Distribution Characteristics Of Vegetation Research Articles

Simulating runoff generation and its spatial correlation with environmental factors in Sancha River Basin: The southern source of the Wujiang River

Runoff generation is an important part of water retention service, and also plays an important role on soil and water retention. Under the background of the ecosystem degradation, which was caused by the vulnerable karst ecosystem combined with human activity, it is necessary to understand the spatial pattern and impact factors of runoff generation in the karst region. The typical karst peak-cluster depression basin was selected as the study area. And the calibrated and verified Soil and Water Assessment Tool (SWAT) was the main techniques to simulate the runoff generation in the typical karst basin. Further, the spatial variability of total/surface/groundwater runoff was analyzed along with the methods of gradient analysis and local regression. Results indicated that the law of spatial difference was obvious, and the total runoff coefficients were 70.0%. The groundwater runoff was rich, about 2–3 times the surface runoff. Terrain is a significant factor contributing to macroscopic control effect on the runoff service, where the total and groundwater runoff increased significantly with the rising elevation and slope. The distribution characteristics of vegetation have great effects on surface runoff. There were spatial differences between the forest land in the upstream and orchard land in the downstream, in turn the surface runoff presented a turning point due to the influence of vegetation. Moreover, the results of spatial overlay analysis showed that the highest value of total and groundwater runoff was distributed in the forest land. It is not only owing to the stronger soil water retention capacity of forest ecosystem, and geologic feature of rapid infiltration in this region, but also reflected the combining effects on the land cover types and topographical features. Overall, this study will promote the development and innovation of ecosystem services fields in the karst region, and further provide a theoretical foundation for ecosystem restoration and reconstruction.

3-D Numerical Investigation on Effect of Flow Structure and Water Level on Vegetation Distribution in an Open Channel

Jeon, H.S.; Hur, D.S.; Park, J.R.; Yoon, J.S.; Kim, I.H., and Lee, W.D., 2018. 3-D numerical investigation on effect of flow structure and water level on vegetation distribution in an open channel. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 71–75. Coconut Creek (Florida), ISSN 0749-0208.The in-stream vegetation is recognized to have significant ecological and aesthetic importance in managing floods and restoring rivers. However, it also disturbs the velocity of running fluid by increasing the resistance of flow, and raises the water level because of reduced discharge area at times of flood. Therefore, it is very important to study the hydraulic characteristics of vegetation distribution, and this study carried out a numeric simulation for quantitative and qualitative analysis. The simulation applied Navier-Stokes solver based on PBM (Porous Body Model), LES (Large Eddy Simulation) and VOF (Volume of Fluid), and the estimated drag coefficients of vegetation with Reynold's number. A comparison between the measured and calculated water depth and depth-averaged velocity found that conventional and new experiments were highly consistent. A numeric water tank was also used in this study to discuss the hydraulic characteristics of vegetation by measuring the velocity and water level depending on different vegetation zones and incidental conditions. The result showed that full vegetation in an open channel reduced velocity and raised water level because of the drag of vegetation, while half vegetation on one side or at certain part of the channel substantially reduced the hike of water level. Therefore, vegetation should be distributed appropriately when applying that in river management or restoration after an accurate analysis on the hydraulic characteristics of vegetation distribution.

大尺度森林碳循环过程模拟模型综述

PDF HTML阅读 XML下载 导出引用 引用提醒 大尺度森林碳循环过程模拟模型综述 DOI: 10.5846/stxb201612122550 作者: 作者单位: 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（41631180，41671376，41571373，41301385）；国家重点研发计划（2016YFA0600103） The simulation models of the forest carbon cycle on a large scale: a review Author: Affiliation: 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:森林生态系统碳循环是全球陆地生态系统碳循环的重要组成部分，而碳循环模型已经成为研究森林碳循环的必要手段。森林碳循环模型可以分为统计模型和过程模型，其中过程模型以其完整的理论框架、严谨的结构分析和清晰的过程机理，逐渐占据了主导地位。从地球化学过程模型、陆面物理过程模型和生物过程模型等3个方面综述区域尺度到全球尺度（本文称为大尺度）森林碳循环过程模型研究进展，论述了各类模型的主要特征、优缺点以及应用现状，探讨了森林碳循环模拟研究中存在的问题，并讨论了森林碳循环过程模型的主流研究方向。可为不同空间尺度下森林生态系统碳循环模拟模型的选择提供参考，以及为森林碳循环研究提供借鉴。 Abstract:The carbon cycle in forest ecosystems is an important part of the global terrestrial ecosystem carbon cycle, and models have become a necessary means used to study the forest carbon cycle. Forest carbon cycle models can be classified into statistical models and process models, and the latter have gradually become dominant due to their complete theoretical framework, rigorous structural analysis, and clear process mechanism. This paper reviews the studies on forest carbon cycle process models on a large scale from three aspects:geochemical process models, terrestrial physical process models, and biological process models. Their main features, advantages, and application status are summarized, and the limitations of these models are also discussed systematically. Geochemical process models focus on the cycle process of important elements (such as carbon, nitrogen, and water) among the vegetation, litter, and soil organic matter, which can be used to simulate the forest carbon balance, vegetation productivity, and nutrient utilization. Terrestrial physical process models focus on the process of energy and momentum exchange between vegetation and the external environment under different atmospheric conditions,which emphasize the interaction between climate and vegetation. Meanwhile, complex processes are considered by terrestrial physical process models, including reflection, absorption, scattering, transmission, and other processes. Biological process models, focus on the analysis of vegetation composition, distribution characteristics, and dynamic changes under different environmental conditions. Biological process models can be further divided into biogeographic models, light-use efficiency models, and dynamic vegetation models. In this review, the existing problems associated with the simulation of forest carbon cycle processes are discussed, such as the uncertainty of input data and model mechanism, scale effect, and topographic effect, which need to be further studied. One of the main problems is the uncertainty of input data, which affects the accuracy of forest carbon cycle process simulation. Furthermore, the uncertainty of model mechanism also makes the simulation difficult. Another issue is the scale effect associated with the mismatch among the observation, model, and surface process scales. The scale effect may cause contrasting results in the simulation of forest carbon cycle processes. Note that there exists obvious topographic effects on simulation models in complex terrains. Finally, the prospects of implementing these models into future studies are discussed. When ignoring the feedback effect of vegetation on atmosphere, geochemical process models are suitable for the simulation of carbon budget on a regional scale, and the biogeographic models are suitable for the study of vegetation distribution characteristics on a global scale. However, under the current background of global change, in order to meet the various needs of forest carbon cycle simulation, such as carbon budget, evapotranspiration process, vegetation succession process, and vegetation feedback to the atmosphere, the terrestrial physical process models and the dynamic global vegetation models will be used as the mainstream research into forest carbon cycle process models in the future. This review can be served as a reference when selecting models for forest ecosystem carbon cycle simulation at various spatial scales. 参考文献 相似文献 引证文献

Distribution Characteristics of Vegetation and Bird of Buffer Green Space in Sihwa Industrial Complex, Siheung City

Distribution Characteristics of Vegetation and Bird of Buffer Green Space in Sihwa Industrial Complex, Siheung City

시설원예단지 조성이 농업생태계의 식생다양성에 미치는 영향 분석

인간은 생태계로부터 다양한 공익적 기능을 제공받고 있지만 시설원예단지 조성은 불투수면적 확장과 생물서식처 손실로 인해 기능저하의 원인이 될 수 있다. 시설원예단지 조성이 식물 종 다양성에 미치는 영향을 파악하였다. 식생분포 특성 분석결과 논에 비해 시설원예단지의 식물다양성이 상당히 낮다는 것을 알 수 있었다. 따라서 저 영향개발, 서식공간 배치, 식물 보전, 화학비료 사용제한, 서식처 조성, 보전비용 등을 제안하였다. 생활형 분석을 통해 일년생식물과 수생식물의 생육기반 환경 조성을 제시하였다. 귀화식물은 총 10과 20종류가 확인되었으며, 귀화율은 유리온실과 연동형 온실이 매우 높게 분석되어 콘크리트 피복을 지양하고 자연토양 피복을 유도 할 것을 제안하였다. 연구결과는 통계분석을 통해 확인하고 불투수면적을 자연형 토양으로 전환을 제안하였다. 본 연구결과는 지속가능한 농업경관 유지와 대규모 간척지 개발 사업에 있어 친환경, 생태적 시설원예단지 조성을 위한 정책자료에 활용되길 기대한다. Although the ecosystem extends numerous functions for the benefit of humankind, construction of horticultural facilities can potentially lead to the degeneration of some of these functions owing to the expansion of impervious regions and loss of habitats. Thus, this study aimed to examine the effect of construction of horticultural facilities on plant biodiversity. Analysis of the vegetation distribution characteristics showed that horticultural facilities had significantly lower plant diversity than did rice paddies. Hence, the proposed approach involved low-impact development, arrangement of habitat space, plant preservation, restricted use of chemical fertilizer, habitat creation, and reduced preservation cost. Lifestyle analysis suggested the importance of developing favorable environments for the growth of annual plants and aquatic plants. In all, 20 species of naturalized plants belonging to 10 families were identified. Furthermore, the proportion of these naturalized plants was higher in glass greenhouses and multi-span greenhouses, suggesting the advantages of employing natural soil mulching while avoiding concrete mulching. Statistical analysis was performed to validate the results, which suggested that impervious regions be converted to natural soils. Collectively, the findings of this study are expected to be used for establishing policies for the construction of eco-friendly and ecological horticultural facilities; this may aid the maintenance of sustainable agricultural landscapes and large-scale development of the reclaimed lands.

Interspecific Association of Dominant Species Analysis of Different Slope Types in Mining Area, Beijing

Water and soil loss due to the mining activities make extremely serious ecological degradation. Vegetation restoration is a vital solution to the construction of ecosystem. However, vegetation recovery is a slow process, thus, it is crucial significant to master the distribution characteristics of vegetation and interspecific association of dominant species in different types of slopes. Compared with rocky and soilrocky slopes, soil slopes had the highest vegetation diversity indexes, in which the interspecific association of dominant species was the closest. In general, the vegetation restoration in soilrocky slopes was more efficient than that in the rocky slopes. Engineering measure, as a method of speeding up the succession process, showed a good effect during the early stage of vegetation restoration. As the succession process continued, interspecific competition got increasingly fierce so that the mid-term vegetation restoration had gained little improvement. At the later stage, the restoration effect in slopes which adopted engineering measures was superior to those in natural restoration, and the community characteristics of vegetation in these slopes had more similarities to the native vegetation's. Our experiment results would contribute to deepening the understanding of interspecific relationships in different site conditions and building a more stable ecosystem.

Scale transformation of Leaf Area Index product retrieved from multiresolution remotely sensed data: analysis and case studies

Climate and land–atmosphere models rely on accurate land-surface parameters, such as Leaf Area Index (LAI). It is crucial that the estimation of LAI represents actual ground truth. Yet it is known that the LAI values retrieved from remote sensing images suffer from scaling effects. The values retrieved from coarse resolution images are generally smaller. Scale transformations aim to derive accurate leaf area index values at a specific scale from values at other scales. In this paper, we study the scaling effect and the scale transformation algorithm of LAI in regions with different vegetation distribution characteristics, and analyse the factors that can affect the scale transformation algorithm, so that the LAI values derived from a low resolution dataset match the average LAI values of higher resolution images. Using our hybrid reflectance model and the scale transformation algorithm for continuous vegetation, we have successfully calculated the LAI values at different scales, from reflectance images of 2.5 m and 10 m spatial resolution SPOT-5 data as well as 250 m and 500 m spatial resolution MODIS data. The scaling algorithm was validated in two geographic regions and the results agreed well with the actual values. This scale transformation algorithm will allow researchers to extend the size of their study regions and eliminate the impact of remote sensing image resolution.

A Vegetation Map of Tasmania

A RECENT review of the plant geography of Tasmania' has pointed, among other things, to the lack of an adequate vegetation map of the island. The only attempt has been that of Stephens2 in 1941; it is incidental to a survey of the soils, and the boundaries are highly generalized. Representation of the vegetation cover in atlases is often misleading. At least two well-known atlases indicate extensive areas of deciduous forest, and the more usual portrayal of mixed forest in the western part of the island is not a true picture either. The contribution made to physiognomy by the coniferous species is very small, particularly since one of the more frequent conifers, Phyllocladus aspleniifolius, is in fact broad-leafed and not needle-leafed. Conversely, there is also a sprinkling of conifers (Callitris) in the east, and several important needle-leafed angiosperms (for example, Casuarina). The map presented here (Fig. 1) is based on photographic interpretation controlled by ground reconnaissance. It was originally prepared at the scale of eight miles to the inch, but this has been greatly reduced for publication; it was felt that the breadth of the vegetation categories used did not warrant a larger scale. It is to be hoped that more detailed work will eventually lead to something better; meanwhile the present attempt may provide an interim picture, adequate for most general purposes. It will serve at least to point to some of the more outstanding characteristics of vegetation distribution, several of which are worthy of general attention.