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1.
Maryam MOSLEHI JOUYBARI 《干旱区科学》2022,14(10):1099-1108
Biological invasions can alter soil properties within the range of their introduced, leading to impacts on ecosystem services, ecosystem functions, and biodiversity. To better understand the impacts of biological invasions on soil, we compared topsoil physiochemical properties at sites with invasive alien tree species (Prosopis juliflora), native tree species (Prosopis cineraria, Acacia tortilis, and Acacia ehrenbergiana), and mixed tree species in Hormozgan Province of Iran in May 2018. In this study, we collected 40 soil samples at a depth of 10 cm under single tree species, including P. juliflora, P. cineraria, A. tortilis, and A. ehrenbergiana, as well as under mixed tree species. The results showed that organic matter, moisture, potassium, calcium, nitrogen, and magnesium in topsoil at sites with A. tortilis and A. ehrenbergiana growing in combination with P. cineraria were higher than that at sites where P. juliflora was present (P<0.05). Sodium at sites with A. tortilis and A. ehrenbergiana growing in combination with P. cineraria and P. juliflora was lower as compared to that at sites with just A. tortilis and A. ehrenbergiana. Electrical conductivity was lower at sites with A. tortilis and A. ehrenbergiana growing in combination with P. cineraria, and it was higher at sites with mixed Acacia and P. juliflora trees. Based on the generally more positive effect of native Acacia and P. cineraria on topsoil physiochemical properties as compared to the P. julifora, afforestation with native tree species is preferable for soil restoration. In addition, due to the negative effects of P. julifora on soil properties, P. julifora spread should be better managed. 相似文献
2.
BAZGIR Masoud 《干旱区科学》2020,12(4):640-652
Plants are an important component in many natural ecosystems. They influence soil properties, especially in arid ecosystems. The selection of plant species based on their adaptations to site conditions is essential for rehabilitation of degraded sites and other construction sites such as check-dams. Other factors to be considered in species selection include their effects on soil properties and their abilities to meet other management objectives. The purpose of this study was to assess the effects of native (Populus euphratica Oliv. and Tamarix ramosissima Ledeb.) and introduced (Eucalyptus camaldulensis Dehnh. and Prosopis juliflora (Swartz) DC.) woody species on soil properties and carbon sequestration (CS) in an arid region of Iran. Soil sampling was collected at three soil depths (0-10, 10-20 and 20-30 cm) at the sites located under each woody species canopy and in an open area in 2017. Soil physical-chemical property was analyzed in the laboratory. The presence of a woody species changed soil characteristics and soil CS, compared with the open area. For example, the presence of a woody species caused a decrease in soil bulk density, of which the lowest value was observed under E. camaldulensis (1.38 g/cm3) compared with the open area (1.59 g/cm3). Also, all woody species significantly increased the contents of soil organic matter and total nitrogen, and introduced species had more significant effect than native species. The results showed that CS significantly increased under the canopy of all woody species in a decreasing order of P. euphratica (9.08 t/hm2)>E. camaldulensis (8.37 t/hm2)>P. juliflora (5.20 t/hm2)>T. ramosissima (2.93 t/hm2)>open area (1.33 t/hm2), thus demonstrating the positive effect of a woody species on CS. Although the plantation of non-native species had some positive effects on soil properties, we recommend increasing species diversity in plantations of native and introduced woody species to provide more diversity for the increased ecosystem services, resilience, health and long-term productivity. 相似文献
3.
Ali MAHDAVI 《干旱区科学》2020,12(5):766-774
Persian oak (Quercus brantii var. persica) is a dominant tree species of Zagros forests in a semi-arid area, western Iran. However, the capacity of biomass and carbon stocks of these forests is not well studied. We selected three types of oak, i.e., seed-originated oak, coppice oak and mixed (seed-originated and coppice) oak of Zagros forests in Dalab valley, Ilam Province, Iran to survey the capacity of biomass and carbon stocks in 2018. Thirty plots with an area of 1000 m2 were systematically and randomly assigned to each type of oak. Quantitative characteristics of trees, such as diameter at breast height (DBH), height, crown diameter and the number of sprouts in each plot were measured. Then, aboveground biomass (AGB), belowground biomass (BGB), aboveground carbon stock (AGCS) and belowground carbon stock (BGCS) of each tree in plots were calculated using allometric equations. The litterfall biomass (LFB) and litterfall carbon stock (LFCS) were measured in a quadrat with 1 m×1 m in each plot. One-way analysis of variance and Duncan's test were performed to detect the differences in biomass and carbon stocks among three types of oak. Results showed that AGB, BGB and BGCS were significantly different among three types of oak. The highest values of AGB, AGCS, BGB and BGCS in seed-originated oak were 76,043.25, 14,725.55, 36,737.79 and 7362.77 kg/hm2, respectively. Also, the highest values of LFB and LFCS in seed-originated oak were 3298.33 and 1520.48 kg/hm2, respectively, which were significantly higher than those of the other two types of oak. The results imply the significant role of seed-originated oak for the regeneration of Zagros forests. Further conservation strategy of seed-originated oak is an important step in the sustainable management of Zagros forests in Iran. 相似文献
4.
Yuanyuan LI 《干旱区科学》2019,11(4):608-622
Boreal forests are important carbon sinks and have tremendous potential to mitigate climate change. Aboveground biomass of Siberian larch (Larix sibirica Ledeb.) stands in the Altay Mountains, Northwest China was studied and allometric equations that are related to the biomass of aboveground components using diameter at breast height (DBH) or both DBH and height (H) as independent variables for L. sibirica trees were derived in this paper. A linear simultaneous equation system by using either DBH or both DBH and H (DBH&H) indices, was used to ensure additivity of the biomass of individual tree components, and was fitted for L. sibirica. Model performance was validated using the jackknifing test. Results indicate that the goodness-of-fit for the regressions was lowest for the needles (R2 ranging from 0.696 to 0.756), and highest for the stem wood (R2 ranging from 0.984 to 0.997) and the aggregated biomass components (R2 ranging from 0.994 to 0.995). The coefficient of determination for each component was only marginally improved in terms of model fit and performance in the biomass equations that used DBH&H as the independent variables compared to that used DBH as the independent variable, and needles yielded an even worse fit. Stem biomass accounted for the largest proportion (87%) of the aboveground biomass. Based on the additive equations that used DBH as the single predicitor in this study, the mean aboveground carbon stock density and the carbon storage values of L. sibirica forests were 74.07 Mg C/hm2 and 30.69 Tg C, respectively, in the Altay Mountains. Empirical comparisons of published equations for the same species growing in the Altay Mountains of Mongolia were also presented. The mean aboveground carbon stock density estimated for L. sibirica forests was higher in the Chinese Altay Mountains than in the Mongolian Altay Mountains (66.00 Mg C/hm2). 相似文献
5.
Geoffrey M NDEGWA 《干旱区科学》2016,8(4):618-631
Provision of woodfuel is an important ecosystem service of dry forests and woodlands.However,charcoal production through selective logging of preferred hardwood species has the potential to alter the physiognomic composition of the residual or re-growth woodlands and may lead to their deterioration and degradation.This study,conducted through forest inventory in Mutomo District in Kenya,assessed the impact of charcoal production on unprotected dry woodlands in terms of tree density,targeted species basal area,species richness,evenness and Shannon diversity.The parameters of the disturbed woodlands were evaluated for significant differences with those of the neighbouring protected Tsavo East National Park,which served as a reference for an ecologically undisturbed ecosystem.By evaluating a consequence of tree harvesting for charcoal production,this study confirmed the overall significant differences between the protected and unprotected woodlands in all the tested parameters.To confirm if the differences in the land-covers of the woodlands had any influence on their degradation,all mentioned parameters were compared between the four differentiated classes and their respective control plots in the protected areas.At the "land-cover level",the statistically significant difference in the basal area of tree species preferred for charcoal production between the protected and unprotected open trees confirms that the class with a high density of large mature trees is the prime target of charcoal producers.In addition,there seems to be a general trend of lower values of tree species richness,evenness and Shannon diversity for the unprotected woodlands subjected to charcoal production.On the other hand,the disturbed woodlands display the potential to recover through their comparably high saplings density.The findings make an important contribution to the discourse on the impact of charcoal production in dry woodlands,a topic that is highly controversial among researchers. 相似文献
6.
山西西南部黄土丘陵沟壑区主要森林生态系统健康评价 总被引：1，自引：0，他引：1
对山西吉县蔡家川流域植被恢复区主要林分进行了实地调查,根据乔木生物量、有机碳、病虫害、灌木丰富度、草本丰富度、土壤有机质等状况6个方面的数据,建立了蔡家川流域的森林健康评价指标和评价标准,并以此评定了14个林分样地的生态系统健康状况,从而对此地区的森林健康做一个整体判断,评价结果表明:研究区森林总体上处于健康与良好健康... 相似文献
7.
Katja KRAMP Thomas SCHMITT Petra LANG Michael JESCHKE Philipp SCHFER Dustin KULANEK ZHANG Ximing YU Ruide Frank M THOMAS 《干旱区科学》2018,10(5):750-766
Many riparian(Tugai) forests growing along rivers in arid and hyper-arid regions of Central Asia are dominated by the Euphrates poplar(Populus euphratica). Besides generative reproduction, which is only possible upon flooding events and at a distance to the groundwater of less than 2 m, this phreatophytic tree species also reproduces vegetatively by forming clones that can cover land surface areas of several hectares. Along a gradient of groundwater distances, we investigated whether the fraction of clones in P. euphratica stands(1) increases with increasing distance to the water table;(2) is higher if supplied with water via river cut-offs; and(3) approaches 100% at a short distance to the groundwater, but at high salt concentrations in the upper soil layers, which would prevent germination and establishment of seedlings. AFLP(Amplified Fragment Length Polymorphism) analyses were conducted on leaf samples taken from mature P. euphratica trees growing at the fringes of the Taklimakan Desert in stands with different distances(2–12 m) to the groundwater at two plots at the middle and the lower reaches of the Tarim River and in a stand close to Ebinur Lake, Xinjiang, China. Genetic diversity was large among plots, but considerably smaller within plots. We found the highest genetic diversity(caused by regeneration from seeds) at plots that have a short distance to the groundwater or are supplied with additional water. There was no significant relationship between groundwater distance and clonal fraction. All investigated trees at the saline Ebinur Lake site belonged to one single clone. Our results demonstrate that the genetic pattern of this widespread species is not easily predictable even over small distances as it is a result of a complex interplay of stand history and dispersal of propagules(pollen, seeds, and vegetative diaspores) by wind and water. In conservation and restoration schemes, P. euphratica stands with a high genetic diversity and stands that grow at short distances to the water table and are regularly subjected to flooding(which favors generative over clonal reproduction) should be prioritized. 相似文献
8.
青海湖流域沙柳河草甸群落结构与数量特征 总被引：1，自引：0，他引：1
沿青海湖流域沙柳河河岸,选取多个断面进行样方调查,分析沿沙柳河距河流入湖处不同距离、垂直河岸方向上草甸群落结构、地上生物量以及物种多样性的变化特征,并讨论影响群落结构变化的生境因子。结果表明：① 在所调查的样地中,有草本植物52种,隶属39属,13科。平均总盖度为70%,平均地上生物量为131 g•m-2。② 随着离湖距离的增加,Shannon-Wiener指数、物种丰富度、物种均匀度指数、地上生物量呈现先增加后略微减小的趋势,盖度的变化趋势是先增加后不变。土壤含水量和土壤含盐量、海拔等可能是影响植物群落空间分布差异的主要原因。③ Shannon-Wiener指数、物种丰富度与地上生物量呈现不明显的线性关系。 相似文献
9.
GOU Qianqian 《干旱区科学》2023,15(1):109-126
Soil erosion is a serious issue in the sandy-hilly region of Shanxi Province, Northwest China. There has been gradual improvement due to vegetation restoration, but soil microbial community characteristics in different vegetation plantation types have not been widely investigated. To address this, we analyzed soil bacterial and fungal community structures, diversity, and microbial and soil environmental factors in Caragana korshinskii Kom., Populus tomentosa Carr., Populus simonii Carr., Salix matsudana Koidz, and Pinus tabulaeformis Carr. forests. There were no significant differences in the dominant bacterial community compositions among the five forest types. The alpha diversity of the bacteria and fungi communities showed that ACE (abundance-based coverage estimator), Chao1, and Shannon indices in C. korshinskii forest were significantly higher than those in the other four forest types (P<0.05). Soil organic matter, total nitrogen, and urease had a greater impact on bacterial community composition, while total nitrogen, β-glucosidase, and urease had a greater impact on fungal community composition. The relative abundance of beneficial and pathogenic microorganisms was similar across all forest types. Based on microbial community composition, diversity, and soil fertility, we ranked the plantations from most to least suitable as follows: C. korshinskii, S. matsudana, P. tabulaeformis, P. tomentosa, and P. simonii. 相似文献
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通过对子长县退耕还林、植被恢复重建中出现的具体问题进行实地调查研究,并结合研究区自然环境条件和前人有关人工植被建设中的研究结果进行分析,以探讨黄土高原丘陵沟壑区植被恢复重建的技术体系.结果表明,在陕北黄土高原丘陵沟壑区退耕还林植被恢复建设中,应充分考虑当地降水条件并结合生态效益与经济效益,具体实施过程中要注意: (1) 依据当地原生态植被结构合理配置乔、灌、草,在以刺槐为主的乔木林内应适当搭配当地适生树种(杨、柳、山杏、榆、杜梨等);(2) 在沟谷及部分阴坡水分条件较好的地方种植耐旱乔木树种,在墚峁坡顶种植灌木和草本植物,半灌木和灌木种植在沟坡上部,坡度大的地方尽量不要人为干扰,自然封育恢复;(3) 秋季植树,初植乔木林密度不要超过2 300株/hm2,成林密度应控制在1 100株/hm2左右;(4) 建立苗圃,提高种苗质量,造林种苗尽量在本地解决,以提高植树成活率. 相似文献
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为探讨内蒙古罕山次生林区木质残体(WD)基础特征的地域差异性,文中以研究区年平均降水量由低到高的分布梯度,以赛罕乌拉、罕山、青山为实验地开展WD的基础特征研究。结果表明:罕山次生林区WD平均分布密度为(1336±53)株·hm-2,主要以干基折断倒木或枯立木形式存在;径级结构总体以中小径级(2.5cm-10cm)为主,分布规律呈倒"J"字型;密度和径级特征均随降水梯度的增加逐渐下降,赛罕乌拉主要以中大径级(>10cm)为主;分解等级除赛罕乌拉以Ⅲ、Ⅳ级为主外,总体处于Ⅱ、Ⅲ级,占同径级WD总数的82.15%-95.06%。WD的积累与森林大面积非正常死亡密切相关,在关注研究区WD对森林生态系统积极作用的同时,还应对火灾防控、病虫害防治、森林健康等经营管理方面的负面影响引起重视。 相似文献
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A research study of establishment techniques in plantations of Eucalyptus nitens (Deane et Maiden) Maiden and Eucalyptus regnans F Mueller was assessed for growth at age 12 years. Biomass of trees and woody weeds was determined in the 13th year to evaluate the long-term effect of herbicide treatment on plots established with optimum seedling tree and site preparation. Eucalyptus regnans produced only 60% of the biomass of E. nitens. Under-storey woody weed biomass under E. regnans comprised 18–30% of the total biomass compared with 6% for E. nitens plots. There was less total under-storey weed biomass under the herbicide-treated plots, but a similar weed leaf biomass. Under-storey weed leaf biomass contributed 14–40% of the total leaf biomass on the plots. Despite under-storey weed biomass being substantially greater on the no-herbicide plots sampled, this competition had not generally reduced growth of the trees compared with the herbicide-treated plots. Suitable site preparation, providing weed-free conditions at the time of planting, resulted in woody weed control adequate to establish seedlings and allow full growth without the use of herbicides, given suitable seedling material. Although pre-planting herbicide treatment was not necessary for optimum growth of E. nitens grown from bare-root transplants, it did improve growth of slower-growing planting stock. 相似文献
14.
Studies on the ecosystem service value(ESV)of gardens are critical for informing evidence-based land management practices based on an understanding of the local ecosystem.By analyzing equivalent value factors(EVFs),this paper evaluated the values of 11 ecosystem services of gardens in the Yellow River Basin of China in 2019.High-precision land use survey data were used to improve the accuracy of the land use classification,garden areas,and spatial distribution of the ESVs of gardens.The results showed that garden ecosystem generally had high ESVs,especially in terms of the ESV of food production,which is worthy of further research and application to the practice of land use planning and management.Specifically,the value of one standard EVF of ecosystem services in 2019 was 3587.04 CNY/(hm2·a),and the ESV of food production of gardens was much higher than that of croplands.Garden ecosystem provided an ESV of 1348.66×108CNY/a in the Yellow River Basin.The areas with the most concentrated ESVs of gardens were located in four regions:downstream in the Shandong-Henan zone along the Yellow River,mid-stream in the Shanxi-Shaanxi zone along the Yellow River,the Weihe River Basin,and upstream in the Qinghai-Gansu-Ningxia-Inner Mongolia zone along the Yellow River.The spatial correlation of the ESVs in the basin was significant(global spatial autocorrelation index Moran's I=0.464),which implied that the characteristics of high ESVs adjacent to high ESVs and low ESVs adjacent to low ESVs are prominent.In the Yellow River Basin,the contribution of the ESVs of gardens to the local environment and economy varied across regions.We also put forward some suggestions for promoting the construction of ecological civilization in the Yellow River Basin.The findings of this study provide important contributions to the research of ecosystem service evaluation in the Yellow River Basin. 相似文献
15.
M ZEBERIO Juan 《干旱区科学》2020,12(4):653-665
Degradation processes affect a vast area of arid and semi-arid lands around the world and damage the environment and people′s health. Degradation processes are driven by human productive activities that cause direct and indirect effects on natural resources, such as species extinction at regional scale, reduction and elimination of vegetation cover, soil erosion, etc. In this context, ecological rehabilitation is an important tool to recover key aspects of the degraded ecosystem. Rehabilitation trials rely on the use of native plant species with characteristics that allow them to obtain high survival and growth rates. The aim of this work was to assess the survival and growth of native woody species in degraded areas of northeastern Patagonia and relate them to plant functional traits and environmental variables. We observed high early and late survival rates, and growth rates in Prosopis flexuosa DC. var. depressa F.A. Roig and Schinus johnstonii F.A. Barkley, and low values in Condalia microphylla Cav. and Geoffroea decorticans (Gillies ex Hook. & Arn.) Burkart. Early survival rates were positively associated with specific leaf area (SLA) and precipitation, but negatively associated with wood density, the maximum mean temperature of the warmest month and the minimum mean temperature of the coldest month. Late survival rates were positively associated with SLA and soil organic matter, but negatively associated with plant height and precipitation. The temperature had a positive effect on late survival rates once the plants overcame the critical period of the first summer after they were transplanted to the field. Prosopis flexuosa and S. johnstonii were the most successful species in our study. This could be due to their functional traits that allow these species to acclimatize to the local environment. Further research should focus on C. microphylla and G. decorticans to determine how they relate to productive conditions, acclimation to environmental stress, auto-ecology and potential use in ecological rehabilitation trials. 相似文献
16.
AISHAN Tayierjiang HALIK Ü mü t Florian BETZ TIYIP Tashpolat DING Jianli NUERMAIMAITI Yiliyasijiang 《干旱区科学》2015,7(4):544-554
Understanding stand structure and height-diameter relationship of trees provides very useful information to establish appropriate countermeasures for sustainable management of endangered forests. Populus euphratica, a dominant tree species along the Tarim River watershed, plays an irreplaceable role in the sustainable development of regional ecology, economy and society. However, as the result of climate changes and human activities, the natural riparian ecosystems within the whole river basin were degraded enormously, particularly in the lower reaches of the river where about 320 km of the riparian forests were either highly degraded or dead. In this study, we presented one of the main criteria for the assessment of vitality of P. euphratica forests by estimating the defoliation level, and analyzed forest structure and determined the height-diameter(height means the height of a tree and diameter means the diameter at breast height(DBH) of a tree) relationship of trees in different vitality classes(i.e. healthy, good, medium, senesced, dying, dead and fallen). Trees classified as healthy and good accounted for approximately 40% of all sample trees, while slightly and highly degraded trees took up nearly 60% of total sample trees. The values of TH(tree height) and DBH ranged from 0–19 m and 0–125 cm, respectively. Trees more than 15 m in TH and 60 cm in DBH appeared sporadically. Trees in different vitality classes had different distribution patterns. Healthy trees were mainly composed more of relatively younger trees than of degraded tress. The height-diameter relationships differed greatly among tress in different vitality classes, with the coefficients ranging from 0.1653 to 0.6942. Correlation coefficients of TH and DBH in healthy and good trees were higher than those in trees of other vitality classes. The correlation between TH and DBH decreased with the decline of tree vitality. Our results suggested that it might be able to differentiate degraded P. euphratica trees from healthy trees by determining the height-diameter correlation coefficient, and the coefficient would be a new parameter for detecting degradation and assessing sustainable management of floodplain forests in arid regions. In addition, tree vitality should be taken into account to make an accurate height-diameter model for tree height prediction. 相似文献
17.
Emmanuel Amoah Boakye Dibi N’da Hyppolite Victor Rex Barnes Stefan Porembski 《Arid Land Research and Management》2017,31(2):219-233
Understanding the impacts of agricultural land use is desired for proper management of riparian forests buffers (RFs) in savannas. In this light, we analyzed the relationship between woody plant diversity and soil properties of RFs in farmlands (FAs) and protected areas (PAs) along Afram (Guinean zone) and Tankwidi (Sudanian zone) Rivers located within the Volta sub-basin of Ghana. ALOS-AVNIR imageries were used to map RFs to facilitate sampling of soil and woody vegetation (dbh ≥5?cm) using stratified randomized design (72 plots; size: 500?m2 each) for the analysis of soil physical and chemical properties and Shannon-Wiener plant species diversity. Although the fractions of sand, silt, and clay varied between the PAs and FAs, they were predominantly categorized as sandy loam. Along the Afram River, there were no significant differences in the concentrations and nutrient stocks of soil C, N, P, and K as well as the pH, moisture content, and bulk density between PA and FA. For the Tankwidi River, the concentrations and nutrient stocks of C and K significantly decreased from PA to FA while N, P, pH, bulk density, and moisture content were not different. Of the soil attributes measured C, N, P, pH, ground slope, and soil moisture had significant relationships with the diversity and density of the riparian woody plants. Controlling agricultural activities in riparian forests could preserve soil properties similar to that found in protected areas. 相似文献
18.
晋西刺槐人工林生长分化过程分析 总被引：1，自引：1，他引：0
提要：利用56株解析木,分析了不同密度、坡向、坡位刺槐林生长分化特征。研究表明：不同密度、坡向、坡位的林分生长量、速生期长短不一,导致了林木分化。分化过程主要表现在分级木的相互转换中。刺槐林以树高、胸径表述的转换率分别为：35．7％,21．4％。将坡向按转换率从高到低的排序为：阳坡、半阳坡、阴坡。不同坡向以树高、胸径表... 相似文献
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ZHOU Honghua 《干旱区科学》2019,11(6):866-879
Populus euphratica Oliv. is a unique woody tree that can be utilized for vegetation restoration in arid and semi-arid areas. The effects of saline water irrigation (0.00, 2.93, 8.78 and 17.55 g/L NaCl solutions) on water transport and water use efficiency (WUE) of P. euphratica saplings were researched for improving the survival of P. euphratica saplings and vegetation restoration in arid and semi-arid areas of Xinjiang, China in 2011. Results showed that hydraulic conductivity and vulnerability to cavitation of P. euphratica saplings were more sensitive in root xylem than in twig xylem when irrigation water salinity increased. Irrigation with saline water concentration less than 8.78 g/L did not affect the growth of P. euphratica saplings, under which they maintained normal water transport in twig xylem through adjustment of anatomical structure of vessels and kept higher WUE and photosynthesis in leaves through adjustment of stomata. However, irrigation with saline water concentration up to 17.55 g/L severely inhibited the photochemical process and WUE of P. euphratica saplings, resulting in severe water-deficit in leaves and a sharp reduction in water transport in xylem. Thus, it is feasible to irrigate P. euphratica forest by using saline groundwater for improving the survival of P. euphratica saplings and vegetation restoration in arid and semi-arid areas of Xinjiang, China. 相似文献