Vegetation Succession Processes Research Articles

Changes in floristic and vegetation structure in a chronosequence of abandoned gold-mining lands in a tropical Amazon forest

This study analyzes floristic and vegetation structure changes during forest succession after disturbances caused by small-scale gold mining in Madre de Dios (Peru). We compared the floristic and vegetation structure of a reference forest against three sites with different periods of abandonment after mining (5, 11 and 23-years). Three 20 × 60 m plots were defined on each site, and all tree species with a DBH >1 cm within the plots were inventoried. To evaluate species diversity and similarity, the Importance Value, effective numbers of species (0D, 1D, and 2D), and Chao-Jaccard similarity index were calculated. We used the Nonmetric multidimensional scaling for similarity ordination and the PERMANOVA test to evaluate differences in floristic composition. We recorded 129 tree species in the study areas and statistically significant differences between initial and intermediate stages were observed regarding floristic composition, basal area, height, and DBH. The transition from the initial successional stage to the reference forest produces an increase in basal area, species diversity, and floristic similarity. The 23-year-old stand had more species in common with the 11-year-old stand than the reference forest. Our results showed a high proportion of pioneer species and anemochory dispersal syndrome in the initial successional stages, but they decreased in later stages of the chronosequence. The floristic and structural attributes of forests throughout the chronosequence showed a fast recovery during secondary succession. After 23 years, the recovery of tree species density was 77 % of reference forest, while the relative recovery of species composition was much slower, on average 23 %. These results provide essential information to guide the selection of suitable species in ecological restoration projects after abandonment. Implementing forest restoration strategies based on reliable information to accelerate the process of vegetation succession is critical for recuperating areas degraded by gold mining at the Peruvian Amazon.

Spatial variations of fungal community assembly and soil enzyme activity in rhizosphere of zonal Stipa species in inner Mongolia grassland

Rhizosphere soil fungal and enzyme activities affect the nutrient cycling of terrestrial ecosystems, and rhizosphere fungi are also important participants in the ecological process of vegetation succession, responding to changes in plant communities. Stipa is an excellent forage grass with important ecological and economic value, and has the spatial distribution pattern of floristic geographical substitution. In order to systematically investigate the synergistic response strategies of fungal communities and enzyme activities in the rhizosphere under the vegetation succession. Here we explored the turnover and assembly mechanisms of Stipa rhizosphere fungal communities and the spatial variation of metabolic activity under the succession of seven Stipa communities in northern China grassland under large scale gradients. The results indicated that the composition, abundance and diversity of fungal communities and microbial enzyme activities in rhizosphere soil differed among different Stipa species and were strikingly varied along the Stipa community changes over the geographic gradient. As the geographical distribution of Stipa community changed from east to west in grassland transect, Mortierellomycetes tended to be gradually replaced by Dothideomycetes. The null models showed that the rhizosphere fungal communities were governed primarily by the dispersal limitation of stochastic assembly processes, which showed decreased relative importance from S. grandis to S. gobica. Moreover, the MAT and MAP were the most important factors influencing the changes in the fungal community (richness, β-diversity and composition) and fungal community assembly, while SC and NP also mediated fungal community assembly processes. These findings deepen our understanding of the responses of the microbial functions and fungal community assembly processes in the rhizosphere to vegetation succession.

High-resolution quantitative vegetation reconstruction in the North China Plain during the early-to-middle Holocene using the REVEALS model

Understanding the process and pattern of vegetation succession during the early-to-middle Holocene can yield valuable information for better predicting future vegetation evolution. In this study, we investigated the humidity evolution pattern in the North China Plain (NCP) during the early-to-middle Holocene by employing principal component analysis on 93 fossil spectra. Furthermore, by integrating the Regional Estimates of Vegetation Abundance from Large Sites (REVEALS) model, we quantitatively reconstructed the process of vegetation succession and discussed vegetation response to climate change events. Our results indicate that the sample scores of the first principal component axis (PCA axis 1) exhibited a consistent negative bias, implying a gradual rise in regional humidity. The quantitatively reconstructed tree coverage was found to be lower than the uncorrected pollen proportions, while the coverage of herb plants showed a significant increase compared to their respective pollen percentages. In the early and middle Holocene, the vegetation of the NCP succeeded from meadow steppe (10,000 ∼ 8,100 cal yr B.P.) to meadow steppe with pine woodland patches (8,100 ∼ 7,100 cal yr B.P.), then to pine forest (7,100 ∼ 5,300 cal yr B.P.). The quantitatively reconstructed vegetation exhibited the most pronounced response to 8.2 ka climate event, with Asteraceae emerging as the dominant taxa. Furthermore, we conducted a comprehensive analysis of the impact of the 8.2 ka climate event on vegetation in northern China, identifying four distinct types of vegetation feedback: (1) negligible alterations in vegetation, (2) expansion of steppe or desert steppe, (3) proliferation of temperate tree species, and (4) augmentation of meadow steppe.

Natural revegetation has dominated annual runoff reduction since the Grain for Green Program began in the Jing River Basin, Northwest China

The Grain for Green Program (GFGP) has successfully increased the vegetation cover in northern China over the last two decades through large-scale natural and artificial revegetation approaches. Unfortunately, an obvious runoff reduction has been observed in many basins, especially on the semiarid Loess Plateau. Past studies generally attributed this runoff reduction to the artificial revegetation of the GFGP, i.e., the land cover type change from cropland to forest, since there was no significant annual precipitation decrease. Such cognition has led to widespread concern about the hydrological effects of the GFGP. In fact, in addition to artificial revegetation, natural revegetation relies on natural processes of vegetation succession without land cover type changes directed by humans. Therefore, it is necessary to separate and quantify the contributions of natural and artificial revegetation to runoff reduction to assess the GFGP and optimize revegetation in the future. In this study, the contributions of natural and artificial revegetation to annual runoff change after the implementation of the GFGP were quantified in fifteen subbasins of the Jing River Basin in the central Loess Plateau. The mean annual runoff of the Jing River Basin decreased by 11.8 mm after the GFGP, although the climate (precipitation and potential evapotranspiration) inversely increased the mean annual runoff by 6.6 mm. This is due to that the direct effect of climate change was much less than the ecohydrological effect of revegetation on runoff reduction, i.e., the revegetation caused the mean annual runoff reduction of 18.4 mm. Natural revegetation (50.5% of basin area) was the dominant reason for runoff reduction rather than artificial revegetation (9% of basin area). The natural revegetated area with vegetation quality improvement, i.e., an NDVI increase without land cover type change, contributed to a runoff reduction of 15.5 mm, accounting for 131.1% of the total runoff reduction after the GFGP, and the grassland of natural revegetation was the main vegetation type, with runoff reductions of 9.8 mm. However, artificial revegetation by area increase and quality improvement, i.e., NDVI increase, contributed to a runoff reduction of 8.4 mm, accounting for 49.6% of the total runoff reduction. These results demonstrated that the GFGP needs to be properly adjusted, i.e., natural revegetated areas should be opened in a timely manner and properly utilized, and improving vegetation quality improvement rather than increasing vegetation area would be a priority management measure in artificial revegetated areas.

Pollen-based quantitative paleoclimatic record spanning the Mid-Brunhes Event in the Nihewan Basin, north China

The Middle Pleistocene is an important period of global climatic and environmental evolution during the Quaternary. We conducted pollen analyses of 144 fossil samples and combined 1436 modern surface samples to characterize the processes of vegetation succession and climate change in the Nihewan Basin during the Middle Pleistocene, especially the Mid-Brunhes Event. The results showed that the pollen assemblages during 0.8–0.3 Ma were dominated by herbaceous pollen (> 60%), indicating that the vegetation in the study area was mainly forest steppe. The quantitative climatic reconstruction indicates that annual average temperature (Tann) was generally >6 °C, and annual average precipitation (Pann) was generally >490 mm. The warm climatic conditions persisted for a long interval, and the interval of cold conditions was shorter. Compared with the warm period, during the interval of cold climate Tann decreased by ∼4 °C, and Pann decreased by ∼130 mm. The interval of 0.478–0.424 Ma, Picea dominated the pollen assemblages (> 80%), Tann was generally <2 °C, and Pann was generally <400 mm, which may be a manifestation of the Mid-Brunhes event in the Nihewan Basin, which is corresponded with MIS 12. During this period, Northern Hemisphere insolation and the atmospheric CO2 concentration were low, the Eurasian ice sheet expanded, the winter monsoon strengthened, and the regional climate was cold and dry. The intervals of 0.742–0.478 Ma and 0.424–0.266 Ma were two pronounced warm periods in the Nihewan Basin, which correspond well with MIS 13 and MIS 11, respectively. MIS 13 was the warmest and wettest period during the studied interval, and it may have been related to the unusually strong summer monsoon caused by the climatic asymmetry between the Northern and Southern Hemispheres.

A Case Study of Initial Vegetation Restoration Affecting the Occurrence Characteristics of Phosphorus in Karst Geomorphology in Southwest China

Phosphorus (P) is one of the necessary nutrient elements in the process of plant growth and development. The temporal and spatial distribution characteristics of phosphorus content can not only reflect the soil structure and availability, but also affect the growth of wetland vegetation, the formation of the environment, and the process of vegetation succession. In this paper, taking Guizhou Caohai Nature Reserve as the research object, the temporal and spatial substitution method was used to study the distribution and influencing factors of soil total phosphorus (TP) and soil available phosphorus (AP) under different geomorphological environments (non-karst landforms, karst landforms, and geomorphology after vegetation restoration (5 years)). The results showed that (1) the TP content in the topsoil of the restored vegetation landform was generally higher than that in the topsoil of the karst landform and non-karst landform, and the distribution difference of the AP content in the three areas was slight. At the top, hillside, and foot of the mountain, the contents of TP and AP in the non-karst landform and karst landform decreased with increasing soil depth and accumulated at the foot of the mountain. (2) The results of the correlation analysis showed that the interpretation rates of TP and AP by each soil physicochemical factor were the highest, reaching 64–86%, while the interpretation rate of TP and AP by the combined action of multiple physicochemical factors was relatively small; in addition, there was a significant correlation between environmental factors and soil TP and AP (p &lt; 0.05). (3) Compared with unrepaired karst landforms, in the process of vegetation restoration (5 years), TP content has convergence between geomorphology after vegetation restoration and non-karst landforms, while AP content fluctuates greatly. The analysis showed that the changes in soil TP and AP contents were mainly affected by vegetation communities, while the changes in soil TP and AP contents in mountain areas were also affected by soil organic matter, pH, soil particle size, and climatic conditions.

Vegetation composition on peatlands with different fire frequency in Musi Banyuasin, South Sumatra

Peatlands that experience fire have the ability to restore their own environment through a process of vegetation succession. Areas with different frequency of fires have different vegetation dominance. Observations were made on areas that experienced a frequency of one, two, three and four times burned. The purpose of this study was to explain the differences in vegetation that make up areas with different fire frequencies. Vegetation growth rates of saplings and understorey were found in all burnt frequency areas, seedling growth rates were found in areas one and three times burned, pole growth rates were found in one burnt area and tree growth rates were found in areas one and two burns. The growth rate of saplings in the one-time burns frequency area was dominated by Sepongol vegetation, the two-burn frequency area was dominated by Bangun -anguns and the three and four-time burnt frequency areas were dominated by Melastoma malabatrihcum. Lower plants in areas with a frequency of one, two and three times burned were dominated by Asplenium longissimum and in areas with four times the frequency of burns was dominated by Athyrium esculentum.

Late Holocene transition from natural to anthropogenic forcing of vegetation change in the semi-arid region of northern China

Understanding the vegetation response to climate change and human activities during the Holocene may help predict the future trajectory of vegetation change. Moreover, in the semi-arid region of northern China, it may also provide a scientific basis for addressing ecological problems and achieving sustainable development goals. Based on 5 AMS 14C dates and 259 fossil pollen samples from the sediments of Lake Gouchi in Shaanxi Province, China, we reconstructed the pattern and process of vegetation succession in the monsoon margin area since the mid-Holocene. Combined with records of regional monsoonal precipitation and archaeological data, we use the results to evaluate changes in the relationship between vegetation, climate change and human activities. The vegetation development during 8–1 ka (1 ka = 1000 cal a BP, BP = before present, where “present” is 1950 AD) was mainly controlled by natural climate change. Optimum vegetation conditions occurred during 7.8–5.3 ka when the monsoon precipitation was the strongest. The vegetation during this interval was mainly grassland with Artemisia. Meanwhile, the percentage of hygrophytes reached its maximum. During 5.3–1 ka, the monsoon precipitation decreased and the proportion of xerophytes increased, while the proportion of hygrophytes decreased. After ∼1 ka, human activities became the dominant driver of vegetation change. The proportion of xerophytes increased during the Medieval Warm Period (MWP, 1000–1300 AD), while the proportion of hygrophytes increased during the early stage of the Little Ice Age (LIA, 1400–1900 AD). This suggests that the shifts between the humid climate of the MWP and the arid climate of the LIA had relatively little influence on the vegetation. The pollen of anthropochores increased substantially after ∼1 ka, together with an increase in the sediment accumulation rate at Lake Gouchi. Thus, it is likely that human activity began to significantly affect the evolution of the regional vegetation as early as ∼1000 years ago. A synthesis of the timing of the transition from natural to anthropogenic forcing of vegetation change in China reveals pronounced spatial differences. In northern China human activity began to dominate vegetation change from ∼2 to 1 ka (especially since 1 ka), while in southern China, a significant human impact on the vegetation occurred much earlier, during ∼5-3 ka. In the future, under the combined effects of a drying climate and the further intensification of human activities in northern China, it will become increasingly important to implement science-based environmental planning in order to restore the regional vegetation and promote the sustainable development of the terrestrial ecosystems of the region.

Changes in Soil Physical and Chemical Properties during Vegetation Succession on Miyake-jima Island

The bare lands formed after volcanic eruptions provide an excellent opportunity to study the interactions between vegetation succession and soil formation. To explore the changes in soil physicochemical properties in the vegetation succession processes and the relationship between them, soil physicochemical properties of different volcanic ash accumulation on Miyake-jima Island were studied at different vegetation succession stages. The results showed that soil bulk density gradually decreased and that soil porosity, soil water content (SWC), pH, cation exchange capacity (CEC), soil total organic carbon (TOC), and total nitrogen (TN) increased significantly with vegetation succession. The physicochemical properties changes in the soil surface horizon were most obvious, and the deep soil accumulated a large amount of relatively stable soil carbon and nitrogen. The forest land formed a thicker organic matter horizon, accumulating more carbon and nitrogen than grassland, and the soil quality index (SQI) was higher than that of grassland and shrubland. In conclusion, our research indicates the significant change in soil physicochemical properties and the improvement in soil quality in the vegetation succession processes, emphasizing a significant relationship between vegetation succession and soil development in bare land.

Spatial characteristics of soil δ13C and δ15N reveal shrub-induced successional process in a coastal wetland

Woody plant encroachment into grasslands is a worldwide phenomenon. Still, there is a research gap in quantifying the ecological processes of coastal wetland ecosystems. Here, we combined soil stable isotope technology with geostatistical methods to quantify the spatial characteristics of soil δ13C and δ15N in a coastal wetland experiencing native shrub Tamarix chinensis encroachment in the Yellow River Delta (YRD), China, and to clarify the possible mechanisms by which shrub-induced successional processes determined the spatial distribution of soil δ13C and δ15N. The results showed that soil δ13C and δ15N significantly decreased from bare land to grass and to shrub at the vegetation type level. Pearson correlation showed that soil δ13C and δ15N were positively related to soil salinity, but negatively related to plant variables (grass cover, shrub crown width and above-ground biomass). Scaling method indicated that soil δ13C variation occurred at two different scales, 40 m and 150 m, representing influences of shrub T. chinensis and environmental heterogeneity, respectively. Soil δ15N variation was observed to occur at the 75 m scale, suggesting the combination effect of T. chinensis and Suaeda glauca-dominated grass species. Furthermore, other soil and plant variables also exhibited two-scale characteristics similar to soil δ13C. Therefore, the vegetation succession processes of coastal wetlands experiencing shrub encroachment could be understood well by combining soil stable isotope with GIS spatial tools. The spatial characteristics of soil stable isotopes help us establish strategies for protecting and managing coastal wetlands.

Vegetation restoration and organic matter accumulation on former agricultural lands in the boreal zone of Russia

This work investigates the influence of vegetation succession processes on the soil changes of former arable lands. It was noted that on post-agricultural soils, accumulation of organic matter in the soil differs, depending on the state of the land plot. The analysis shows that influence of vegetation on the accumulation of organic matter in the former arable horizon has a distinctly linear nature. The dominant species are mesotrophic and mesophyte plants, requiring little more than soils with mineral nutrients and sufficient humidity. The amount of organic matter accumulated in the upper horizon of the soil is greater than that of the underlying horizon. The content of organic matter in the soil horizons of the studied area is characterized by a distinct decreasing pattern in the direction from the forest edge to the field edge. Overall, it can be noted that farther away from the forest edge, the soils change from moderately acidic to slightly acidic. At this stage, depending on the succession state of the post-agricultural soil plot, the amount of organic matter in it is determined either by the species forming the soil cover and (or), to a greater extent, by tree and shrub vegetation. The optimum of the organic matter accumulation shifts to the zone with a large share of tree species.

Long-term forest succession improves plant diversity and soil quality but not significantly increase soil microbial diversity: Evidence from the Loess Plateau

Many studies have focused on the processes of vegetation succession, however, the dynamics of soil microbes and the synergy between vegetation and soil are still poorly understood following vegetation succession. This study focused on a forest succession sequence including farmland, grassland, shrubland (i.e., Hippophae rhamnoides), pioneer forest (i.e., Populus davidiana), and climax forest (i.e., Quercus liaotungensis) on the Loess Plateau of China, to explore plant and soil changes, as well as soil microbial community dynamics. The results showed that litter biomass, soil organic carbon (SOC), total nitrogen (TN) and the ratio of SOC to TN exhibited an increasing trend in the whole process of the forest succession, and NH4+, microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and the ratio of dissolved organic carbon (DOC) to dissolved organic nitrogen (DON) had significantly increased before the shrubland stage, and then they were going to be stable. During the forest succession, the main bacterial phyla present were Proteobacteria, Actinobacteria, and Acidobacteria, and the predominant fungal phyla were Ascomycota and Basidiomycota. The soil microbial community composition was stable and did not change significantly, but the bacteria and fungal communities were associated with specific plant or soil properties. It was proved that the change of soil microbial community was closely related to vegetation and soil community changes. The results suggested that long-term forest succession not only improves plant diversity, but also improves soil biology and quality, even though it does not significantly increase soil microbial diversity. The findings enhance the understanding of the impact of soil microbial ecological characteristics and provide an important guidance for the sustainable management of forest ecosystems following long-term natural vegetation restoration.

Pollen record of precipitation changes during the Younger Dryas and Early Holocene in the North China Plain

The Younger Dryas event, which was the most recent millennial-scale cold event, had a major impact on the global environment. However, there were substantial regional differences in precipitation during the Younger Dryas. Ningjinpo Lake was formed at the end of Late Pleistocene and was formerly the largest lake in the North China Plain. Its sedimentary record is well suited for studying environmental changes during the Younger Dryas. We used pollen and grain-size analyses of 69 lake sediment samples, combined with 1190 modern surface samples and a radiocarbon chronology, to characterize the processes of vegetation succession and precipitation change during the Younger Dryas and Early Holocene in the Ningjinpo area of North China Plain. The results show that during the Younger Dryas the sediments were relatively coarse-grained and the pollen assemblages were dominated by herb taxa such as Poaceae, Artemisia, and Asteraceae, indicating that the vegetation was mainly meadow steppe or forest meadow, and that the climate was generally dry. The annual average precipitation was ~510 mm, which was ~100 mm lower than today. However, four events of enhanced centennial-scale precipitation are evident in the record, characterized by increases in tree pollen representation: during 12,350–12,250, 12,200–12,100, 11.900–11,800 and 12,650–12,550 cal yr B.P. During these events, precipitation was ~50 mm higher than before and afterwards. In the late part of the Younger Dryas (after 12,100 cal yr B.P.), the representation of tree pollen increased, indicating an increase in forest dominated by Pinus and Betula, and precipitation increased to ~560 mm. After 11,440 cal yr B.P., at the beginning of the Holocene, the arboreal pollen percentages exceeded 60%, indicating that the regional vegetation was dominated by Pinus, Ulmus and Quercus forest, and the annual average precipitation was ~620 mm, which was close to that of today.

Late Pliocene and early Pleistocene vegetation and climate change revealed by a pollen record from Nihewan Basin, North China

The Nihewan Formation is an important early Quaternary sedimentary formation in North China. We conducted pollen analyses of 183 samples and 1611 modern surface samples to characterize the processes of vegetation succession and climate change during the Pliocene-Pleistocene transition (2.89–2.34 Ma) in the Nihewan Basin. The results show that pollen assemblages are dominated by arboreal pollen, indicating that the vegetation in the study area was forest dominated and that the climate was more humid than today, however, the temperature varied substantially. The most substantial vegetation and climate changes occurred at ∼2.8 Ma, when the pollen representation of warm and humid tolerant taxa such as evergreen Quercus and Carya disappeared, and also broadleaved deciduous types such as Ulmus, deciduous Quercus and Betula decreased obviously, on the contrary, the pollen representation of cold and drought tolerant taxa increased substantially: e.g. Picea (from generally less than 20% to more than 30%) and Chenopodiaceae (from generally less than 10% to more than 20%). The quantitative reconstructed results indicating that Tann decreased by about 2–3 °C and Pann decreased by ∼150 mm compared to before 2.8 Ma, with a maximum decrease of ∼9 °C for Tann and ∼450 mm for Pann. Another important vegetation and climate changes occurred at ∼2.6 Ma, which was the coldest and driest of the studied interval, when the vegetation was substantially simplified with spruce (generally above 80%) as the dominated types.

Effects of Vegetation Pattern and Spontaneous Succession on Remediation of Potential Toxic Metal-Polluted Soil in Mine Dumps

The ecological rehabilitation of potential toxic metal-contaminated soils in sites disturbed by mining has been a great challenge in recent decades. Phytoremediation is one of the most widely promoted renovation methods due to its environmental friendliness and low cost. However, there is a lack of in situ investigation on the influence of vegetation pattern and spontaneous succession on the rehabilitation of potential toxic metal-polluted soil. To clarify how the vegetation pattern in the early stage of restoration and the spontaneous succession influence the remediation of the soil, we investigated a metal mining dump in Sichuan, China, by field investigation and laboratory analysis. We determined the plant growth, soil fertility, and the capacity of potential toxic metals (PTMs) in metal mining soil under different initial vegetation patterns for different years to understand the role of vegetation pattern and spontaneous succession in PTM pollution phytoremediation projects. The results show that: (1) Phytoremediation with a simple initial vegetation pattern (RP rehabilitative plant pattern) which involves two rehabilitation plants, Agave sisalana and Neyraudia reynaudiana, achieves a PTM pollution index that is 9.28% lower than that obtained with the complex vegetation pattern (RP&amp;LP rehabilitation plants mixed with local plants pattern), 21.86% lower in the soil fertility index, and 73.69% lower in the biodiversity index; (2) The phytoremediation with the 10-year RP&amp;LP pattern was associated with a PTM pollution index that was 4.04% higher than that for the 17-year RP&amp;LP pattern, a soil fertility index that was 4.48% lower, and a biodiversity index that was 12.49% lower. During the process of vegetation succession, if accumulator plants face inhibition of growth or retreat, the reclamation rate will decrease. The vegetation patterns influence the effect of phytoremediation. Spontaneous vegetation succession will cause the phytoremediation process to deviate from the intended target. Therefore, according to the goal of vegetation restoration, choosing a suitable vegetation pattern is the main premise to ensure the effect of phytoremediation. The indispensable manipulation of succession is significant during the succession series, and more attention should be paid to the rehabilitative plants to ensure the stable effect of reclamation. The results obtained in this study could provide a guideline for the in situ remediation of PTM-polluted soil in China.

五大连池新期火山熔岩台地不同植被类型土壤微生物群落的功能多样性

PDF HTML阅读 XML下载 导出引用 引用提醒 五大连池新期火山熔岩台地不同植被类型土壤微生物群落的功能多样性 DOI: 10.5846/stxb201808051668 作者: 作者单位: 哈尔滨师范大学地理科学学院,黑龙江省科学院自然与生态研究所,黑龙江省科学院自然与生态研究所,黑龙江省科学院自然与生态研究所,黑龙江省科学院自然与生态研究所,黑龙江省科学院自然与生态研究所,黑龙江省科学院自然与生态研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31770497）；黑龙江省院所基本应用技术专项（ZNBZ2017ZR-08/ZNJZ2019ZR-01）；黑龙江省科学院杰出青年项目（CXJQ2018ZR03） Effect of vegetation type on the diversity of soil microbial communities at the new stage Volcanic Lava Platform, Wudalianchi area, Northeast China Author: Affiliation: College of Geological Science,Harbin Normal University,Institute of Natural Ｒesources and Ecology,Science Academy of Heilongjiang Province,Institute of Natural Ｒesources and Ecology,Science Academy of Heilongjiang Province,Institute of Natural Ｒesources and Ecology,Science Academy of Heilongjiang Province,Institute of Natural Ｒesources and Ecology,Science Academy of Heilongjiang Province,Institute of Natural Ｒesources and Ecology,Science Academy of Heilongjiang Province,Institute of Natural Ｒesources and Ecology,Science Academy of Heilongjiang Province Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:土壤微生物群落是陆地生态系统的重要生物活性成分，其结构和功能多样性直接影响到系统的碳、氮等生态过程，微生物群落功能多样性与地上植被类型变化密切相关，开展植被类型对土壤微生物群落功能多样性的影响研究具有重要意义。以五大连池新期火山熔岩台地苔藓、草本、灌丛、矮曲林、针阔混交林5种典型植被类型为对象，利用BIOLOG微孔板法研究不同演替阶段植被类型土壤微生物群落功能多样性特征。结果表明：不同植被类型土壤微生物群落功能多样性存在显著差异。平均颜色变化率（AWCD）随培养时间延长而逐渐增加，大小顺序为：苔藓 > 针阔混交林 > 矮曲林 > 草本 > 灌丛。灌丛土壤微生物多样性指数与其他植被类型间差异显著。主成分分析结果表明，主成分1和主成分2分别能解释变量方差的56.24%和29.59%，不同植被类型下土壤微生物的碳源利用格局差异主要是由氨基酸类和带磷基糖类引起，二者合计解释总变异量的47.51%。冗余分析表明，速效磷、铵态氮、C：N和pH对微生物功能多样性具有显著的影响，羧酸类、氨基酸类、酯类和胺类的降解更易受到环境因素的影响。研究结果为进一步探讨植被类型与土壤微生物之间在植被演替过程中的关系提供参考。 Abstract:Soil microorganisms are an important component of ecosystems and play an important role in the succession of new volcanic environments and vegetation. Furthermore, vegetation type is one of the most important factors influencing the functional diversity of soil microbial communities. However, the influence of vegetation types on soil microbial diversity during the process of vegetation succession, especially primary succession, remain poorly understood. Accordingly, the present study used a spatial, rather than temporal, approach to investigate the differences and changes of soil microbial community function in different stages of primary succession and to establish a basis for studying co-evolutionary relationships between soil microbial community function and environmental factors in the new volcanic lava platform. The aim of the study was to investigate the microbial characteristics of soil at different successional stages; Biolog microplate analysis was used to investigate the functional diversity of microbial communities associated with five typical vegetation types (i.e., moss, herbs, shrubs, elfin woods, and mixed broadleaf-conifer forest) at a new volcanic lava platform in the Wudalianchi area of China. Vegetation type had a significant effect on the functional diversity of the soil microbial communities. The average well colour development, which reflects soil microbial activity and functional diversity, increased with increasing incubation time and varied as follows:moss > mixed broadleaf-conifer forest > elfin woods > herbs > shrubs. The soil microbial diversity indices of the shrubs were significantly different than those of the other vegetation types. Principal component analysis identified two principal component factors that were related to carbon sources and explained 56.24% and 29.59% of the variance, respectively. Differences in the utilization of carbon sources by the soil microbial communities of different vegetation types were mainly caused by amino acids and carbohydrates containing phosphate rest, which explained 47.51% of the total variation. Redundancy analysis showed that available phosphorus, NH4+-N, C/N, and pH had significant effects on microbial functional diversity. The degradation of carboxylic acids, amino acids, esters, and amines was more susceptible to environmental factors. These findings provide a reference for future studies regarding the complex interactions between vegetation type and soil microbes under different states of vegetation succession. 参考文献 相似文献 引证文献

Post-Fire Vegetation Succession and Surface Energy Fluxes Derived from Remote Sensing

The increasing frequency of fires inhibits the estimation of carbon reserves in boreal forest ecosystems because fires release significant amounts of carbon into the atmosphere through combustion. However, less is known regarding the effects of vegetation succession processes on ecosystem C-flux that follow fires. This paper describes intra- and inter-annual vegetation restoration trajectories via MODIS time-series and Landsat data. The temporal and spatial characteristics of the natural succession were analyzed from 2000 to 2016. Finally, we regressed post-fire MODIS EVI, LST and LSWI values onto GPP and NPP values to identify the main limiting factors during post-fire carbon exchange. The results show immediate variations after the fire event, with EVI and LSWI decreasing by 0.21 and 0.31, respectively, and the LST increasing to 6.89 °C. After this initial variation, subsequent fire-induced variations were significantly smaller; instead, seasonality began governing the change characteristics. The greatest differences in EVI, LST and LSWI were observed in August and September compared to those in other months (0.29, 6.9 and 0.35, respectively), including July, which was the second month after the fire. We estimated the mean EVI recovery periods under different fire intensities (approximately 10, 12 and 16 years): the LST recovery time is one year earlier than that of the EVI. GPP and NPP decreased after the fire by 22–45 g C·m−2·month−1 (30–80%) and 0.13–0.35 kg C·m−2·year−1 (20–60%), respectively. Excluding the winter period, when no photosynthesis occurred, the correlation between the EVI and GPP was the strongest, and the correlation coefficient varied with the burn intensity. When changes in EVI, LST and LSWI after the fire in the boreal forest were more significant, the severity of the fire determined the magnitude of the changes, and the seasonality aggravated these changes. On the other hand, the seasonality is another important factor that affects vegetation restoration and land-surface energy fluxes in boreal forests. The strong correlations between EVI and GPP/NPP reveal that the C-flux can be simply and directly estimated on a per-pixel basis from EVI data, which can be used to accurately estimate land-surface energy fluxes during vegetation restoration and reduce uncertainties in the estimation of forests’ carbon reserves.

Vegetation succession processes and fluvial dynamics of a mobile temperate riparian ecosystem: the lower Allier River (France)

Many riparian ecosystems in European temperate regions have lost their inherent, highly dynamic character due to human-induced impacts such as river channelization and low regulation. he lower course of the Allier River (France) is one of the last remaining free meandering river segments, and thus, constitutes an opportunity to investigate riparian succession processes of a dynamic, temperate river system. We analyzed (i) the dynamics of the succession phases based on eight sets of aerial images of the riparian corridor over the last five decades (1967-2014), (ii) the dominant succession trajectories and (iii) their relation with the Allier River low regime. Results revealed that the study site was characterized by a shifting habitat mosaic between 1967 and 2005, whilst floods did not change the overall habitat composition of the riparian corridor but their distribution in space. After the year 2005, progression and retrogression processes have been drastically reduced, with an increase of stability (i.e. no more channel migration and neither progression nor retrogression of patches), and a concomitant reduction of high and moderate magnitude floods. his study depicts a clear threshold of trajectory change in succession processes since the beginning of the 21st century and facilitates a better understanding of future trajectories under current global climate change.

Plant community composition and interspecific relationships among dominant species on a post-seismic landslide in Hongchun Gully, China

The 5.12 Earthquake in 2008 and 8.14 Debris Flow in 2010 resulted in large-scale landslides that disturbed vast areas of vegetation in the Hongchun Gully, Wenchuan County, China. To define the specific characteristics of vegetation restoration during natural recovery after catastrophic events, vegetation species composition and interspecific associations were investigated on this typical landslide. Field survey data selected from a total of 51 sample plots belonged to seven belt transects and were analysed by Schluter’s variance ratio, pearson's chi-squared test, Spearman’s correlation coefficients and ecological species groups. Plant communities on the landslide consisted of 78 species, 65 genera and 52 families. Of the total of 78 species, 25 are identified as dominant species, among which Camptotheca acuminate, Toxicodendron vernicifluum, Coriaria nepalensis, Robinia pseudoacacia, Buddleja alternifolia, Anemone vitifolia and Nephrolepis auriculata play a constructive role during the natural afforestation. Moreover, according to environmental and ecological factors, these 25 dominant species could be divided into four ecological species groups. This study found that even though the landslide had frequently suffered from interference due to heavy rain, the vegetation succession processes are ongoing, and it is now at a shrub–herb community succession stage, which indicates that vegetation can naturally recover in the denuded sites. This study provides a useful insight into the ecological interactions and interdependence between plant species during the natural recovery of vegetation and provides valuable information on vegetation recovery modelling in the landslide area.

三峡工程运行后对洞庭湖湿地的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 三峡工程运行后对洞庭湖湿地的影响 DOI: 10.5846/stxb201503300611 作者: 作者单位: 中国科学院生态环境研究中心,中国科学院生态环境研究中心 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点基础研究发展计划（973）项目（2009CB421103）；国家水体污染控制与治理科技重大专项课题（2014ZX07405-003） Effects of three gorges dam project on dongting lake wetlands Author: Affiliation: Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:长江三峡工程建成运行后，其下游第一个大型通江湖泊——洞庭湖的水文、水质以及湿地环境等均发生了很大变化。三峡工程已经开始影响到洞庭湖的泥沙淤积、水位波动、水质以及植被演替等。以三峡水库调度运行方案、河湖交互作用和洞庭湖湿地植被分布格局为基础，从长江三峡工程对洞庭湖水文、水质以及湿地植被演替等方面综述了三峡工程对洞庭湖湿地的综合影响。三峡工程减缓了长江输入洞庭湖泥沙的淤积速率，对短期内增加洞庭湖区调蓄空间、延长洞庭湖寿命有利。总体上减少了洞庭湖上游的来水量，改变了洞庭湖原来的水位/量变化规律。给洞庭湖水环境质量造成了直接或间接的影响，对其水质改变尚存一定争议，但至少在局部地区加剧了污染。水位变化和泥沙淤积趋缓协同改变了洞庭湖湿地原有植被演替方式，改以慢速方式演替，即群落演替的主要模式为：水生植物-虉草或苔草-芦苇-木本植物。展望了今后的研究趋势与方向，为三峡工程与洞庭湖关系的进一步研究提供参考。 Abstract:The Three Gorges Dam Project (TGP) on the Yangtze River is the world's largest hydropower complex project. Dongting Lake is the first large lake downstream of the TGP, and substantial changes have been noted in the hydrological regimes, water quality, and wetland environments since the TGP began operation. This review summarizes the influence of the TGP on Dongting Lake based on the reservoir dispatch scheme, interaction between the river and lake, and vegetation distribution patterns of lake wetlands. The TGP reduced the sediment discharge from the Yangtze River to Dongting Lake and slowed the sediment deposition rate. This was beneficial for the lake in the short term because it increased water regulation space and extended the life of Dongting Lake. The TGP reduced water inflow from upstream and changed the variation pattern in water level. The TGP exerted direct and indirect effects on water quality of Dongting Lake. There are still controversies regarding water quality impacts of the TGP operation on Dongting Lake, and the TGP has exacerbated pollution in some regions. Reduced water level variation and sedimentation have jointly changed the process of vegetation succession in Dongting Lake. The succession rate becomes slow, and the vegetation succession sequence is aquatic plants, Phalaris arundinacea or Carex sp., Phragmites australis, and ligneous plants. Trends and directions of future research on these subjects are discussed. This study will provide a reference for further studies on the relationships between Dongting Lake and the TGP. 参考文献 相似文献 引证文献