为探寻天宝岩自然保护区天然柳杉群落主要乔木种群的种间联结性,揭示柳杉群落的种间关系以及演替趋势,以天宝岩柳杉群落重要值排前15位的主要乔木种群为研究对象,运用方差比率法(RV)、χ2检验、联结系数(CA)、共同出现百分率(PC)和点相关系数(CPC),对其进行种间联结性分析测定与生态种组划分.结果表明:天宝岩柳杉群落15个主要乔木种群总体呈不显著负联结,种间联结相对松散,独立性较强.χ2检验结果显示,105个种对中,呈正联结的种对有46对,负联结种对有59对,正负联结比为0.78,其中不显著联结种对有75对,占总数的71.4％.CA、PC和CPC结果均表明各种群之间多呈不显著联结,有较大的随机性,对生境需求不一致,种对共同出现概率较低.根据种群聚类分析结果和种间联结性分析及生态习性,把柳杉群落15个主要种群划分为3个生态种组,同一组内树种具有相似的生态习性和资源需求,种对间相互依赖共存,多呈正联结,不同生态种组间树种多呈负联结.因此,在对柳杉天然林保护的同时应选取与其呈正相关性的物种作为柳杉天然群落更新的主要物种,增加群落多样性,同时降低人为干扰,促进群落趋于稳定.

In order to clarify the impact of different forest management modes on natural forest carbon storage,promote forests ' protection,development and sustained utilization of business district,the author used indirectly harvesting method to obtain the sample,and the content of carbon in plants was determined with the method of potassium dichromate colorimetric,the natural forest carbon storage was carried on the comparative analysis under 9 kinds of management modes.The result showed that:the combination of cutting patterns were more conducive to improve the forest tree trunks,branches and roots of carbon storage,but the carbon storage of leaves had little difference under a variety of operating modes.The distributions of the carbon storage for the natural forest stands was generally subjected to the tree layer>litter layer>herb layer>shrub layer,natural forest carbon storage was ready for the greatest in the combination of cutting patterns,and the conservation replanting mode was in the minimum,orientation training mode and thinning adjustment mode was in the medium.Forest carbon storage mainly concentrated in the tree layer,stands for each layer of the management mode were different,judging from the total amount of carbon storage,natural forest management mode selected combination of cutting patterns was more reasonable,more conducive to increase carbon storage of forest resource,promote to form the natural mixed forest which both were of high ecological and economic,push forward material cycle of forest ecosystem,promote the health of the ecological system and sustainable development.

Distribution and accumulation of Zn,Cd and Cu in Kandelia candel mangrove community of Fuding were investigated between the natural forest and the monoculture plantations,the results showed that the average contents of the respective elements of natural K.candel plant were(19.21±0.039) mg·kg-1 of Zn,(1.30±0.111) mg·kg-1 of Cd and(30.07±0.042) mg·kg-1 of Cu,which were 1.28 times,1.16 times and 0.60 times as much as that in the monoculture plantations.The enrichment coefficient of plant to soil(0-30 cm depth) were 0.767,0.339 and 1.464 respectively,which were 4.62 times,1.45 times and 1.30 times as much as that of monoculture plantations.The storages of the natural forest were 304.33 mg·m-2 of Zn,21.78 mg·m-2 of Cd and 396.86 mg·m-2 of Cu,which were 4.78 times,2.06 times and 1.58 times as much as that of monoculture plantations.The average of the respective element reserves of the monoculture plantations were 9682.44 mg·m-2 of Zn,489.61 mg·m-2 of Cd and 5287.46 mg·m-2 of Cu,which were 1.10 times,1.18 times and 1.54 times as much as that in the natural forest.

Fuding Municipality in east part of Fujian Province is the northernmost part for natural distribution of mangrove forest in China,which plays an important role in mangrove study.The biomass and its distribution law of Kandelia candel forests in Fuding,costal area of Fujian Province with different origins were studied by applying standard plant method and harvesting method.The results showed that the total biomass of the natural K.candel forests was 58.305 t/hm2 with the aboveground biomass for 32.919 t/hm2 and the underground part for 25.386 t/hm2.Whereas the total biomass of K.candel plantation in the same area was 25.359 t/hm2,among which the aboveground part was 14.711 t/hm2 and the underground part was 10.648 t/hm2 respectively.The study on the biomass distribution showed that the order by the biomass allocation for K.candel population was: twigs stems staple roots leaves mid roots stump fiber roots flowers.The characteristics of biomass of K.candel forest or plantation and the organ distribution explained its adaptability to high latitude habitat.

The community structure and water holding capacity of litter and soil of Eucalyptus urophylta ×E.eamalducensis plantations under different management densities in Yong'an City were studied.The results showed that the management density obviously affected the plantation structure,which had significant correlations to DHB and tree height,with correlation coefficient of-0.99 and-0.93,respectively,and that to stand volume with r=0.84.The effects of densities on species diversities from shrub layer to herb layer were different,which had significant correlation to shrub layer with r=0.94,and poor correlation to herb layer with r=-0.52.The species composition of undergrowth layer were great different under 5 different densities,and the vegetation yield under low density was the biggest.The litter maximum water holding capacity had significant correlation to stand densities with r=0.94.

The nylon bag method was adopted to make a one-year observation of the decomposition of four natural forests litter in Wuyishan Scenery District.The results showed that the weightlessness ratio of four natural forests could be ranked in a decreasing order,that is,broadleaf leaf litter(63.1%) Phyllostachys heterocycla cv.Pubescens leaf litter(60.2%) Chinese fir leaf litter(51.6%) broadleaf twig litter(45.6%) Chinese fir twig litter(39.3%) Phyllostachys pubescens twig litter(39.2%) Pinus massoniana leaf litter(36.7%) Pinus massoniana twig litter(25.3%).The order of decomposition concentration(K values) of the four forest types was broadleaf leaf litter(0.996 a-1) Phyllostachys pubescens leaf litter(0.921 a-1) Chinese fir leaf litter(0.725 a-1) broadleaf twig litter(0.608 a-1) Phyllostachys pubescens twig litter(0.499 a-1) Chinese fir twig litter(0.497 a-1) Pinus massoniana leaf litter(0.457 a-1) Pinus massoniana twig litter(0.305 a-1).The organic C concentration of 8 kinds of litters decreased gently and gradually in general,and the loss proportion of the organic C of broadleaved forest and Phyllostachys heterocycla forest was higher than that of Pinus massoniana and Cunninghamia lanceolata forest.The content of P was in a fluctuating state of enrichment,and the P returning amount of Phyllostachys heterocycla was lower than that of other natural forests.The changing tendency of N concentration differed greatly,and the leaf decomposing rate of the broadleaved forests was the highest,most of whose composition was enriched in the later period.Except the branches of broadleaved trees,K concentration of all other litters decreased monotonously with the passage of decomposing time,which falls into leaching-release mode.The study aimed to discover the ecosystem function,nutrient decomposition rule,soil fertility condition of the four kinds of sub-tropical natural forest,providing scientific basis for protection and management of natural forests in Wuyishan Scenery District.

Based on the investigation of the Cryptromeria fortunei communities in Tianbaoyan National Nature Reserve,the variation of competition index of the natural population of C.fortunei under varied disturbance intensities was analyzed by means of Hegyi single tree competition index model,and the correlation model was set up between the DBH value of the natural population of C.fortunei and the change of the competition index of C.fortunei populations under disturbance of different intensities.The mathematic model was established according to the relationship between competition index and DBH.The results showed that with the increase of the disturbance intensities,both the general competition index of the natural population of C.fortunei and the intra-specific competition index of the surveyed three sample plots decreased obviously,whereas the inter-specific competition index increased significantly.The order of the general and inner-specific competition intensity was CI(1) CI(2) CI(3) and CIinner(1) CIinner(2) CIinner(3).The relationship between the competition intensity and DBH value of the studied plants closely followed the power function model as CI=161.163 9 ·D1.112 6,and it was proven by trial tests that the model could be well used to predict the competition intensity of C.fortunei populations in this area.

Species diversity of natural Cryptomeria fortunei community at different altitude levels in Tianbaoyan national Nature Reserve was studied by means of field investigation,and was calculated and analyzed through the measure methods of species diversity.The results showed that the tree layer diversity of Cryptomeria fortunei community presented a hump-shaped pattern along the elevational gradient with a peak at high-elevations;What's more,the shrub layer diversity presented a mid-altitude bulge with a peak at high-elevations.The species diversity of Cryptomeria fortunei communities were not affected by altitude,which indicated the consistency of species diversity in Tianbaoyan national Nature Reserve.It was concluded that the abundant species at high-elevation(1200～1600 m) resulted from better thermal and humid conditions,while the conspicuous decline of species richness at mid-elevation(1000～1200 m) and low-elevation(900～1000 m) was a result of human disturbance.

In this paper,concentrations,distribution and accumulation of heavy metals in Wetland of Mindong were investigated.The highest values for heavy metals concentrations in sediments before the modern industrialization of the world and the environmental background values of Kandelia cande1 Mangrove Wetland of Fuding were used to analyze the accumulation coefficient and potential ecological risk(PER)coefficients for heavy metal.The PER index for each sample location was also discussed.The method for evaluating PER index presented by Lars Hankanson was applied to assess the ecological risk.The distribution of various heavy metal contents revealed the regional distributive characteristics,and the concentrations were higher in the Nod village(the four sample location)than the others.When the highest values for heavy metals concentrations in sediments before the modern industrialization of the world were taken as references,the accumulating order for these heavy metals was CdPbCuZn,and the order of pollution level was CdPbCuZn;Zn.When the environmental background values of Kandelia cande1 Mangrove Wetland of Fuding worked as references,the accumulating order was PbCdCuZn,and the order of pollution level was CdPbCuZn.

Two phases of remote sensing image data taken respectively in 1992 and 2000 were interpreted through ERDAS software and the change in landscape pattern of Longkou Municipality was analyzed with two categories of indices from the landscape pattern and landscape levels by means of using FRAGSTATS software.The results showed that the orchard land area,farming land area without irrigation facilities and the construction land area significantly increased,while the irrigated land area and forested land area decreased.The reasons for the change in landscape pattern were also analyzed in the paper.

Based on the investigation of the Cryptromeria fortunei populations in the Tianbaoyan National Nature Reserve of Yong'an City,the concerntration class index,Iwao M*-x-and Taylor principle were used to research spatial distribution pattern of the Cryptromeria fortunei populations at different altitude levels.The result showed that at the altitude from 1 000 m to 1 200 m and from 1 200 m to 1 600 m,the Cryptromeria fortunei populations performed the pattern of clustering distribution,and at the altitude from 900 m to 1 000 m it showed uniform distribution.Analysis of the distribution pattern of the Cryptromeria fortunei at different sampling sizes at different altitude levels,the aggregating intensity at the quadrat of 25 m2 was the highest.