2016年 第26卷 第1期
2016, 26(1): 1-9.
doi: 10.1007/s11769-015-0782-x
摘要:
Change in plant phenology is one of the most sensitive ecological responses to climate warming. Little information is known about the effects of climate warming on phenology of urban tree species in the northern forest of China. In this study, we investigated the phenological characteristics of the main tree species in the urban forest of Shengyang City in China and the correlation between phenology and atmospheric temperature from the discontinuous data during past 42 years over three time periods (from 1962 to 1965, 1977 to 1978, and 2000 to 2005). The results showed that the annual average temperature in Shenyang City showed an increasing trend and increased by 0.96℃ from 1962 to 2005 due to climate warming. The germination phenology of the urban trees was negatively correlated with the temperature in winter and early spring. The leafing phenology was mainly influenced by the temperature in spring before leafing. Influenced by climate warming, the germination, leafing, and flowering phenologies of this urban forest in 2005 were 14, 13, and 10 days earlier than those in 1962, respectively. We inferred that further warming in winter might prolong the growing season of urban trees in the northern forest of China.
Change in plant phenology is one of the most sensitive ecological responses to climate warming. Little information is known about the effects of climate warming on phenology of urban tree species in the northern forest of China. In this study, we investigated the phenological characteristics of the main tree species in the urban forest of Shengyang City in China and the correlation between phenology and atmospheric temperature from the discontinuous data during past 42 years over three time periods (from 1962 to 1965, 1977 to 1978, and 2000 to 2005). The results showed that the annual average temperature in Shenyang City showed an increasing trend and increased by 0.96℃ from 1962 to 2005 due to climate warming. The germination phenology of the urban trees was negatively correlated with the temperature in winter and early spring. The leafing phenology was mainly influenced by the temperature in spring before leafing. Influenced by climate warming, the germination, leafing, and flowering phenologies of this urban forest in 2005 were 14, 13, and 10 days earlier than those in 1962, respectively. We inferred that further warming in winter might prolong the growing season of urban trees in the northern forest of China.
2016, 26(1): 10-21.
doi: 10.1007/s11769-015-0772-z
摘要:
The overall goal of this study was to understand carbon (C) stock dynamics in four different-aged Japanese larch (Larix kaempferi) plantations in Northeast China that were established after clear-cutting old-growth Korean pine deciduous forests. Four Japanese larch plantations which were at 10, 15, 21, and 35 years old and an old-growth Korean pine deciduous forest which was 300 years old in Northeast China were selected and sampled. We compared the C pools of biomass (tree, shrub and herb), litterfall (LF), and soil organic carbon (SOC) among them. The biomass C stock of larch plantation at 10, 15, 21, and 35 years old was 26.8, 37.9, 63.6, and 83.2 Mg/ha, respectively, while the biomass C stock of the old-growth Korean pine deciduous forest was 175.1 Mg/ha. The SOC stock of these larch plantations was 172.1, 169.7, 140.3, and 136.2 Mg/ha respectively, and SOC stock of 170.4 Mg/ha in the control of old-growth forest. The biomass C stock increased with stand age of larch plantations, whereas SOC stock decreased with age, and C stock of LF did not change significantly (P > 0.05). The increase of biomass C offset the decline of SOC stock with age, making total carbon stock (TCS) of larch plantations stable from stand ages of 10-35 years. The TCS in larch plantations was much smaller than that in the old-growth forest, suggesting that the?conversion of old-growth forests to young larch plantations releases substantial C into the atmosphere.
The overall goal of this study was to understand carbon (C) stock dynamics in four different-aged Japanese larch (Larix kaempferi) plantations in Northeast China that were established after clear-cutting old-growth Korean pine deciduous forests. Four Japanese larch plantations which were at 10, 15, 21, and 35 years old and an old-growth Korean pine deciduous forest which was 300 years old in Northeast China were selected and sampled. We compared the C pools of biomass (tree, shrub and herb), litterfall (LF), and soil organic carbon (SOC) among them. The biomass C stock of larch plantation at 10, 15, 21, and 35 years old was 26.8, 37.9, 63.6, and 83.2 Mg/ha, respectively, while the biomass C stock of the old-growth Korean pine deciduous forest was 175.1 Mg/ha. The SOC stock of these larch plantations was 172.1, 169.7, 140.3, and 136.2 Mg/ha respectively, and SOC stock of 170.4 Mg/ha in the control of old-growth forest. The biomass C stock increased with stand age of larch plantations, whereas SOC stock decreased with age, and C stock of LF did not change significantly (P > 0.05). The increase of biomass C offset the decline of SOC stock with age, making total carbon stock (TCS) of larch plantations stable from stand ages of 10-35 years. The TCS in larch plantations was much smaller than that in the old-growth forest, suggesting that the?conversion of old-growth forests to young larch plantations releases substantial C into the atmosphere.
2016, 26(1): 22-34.
doi: 10.1007/s11769-015-0789-3
摘要:
Distribution of monsoon forests is important for the research of carbon and water cycles in the tropical regions. In this paper, a simple approach is proposed to map monsoon forests using the Normalized Difference Vegetation Index (NDVI) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) data. Owing to the high contrast of greenness between wet season and dry season, the monsoon forest can be easily discriminated from other forests by combining the maximum and minimum annual NDVI. The MODIS-based monsoon forest maps (MODMF) from 2000 to 2009 are derived and evaluated using the ground-truth dataset. The MODMF achieves an average producer accuracy of 80.0% and the Kappa statistic of 0.719. The variability of MODMF among different years is compared with that calculated from MODIS land cover products (MCD12Q1). The results show that the coefficient of variation of total monsoon forest area in MODMF is 7.3%, which is far lower than that in MCD12Q1 with 24.3%. Moreover, the pixels in MODMF which can be identified for 7 to 9 times between 2001 and 2009 account for 53.1%, while only 7.9% of MCD12Q1 pixels have this frequency. Additionally, the monsoon forest areas estimated in MODMF, Global Land Cover 2000(GLC2000), MCD12Q1 and University of Maryland (UMD) products are compared with the statistical dataset at national level, which reveals that MODMF has the highest R2 of 0.95 and the lowest RMSE of 14014 km2. This algorithm is simple but reliable for mapping the monsoon forests without complex classification techniques.
Distribution of monsoon forests is important for the research of carbon and water cycles in the tropical regions. In this paper, a simple approach is proposed to map monsoon forests using the Normalized Difference Vegetation Index (NDVI) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) data. Owing to the high contrast of greenness between wet season and dry season, the monsoon forest can be easily discriminated from other forests by combining the maximum and minimum annual NDVI. The MODIS-based monsoon forest maps (MODMF) from 2000 to 2009 are derived and evaluated using the ground-truth dataset. The MODMF achieves an average producer accuracy of 80.0% and the Kappa statistic of 0.719. The variability of MODMF among different years is compared with that calculated from MODIS land cover products (MCD12Q1). The results show that the coefficient of variation of total monsoon forest area in MODMF is 7.3%, which is far lower than that in MCD12Q1 with 24.3%. Moreover, the pixels in MODMF which can be identified for 7 to 9 times between 2001 and 2009 account for 53.1%, while only 7.9% of MCD12Q1 pixels have this frequency. Additionally, the monsoon forest areas estimated in MODMF, Global Land Cover 2000(GLC2000), MCD12Q1 and University of Maryland (UMD) products are compared with the statistical dataset at national level, which reveals that MODMF has the highest R2 of 0.95 and the lowest RMSE of 14014 km2. This algorithm is simple but reliable for mapping the monsoon forests without complex classification techniques.
2016, 26(1): 35-47.
doi: 10.1007/s11769-015-0762-1
摘要:
In recent years, with the constant change in the global climate, the effect of climate factors on net primary productivity (NPP) has become a hot research topic. However, two opposing views have been presented in this research area:global NPP increases with global warming, and global NPP decreases with global warming. The main reasons for these two opposite results are the tremendous differences among seasonal and annual climate variables, and the growth of plants in accordance with these climate variables. Therefore, it will fail to fully clarify the relation between vegetation growth and climate changes by research that relies solely on annual data. With seasonal climate variables, we may clarify the relation between vegetation growth and climate changes more accurately. Our research examined the arid and semiarid areas in China (ASAC), which account for one quarter of the total area of China. The ecological environment of these areas is fragile and easily affected by human activities. We analyzed the influence of climate changes, especially the changes in seasonal climate variables, on NPP, with Climatic Research Unit (CRU) climatic data and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite remote data, for the years 2000-2010. The results indicate that:for annual climatic data, the percentage of the ASAC in which NPP is positively correlated with temperature is 66.11%, and 91.47% of the ASAC demonstrates a positive correlation between NPP and precipitation. Precipitation is more positively correlated with NPP than temperature in the ASAC. For seasonal climatic data, the correlation between NPP and spring temperature shows significant regional differences. Positive correlation areas are concentrated in the eastern portion of the ASAC, while the western section of the ASAC generally shows a negative correlation. However, in summer, most areas in the ASAC show a negative correlation between NPP and temperature. In autumn, precipitation is less important in the west, as opposed to the east, in which it is critically important. Temperatures in winter are a limiting factor for NPP throughout the region. The findings of this research not only underline the importance of seasonal climate variables for vegetation growth, but also suggest that the effects of seasonal climate variables on NPP should be explored further in related research in the future.
In recent years, with the constant change in the global climate, the effect of climate factors on net primary productivity (NPP) has become a hot research topic. However, two opposing views have been presented in this research area:global NPP increases with global warming, and global NPP decreases with global warming. The main reasons for these two opposite results are the tremendous differences among seasonal and annual climate variables, and the growth of plants in accordance with these climate variables. Therefore, it will fail to fully clarify the relation between vegetation growth and climate changes by research that relies solely on annual data. With seasonal climate variables, we may clarify the relation between vegetation growth and climate changes more accurately. Our research examined the arid and semiarid areas in China (ASAC), which account for one quarter of the total area of China. The ecological environment of these areas is fragile and easily affected by human activities. We analyzed the influence of climate changes, especially the changes in seasonal climate variables, on NPP, with Climatic Research Unit (CRU) climatic data and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite remote data, for the years 2000-2010. The results indicate that:for annual climatic data, the percentage of the ASAC in which NPP is positively correlated with temperature is 66.11%, and 91.47% of the ASAC demonstrates a positive correlation between NPP and precipitation. Precipitation is more positively correlated with NPP than temperature in the ASAC. For seasonal climatic data, the correlation between NPP and spring temperature shows significant regional differences. Positive correlation areas are concentrated in the eastern portion of the ASAC, while the western section of the ASAC generally shows a negative correlation. However, in summer, most areas in the ASAC show a negative correlation between NPP and temperature. In autumn, precipitation is less important in the west, as opposed to the east, in which it is critically important. Temperatures in winter are a limiting factor for NPP throughout the region. The findings of this research not only underline the importance of seasonal climate variables for vegetation growth, but also suggest that the effects of seasonal climate variables on NPP should be explored further in related research in the future.
2016, 26(1): 48-58.
doi: 10.1007/s11769-015-0775-9
摘要:
The vegetation of alpine tundra in the Changbai Mountains has experienced great changes in recent decades. Narrowleaf small reed (Deyeuxia angustifolia), a perennial herb from the birch forest zone had crossed the tree line and invaded into the alpine tundra zone. To reveal the driven mechanism of D. angustifolia invasion, there is an urgent need to figure out the effective seed distribution pattern, which could tell us where the potential risk regions are and help us to interpret the invasion process. In this study, we focus on the locations of the seeds in the soil layer and mean to characterize the effective seed distribution pattern of D. angustifolia. The relationship between the environmental variables and the effective seed distribution pattern was also assessed by redundancy analysis. Results showed that seeds of D. angustifolia spread in the alpine tundra with a considerable number (mean value of 322 per m2). They were mainly distributed in the low elevation areas with no significant differences in different slope positions. Effective seed number (ESN) occurrences of D. angustifolia were different in various plant communities. Plant communities with lower canopy cover tended to have more seeds of D. angustifolia. Our research indicated reliable quantitative information on the extent to which habitats are susceptible to invasion.
The vegetation of alpine tundra in the Changbai Mountains has experienced great changes in recent decades. Narrowleaf small reed (Deyeuxia angustifolia), a perennial herb from the birch forest zone had crossed the tree line and invaded into the alpine tundra zone. To reveal the driven mechanism of D. angustifolia invasion, there is an urgent need to figure out the effective seed distribution pattern, which could tell us where the potential risk regions are and help us to interpret the invasion process. In this study, we focus on the locations of the seeds in the soil layer and mean to characterize the effective seed distribution pattern of D. angustifolia. The relationship between the environmental variables and the effective seed distribution pattern was also assessed by redundancy analysis. Results showed that seeds of D. angustifolia spread in the alpine tundra with a considerable number (mean value of 322 per m2). They were mainly distributed in the low elevation areas with no significant differences in different slope positions. Effective seed number (ESN) occurrences of D. angustifolia were different in various plant communities. Plant communities with lower canopy cover tended to have more seeds of D. angustifolia. Our research indicated reliable quantitative information on the extent to which habitats are susceptible to invasion.
2016, 26(1): 59-67.
doi: 10.1007/s11769-015-0785-7
摘要:
In order to identify a harvesting model which is beneficial for broadleaf-Korean pine mixed forest (BKF) sustainability, we investigated four types of harvested stands which have been logged with intensities of 0(T0, control), 15% (T1, low intensity), 35% (T2, moderate intensity), and 100% (T3, clear-cutting), and examined the impacts of logging intensity on composition and structure of these stands. Results showed that there were no significant differences between T0 and T1 for all structural characteristics, except for density of seeding and large trees. The mean diameter at breast height (DBH, 1.3 m above the ground), stem density and basal area of large trees in T2 were significantly lower than in T0, while the density of seedlings and saplings were significantly higher in T2 than in T0. Structural characteristics in T3 were entirely different from T0. Dominant tree species in primary BKF comprised 93%, 85%, 45% and 10% of the total basal area in T0, T1, T2 and T3, respectively. Three community similarity indices, the Jaccard's similarity coefficient (CJ); the Morisita-Horn index (CMH); and the Bray-Curtis index (CN), were the highest for T0 and T1, followed by T0 and T2, and T0 and T3, in generally. These results suggest that effects of harvesting on forest composition and structure are related to logging intensities. Low intensity harvesting is conductive to preserving forest structure and composition, allowing it to recover in a short time period. The regime characterized by low logging intensity and short rotations appears to be a sustainable harvesting method for BKF on the Changbai Mountains.
In order to identify a harvesting model which is beneficial for broadleaf-Korean pine mixed forest (BKF) sustainability, we investigated four types of harvested stands which have been logged with intensities of 0(T0, control), 15% (T1, low intensity), 35% (T2, moderate intensity), and 100% (T3, clear-cutting), and examined the impacts of logging intensity on composition and structure of these stands. Results showed that there were no significant differences between T0 and T1 for all structural characteristics, except for density of seeding and large trees. The mean diameter at breast height (DBH, 1.3 m above the ground), stem density and basal area of large trees in T2 were significantly lower than in T0, while the density of seedlings and saplings were significantly higher in T2 than in T0. Structural characteristics in T3 were entirely different from T0. Dominant tree species in primary BKF comprised 93%, 85%, 45% and 10% of the total basal area in T0, T1, T2 and T3, respectively. Three community similarity indices, the Jaccard's similarity coefficient (CJ); the Morisita-Horn index (CMH); and the Bray-Curtis index (CN), were the highest for T0 and T1, followed by T0 and T2, and T0 and T3, in generally. These results suggest that effects of harvesting on forest composition and structure are related to logging intensities. Low intensity harvesting is conductive to preserving forest structure and composition, allowing it to recover in a short time period. The regime characterized by low logging intensity and short rotations appears to be a sustainable harvesting method for BKF on the Changbai Mountains.
2016, 26(1): 68-77.
doi: 10.1007/s11769-015-0747-0
摘要:
Seed long-distance dispersal (LDD) events are typically rare, but are important in the population processes that determine large-scale forest changes and the persistence of species in fragmented landscapes. However, previous studies focused on species dispersed via animal-mediated LDD, and ignored those dispersed by wind. The aim of this study was to assess the effects of canopy openness, edge, seed source, and patch tree density on the LDD of seeds by wind in forest. We collected birch seeds, a typical wind-dispersed species, throughout a larch plantation. We then assessed the relationship between birch LDD and each factor that may influence LDD of seeds by wind including distance to edge, canopy openness size, distance to mature forest, and the tree density of the larch plantation. We used univariate linear regression analysis to assess the influence of those factors on birch LDD, and partial correlations to calculate the contribution of each factor to LDD. The results showed that both canopy openness and edge had significant influences on birch LDD. Specifically, a negative relationship was observed between distance to edge and birch LDD, whereas there was a positive correlation between canopy openness size and LDD. In contrast, the distance to the mature forest was not correlated with birch LDD. Our results suggest that patch tree density could potently affect the probability of LDD by wind vectors, which provides novel and revealing insights regarding the effect of fragmentation on wind dynamics. The data also provide compelling evidence for the previously undocumented effect of habitat fragmentation on wind-dispersed organisms. As such, these observations will facilitate reasonable conservation planning, which requires a detailed understanding of the mechanisms by which patch properties hamper the delivery of seeds of wind-dispersed plants to fragmented areas.
Seed long-distance dispersal (LDD) events are typically rare, but are important in the population processes that determine large-scale forest changes and the persistence of species in fragmented landscapes. However, previous studies focused on species dispersed via animal-mediated LDD, and ignored those dispersed by wind. The aim of this study was to assess the effects of canopy openness, edge, seed source, and patch tree density on the LDD of seeds by wind in forest. We collected birch seeds, a typical wind-dispersed species, throughout a larch plantation. We then assessed the relationship between birch LDD and each factor that may influence LDD of seeds by wind including distance to edge, canopy openness size, distance to mature forest, and the tree density of the larch plantation. We used univariate linear regression analysis to assess the influence of those factors on birch LDD, and partial correlations to calculate the contribution of each factor to LDD. The results showed that both canopy openness and edge had significant influences on birch LDD. Specifically, a negative relationship was observed between distance to edge and birch LDD, whereas there was a positive correlation between canopy openness size and LDD. In contrast, the distance to the mature forest was not correlated with birch LDD. Our results suggest that patch tree density could potently affect the probability of LDD by wind vectors, which provides novel and revealing insights regarding the effect of fragmentation on wind dynamics. The data also provide compelling evidence for the previously undocumented effect of habitat fragmentation on wind-dispersed organisms. As such, these observations will facilitate reasonable conservation planning, which requires a detailed understanding of the mechanisms by which patch properties hamper the delivery of seeds of wind-dispersed plants to fragmented areas.
2016, 26(1): 78-89.
doi: 10.1007/s11769-015-0787-5
摘要:
The vegetation and soil are mutual environmental factors, soil characteristics, such as chemical properties and microorganism that affect the vegetation occurrence, development and succession speed. In this study, we evaluated the structure of microbial communities of rhizosphere of Cowskin Azalea (Rhododendron aureum Georgi) populations and compared with non-rhizosphere soils at four sample sites of the Changbai Mountains, China, and analyzed the correlation between chemical properties of soil and microbial communities. The results showed that microbial structure and soil chemical properties are significant superior to non-rhizosphere at all four sample sites. The rhizosphere microorganisms are mainly composed of bacteria, actinomycetes, followed by fungi least. The principal component analysis (PCA) biplot displayed that there are differences between rhizosphere and non-rhizosphere soils for microflora; Through correlation analysis, we found that the bacteria is clearly influenced by pH on the Changbai Mountains, besides pH, other soil features such as NO3-—N. These data highlight that R. aureum as the dominant vegetation living in the alpine tundra is a key factor in the formation of soil microorganism and improving soil fertility, and is of great significance for the maintenance of alpine tundra ecosystem.
The vegetation and soil are mutual environmental factors, soil characteristics, such as chemical properties and microorganism that affect the vegetation occurrence, development and succession speed. In this study, we evaluated the structure of microbial communities of rhizosphere of Cowskin Azalea (Rhododendron aureum Georgi) populations and compared with non-rhizosphere soils at four sample sites of the Changbai Mountains, China, and analyzed the correlation between chemical properties of soil and microbial communities. The results showed that microbial structure and soil chemical properties are significant superior to non-rhizosphere at all four sample sites. The rhizosphere microorganisms are mainly composed of bacteria, actinomycetes, followed by fungi least. The principal component analysis (PCA) biplot displayed that there are differences between rhizosphere and non-rhizosphere soils for microflora; Through correlation analysis, we found that the bacteria is clearly influenced by pH on the Changbai Mountains, besides pH, other soil features such as NO3-—N. These data highlight that R. aureum as the dominant vegetation living in the alpine tundra is a key factor in the formation of soil microorganism and improving soil fertility, and is of great significance for the maintenance of alpine tundra ecosystem.
2016, 26(1): 90-98.
doi: 10.1007/s11769-015-0786-6
摘要:
Alpine tundra ecosystems have specific vegetation and environmental conditions that may affect soil phosphorus (P) composition and phosphatase activities. However, these effects are poorly understood. This study used NaOH-EDTA extraction and solution 31P nuclear magnetic resonance (NMR) spectroscopy to determine soil P composition and phosphatase activities, including acid phosphomonoesterase (AcP), phosphodiesterase (PD) and inorganic pyrophosphatase (IPP), in the alpine tundra of the Changbai Mountains at seven different altitudinal gradients (i.e., 2000 m, 2100 m, 2200 m, 2300 m, 2400 m, 2500 m, and 2600 m). The results show that total P (TP), organic P (OP), OP/TP, NaOH-EDTA extracted P and AcP, PD, and IPP activities over the altitude range of 2500-2600 m are significantly lower than those below 2400 m. The dominant extracted form of P is OP (73%-83%) with a large proportion of monoesters (65%-72%), whereas inorganic P is present in lower proportions (17%-27%). The activity of AcP is significantly positively correlated with the contents of soil OP, total carbon (TC), total nitrogen (TN), and TP (P < 0.05), indicating that the AcP is a more sensitive index for responding P nutrient storage than PD and IPP. Soil properties, P composition, and phosphatase activities decrease with increased altitude and soil pH. Our results indicate that the distribution of soil P composition and phosphatase activities along altitude and AcP may play an important role in P hydrolysis as well as have the potential to be an indicator of soil quality.
Alpine tundra ecosystems have specific vegetation and environmental conditions that may affect soil phosphorus (P) composition and phosphatase activities. However, these effects are poorly understood. This study used NaOH-EDTA extraction and solution 31P nuclear magnetic resonance (NMR) spectroscopy to determine soil P composition and phosphatase activities, including acid phosphomonoesterase (AcP), phosphodiesterase (PD) and inorganic pyrophosphatase (IPP), in the alpine tundra of the Changbai Mountains at seven different altitudinal gradients (i.e., 2000 m, 2100 m, 2200 m, 2300 m, 2400 m, 2500 m, and 2600 m). The results show that total P (TP), organic P (OP), OP/TP, NaOH-EDTA extracted P and AcP, PD, and IPP activities over the altitude range of 2500-2600 m are significantly lower than those below 2400 m. The dominant extracted form of P is OP (73%-83%) with a large proportion of monoesters (65%-72%), whereas inorganic P is present in lower proportions (17%-27%). The activity of AcP is significantly positively correlated with the contents of soil OP, total carbon (TC), total nitrogen (TN), and TP (P < 0.05), indicating that the AcP is a more sensitive index for responding P nutrient storage than PD and IPP. Soil properties, P composition, and phosphatase activities decrease with increased altitude and soil pH. Our results indicate that the distribution of soil P composition and phosphatase activities along altitude and AcP may play an important role in P hydrolysis as well as have the potential to be an indicator of soil quality.
2016, 26(1): 99-108.
doi: 10.1007/s11769-015-0746-1
摘要:
In recent years, herbaceous species such as Deyeuxia angustifolia (Kom.) Y. L. Chang has invaded alpine tundra regions of the western slope of the Changbai Mountains. Because atmospheric nitrogen deposition is predicted to increase under a warming climate and D. angustifolia is sensitive to nitrogen addition, field experiments were conducted from 2010 to 2013 to determine the effect of increased nitrogen deposition on the mechanisms of D. angustifolia invasion. The goal of this study is to evaluate the impact of increased nitrogen deposition on the changes in alpine tundra vegetation (consisting mostly of Rhododendron chrysanthum Pall. and Vaccinium uliginosum Linn.). The results showed that:1) simulated nitrogen deposition affected overall characteristics and structure of R. chrysanthum and V. uliginosum communities and had a positive impact on the growth of tundra vegetation invaded by D. angustifolia; 2) R. chrysanthum was more resistant to invasion by D. angustifolia than V. uliginosum; 3) simulated nitrogen deposition could improve the growth and enhance the competitiveness of D. angustifolia, which was gradually replacing R. chrysanthum and V. uliginosum and might become the dominant species in the system in future, transforming alpine tundra into alpine meadow in the Changbai Mountains.
In recent years, herbaceous species such as Deyeuxia angustifolia (Kom.) Y. L. Chang has invaded alpine tundra regions of the western slope of the Changbai Mountains. Because atmospheric nitrogen deposition is predicted to increase under a warming climate and D. angustifolia is sensitive to nitrogen addition, field experiments were conducted from 2010 to 2013 to determine the effect of increased nitrogen deposition on the mechanisms of D. angustifolia invasion. The goal of this study is to evaluate the impact of increased nitrogen deposition on the changes in alpine tundra vegetation (consisting mostly of Rhododendron chrysanthum Pall. and Vaccinium uliginosum Linn.). The results showed that:1) simulated nitrogen deposition affected overall characteristics and structure of R. chrysanthum and V. uliginosum communities and had a positive impact on the growth of tundra vegetation invaded by D. angustifolia; 2) R. chrysanthum was more resistant to invasion by D. angustifolia than V. uliginosum; 3) simulated nitrogen deposition could improve the growth and enhance the competitiveness of D. angustifolia, which was gradually replacing R. chrysanthum and V. uliginosum and might become the dominant species in the system in future, transforming alpine tundra into alpine meadow in the Changbai Mountains.
2016, 26(1): 109-116.
doi: 10.1007/s11769-015-0761-2
摘要:
Many ecosystems extend across national or political boundaries. The consistent and effective protection of these ecosystems in transboundary areas (ETAs) is an important global research focus. Previous research on the protection of such areas can be categorized into seven themes:1) ecological conservation of a single ETA; 2) investigation of the effects of a single conservation measure on a specific ETA; 3) determination of species-level effects due to ETA conservation; 4) comparison of the same protection measures between different ETAs; 5) introduction of a single conservation measure to a specific ETA; 6) understanding the relationship between conservation and sustainable development; and 7) generalization across multiple ETA conservation cases. The protection of ETAs involves various considerations, including funding support, demand and will for collaboration, community and public participation, historical and cultural factors, political backgrounds, uniqueness of biological resources, formulation of laws and regulations, founding of specialized administrative departments, non-governmental organizations, and fairness. Here, we briefly explain the research themes and considerations related to ETA conservation. The most important finding is that most major research themes do not focus on the challenges of ETA conservation. We use two nature reserves located between China and North Korea as examples to identify specific ways to improve ETA conservation on Changbai Mountains. The efficiency of ETA administration still remains low. The study of ETA conservation should focus on concrete regional information and aim to improve existing measures through the accumulation of experience.
Many ecosystems extend across national or political boundaries. The consistent and effective protection of these ecosystems in transboundary areas (ETAs) is an important global research focus. Previous research on the protection of such areas can be categorized into seven themes:1) ecological conservation of a single ETA; 2) investigation of the effects of a single conservation measure on a specific ETA; 3) determination of species-level effects due to ETA conservation; 4) comparison of the same protection measures between different ETAs; 5) introduction of a single conservation measure to a specific ETA; 6) understanding the relationship between conservation and sustainable development; and 7) generalization across multiple ETA conservation cases. The protection of ETAs involves various considerations, including funding support, demand and will for collaboration, community and public participation, historical and cultural factors, political backgrounds, uniqueness of biological resources, formulation of laws and regulations, founding of specialized administrative departments, non-governmental organizations, and fairness. Here, we briefly explain the research themes and considerations related to ETA conservation. The most important finding is that most major research themes do not focus on the challenges of ETA conservation. We use two nature reserves located between China and North Korea as examples to identify specific ways to improve ETA conservation on Changbai Mountains. The efficiency of ETA administration still remains low. The study of ETA conservation should focus on concrete regional information and aim to improve existing measures through the accumulation of experience.
2016, 26(1): 117-128.
doi: 10.1007/s11769-015-0757-y
摘要:
Urbanization in modern times led to a series of development strategies that brought new opportunities in China. Rapid urbanization caused severe stress to the ecosystems and the environment. Using the center-of-gravity (COG) method and parameters such as population, economy, and land, we studied the urbanization pattern in Songhua River Basin and its southern source sub-basin from 1990 to 2010. Urbanization was analyzed based on the COG position, eccentric distance, movement direction of COG, and distance of COG movement. Various characteristics of urbanization in the southern source sub-basin of the Songhua River were explained in relation to the whole Songhua River Basin. Urbanization in the southern source sub-basin of the Songhua River is balanced, relatively advanced, and stable compared to the whole Songhua River Basin. The average eccentric distance between the urbanization COGs in the Songhua River's south source basin indicated rapid expansion of land urbanization during the span of this study. A basic pattern of urbanization COG in the whole Songhua Basin was observed, but there existed differences among the three aspects of urbanization process. Land urbanization is still in its active stage, so future studies should focus on analysis of such urbanization trends.
Urbanization in modern times led to a series of development strategies that brought new opportunities in China. Rapid urbanization caused severe stress to the ecosystems and the environment. Using the center-of-gravity (COG) method and parameters such as population, economy, and land, we studied the urbanization pattern in Songhua River Basin and its southern source sub-basin from 1990 to 2010. Urbanization was analyzed based on the COG position, eccentric distance, movement direction of COG, and distance of COG movement. Various characteristics of urbanization in the southern source sub-basin of the Songhua River were explained in relation to the whole Songhua River Basin. Urbanization in the southern source sub-basin of the Songhua River is balanced, relatively advanced, and stable compared to the whole Songhua River Basin. The average eccentric distance between the urbanization COGs in the Songhua River's south source basin indicated rapid expansion of land urbanization during the span of this study. A basic pattern of urbanization COG in the whole Songhua Basin was observed, but there existed differences among the three aspects of urbanization process. Land urbanization is still in its active stage, so future studies should focus on analysis of such urbanization trends.
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