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The five main forest types, i. e. larch forest, birch forest, coniferous mixed forest, broad-leaved mixed forest, and coniferous and broadleaved mixed forest, with varied age classes (young, mid-agedv, pre-mature, and over mature) were selected to investigate the variation of soil organic carbon density in the forest region of Northeast China. Results showed that both soil organic carbon content and density were relatively larger in the top soil layer across the five forest types, decreased gradually with soil depth, and varied insignificantly with either forest type or forest age class. The forest soil carbon density was concentrated in the top 20 cm of soil which accounted for 84. 7% - 86-1%, 51. 7% -59. 8% and 51. 2% -53. 4% of total soil carbon density in the Daxing' an, Xiaoxing' an and Changbai mountains, respectively. The total soil organic carbon density decreased significantly with increasing latitude, which might be attributed mainly to the thickness of soil layers in forest region of Northeast China. [ABSTRACT FROM AUTHOR]

A sampling plot investigation was conducted to study the soil organic carbon (SOC) storage in 0-40 cm layer in 10-, 15-, 26-and 61 years old Larix gmelinii plantations in Great Xing'an Mountains of Northeast China as well as the temporal variation pattern of the SOC source/ sink during the plantation management after the clear cutting of primary L. gmelinii forest. With the increasing age of the plantations, the SOC storage increased after an initial decrease, and the inflection point was at a stand age between 15-and 26-years old. Compared with that of primary forest, the SOC storage of the plantations played a role of carbon source at early stage (10-26 years old), but gradually transformed into carbon sink then, with a SOC storage of 158. 91 t · hm-2 in 61-year-old plantation. The SOC storage of the plantations increased with soil depth initially, but was higher in upper soil layer than in deeper soil layer after the stand age being 26, which implied that human disturbance had strong effects on the vertical distribution of SOC. It was considered that the appropriate cutting age for the L. gmelinii plantations in Great Xing'an Mountains could be at least 60 years old. [ABSTRACT FROM AUTHOR]

Taking Betula ermanii forests distributed at the altitudes 1800-2050 m on the northern slope of Changbai Mountains as test objects, and using leaf carbon isotope content (&dgr;13C) as an indicator of B. ermanii water use efficiency (WUE), this paper studied the effects of altitudinal gra? dient on the WUE of B. ermanii forests in the area. With the increase of altitude, the soil volumetric water content (VMC) and the leaf mass per area (LMA) of B. ermanii increased significantly, while the leaf water content (LWC) and soil temperature were in adverse. There was a significant positive correlation between leaf &dgr;13 C and altitude, with the increment of leaf &dgr;13 C being 1.013 %·(100 m)-1, and the leaf &dgr;13C was positively correlated with soil VWC and LMA but negatively correlated with soil temperature and LWC. Temperature was not the sole limiting factor for the dis tribution of treeline in Changbai Mountains, whereas the physiological drought of B. ermanii during its growing season caused by the different water and heat conditions and their interactions along the altitudinal gradient could be the other limiting factors. [ABSTRACT FROM AUTHOR]

By using forest resources inventory data and field investigation data, this paper studied the carbon storage, density, and distribution characteristics in forest ecosystems in Jilin Province of Northeast China. The total carbon storage in the forest ecosystems was 1827.293 Tg C, and the carbon storages in arbor layer, shrub-grass layer, litter layer, and soil were 439.152 Tg C, 5.195 Tg C, 45.600 Tg C, and 1330.466 Tg C, accounting for 24.1%, 0.3%, 2.5%, and 73.1% of the total, respectively. The carbon density in the forest ecosystems was 225.304 Mg C·hm-2, with 54.352 Mg C·hm-2 in arbor layer, 0.643 Mg C·hm-2 in shrub-grass layer, 5.644 Mg C·hm-2 in litter layer, and 164.666 Mg C·hm-2 in soil. Different types of the forest ecosystems had a carbon storage varied from 9.357 Tg C to 959.716 Tg C and a carbon density ranged from 180.648 Mg C·hm-2 to 254.627 Mg C·hm-2, with the highest values in soil and the lowest values in shrub-grass layer. Overall, the carbon storage and density in the forest ecosystems were greater in eastern mountainous area than in central and western plains. In the Province, middle-aged forests had a greater proportion than the forests in other age classes, and thereby, a proper management of the present forests could increase the carbon sequestration of the forest ecosystems. [ABSTRACT FROM AUTHOR]

Through sampling site investigation, this paper studied the carbon storage of arbor, herb, and whole vegetation in 10-, 12-, 15-, 26-, and 61-year old Larix gmelinii plantations in Huzhong Forestry Bureau of Great Xing'an Mountains, Northeast China, and 'temporal for spatial' method was employed to approach the variations of the vegetation carbon storage during the growth of the plantations. The results revealed that the vegetation carbon storage in the plantations increased with stand age, and reached 105.69 t·hm-2 at age of 61 years, representing a marked role as a carbon sink. The L. gmelinii plantations at the ages from 15 to 26 years had the strongest capability in carbon sequestration, in which, the carbon storage in trunk occupied 54.3%-73.9% of the total carbon storage of arbor, and, with the increase of stand age, the trunk's carbon storage to the total carbon storage of arbor as well as the trunk's carbon density increased. As for the other organs, the rate of their carbon storage to the total carbon storage of arbor decreased with stand age, while their carbon density increased first but eventually leveled off or had a slight decrease till at age of 61 years. Based on these results, the rotation age for the L. gmelinii plantations in Great Xing'an Mountains would properly be lengthened to at least 60 years. [ABSTRACT FROM AUTHOR]

Global climate change is one of the most concerned environmental problems in the world since the 1980s, giving significant effects on the plant productivity and the water transport and use patterns. These effects would be reflected in the water use efficiency (WUE) of individual plants, communities, and ecosystems, and ultimately, in the vegetation distribution pattern, species composition, and ecosystem structure. To study the WUE of plants would help to the understanding and forecasting of the responses of terrestrial vegetation to global climate change, and to the adoption of adaptive strategies. This paper introduced the concept of plant WUE and the corresponding measurement techniques at the scales of leaf, individual plant, community, and ecosystem, and reviewed the research progress in the effects of important climatic factors such as elevated atmospheric CO2 concentration, precipitation pattern, nitrogen deposition, and their combination on the plant WUE, as well as the variation characteristics of plant WUE and the adaptive survival strategies of plants under different site conditions. Some problems related to plant WUE research were pointed out, and the future research directions in the context of global climate change were prospected. [ABSTRACT FROM AUTHOR]

Based on the forest management inventories in Lushihe Forest Bureau of Changbai Mountains in 1987, 1995 and 2003, and by using ArcGIS and Fragstats spatial analysis software, this paper analyzed the relationships between landscape pattern change and forest management mechanism in the study area at landscape and patch scales. During the study period, the landscape fragmentation degree and heterogeneity in the study area increased. From 1987 to 2003, the patch number increased by 979, while the proportion of the largest patch area decreased from 28.7% to 12.7%. With the change of management strategy, the landscape matrix changed from mixed broadleaved forest matrix in 1987 to compound matrix in 1995. The extent of landscape fragmentation in 1995-2003 was somewhat reduced, compared with that in 1987-1995. During the study period, the mean patch area and edge density of broadleaved mixed forest decreased most, suggesting that natural secondary forest suffered most from human disturbances. [ABSTRACT FROM AUTHOR]

Stand age is a key factor affecting carbon stocks and fluxes of forest ecosystem. Quantification of the changes in forest productivity with stand development is critically important for optimizing forest age structure, facilitating maximum utilization of resources, and better realizing the role of forests in regulating the uptake, storage, and emission of CO 2 . In this study, using space for time substitution approach, we established 12 chronosequence plots in the broadleaf-Korean pine forests of Lushuihe. Using a locally parameterized Biome-BGC model, we simulated the dynamics of net primary productivity (NPP) with stand development and examined the changes with stand development in NPP of broadleaf-Korean pine forests under four developmental scenarios. Results showed that the biomass in broadleaf-Korean pine forests of different age-classes ranked in the order of young stand < mid-age stand < mature stand < over-mature stand, with the average value of (224.35±20.68), (237.23±39.96), (259.16±19.51), and (357.57±84.74) t·hm -2 , respectively. Modelled NPP in broadleaf-Korean pine forests of different developmental stages varied in the range of 489.8-588 g C·m -2 ·a -1 , which were consistent with the observed data of MODIS NPP, highlighting the adequacy and accuracy of Biome-BGC model in simulating the carbon flux of broadleaf-Korean pine forests. Simulated NPP displayed a pattern of initial increase and later decrease with stand development, reaching peak in the mid-age stand and being smallest in the over-mature stand. Simulations of NPP in broadleaf-Korean pine forest under four developmental scenarios showed that, for the two scenarios with planted Korean pine forests experiencing either natural development or controlled cutting, NPP was highest in the mature stage; whereas for the two scenarios with initial natural secondary birch forests experiencing either natural development or controlled cutting, NPP was highest in the young stage.

Selective cutting changes tree species composition and stand structure, modifies tree competition intensity in the stand, with consequences on tree growth and population dynamics. Key tree species play a crucial role in maintaining community structure and ecosystem function. To clarify the competitive characteristics of three key species (Pinus koraiensis, Tilia amurensis, and Fraxinus mandshurica, which accounted for about 70% of growing stock) of typical forest types in broadleaved-Korean pine mixed forest, Hegyi competition index was used in four permanent 1-hm 2 plots, i.e. virgin forest (VF), low-intensity cutting forest (LCF), moderate-intensity cutting forest (MCF) and high-intensity cutting forest (HCF). Compared with VF, the stand density and mean DBH of big trees (DBH≥20 cm) significantly decreased in MCF and HCF, but the stand density of young trees (2 cm≤DBH<10 cm) increased, but no significant changes of stand or DBH in LCF. In all the four forest types, individual competition index (CI) of the three species decreased with increasing DBH. There was a power function relation between CI and DBH. CI curve turned to be gentle at DBH reaching 20 cm, and this rule was not affected by selective cutting. In VF, LCF and HCF, most of competition pressure of young trees of all key species derived from other tree species in secondary canopy or understory, but the competition pressure of small trees (10 cm≤DBH<20 cm) and big trees of P. koraiensis originated mainly from intra-species and other species in secondary canopy or understory. The competition stress of F. mandshurica was mainly affected by P. koraiensis and other species in secondary canopy or understory. T. amurensis was mainly affected by intra-species and P. koraiensis. Betula platyphylla contributed most of the competition stress (over 50%) to all three key species in HCF. Our results suggested that removing the trees which are in secondary canopy or understory but suppress the three key trees species intensively would be beneficial to the regeneration and growth of key species before tree DBH exceeds 20 cm. We proposed to regulate the density of key tree species in overstory to cultivate large diameter timber according to the competition among the key trees species. Once tree DBH exceeds 20 cm, tree growth would not be affected by competition. This study had guiding significance for the cultivation of key tree species and rapid recovery of natural forests after selective cutting.

Non-structural carbohydrates (NSC, including soluble sugars and starch) are key meta-bolites in tree, the storage characteristics of which in tree organs have received extensive attention. It is still unclear how NSC are allocated in the tissues (phloem and xylem) that have different function. In this study, we analyzed the concentration and allocation of NSC in the roots, and in phloem and xylem of the trunk in three dominant species of broadleaved Korean pine forest in the Changbai Mountain, Pinus koraiensis, Fraxinus mandschurica, and Tilia amurensis. The results showed that there was a significant difference in the concentration of NSC between the phloem and xylem. The soluble sugar dominated in the phloem, while starch dominated in the xylem. The concentration of NSC in trunk outside (divided by annual rings, 0-20 years), intermediate (20-40 years) and inner (>40 years) of different tree species was significantly different, but with no difference in the roots. The total soluble sugar concentration in the phloem of P. koraiensis and F. mandschurica was significantly higher than that of T. amurensis, while the difference in xylem was not significant. The results indicated that NSC allocation in the phloem and xylem of the tree had clear tissue differentiation, which might be related to the succession stage of the tree species or the functional evolution of the tissue. These findings would improve our understanding of the carbon storage characteristics and allocation mechanism in temperate trees.

Competition is the main factor affecting the growth, morphology and death of trees in fore-sts. The analysis of individual competition can reflect the characteristics of interaction among individuals and their interaction ranges, which is important for reducing individual competition and promoting tree growth. To understand the effects of competition on tree growth in broad-leaved Korean pine forest, based on Hegyi single-tree competition index and neighborhood analysis method, we explored the neighborhood radius of competition for five key tree species, i.e. Pinus koraiensis, Tilia amurensis, Fraxinus mandshurica, Quercus mongolica and Ulmus japonica (80% of basal area at breast height in total), and analyzed the effects of competition on the growth and death of the key tree species. The results showed that the neighborhood radius of single-tree competition of four tree species, P. koraiensis, T. amurensis, F. mandshurica and Q. mongolica was 11 m, while that of U. pumila was 13 m. The single-tree competition intensity for all five key tree species was negatively correlated with the logarithm of its growth increment, and positively correlated with the size of individual trees. The relative importance of competition intensity on tree growth decreased with tree growth. Neighborhood competition significantly increased tree mortality. Our results revealed the effects of neighborhood competition on the growth and survival of the key tree species at different developmental stages in broad-leaved Korean pine forests in Changbai Mountain. The results are instructive to the adjustment of competitive environment and the improvement of productivity of key tree species in broad-leaved Korean pine forests.

Changbai Mountain is located in the eastern mountain forest region of Northeast China, with broad-leaved Korean pine forest (BKF) as the climax vegetation type. The region is rich in species diversity and serves as an important carrier for precious wood production and forest belts in Northeast China. In the recent 120 years, the vast primary forests in Changbai Mountains have almost disappeared, and have been replaced by secondary forests, over-cut forests, and plantations. Since the founding of the People's Republic of China, the theory and technology of forest management for BKF in Northeast China have gradually improved along with the researches and understanding on the structure and function of BKF, the disputes of Korean pine regeneration characteristics, and the debate about clear cutting and selective cutting. However, the problem of insufficient Korean pine regeneration still exists, and forest management is very extensive. We tried to untangle the management technology trail and research history of BKF in the past 70 years, and to analyze the current forest types and the formation process of the management regulations, with the aim to provide reference for the sustainable management and quality improvement of natural forests in the region.

Changbai Mountain is one of the hotspots for tree ring research in Northeast China, with a large number of related research results having been published. To clarify the advance of tree ring research in Changbai Mountain and understand the responses of tree radial growth to climate factors, we reviewed the related literature and analyzed the differences among them based on tree species identity, elevation, and detrended methods. The radial growth of trees in Changbai Mountain was generally affected by temperature and precipitation, with greater influence of temperature. The relationship between tree radial growth and climate variables varied across both species and altitudes. Most studies reported that the radial growth of conifers were mainly affected by temperature in early growing season (April-May) and growing season precipitation (June-August). The radial growth of broadleaved trees were mainly affected by the temperature in previous and current growing season, the precipitation in dormancy season (November-March), and the precipitation in the current growing season. The previous September precipitation had significant effects on the radial growth of conifers and broadleaved trees. However, many studies had reported different or even opposite results. Most of the differences in the results of the studies appeared at low and medium altitudes, indicating that the altitudinal location of sampling points had impacts on the results. In addition, the detrended method was also the main cause for the variation of results across different studies. Comparatively, the linear or negative exponential detrended method might increase the effective significance of precipitation, especially the effect of precipitation on tree growth during dormancy period, and also strengthen the effective significance of the temperature at the end of the growing season. This study showed the habitat and the detrended method used in chronology were the main reasons for the difference of results among the studies. Therefore, for tree ring research in Changbai Mountain, the number of sampling sites should be increased and the detrended method should be carefully selected.

Exploring the ecological vulnerability of nature reserve and its surrounding area is essential to the maintenance of regional ecological security and sustainability of human development, especially under the stress of global change and human activities. Based on the integration of "sensitivity-resilience-pressure" conceptual model and spatial principal component analysis (SPCA), we analyzed the ecological vulnerability of Changbai Mountain National Nature Reserve and its surrounding 30 km buffer in 2005 and 2015. The main driving factors were further analyzed. The results showed that the ecological vulnerability of Changbai Mountain Nature Reserve was mainly potential, slight, and light levels in 2005 and 2015, indicating the ecological vulnerability inside and outside the reserve was in a good condition. For the whole region, the ecological vulnerability showed a slight downward trend from 2005 to 2015. The degradation area inside and outside the reserve were 254 and 967 km 2 , respectively, with the contribution rate to the increase of overall vulnerability being 30.8% and 69.2%, respectively. The changes in ecological vulnerability inside the reserve were mainly related to the changes in net primary production (NPP), vegetation coverage, and the nearest distance to the road, whereas it was mainly related to the changes in NPP, vegetation coverage and gross domestic product (GDP) density outside the reserve.

To clarify the responses of radial growth of different tree species to climate change and its stability, we explored the relationships between radial growth and climate factors of larch (Larix olgensis) and spruce (Picea jezoensis var. komarovii) distributed at high altitude (1600-1750 m) on the northern slope of Changbai Mountain, using the chronological method. The results showed that the growth of larch was significantly positively correlated with the maximum temperature in June and negatively correlated with the precipitation in June. The radial growth of spruce was significantly positively correlated with the maximum temperature in May. Results from redundancy analysis showed that larch growth was mainly affected by summer temperature, while spruce growth was significantly restricted by spring temperature. During 1959-2014, the relationship between larch growth and summer temperature was relatively stable. For spruce, the correlation between radial growth and spring temperatures had gradually weakened since 1986, mainly due to the growth slowdown because of decreased maximum air temperature. Our results provide theoretical references for predicting the growth response of conifers at Changbai Mountain region in the context of climate change.

The alpine tundra ecosystem, with low soil inorganic nitrogen (N) availability, has a weak buffer against nitrogen and is susceptible to exogenous N enrichment. Here, with a laboratory incubation experiment, we investigated the response of soil carbon and nitrogen mineralization to N deposition with soil samples from the tundra zone on the northern slope of the Changbai Mountain. We set three N levels, control (CK, 0 kg·hm -2 ), low N (N 1 , 25 kg·hm -2 ), and high N (N 2 , 50 kg·hm -2 ), with N being added as NH 4 NO 3 . The results showed that N addition had no significant effect on soil C mineralization rate, but significantly affected the accumulation of soil C minera-lization. The N 2 treatment inhibited soil C mineralization. After the 40 d incubation, soil inorganic N content increased with increasing N addition. After the 80 d incubation, soil inorganic N content in the N 2 and N 1 was similar and significantly higher than that of CK. Those results indicated that N addition promoted soil N mineralization. The soil microbial biomass C and N in the N 1 was higher than that in the N 2 and CK, indicating that low N input had stronger effects on soil microbial activity. Increasing N deposition might accelerate C and N turnover in the tundra soils and enhance the soil inorganic N content. While it could provide more N for plants, it may increase the risk of N loss.

The five main forest types, i. e. larch forest, birch forest, coniferous mixed forest, broad-leaved mixed forest, and coniferous and broad-leaved mixed forest, with varied age classes (young, mid-aged, pre-mature, and over mature) were selected to investigate the variation of soil organic carbon density in the forest region of Northeast China. Results showed that both soil organic carbon content and density were relatively larger in the top soil layer across the five forest types, decreased gradually with soil depth, and varied insignificantly with either forest type or forest age class. The forest soil carbon density was concentrated in the top 20 cm of soil which accounted for 84.7% - 86.1%, 51.7% - 59.8% and 51.2% - 53.4% of total soil carbon density in the Daxing' an, Xiaoxing' an and Changbai mountains, respectively. The total soil organic carbon density decreased significantly with increasing latitude, which might be attributed mainly to the thickness of soil layers in forest region of Northeast China.

A sampling plot investigation was conducted to study the soil organic carbon (SOC) storage in 0-40 cm layer in 10-, 15-, 26- and 61 years old Larix gmelinii plantations in Great Xing' an Mountains of Northeast China as well as the temporal variation pattern of the SOC source/sink during the plantation management after the clear cutting of primary L. gmelinii forest. With the increasing age of the plantations, the SOC storage increased after an initial decrease, and the inflection point was at a stand age between 15- and 26-years old. Compared with that of primary forest, the SOC storage of the plantations played a role of carbon source at early stage (10-26 years old), but gradually transformed into carbon sink then, with a SOC storage of 158.91 t x hm(-2) in 61-year-old plantation. The SOC storage of the plantations increased with soil depth initially, but was higher in upper soil layer than in deeper soil layer after the stand age being 26, which implied that human disturbance had strong effects on the vertical distribution of SOC. It was considered that the appropriate cutting age for the L. gmelinii plantations in Great Xing' an Mountains could be at least 60 years old.

Taking Betula ermanii forests distributed at the altitudes 1800-2050 m on the northern slope of Changbai Mountains as test objects, and using leaf carbon isotope content (813 C) as an indicator of B. ermanii water use efficiency (WUE), this paper studied the effects of altitudinal gradient on the WUE of B. ermanji forests in the area. With the increase of altitude, the soil volumetric water content (VMC) and the leaf mass per area (LMA) of B. ermanji increased significantly, while the leaf water content (LWC) and soil temperature were in adverse. There was a significant positive correlation between leaf delta13 C and altitude, with the increment of leaf delta13 C being 1.013 % per hundred x (100 m)(-1), and the leaf delta13C was positively correlated with soil VWC and LMA but negatively correlated with soil temperature and LWC. Temperature was not the sole limiting factor for the distribution of treeline in Changbai Mountains, whereas the physiological drought of B. ermanii during its growing season caused by the different water and heat conditions and their interactions along the altitudinal gradient could be the other limiting factors.

By using forest resources inventory data and field investigation data, this paper studied the carbon storage, density, and distribution characteristics in forest ecosystems in Jilin Province of Northeast China. The total carbon storage in the forest ecosystems was 1827.293 Tg C, and the carbon storages in arbor layer, shrub-grass layer, litter layer, and soil were 439.152 Tg C, 5.195 Tg C, 45.600 Tg C, and 1330.466 Tg C, accounting for 24.1%, 0.3%, 2.5%, and 73.1% of the total, respectively. The carbon density in the forest ecosystems was 225.304 Mg C x hm(-2), with 54.352 Mg C x hm(-2) in arbor layer, 0.643 Mg C x hm(-2) in shrub-grass layer, 5.644 Mg C x hm(-2) in litter layer, and 164.666 Mg C x hm(-2) in soil. Different types of the forest ecosystems had a carbon storage varied from 9.357 Tg C to 959.716 Tg C and a carbon density ranged from 180.648 Mg C * hm(-2) to 254.627 Mg C x hm(-2), with the highest values in soil and the lowest values in shrub-grass layer. Overall, the carbon storage and density in the forest ecosystems were greater in eastern mountainous area than in central and western plains. In the Province, middle-aged forests had a greater proportion than the forests in other age classes, and thereby, a proper management of the present forests could increase the carbon sequestration of the forest ecosystems.

Through sampling site investigation, this paper studied the carbon storage of arbor, herb, and whole vegetation in 10-, 12-, 15-, 26-, and 61-year old Larix gmelinii plantations in Huzhong Forestry Bureau of Great Xing' an Mountains, Northeast China, and 'temporal for spatial' method was employed to approach the variations of the vegetation carbon storage during the growth of the plantations. The results revealed that the vegetation carbon storage in the plantations increased with stand age, and reached 105.69 t x hm(-2) at age of 61 years, representing a marked role as a carbon sink. The L. gmelinii plantations at the ages from 15 to 26 years had the strongest capability in carbon sequestration, in which, the carbon storage in trunk occupied 54.3% -73.9% of the total carbon storage of arbor, and, with the increase of stand age, the trunk's carbon storage to the total carbon storage of arbor as well as the trunk's carbon density increased. As for the other organs, the rate of their carbon storage to the total carbon storage of arbor decreased with stand age, while their carbon density increased first but eventually leveled off or had a slight decrease till at age of 61 years. Based on these results, the rotation age for the L. gmelinii plantations in Great Xing' an Mountains would properly be lengthened to at least 60 years.

Global climate change is one of the most concerned environmental problems in the world since the 1980s, giving significant effects on the plant productivity and the water transport and use patterns. These effects would be reflected in the water use efficiency (WUE) of individual plants, communities, and ecosystems, and ultimately, in the vegetation distribution pattern, species composition, and ecosystem structure. To study the WUE of plants would help to the understanding and forecasting of the responses of terrestrial vegetation to global climate change, and to the adoption of adaptive strategies. This paper introduced the concept of plant WUE and the corresponding measurement techniques at the scales of leaf, individual plant, community, and ecosystem, and reviewed the research progress in the effects of important climatic factors such as elevated atmospheric CO2 concentration, precipitation pattern, nitrogen deposition, and their combination on the plant WUE, as well as the variation characteristics of plant WUE and the adaptive survival strategies of plants under different site conditions. Some problems related to plant WUE research were pointed out, and the future research directions in the context of global climate change were prospected.

Based on the forest management inventories in Lushihe Forest Bureau of Changbai Mountains in 1987, 1995 and 2003, and by using ArcGIS and Fragstats spatial analysis software, this paper analyzed the relationships between landscape pattern change and forest management mechanism in the study area at landscape and patch scales. During the study period, the landscape fragmentation degree and heterogeneity in the study area increased. From 1987 to 2003, the patch number increased by 979, while the proportion of the largest patch area decreased from 28. 7% to 12.7%. With the change of management strategy, the landscape matrix changed from mixed broad-leaved forest matrix in 1987 to compound matrix in 1995. The extent of landscape fragmentation in 1995-2003 was somewhat reduced, compared with that in 1987-1995. During the study period, the mean patch area and edge density of broadleaved mixed forest decreased most, suggesting that natural secondary forest suffered most from human disturbances.

By using 3D visualization software WCS 6.0, the virtual forest landscape of Pulepu Town in eastern Liaoning mountainous region was constructed, and the dynamic changes of forests under four different management scenarios, i.e., enclosing undeveloped forest, small area clear-cutting, selective-logging, and two-step progressive logging, were modeled. The results showed that under enclosure, 10-30 years old Larix olgensis var. changpaiensis grew faster (ca. 0.6 m x a(-1)), while 10-30 years old Quercus mongolica grew slower (ca. 0.4 m x a(-1)). Small area clear-cutting had the greatest effects on the forests, followed by two-step progressive logging, and low intensity selective-logging. The WCS software could visually display the outcomes of different scenarios, which would benefit the decision-making in forest management.