恢复林5个树种)。结果显示:该32个物种的叶片和枝条中硫含量平均值分别为(0.24±0.02)%和(0.14±0.02)%,叶片硫含量显著高于枝条中的(P=0.000)。相同森林类型不同物种间叶片(和枝条)中硫含量呈现显著差异。帽峰山和南沙森林样地中优势种叶片(和枝条)中硫含量近似,分别为(0.22±0.01)%和(0.22±0.02)%(枝条:(0.13±0.01)%和(0.10±0.01)%);而龙凤山的最高,叶片和枝条中分别为(0.39±0.13)%和(0.28±0.09)%;多重检验结果显示,在龙凤山森林类型植物体吸储硫元素的量,显著大于帽峰山和南沙森林类型,这与不同森林类型所处空气环境中S污染物格局较为吻合。在近缘类群中(如豆科、樟科),叶片(和枝条)中硫含量的差异显著,暗示近缘植物类群(在科的水平上)在吸储硫元素方面受系统发育约束作用不明显。在本土树种和引进树种中,叶片(和枝条)中硫含量没有显著差异,可能与所处环境的过滤作用相关。广州和佛山地区各林型的植物体内硫含量存在的差异,基本反映出该两地区空气环境中受含硫污染物的影响程度。今后在该地区的造林过程中,应更多考虑应用S污染物吸储能力较强的树种,并注重本土树种和引进树种的组配,构建适应当地环境条件的森林群落。 Abstract:Plants play an important role in reducing the concentrations of sulfur-containing pollutants by means of biological absorption. The present study sampled 32 tree species, and measured the sulfur (S) contents in leaves and branches (in dry weight) of dominant species for three main forest types in the Pearl River Delta, specifically coniferous and broadleaved mixed restoration (CBMR) forest in Longfeng Mountain (5 species), Foshan city; seashore shelter evergreen broadleaved (SSEB) forest of Nansha Forest Plot (11 species) and secondary evergreen broadleaved (SEB) forest (16 species) in Maofeng Mountain, Guangzhou city. Firstly, we compared the S contents in leaves and branches of three main forest types. Our results showed that mean value of S content was (0.24±0.02)% in leaves and (0.14±0.02)% in branches for these tree species; and S content in leaves was significantly higher than that of in branches (P=0.000). A significant interspecific difference (P=0.000) of S content in leaves (and branches) was also detected. Among the three forest types, CBMR forest exhibited the highest S content both in leaves (0.39±0.13)% and branches (0.28±0.09)%, followed by SEB forest ((0.22±0.01)% in leaves, and (0.13±0.01)% in branches), and SSEB forest ((0.22±0.02)% in leaves, and (0.10±0.01)% in branches). Result of a Turkey Post Hoc Test showed that the amount of S elements absorbed by tree organs in CBMR forest was significantly higher than that of in SEB forest and SSEB forest, which was generally consistent with the pattern of atmospheric S-containing pollutants in heterogeneous environment in the Pearl River Delta. Secondly, we attempted to compare the S content between closely related species as well as distantly related species. In closely related species (e.g., four species in Fabaceae, and three species in Lauraceae), S contents in leaves (and branches) exhibited a significant difference respectively. The results suggested that environmental filtering effect, rather than phylogenetic constraint effect, played a more important role in the S-absorption process at the Family level. Finally, we compared the S content in leaves and branches between native species and introduced species. For native and introduced tree species, no significant difference was detected in either leaves or branches, suggesting that local habitat may determine the physiological and ecological behaviors of tree species. In conclusion, the results from three analyses collectively showed that the differences of leaves and branches of dominant species in three main forest types in Guangzhou and Foshan reflected a general status of S pollution in the atmosphere. Our results implied important strategies for urban forest management that top priorities should be given to selection of tree species with higher ability of S-absorption and a combination of native and introduced tree species for urban afforestation. 参考文献 相似文献 引证文献

外来树种桉树引种的景观生态安全格局

PDF HTML阅读 XML下载 导出引用 引用提醒 外来树种桉树引种的景观生态安全格局 DOI: 10.5846/stxb201210011366 作者: 作者单位: 云南大学资源环境与地球科学学院,云南国土资源职业学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金(40961031);云南省应用基础研究面上项目(2009CD022);云南大学"中青年骨干教师培养计划"项目(XT412003)资助 Landscape ecological security pattern associated with the introduction of exotic tree species Eucalyptus Author: Affiliation: College of Resource Environment and Earth Science, Yunnan University,Yunnan College of Land and Resources Vocational Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以大面积桉树引种区云南省澜沧县为研究区,以自然栖息地和生物多样性的整体保护为目标,利用最小累积阻力模型开展了桉树引种的景观生态安全格局的定量研究。结果表明:(1)基于GIS技术和"成本距离加权"制图分析工具,将生物和景观等综合因素融入最小累积阻力模型,把"源"扩展的生态过程与景观格局结合起来,应用于桉树引种的景观生态安全格局构建中是可行的。(2)选择次生常绿阔林为保护"源",地表覆盖类型、海拔、坡度、土壤质地和公路等为阻力因子,建立最小累计阻力面,识别了廊道、辐射道和战略点等生态安全格局组分;用最小累积阻力阈值划分了生态缓冲区、生态过渡区、生态边缘区、农业耕作区和居民生活区等生态功能区,并界定桉树禁止种植区和桉树可种植区,最终组合成两个方案的中级和高级景观生态安全格局。方案一,中级和高级安全水平的桉树可种植区面积分别占研究区面积的33.48%和19.27%。方案二,中级和高级安全水平的桉树可种植区面积分别占研究区面积的28.37%和15.17%。(3)从"源"的扩展效果、保护广度、管理成本、难易程度及生态环境和经济社会发展要求等方面评价,认为方案二的中级安全水平格局能够相对满足澜沧县对生态、经济发展的要求。研究结果为制定研究区生态安全策略提供参考。 Abstract:With rapid introduction of exotic trees, natural habitat loss and landscape fragmentation were aggravated in mountainous areas. Construction of landscape eco-security pattern can provide feasible option to prevent landscape fragmentation and to protect natural habitats and biodiversity. Since 2003, a large amount of exotic tree species, Eucalyptus has been introduced into Lancang county of Yunnan province. The Eucalyptus replaced the native forest, farmland, wasteland and other ecosystems, leading to serious natural habitat loss, landscape fragmentation and biodiversity threatening. In this paper, the large areas in Lancang County of Yunnan Province, where Eucalyptus have been extensively introduced were selected as the case study sites to examine the landscape eco-security pattern for Eucalyptus introduction by using the minimum cumulative resistance model. The results indicated: (1) it's feasible, based on the GIS and "cost distance weighing" mapping analysis tool, to construct the landscape eco-security pattern of Eucalyptus introduction by integrating the biological factors and landscape factors into minimum cumulative resistance (MCR) model and combining the "source" extended ecological process with Landscape pattern. This can be a reference approach to constructing the landscape eco-security pattern for the exotic tree introduction in other areas. (2) the components of ecological security pattern such as corridor, radiating routes and strategic point etc. indentified by the minimum cumulative resistances surface which were derived from the GIS-based and MCR model using land cover types, altitude, slope, soil texture and road etc. as resistance factors can preserve ecosystem functions in Eucalyptus-introduced and affect positively the species migration and diffusion in " protection source", which was secondary evergreen broad-leaved forest in natural habitat in this study. By using the minimum cumulative resistance threshold values, we divided the eco-buffer zone, eco-transition zone, eco-fringe zone, farming zone and residential zone for the landscape eco-security construction. We also defined the banned zone and planting zone for Eucalyptus plantation. The medium-security and high-security landscape eco-security patterns were developed on the basis of minimum cost but maximum ecological and economic benefit for the introduction areas in Eucalyptus plantation. To achieve this goal, there will be two schemes. In the first scheme, medium-security and high-security areas for Eucalyptus plantation account for 33.48% and 19.27% of total study areas. In the second scheme, medium-security and high-security areas for Eucalyptus plantation account for 28.37% and 15.17% of total study areas. (3) the second scheme of medium-security pattern could fit ecological and economic conditions of Lancang County better when compared these two schemes from the expansion effect of "source", protection range, management cost, difficulty level, eco-environment capacity as well as economic and social development. In the second scheme, the large and small patches of protection 'sources' were spaced in-between, and large patches can work well for protecting the species and ecosystems better, small patches could be settled foothold to protect distributed rare species or ecological niches. As the "source" patches were small and concentrated, the fragmentation was relatively low, so the protection and management of the "source" will be less difficult and costly. There were 22 corridors and combined circular, so the connectivity among "sources" was good. There were 6 radiating routes, meaning less opportunity for "sources" expansion. There were many strategic points of native tree species for improving the integrity of the "sources". All these results may provide some useful references for developing eco-security strategies in the study areas. 参考文献 相似文献 引证文献

Study on the Wild Plants Biodiversity and Vegetation of Cheung Chau Island,Hong Kong

We determined there were 237 wild vascular plants from 184 genera in 73 families in Cheung Chau Island.The dominant vegetation types were secondary evergreen broad-leaved forest,followed by shrubland.The flora was dominated by tropical and subtropical elements.The flora of Cheung Chau Island is very important in Hong Kong and is similar to its neighboring regions.Because of human activities and exotic plant introduction,the floristic composition,species diversity,and vegetation protection should be an important area of focus.

Individual-tree radial growth in a subtropical broad-leaved forest: The role of local neighbourhood competition

Establishing the competitive relationships at the local neighbourhood level is essential for improving our understanding of tree growth dynamics in structurally heterogeneous and species-rich forests. We studied the competitive interactions influencing individual-tree five-year radial growth of the two species Castanopsis fargesii (Franch.) and Quercus fabri (Hance) in a diverse young secondary evergreen broad-leaved forest (EBLF) in eastern China. Different spatially explicit individual-based competition indices were examined for their effectiveness at predicting radial growth. These indices were based on one of the three tree size variables – diameter at breast height (dbh), total height, and crown projection area – and were combined with different approaches to identify potential competitors. Furthermore, we tested for competitive equivalence of conspecific and heterospecific neighbours and analysed the effects of local diversity, initial dbh (measured at the beginning of the five-year growth period) and abiotic environmental variables on individual-tree radial growth. Competition accounted for up to 78% and 75% of radial growth variation in C. fargesii and Q. fabri, respectively. The best results were provided by competition indices using crown projection area as the variable describing tree size and the angular height method as the approach to identify potential competitors (i.e. neighbours greater than the minimum angular height, measured from the base of the target trees, are selected as competitors). Competitive equivalence of conspecific and heterospecific neighbours was found in C. fargesii, whereas heterospecifics were stronger competitors than conspecifics in Q. fabri. We could not detect diversity effects on radial growth. The addition of initial dbh or abiotic environmental variables as further explanatory variables failed to improve the predictive ability of growth models. Our results indicate that diameter growth in this EBLF is largely a function of local neighbourhood competition and suggest that the mode of competition is primarily size-asymmetric. It appears that there may be high competitive equivalence among different species, but this remains to be experimentally tested.

Leaf nutrient concentration, nutrient resorption and litter decomposition in an evergreen broad-leaved forest in eastern China

While plant mineral nutrition has been well addressed in temperate ecosystems, our knowledge of this topic in subtropical evergreen broad-leaved forests remains weak. We examined various plant leaf traits and litter decomposition rates among three groups—deciduous species (DB) and evergreen broad-leaved species with leaf life span <1.5 years (EBS) and >1.5 years (EBL) in a secondary evergreen broad-leaved forest in eastern China. Relative to DB, EBS and EBL classes contained 33 and 44% less leaf N, and 28 and 45% less leaf P, respectively. N resorption efficiency varied from 27 to 65%, 21 to 52% and 22 to 51% in DB, EBS and EBL, respectively. P resorption efficiency varied from 38 to 77% in DB, 6 to 58% in EBS and 15 to 55% in EBL. P resorption efficiency was greater in DB than in EBS and EBL while N resorption efficiency did not differ among the three classes. N resorption efficiency was not correlated with either leaf N or N:P ratio. In contrast, P resorption efficiency was positively correlated with leaf P. Litter decomposition rates were 2.45, 1.33 and 2.30 year −1 for DB, EBS and EBL, respectively, but the rates did not significantly differ between groups. Litter decomposition rate was positively correlated with specific leaf area (SLA) and initial litter N but not litter P. In conclusion, there were no significant differences between EBS and EBL for any of the leaf traits measured, but these two classes were different from DB. Plants with long leaf life span tend to minimize nutrient loss more by reducing N concentration in leaf litter than by increasing N resorption efficiency.

Stand structure of a fragmented evergreen broad-leaved forest at a shrine and changes of landscape structures surrounding a suburban forest, in northern Kyushu.

Stand structure such as species composition and canopy gap formation in a fragmented evergreen broad-leaved forest and changing patterns of a matrix surrounding the forest over the past 42 years based on vegetation maps made from aerial photos were examined. The suburban landscape had changed significantly. Some forest-type elements such as scrub and secondary deciduous broad-leaved forests had decreased in area, although plantations, Phyllostachys forests and secondary evergreen broad-leaved forests had increased in area. The area of the fragmented forest, which was well-developed secondary evergreen broad-leaved forest at a shrine, had not significantly changed. Some species such as Distylium racemosum, Persea thunbergii, Camellia japonica and Eurya japonica regenerated in the forest the same way as in old-growth evergreen broad-leaved forests, suggesting that population structure and dynamics of those species were not greatly influenced by landscape ecological factors or secondary succession of the forest. Regeneration behaviour of some species such as Neolitsea sericea and Quercus salicina in the forest differed significantly from that in the old-growth forests. Furthermore, the density of N. sericea seedlings was extremely high, although only a few mature individuals and saplings of the species occurred in the forest. Population structure of the species might be influenced by changing patterns of the matrix surrounding the fragmented forest.