作者机构:
[田大伦; 方晰; 李斌; 项文化; 闫文德] 中南林业科技大学,生命科学与技术学院,长沙410004;[李斌] 国家林业局,北京100714;[田大伦; 方晰; 项文化; 闫文德] 南方林业生态应用技术国家工程实验室,长沙410004;Division of Science, College of Arts and Sciences, Governors State University, University Park, Illinois 60484(USA);湖南省邵阳县林业局,邵阳,422100
通讯机构:
College of Life science and technology, Central South University of Forestry and Technology, Changsha, China
关键词:
Koelreuteria paniculata;Lateral fine root development;Manganese mine wastes;Phytoremediation;Seedling biomass
摘要:
The planting of trees on mine wastelands is an effective, long-term technique for phytoremediation of heavy metal-contaminated wastes. In this study, a pot experiment with seedlings of Koelreuteria paniculata under six treatments of local mine wastes was designed to determine the major constraints on tree establishment and to evaluate the feasibility of planting K. paniculata on manganese mine wastelands. Results showed that K. paniculata grew well in mine tailings, and also under a regime of equal amounts of mine tailings and soil provided in adjacent halves of pots. In contrast, mine sludge did not favor survival and growth because its clay texture limited fine root development. The bio-concentration factor and the translocation factor were mostly less than 1, indicating a low phytoextraction potential for K. paniculata. K. paniculata is suited to restore manganese mine sludge by mixing the mine sludge with local mine tailings or soil.
作者机构:
[Tian, Dalun; Peng, Yuanying; Xiang, Wenhua; Yan, Wende; Deng, Xiangwen] Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Forest Ecol Program, Changsha, Hunan, Peoples R China.;[Tian, Dalun; Xiang, Wenhua; Yan, Wende; Deng, Xiangwen; Chen, Xiaoyong] Natl Engn Lab Appl Forest Ecol Technol Southern C, Changsha, Hunan, Peoples R China.;[Chen, Xiaoyong] Governors State Univ, Coll Arts & Sci, Div Sci, University Pk, IL USA.;[Peng, Yuanying] Coll DuPage, Div Nat Sci, Glen Ellyn, IL USA.
通讯机构:
[Yan, Wende] C;Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Forest Ecol Program, Changsha, Hunan, Peoples R China.
关键词:
Chinese fir plantation;rainfall interception;interception ratio;throughfall;stemflow;growth stage of forests;plantation de sapins;interception des precipitations;rapport interception;pluie au sol;ruissellement le long des troncs;stade de croissance des forets
摘要:
The dynamic properties of rainfall interception were investigated at three growth stages in Chinese fir plantations. The results showed that the annual interception ratio was significantly higher in mature stands than in young stands. For a storm event, interception rainfall amount increased with increasing rainfall, but interception ratio decreased. In contrast to dry season conditions, the interception amount was high in the wet seasons, while the interception ratio was low. The rates of change in interception ratio were extremely rapid in small rainfall events. There was little stemflow in Chinese fir forests due to the pyramid-shaped crowns and thick rough bark of the trees. The power model was suitable to describe the interception process for an individual rainfall event for stands of any age. Our results indicate that the interception process varied for stands of different ages in Chinese fir plantations due to contrasting canopy structures. ResumeLes proprietes dynamiques de l'interception des precipitations ont ete etudiees a trois stades de croissance dans des plantations de sapins chinois. Les resultats ont montre que la proportion de precipitations interceptees a l'echelle annuelle etait significativement plus elevee dans les peuplements matures que dans les jeunes peuplements. Pour une averse, la quantite interceptee augmente avec les precipitations, mais le rapport d'interception diminue avec elles. La quantite interceptee etait plus elevee durant les saisons humides qu'en saisons seches, tandis que le rapport d'interception etait plus faible. Les taux de changement du rapport d'interception ont ete extremement rapides pour les petits evenements de precipitations. Il y avait peu de ruissellement le long des troncs dans les forets de sapins chinois en raison de leur forme de pyramide et de l'ecorce epaisse et rugueuse des arbres. Un modele puissance etait approprie pour decrire le processus d'interception pour un evenement de precipitations individuelle pour n'importe quel peuplements age. Nos resultats indiquent que le processus d'interception varie avec l'age des peuplements de sapins chinois en raison de contrastes de structure de la canopee.
摘要:
土壤有机碳和氮素是植物生长所必须的营养元素,也是土壤养分和生态系统中的关键生态因子,是陆地碳库和氮库的重要组成部分,其含量多少将会直接影响土壤中微生物数量和凋落物的分解速率(Nasholm et al.,1998; Dormaar et al.,1990; 任书杰等,2006) 。土壤有机碳和氮素的变化与土地利用/覆盖密切相关,地表植物群落的变化,往往会造成土壤碳和氮分布格局的变化,进而影响整个生态系统的稳定性和可持续性(刘全友等,2005) 。
摘要:
Acidic deposition,which is mainly caused by atmospheric pollution,is one of the global environmental problems.Thinning is an effective management to improve the tree productivity,reduce the wildfire risk and maintain a healthy forest.Since thinning may reduce the effect of acidic deposition,the effect of thinning on acidic deposition was estimated.The biomass,soil properties,pH value of runoff and groundwater in both unthinned and thinned Chinese fir plantations were measured and compared over a 5-year period(2-6 years after thinning).The results indicated that acidic deposition in the Huitong State Ecosystem Research Station was serious,and it got worse with time.Forest thinning resulted in a huge change in biomass and soil properties.During the 5-year monitoring period,biomasses of understory and litter,plant species richness,coverage of undergrowth plant layer were significantly higher in thinned site than in unthinned site.Moreover,higher soil fertility as well as lower amounts of runoff and groundwater were found in thinned site.It was suggested that thinning could improve the structure of forest,leading to restoring the effluent(runoff and groundwater) pH to the normal value.
关键词:
broadleaved forest;carbon;coniferous forest;soil temperature;soil water content
摘要:
The flux of carbon dioxide (CO2) from soil surface presents an important component of carbon (C) cycle in terrestrial ecosystems and is controlled by a number of biotic and abiotic factors. In order to better understand characteristics of soil CO2 flux (FCO2) in subtropical forests, soil FCO2 rates were quantified in five adjacent forest types (camphor tree forest, Masson pine forest, mixed camphor tree and Masson pine forest, Chinese sweet gum forest, and slash pine forest) at the Tianjiling National Park in Changsha, Hunan Province, in subtropical China, from January to December 2010. The influences of soil temperature (Tsoil), volumetric soil water content (θsoil), soil pH, soil organic carbon (SOC) and soil C/nitrogen (N) ratio on soil FCO2 rates were also investigated. The annual mean soil FCO2 rate varied with the forest types. The soil FCO2 rate was the highest in the camphor tree forest (3.53 ± 0.51 μmol m−2 s−1), followed by, in order, the mixed, Masson pine, Chinese sweet gum, and slash pine forests (1.53 ± 0.25 μmol m−2 s1). Soil FCO2 rates from the five forest types followed a similar seasonal pattern with the maximum values occurring in summer (July and August) and the minimum values during winter (December and January). Soil FCO2 rates were correlated to Tsoil and θsoil, but the relationships were only significant for Tsoil. No correlations were found between soil FCO2 rates and other selected soil properties, such as soil pH, SOC, and C/N ratio, in the examined forest types. Our results indicated that soil FCO2 rates were much higher in the evergreen broadleaved forest than coniferous forest under the same microclimatic environment in the study region.
摘要:
Secondary evergreen broadleaved forests are precious remnants for biodiversity conservation and templates for sustainable management of natural forests in subtropical China. Floristic composition, size structure, and spatial pattern of dominant tree species have been investigated for a subtropical secondary evergreen broadleaved forest in the Huitong Yingzuijie National Forest Reserve, Hunan, China. The location of all trees greater than 4 cm in diameter at breast height (DBH) were mapped within a 0.96-ha plot in which species, DBH, and total tree height were recorded. Ripley’s K(t) function was used to analyze spatial patterns and associations. The secondary forest consisted of 74 tree species and 1,596 stems per hectare. A reverse-J shaped DBH classes distribution was observed for all stems and trees of later seral species whereas trees of earlier successional species were distributed irregularly. Significant aggregated spatial patterns were observed for all trees within the forest and for conspecific trees of each dominant species. This result, and a repulsive spatial pattern for interspecific trees of Choerospondias axillaries and Cyclobalanopsis glauca against other dominant tree species, support segregation hypothesis. Contributions of seed dispersal, topographic heterogeneity, and competition to spatial patterns of conspecific trees vary depending on tree species. Attractive spatial pattern among interspecific trees of Liquidambar fortunei, Liquidambar formosana, and Pinus massoniana reflects stochastic colonization of pioneer tree species and a facilitation relationship. Although deciduous species are long-lived and persist over long successional processes, they will eventually be replaced by late seral evergreen species within the secondary forest if no disturbance events occur.
摘要:
Climate change is expected to cause the alteration of litter production in forests, which may result in substantial changes in soil CO2 efflux (FCO2) process as litter represents a major pathway of carbon from vegetation to the soils. In this study, we conducted an aboveground litter manipulation experiment to examine the influence of litter addition and exclusion on soil FCO2 in Camphor tree, Masson pine, and mixed Camphor tree and Masson pine forests in central south China. Litter input manipulation included three treatments: non-litter input (litter exclusion), double litter input (litter addition), and natural litter input (control). On average, litter exclusion significantly reduced soil FCO2 rate by approximately 39%, 24% and 22% in Camphor tree forests, the Mixed forests, and Masson pine forests, respectively. On a yearly basis, double litter addition significantly increased soil CO2 by 12% in the Mixed forests (P=0.02) but not in both Camphor tree and Masson pine forests (P>0.05), when compared with their corresponding control treatments. However, litter addition increased soil FCO2 rates in the months of June-August in Camphor tree and Masson pine forests, coinciding with high soil temperature of summer conditions. Litter exclusion reduced soil FCO2 more than litter addition increased it in the study sites. Responses of soil respiration to litter input treatments varied with forest types. Litter input treatments did not alter the seasonal patterns of soil temperature and soil water content. Our results indicated that changes in aboveground litter as a result of global climate change and/or forest management have a great potential to alter soil respiration and soil carbon balance in forest ecosystems.