风电场带来的水土流失、生态环境破坏等问题广受关注.文章以华南典型地区风电场为例,通过样品采集和土壤性质分析,研究风电场对周边土壤物理性质的影响.结果 表明,风电场对周边土壤粒级组成、容重、持水量、孔隙度等均产生了不同程度的影响.具体如下:对比在建场地,2012年建设场地周边苦竹Pleioblastus amarus林、阔叶林土壤粒级组成变化相对较小,容重显著升高(P＜0.05)、持水量显著降低(P＜0.05)、孔隙度显著减小(P＜0.05).其中阔叶林土壤粒级组成距离风电场地越近,变化越剧烈.多因素方差分析结果显示,除粉粒含量外的土壤物理性质受到林分类型、距离、建设时间三者主效应及其交互作用的综合影响.因此,在风电场建设和运营中,应尽可能减少对土壤性质的破坏,避免造成水土流失.

为探讨银叶树幼苗光合作用和叶绿素荧光在不同干旱胁迫下的响应和适应能力,进一步揭示银叶树的抗旱机制,以1.5年生银叶树幼苗为研究对象,采用盆栽控水试验,设置对照(CK)、轻度干旱(LS)、中度干旱(MS)、重度干旱(SS)4个处理,测定银叶树幼苗的生长指标、相对叶绿素含量(SPAD值)、光合生理指标及叶绿素荧光参数,分析其变化规律.结果表明,与CK相比,LS处理对银叶树幼苗生长、光合生理特征及叶绿素荧光参数均无显著影响;MS和SS处理均显著降低了银叶树幼苗的生长量、SPAD值、个体叶片数量、最大净光合速率(Pn,max)、表观量子效率(AQY)、光饱和点(LSP)、实际光量子效率(ΦPSⅡ)和电子传递速率(ETR)(P<0.05),且在SS处理下各指标降低幅度更大;光补偿点(LCP)和非光化学猝灭系数(NPQ)两者则在历经MS、SS处理时显著升高(P<0.05);银叶树暗呼吸速率(Rd)、初始荧光(F0)及最大光化学效率(Fv/Fm)在不同处理下差异不显著.银叶树叶片通过调节光合效能来适应干旱逆境,LS和MS处理对银叶树幼苗的正常生长影响较小,表现出一定的适应性,在SS处理下,银叶树幼苗正常生理代谢受到较严重的影响.

为探索深圳市盐田区森林群落优势种生态位特征,分析优势种群对于环境资源的利用状况,讨论种群间的竞争与共存机制,在野外样地调查的基础上,采用生态位宽度和生态位重叠指标对群落乔木层、灌木层的优势种生态位进行分析与讨论.结果 表明:Levins和Shannon生态位宽度指数排序基本一致,但是与重要值排序并不相同.乔木层中生态位宽度较大的为变叶榕、山油柑和鹅掌柴,木荷和罗浮杜鹃最小,灌木层中狗骨柴、鹅掌柴和毛冬青较大,吊钟花和老鼠矢最小.生态位宽度较大的种对生态位重叠较大,但并不完全一致,如乔木层中的木荷与台湾相思,生态位宽度均较小,生态位重叠值达到0.9.乔木层、灌木层生态位重叠平均值分别为0.40和0.32,大多数种对的重叠值在0.5以下,说明群落中主要的优势种竞争并不激烈,群落比较稳定.

以深圳市铁岗-石岩市级湿地自然保护区4个典型次生林固定样地为研究对象,对其物种多样性进行调查,用常规分析方法测定土壤的主要化学性质.研究结果显示:(1)调查样地中共有39科67属89种植物,以海南蒲桃(Syzygium hainanense)、阴香(Cinnamomum burmannii)、木荷(Schima superba)和樟(Cinnamomum camphora)等为主要数量优势种;(2)不同样地物种丰富度指数和Shannnon-Wiener多样性指数排序分别为乔木层>灌木层>草本层和灌木层>乔木层>草本层,乔木层Simpson优势度指数高于灌木层和草本层;灌木层Pielou均匀度指数高于乔木层和草本层;(3)土壤pH值为4.28～4.51,EC为0.031～0.062 ms/cm,有机质和全氮含量分别为12.37～39.56 g/kg和0.50～1.47 g/kg,全磷含量为0.35～0.39 g/kg,全钾含量为14.63～37.17 g/kg,碱解氮含量为39.19～140.36 mg/kg,有效磷含量为0.94～8.90 mg/kg,速效钾含量为35.15～97.03 mg/kg;(4)4个样地物种多样性指数和土壤化学性质之间不存显著相关关系.研究结果显示,土壤氮、磷、钾含量是影响铁岗—石岩自然保护区植被分布的主要因素.

The carbon sequestration capacity of the forest ecosystem normally increases overage due to the carbon dynamic in below canopy and soil. The carbon dynamic is reflective of the forest characteristics and their interactions with climate, topographic, and soil conditions. In this study, we measured the carbon content and carbon density of canopy, shrub, understory vegetation, litter, and soil, and assessed carbon dynamics in three forest ecosystems (Cunninghamia lanceolate, Pinus massoniana, and Evergreen broad-leaved forests) with a combination of data from Fujian Provincial forest resource inventory. This study showed that the carbon content of the canopy layers increased over time, and the carbon content of the topsoil (0–30 cm) in the young forests was significantly higher than that in other age groups in Cunninghamia lanceolata forest and Pinus massoniana forest. Due to the carbon differences in the soil layer, the carbon stocks of the C. lanceolata forest and the P. massoniana forest declined from 1996 to 2007, but the carbon stocks of Evergreen broad-leaved forest increased. Besides, using the traditional carbon content coefficient (0.5) might underestimate the carbon sequestration potential of these forest ecosystems, especially for the mature forests. The coniferous forests displayed a short-term reduction in the carbon stocks of ecosystems between 10 and 20 years after afforestation, and the decline cannot be ignored in the carbon budget.

为明确大气CO 2 浓度升高对施盐处理下银叶树光合特性的影响,利用LI 6800便携式光合测定仪测定施盐处理60 d后银叶树幼苗叶片在不同CO 2 浓度（400、600和800μmol/mol）下对光的响应曲线以及CO 2 响应曲线。结果表明:1)随着CO 2 浓度的升高,银叶树幼苗叶片净光合速率（P n ）、最大净光合速率(P nmax )、表观量子利用效率（AQY）、光饱和点（LSP）、暗呼吸速率（R d ）、水分利用效率（WUE）和胞间CO 2 浓度（C i ）均呈上升趋势,而光补偿点（LCP）、蒸腾速率（T r ）和气孔导度（G s ）则呈下降趋势;2)同一CO 2 浓度下,施盐处理下银叶树幼苗叶片P n 、P nmax 、AQY、LSP、LCP、R d 、T r 和G s 均低于对照处理,而WUE和C i 则差异不大;3)随着光合有效辐射（PAR）的增加,银叶树幼苗叶片T r 和G s 呈增加的趋势,WUE先增加后缓慢减小,C i 则先直线下降,之后达到稳定状态;4)施盐处理下银叶树幼苗叶片最大羧化速率(V cmax )、最大电子传递速率(J max )、磷酸丙糖利用效率（TPU）、P nmax 、初始羧化效率（CE）和光呼吸速率（R P ）均低于对照处理,而CO 2 饱和点(C isat )和CO 2 补偿点（Γ）则更高;5)随着CO 2 浓度的增加,银叶树幼苗叶片T r 和G s 大致呈下降的趋势,WUE和C i 则呈直线增加的趋势。本研究结果说明CO 2 浓度的增加对银叶树幼苗的生长有促进作用,而施盐处理则抑制其生长。

为了解坝光湿地园水塘区生态修复效果,将14个水塘划分参照区和修复区,分别对两区植被及生境修复效果进行野外调查.调查发现坝光湿地园水塘区植物共有68种,隶属于23科56属.多数水塘水面与岸带植被以草本植物为主,植被种类较多但覆盖度不高,人为干扰痕迹明显.与参照区相比,修复区水塘植被多样性指数较高,均匀度指数较低,水质状况和土壤环境有所改善但统计不显著.生境因子中,土壤pH和水中NO3--N两个指标属于普适性变量,会促进岸带植被的共同生长,而土壤OM和TN、水中EC和TP属于筛选性变量,对先锋植被生长的促进作用更为明显,会加剧岸带植被种间竞争.坝光湿地园水塘湿地虽处于修复初期,但已是较为完整的生态系统,建议今后以自然更新修复措施为主.

以种群生命表和生存力分析理论为基础,应用径级法及匀滑技术,编制深圳坝光古银叶树(Heritiera littoralis)种群特定时间生命表,绘制其死亡率曲线、消失率曲线、存活曲线和生存率函数曲线,同时分析种群数量动态变化.结果表明:(1)坝光银叶树种群以幼苗和幼树体数量居多,老龄体数量较少,表明现阶段银叶树整体为增长型种群,考虑来潜在干扰影响时种群仍处于稳定状态;(2)银叶树种群存活曲线趋于Deevey-Ⅲ型,死亡率和消失率均在第Ⅰ龄级和第Ⅲ龄级出现2峰值,曲线的变化趋势基本一致;(3)种群生存分析结果显示,生存率函数曲线呈单调上升趋势,累计死亡率函数曲线单调下降,且前期上升或下降的幅度高于后期,种群死亡密度函数曲线较为平缓,危险率函数从第Ⅲ到第Ⅻ龄级随龄级的增大不断增大,死亡密度和危险率函数在第Ⅱ龄级最大.

森林经营在增强二氧化碳吸收方面具有重要作用,在全球气候变化背景下,本文阐述了《联合国气候变化框架公约》中我国的履约目标,并评估了2005年和2010年广东省土地利用变化和林业领域的固碳量.结果显示广东省2005年森林生物量生长碳吸收合计总量为47.02×109 kg二氧化碳当量,乔木林固碳占总固碳量的88.87％,采伐消耗温室气体排放11.47×109 kg二氧化碳当量,采伐消耗温室气体排放二氧化碳当量占总排放量的76.12％.2010年固碳量增长11.68％,采伐消耗温室气体排放增加了19.85％.通过对比分析,探讨了广东省林业碳汇的提升潜力及方向.

Soil microbial communities play a vital role in soil carbon and carbon sequestration in forest ecosystems.In this study, soils were sampled in Tianbaoyan National Nature Reserve in southeastern China from four Nothotsuga longibracteata forests, including a pure N. longibracteata forest (NF), N. longibracteata + hardwood mixed forest (NHF), N. longibracteata + Rhododendron simiarum mixed forest (NRF), and N. longibracteata + Phyllostachys pubescens mixed forest (NPF).Our objective was to precisely quantify soil physicochemical properties, microbial biomass, microbial communities, and to evaluate their interrelationships.We used biochemical measurements, a fumigation-extraction method, and phospholipid fatty acid (PLFA) analysis method to show that -except for pH and soil bulk density (SBD) -soil physicochemical properties differed markedly among the forest types.Microbial biomass carbon (MBC) and nitrogen (MBN) were highest in NHF soils, while the ratio of microbial biomass carbon to nitrogen (MBC:MBN) was highest in NRF and NPF soils.Moreover, the microbial communities of the four forest types exhibited distinct profiles: the highest total PLFA content and content of Grampositive bacteria (Gram(+)), Gram-negative bacteria(Gram(-)), and fungi were found in NRF.Additionally, NHF soil exhibited the highest actinomycetes content, while the highest protozoal content was found in NF soil.The analysis of individual PLFAs using principal component analysis (PCA) demonstrated a clear association of distinct soil PFLA characteristics for each forest type.In conclusion, the soil microbial community structure can be significantly influenced by changes in soil organic carbon (SOC) and MBN.Comparing soil microbial properties in different N. longibracteata forests can help us understand the influence of forest types on the structure of microbiota within a system.

The evaluation of ecosystem health is a hotspot in macro-ecology and ecosystem management. The objective of this paper is to introduce an ecosystem health assessment framework that combines ecosystem service concepts and indicators. We analyzed ecological services on Dongshan Island for regulating heavy rainfall by explicitly addressing the spatial distribution of ecosystem service demand and supply. An index system was then developed for both the areas that provide the ecological service and those that benefit from it. These areas are linked by small watersheds that were extracted using the hydrological analysis function in ArcGIS 10.2. Weights of the indicators were assigned and calculated based on principal component analysis. Finally, at the small watershed scale, the forested area and "other" land area ratios were weighted to assess the overall health of the areas that provide and benefit from this ecological service. The results revealed that the forest health conditions in the northwestern and northern parts of the island were weak, especially in the vicinity of the county seat. The analysis indicated that forested areas in the regions were relatively small, and the functional ecological service related to the redistribution of rainfall provided by these forested areas was minimal. The health states of areas benefiting from this ecological service generally appeared problematic. Areas benefiting from the service were characterized by dense populations, intense urbanization, and high risk of rain-related disaster. Moreover, only small and scattered forests were observed in the urban areas and towns on Dongshan Island. These urbanized areas rarely support large forest patches, and they fail to provide adequate green corridors or significant green space. This forest condition in urban areas cannot provide commendably protective functionality to mitigate heavy rain disasters. Therefore, to improve the ecological health of Dongshan Island, a system of green areas within urban landscapes must be planned and developed.

为科学评估湛江红树林国家级自然保护区湿地生态系统最终服务价值,综合运用生态学和经济学方法,对2013年湛江红树林国家级自然保护区高桥和营仔小区湿地生态系统的供给、调节和文化3类10项最终生态服务进行评估.结果表明,2013年湛江红树林国家级自然保护区湿地生态系统总服务价值为191.95×106元.其中,海产品供给、气候调节和水质净化是湛江红树林国家级自然保护区湿地生态系统的3大核心服务功能,三者占服务总价值的73.17％.调节服务是其主要的服务类型,占总服务价值的55.99％.其中,固碳、大气组分调节和消浪护岸等调节服务功能较弱,仅占总服务价值的7.37％.该区湿地生态系统的单位服务价值为4.26元·m-2·a-1,低于同纬度带内的红树林等自然生态系统,加强湿地保护与野外长期定位监测,并结合新的评估方法与研究手段,或可提高湛江红树林湿地服务功能及价值.

Five different forest types (pure Cunninghamia lanceolata forest, pure Castanopsis hystrix forest, 1 : 1, 1 : 2, 1 : 3 Cun. lanceolata and Cas.hystrix mixed forest) were selected to investigate soil fertility at 5 different soil layers(0-10 cm,10-20 cm, 20-40 cm,40-60 cm and 60-100 cm) in the south subtropics of China.Soil fertility of these forests was assessed by principal component analysis and fuzzy mathematical evaluation method. The results were as follows: pH value ranged from 3.98-4.65 and showed an increase trend with the soil layer going deep. Total potassium content increased, with the increase of soil depth, while soil organic matter,total nitrogen,hydrolyzable nitrogen,available phosphate and available potassium decreased. The differences of soil chemical properties among different forest types were not significant.Pearson correlation analysis indicated that there were significant correlation among soil fertility factors. The results of principal component analysis and fuzzy evaluation method both suggested that soil fertility level decrease with the increase of soil depth. The soil fertility in pure Cas. hystrix forest was relatively higher, while in pure Cun. lanceolata forest was lower than that in other forest types.

Using space method instead of time, and combined with variance analysis, multiple comparison and Pearson related analysis, differential analysis in soil physicochemical properties, enzyme activity and their correlations were made in different stages of community types ( Kandelia candel red wood community, Kandelia candel red wood-Spartina alterniflora symbiosis community, Spartina alterniflora community and bare beach) invaded by Spartina alterniflora in eastern Fujian coastal wetland, trying to explain the soil science mechanism of Spartina alterniflora invasion. Results showed that:Spartina alterniflora’ s invasion increased soil density, decreased the pH value of soil, moisture content, and reduced the concentrations of soil organic carbon, organic matter, total nitrogen and total phosphorus. It also increased the soil&nbsp;enzyme activities of invertase, alkaline phosphatase and catalase, and decreased urease activity. Correlation analysis showed that, there was a close relationship between soil enzyme activity and soil physicochemical factors. Among them, sucrose enzyme was very significantly positively correlated with total nitrogen, total P and water content, was very significantly negatively correlated with pH value and soil density; urea enzyme was significantly positively correlated with water content, was significantly negatively correlated with soil density; alkaline phosphate enzyme was significantly positively correlated with total P and water content, was significantly negatively correlated with soil density;hydrogen peroxide enzyme had no correlations with physicochemical factors. This study provides theoretical basis for the treatment of Spartina alterniflora.

Fallen logs are essential structural and functional components of the forest ecosystem,but the decomposition of fallen logs is very slow.Until recently,there has been a lack of knowledge about the effect of fallen logs on soil biological properties.The objective of this study was to determine the temporal and spatial distribution patterns of soil enzyme activities under fallen logs and how they were influenced by environmental variables during log decomposition in the Tianbaoyan National Nature Reserve.A multivariate analysis was performed to investigate the connections between environmental variables and soil enzyme activity.This study took place in Tsuga longibracteata forest,which is in the Tianbaoyan National Nature Reserve,Fujian Province,China.In the forest,the coefficient of variance for soil enzyme activity shows a high degree of variation.The cellulase spatial distribution pattern showed the greatest change,whereas changes to protease,urease,and invertase activities were lower.The increase in decay class caused a decreasing trend in protease and urease activities,but cellulase activity increased.Soil enzyme activities were positively associated with soil organic carbon (SOC)and total nitrogen (TN).Among the environmental variables,soil chemical properties had the greatest effect on soil enzyme activities,which suggested that soil chemical properties should be taken into account when assessing the effect of fallen logs on soil enzyme activity.These activities were positively associated with TN,SOC,elevation,and slope.We identified the interactive relationship between fallen logs and soil enzyme activities and showed that the presence of fallen logs plays an important role in forest C recycling.

Based on cumulation cultivation,filter paper disintegrating,carboxymethyl cellulose (CMC) enzyme activity determination,strains with great capacity in cellulose decomposition were isolated to analyze the CMC enzyme activities of fallen logs in the Tsuga longibracteata W.C.Cheng forest of Tianbaoyan National Nature Reserve.18S rRNA sequencing analysis of the selected stains was carried out and identified as Penicillium spinulosum which the CMC enzyme activity was 243.73 U·mL-1.The P.spinulosum strain had the ability in cellulose degradation in the T.longibracteata forest of Tianbaoyan National Nature Reserve.

Based on Landsat remote sensing images of Xiamen City in 1995, 2005 and 2015, atmospheric correction was performed with the second simulation of the satellite signal in the solar spectrum ( 6S) model and the surface reflectivity was calculated. With the support of ENVI 5.2, normalized difference vegetation index ( NDVI) and fractional vegetation cover ( FVC) of 3 years were obtained, and the average FVC of Xiamen City in 1995, 2005 and 2015 were 0. 35, 0. 22 and 0. 31 respectively. The land use information was extracted by the maximum likelihood method, the FVC and land use classification map were overlaid by ArcGIS 10.1 software, and the response of vegetation coverage to land use change was obtained from 1995 to 2015 in Xiamen. The results showed that FVC in Xiamen decreased by 37% from 1995 to 2005 and increased by 29% from 2005 to 2015. The average FVC have an increase of 17% in water land, 35% in construction land, 22% in arable land, but 27% decrease in forestland of Xiamen City from 1995 to 2015. And thus suggestions for Xiamen City development and ecological construction was provided.

Downed logs are important carbon and nutrient pools in forest ecosystems. Monitoring of dynamics of microbial biomass and dissolved organic carbon/nitrogen are of great significance to in-depth understanding of the mechanism of downed log decomposition. Microbial biomass carbon ( MBC) , microbial biomass nitrogen ( MBN) , dissolved organic car-bon (DOC), dissolved organic nitrogen (DON), and ratio of carbon to nitrogen in bark, sapwood and heartwood of downed T. longibracteata logs various in decaying degree from Grade I to Grade V in the Tianbaoyan National Nature Re-serve, Fujian Province of China was analyzed. Results show:(1) The downed logs varied from 7. 41% to 63. 27% in wa-ter content, and were 311. 66-564. 87, 2. 34-5. 82 and 0. 09-0. 35 g·kg-1, respectively, in organic carbon, TN and TP; ( 2) In terms of MBC and MBN, the three components of the highly decayed downed logs ( GradesⅣandⅤin deca-ying degree) displayed an decreasing order of heartwood > sapwood > bark; ( 3) Sapwood and heartwood was higher in DOC than bark of the logs the same in decaying degree, while sapwood was higher in DON than bark and heartwood, ex-cept for logs of Grade Ⅱ in decaying degree;( 4) Microbial biomass C/N ratio in heartwood varied sharply between logs different in decaying degree, whereas DOC/DON ratio in sapwood did;(5) Position in the log, decaying degree and their interactions all had remarkable impacts on MBC, MBN, DOC, DON, MBC/MBN and DOC/DON ( P<0. 01 ); and (6) MBC, DOC and DON were extremely and positively related to water content in the log (P<0. 01), whereas NBC/MBN and DOC/DON negatively to TP in the log ( P<0. 05) . To sum up, during the downed log decaying or decomposing process, water content is the major factor affecting MBC, MBN, DOC and DON in decaying downed logs.

The rhizosphere, distinct from bulk soil, is defined as the volume of soil around living roots and influenced by root activities. We investigated protease, invertase, cellulase, urease, and acid phosphatase activities in rhizosphere and bulk soils of six Nothotsuga longibracteata forest communities within Tianbaoyan National Nature Reserve, including N. longibracteata + either Phyllostachys pubescens, Schima superba, Rhododendron simiarum, Cunninghamia lanceolata, or Cyclobalanopsis glauca, and N. longibracteata pure forest. Rhizosphere soils possessed higher protease, invertase, cellulase, urease, and acid phosphatase activities than bulk soils. The highest invertase, urease, and acid phosphatase activities were observed in rhizosphere samples of N. longibracteata + S. superba. Protease was highest in the N. longibracteata + R. simiarum rhizosphere, while cellulase was highest in the pure N. longibracteata forest rhizosphere. All samples exhibited obvious rhizosphere effects on enzyme activities with a significant linear correlation between acid phosphatase and cellulase activities (p < 0.05) in rhizosphere soils and between protease and acid phosphatase activities (p < 0.05) in bulk soils. A principal component analysis, correlating 13 soil chemical properties indices relevant to enzyme activities, showed that protease, invertase, acid phosphatase, total N, and cellulase were the most important variables impacting rhizosphere soil quality.

To determine the soil fertility of pure Castanopsis hystrix forest, C. hystrix –Pinus elliottii mixed forest and pure P. elliottii forest in the south subtropical area, soil pH values, organic matter, total nitrogen, total phosphate, total potassium, hydrolysable nitrogen, available phosphate, and available potassium was chosen as evaluation indicators. Soil fertility was analyzed by grey correlative degree analysis, and ranked by correlation degrees comprehensively. The results indicated that the contents of organic matter, total nitrogen, hydrolysable nitrogen, available phosphate and available potassium had decline tendency with the increase of soil layer depth, while pH value, the content of total phosphate and total potassium have no difference in five different soil layers. The grey correlative degree analysis shows the best soil fertility was observed in pure C. hystrix forest, followedby C. hystrix –P. elliottii mixed forest, and pure P.elliottii forest has poorest soil fertility status.