Monsoon Evergreen Broad-leaved Forest Research Articles

Climatic drivers of litterfall production and its components in two subtropical forests in South China: A 14-year observation

Understanding the climatic triggers of litterfall production is essential for simulating nutrient cycling in forest ecosystems. However, the mechanisms underlying litterfall dynamics in subtropical forests remain unclear because of the complex canopy phenological strategies. Herein, we explored this by investigating a unique litterfall dataset (including components such as leaves, branches, flowers and fruits, and miscellaneous, etc.) spanning a 14-year observation period (2005–2018) in two typical subtropical evergreen forest ecosystems in South China: a mixed conifer-broadleaf forest (MF) and a monsoon evergreen broadleaved forest (MEBF). We found that the annual total litterfall production, often dominated by leaf litterfall, was significantly higher in MF (10.21 ± 2.09 t∙hm−2) than in MEBF (7.74 ± 2.21 t∙hm−2) (P < 0.01). Generally, forest litterfall production occurred mostly during the wet season and was profoundly correlated with the monthly maximum wind speed (rMF = 0.70, rMEBF = 0.71, P < 0.01), it contributed exceeded 80% to the total litterfall and the leaf and branch components. Whereas during the dry season, the forest litterfall process was dramatically weakened, showing a significant correlation with the mean temperature (rMF = 0.48, rMEBF = 0.68, P < 0.01). Further analysis showed that during the dry season, the cumulative contribution rates of temperature factors to the total litterfall and the leaf and branch components exceeded 60%, indicating a leading role of temperature in triggering forest litterfall processes. Notably, when excluding the typhoon disturbances, it is observed that temperature, alongside wind speed, emerges as a significant determinant of forest litterfall production during the wet season. Those two factors collectively account for almost 60% of the total litterfall and the leaf and branch components. Our findings have potential significance in improving our understanding of carbon and nutrient cycling in subtropical forest ecosystems under climate change conditions.

Morphology, phylogeny and host specificity of two new Ophiocordyceps species belonging to the "zombie-ant fungi" clade (Ophiocordycipitaceae, Hypocreales).

Species of the genus Ophiocordyceps, which include species able to manipulate the behaviour of ants, are known as the "zombie-ant fungi" and have attracted much attention over the last decade. They are widespread within tropical, subtropical and even temperate forests worldwide, with relatively few reports from subtropical monsoon evergreen broad-leaved forest. Fungal specimens have been collected from China, occurring on ants and producing hirsutella-like anamorphs. Based on a combination of morphological characters, phylogenetic analyses (LSU, SSU, TEF1a, RPB1 and RPB2) and ecological data, two new species, Ophiocordycepstortuosa and O.ansiformis, are identified and proposed herein. Ophiocordycepstortuosa and O.ansiformis are recorded on the same species of Colobopsis ant, based on phylogenetic analyses (COI), which may be sharing the same host. Ophiocordycepstortuosa and O.ansiformis share the morphological character of producing lanceolate ascospores. They have typical characteristics distinguished from other species. The ascospore of O.tortuosa are tortuously arranged in the ascus and the ascospore of O.ansiformis have a structure like a handle-shape in the middle. Our molecular data also indicate that O.tortuosa and O.ansiformis are clearly distinct from other species.

A dataset of bird checklist and community characteristics during breeding and wintering seasons in typical forest ecosystems of Dinghushan (2015–2018)

Bird diversity and its community structure are important indicators for the long-term monitoring of biodiversity in ecosystems. Three typical forest vegetation types have been well preserved in Dinghushan National Nature Reserve, including the monsoon evergreen broad-leaved forest, the mixed Pinus massoniana/broad-leaved forest and the Pinus massoniana coniferous forest. In particularly, the monsoon evergreen broad-leaved forest has a conservation history of more than 400 years without any human disturbance. The dataset consists of organized data on the long-term monitoring of bird communities during breeding and wintering seasons from 2015 to 2018 in all three forest types. Field surveys recorded information such as bird species, number, time, distance, ground height, habitat type, activity substrate and behavior. Moreover, we carried out various data analyses of diversity index, evenness index, dominance index, similarity coefficient of bird community and occurrence frequency, individual number, as well as average density of bird species in different survey periods. The dataset includes a total of 89 species from 9 orders and 35 families. This dataset provides valuable information for future studies on bird communities, and for better understanding inter-species interaction between multiple groups of plants and animals. It is further expected to support the protection and management of forest ecosystems in this region.

Community structure and species diversity dynamics of a subtropical evergreen broad-leaved forest in China: 2005 to 2020

Here, we characterize the temporal and spatial dynamics of forest community structure and species diversity in a subtropical evergreen broad-leaved forest in China. We found that community structure in this forest changed over a 15-year period. Specifically, renewal and death of common species was large, with the renewal of individuals mainly concentrated within a few populations, especially those of Aidia canthioides and Cryptocarya concinna. The numbers of individual deaths for common species were concentrated in the small and mid-diameter level. The spatial distribution of community species diversity fluctuated in each monitoring period, showing a more dispersed diversity after the 15-year study period, and the coefficient of variation on quadrats increased. In 2010, the death and renewal of the community and the spatial variation of species diversity were different compared to other survey years. Extreme weather may have affected species regeneration and community stability in our subtropical monsoon evergreen broad-leaved forests. Our findings suggest that strengthening the monitoring and management of the forest community will help better understand the long- and short-term causes of dynamic fluctuations of community structure and species diversity, and reveal the factors that drive changes in community structure.

Microbial network complexity and diversity together drive the soil ecosystem multifunctionality of forests during different woodland use intensity in dry and wet season

Global change (e.g., woodland use change) affects ecosystem functioning directly by modifying various physicochemical processes and indirectly by altering biological metabolism and interactions. To determine whether woodland use intensity (WUI) affects soil ecosystem multifunctionality (EMF) via microbial diversity and network complexity and whether the dry and wet season drivers are the same. We analyzed the relationships of soil EMF to soil microbial (bacteria and fungi) diversity and network complexity, considering the WUI in the monsoon evergreen broad-leaved forest in dry and wet seasons in subtropical China. The findings showed that with increasing of WUI, soil microbial (bacteria and fungi) diversity increased, whereas soil EMF decreased. The microbial network complexity decreased in the dry season but increased in the wet season. Soil EMF was jointly regulated by indirect effects from WUI in addition to microbial diversity and network complexity. WUI and abiotic factors can indirectly affect soil EMF through microbial diversity and network complexity, among which soil water content is the main environmental factor affecting soil EMF in dry season, and fungal diversity is the main factor affecting soil EMF in wet season. In addition to demonstrating how multiple anthropogenic drivers differ in their impact via different pathways on soil EMF components, our results will facilitate the prediction of ecosystem responses to multiple simultaneous environmental changes.

Consistent effects of nitrogen addition on soil microbial communities across three successional stages in tropical forest ecosystems

Global nitrogen (N) deposition has been having broad impacts on soil microorganisms. It remains unclear how soil microbial biomass and community structure respond to elevated N deposition during forest succession, especially in tropical forest ecosystems. In this study, we conducted a field manipulative experiment of long-term N addition (14 years) at three levels (CK, LN, MN, which stand for 0, 50 kg N ha−1 yr−1 and 100 kg N ha−1 yr−1) along a 3-step succession sequence of tropical forests (early stage: a pine conifer forest, CF; middle stage: a mixed pine conifer and broad-leaved forest, MF; and late stage: a monsoon evergreen broad-leaved forest, BF), and investigated the responses of microbial composition, biomass and community structure using fumigation-extraction and phospholipid fatty acid (PLFA) methods. We found that: 1) Microbial biomass (microbial biomass carbon and nitrogen and PLFA contents) remained stable under long-term N addition, even though N addition significantly increased soil N nutrients (P < 0.05); it increased significantly with forest succession (P < 0.05), and was dominated by soil water content, which was not affected by N treatment; 2) microbial community structure was significantly changed by N addition, but not by forest succession. N addition, especially MN, significantly increased the ratio of cyclopropyl to its precursor (cyc/pre) in the MF and BF (P < 0.05), and cyc/pre of the BF showed the highest correlations with ammonium-N, nitrate-N and electrical conductivity (>0.85, P < 0.05). Consistently, the pure N treatment effect could explain 71.13% of the variance of cyc/pre; and 3) N treatment contributed more variance to the fungal community than to the bacterial community. Our results indicated that soil microbial community structure was more sensitive to N addition than community biomass under long-term N addition, and the structure would be more severely altered under N addition during forest succession or with the increase in N input.

A dataset of groundwater level in the small watershed of Dinghushan Forest (2002 – 2020)

Groundwater is one of the important components in the hydrological cycle of the basin. Its dynamic change is of great value for understanding the hydrological regulation mechanism, the cycle of material elements and ecosystem service function of terrestrial ecosystem. Covered with subtropical monsoon evergreen broad-leaved forest and its transitional vegetation types, Dinghushan National Nature Reserve has been well protected since the 1950s. Dinghushan Forest Ecosystem Research Station set up four groundwater level observation wells downstream of the complete catchment area of Dinghushan Nature Reserve according to the observation specifications and quality control requirements of terrestrial ecosystem water environment, so as to carry out long-term standardized positioning observation of the depth of groundwater level. This dataset collates the long-term monitoring data of four groundwater level observation wells from 2002 to 2020. It is aimed to provide basic data support for the study of groundwater response process, the evaluation of hydrological service function of forest ecosystem and the sustainable management of forest resources under the background of global climate change.

Effects of topography and historical disturbance on canopy height structure of tropical forests in Menglun, Xishuangbanna, China.

With the combination of airborne Lidar and panchromatic images in 1981 and 2021, we investigated the canopy height structure of tropical forests in Menglun sub-reserve in the Xishuangbanna National Nature Reserve of Yunnan Province, and analyzed its relationship with environmental factors by using multiple regression tree (MRT) method. The results showed that forests in the Menglun sub-reserve could be clustered into seven types based on canopy height structures, with tropical rainforest, monsoon evergreen broad-leaved forest, secondary forest, and flood plain forest as the main types. The potential solar radiation, altitude, terrain profile curvature, slope and the brightness value of imageries in 1981 and 2021 were main factors that drove the classification. The tropical seasonal rainforest dominated by Pometia pinnata occupied the largest area in valley and low-land. The monsoon evergreen broad-leaved forest dominated by Castanopsis echinocarpa mainly distributed in the ridge and disturbed areas. The secondary forests had homogeneous canopy surface, which was significantly different from the primary forests. The activities of swidden agriculture about three decades ago had legacy impacts on the physiognomy of secondary forests.

Spatial pattern of dominant species with different seed dispersal modes in a monsoon evergreen broad-leaved forest in Pu’er, Yunnan Province

Spatial pattern of dominant species with different seed dispersal modes in a monsoon evergreen broad-leaved forest in Pu’er, Yunnan Province

Seasonal Water Uptake Patterns of Different Plant Functional Types in the Monsoon Evergreen Broad-Leaved Forest of Southern China

The precipitation changes induced by climate warming have substantially increased extreme precipitation and seasonal drought events. Different plant functional types (PFTs) could exert an important role in resisting extreme climate. However, the patterns of plant water uptake in different PFTs remain uncertain, especially under different magnitudes of rainfall events. Here, we employed a stable hydrogen isotope (δD) to determine the water sources of different PFTs, including Castanopsis chinensis in the canopy layer, Schima superba in the canopy sublayer, Psychotria asiatica in the shrub layer, and Blechnum orientale on the forest floor in the monsoon evergreen broad-leaved forest in Dinghushan Biosphere Reserve, China. We further used a two-end linear mixing model to explore the water utilization among different PFTs. Our results revealed that precipitation and soil water before rainfall were the water sources of different PFTs. Furthermore, the proportions of precipitation utilized by S. superba in the canopy sublayer under light and moderate rainfalls were 6.9%–59.4% and 30.5%–66.3%, respectively, which were significantly higher than those of other species in both the dry and wet seasons. After heavy rainfall, the proportion of precipitation utilized by S. superba was the lowest (4.7%–26.5%), while B. orientale had the highest proportion of precipitation utilization (31.6%–91.5%), whether in the dry or wet season. These findings imply that different PFTs would compete with one another for water uptake. Especially under climate warming, the uneven distribution of precipitation would intensify the water competition among species, ultimately resulting in the plant community structure becoming much more unstable than before.

Nitrogen budgets of a lower subtropical forest as affected by 6 years of over-canopy and understory nitrogen additions

Although tropical and subtropical regions have replaced temperate regions as the global-change hotspots for increased atmosphere nitrogen (N) deposition, whether the regional forests reach N saturation is still unclear. Understory or floor N addition has been commonly used in N-deposition studies, but the results of such studies have recently been challenged because they fail to account for canopy interception, assimilation, and leaching processes. Here, we conducted a field experiment to quantify the effects of over-canopy and understory N addition on N budgets in a lower subtropical monsoon evergreen broadleaved (LSMEB) forest. We found that the LSMEB forest was not N saturated after receiving additional N at 25 and 50 kg ha−1 yr−1 for 6 years. Plants were able to absorb the added N by increasing the N concentrations in their organs, with 120–412 % increasing trend of plant N pools under N-addition treatments. Canopy absorption of N resulting from over-canopy N addition led to increases in N concentrations in tree organs but not to increases in tree biomass. Understory N addition could underestimate the effects of N deposition in forests due to neglecting canopy N interception and canopy effects on N redistribution. Additional experiments using over-canopy N addition are needed to assess the true effects of N deposition on different forest ecosystems in different climate zones.

Two New Species of Allodiatrype from Monsoon Evergreen Broad-leaved Forest in Pu’er, Yunnan, China

Two species that morphologically resemble Diatrype s. str. were collected from the monsoon evergreen broad-leaved forest in Pu’er, Yunnan, China. DNA sequence based phylogenetic analyses (combined ITS and β-tubulin2) confi rmed that these taxa belong to Allodiatrype s. str. (Diatrypaceae, Xylariales, Sordariomycetes) but are distinct from other species, thus introduced as new species A. taiyangheensis and A. albelloscutata. Both species are compared with other taxa of Allodiatrype. These two species are the second records of Allodiatrype from China.

Soil moisture dominated the temporal dynamics of litter moisture content in subtropical forests: a 7-year observation in south China

Study regionDinghushan watershed, China. Study focusThe dynamics of litter moisture content play an important role in understanding the forest’s internal environmental changes, forest fire forecast and prediction of general forest health and so on. These characteristics have not been extensively analyzed in lower subtropical China and therefore, three typical subtropical evergreen forest ecosystems, Pinus massoniana coniferous forest (PF), mixed conifer-broadleaf forest (CBF), and monsoon evergreen broadleaved forest (MBF), were chosen to explore the changes of the litter moisture content and its response to environmental factors. New hydrological insights for the regionOver a 7-year observation period, the mean annual litter moisture content was 72.0 ± 7.3%, 87.9 ± 11.3%, and 100.5 ± 15.7% for PF, CBF, and MBF respectively. The litter moisture content increased while the litter standing mass decreased after vegetation restoration. The litter moisture content in the three forests during the wet season was substantially higher than that in the dry season. Compared to the soil layer, the coefficient of variation of the litter moisture content during the dry and wet seasons was higher as compared to the topsoil (0–30 cm) water content, indicating the litter layer was more sensitive to changes in external environmental factors. Further analysis revealed that soil water content was the dominating factor controlling the dynamics of litter moisture content both during the dry and wet seasons. Analyses of the litter moisture can be very useful in forests around the world as a guideline in indicating the change in a forest’s environment.

Plant diversity and soil properties regulate the microbial community of monsoon evergreen broad-leaved forest under different intensities of woodland use

A key aspect of global forest management, woodland use intensity (WUI) greatly affects the composition and diversity of soil microbial communities, thereby affecting multiple ecosystem functions and services. However, the effects of WUI on soil microbial community composition and enzymatic activities remains unclear. The effects of anthropomorphic alterations to a natural monsoon evergreen broad-leaved forest in terms of the composition and diversity of soil fungal and bacterial communities, was investigated at a site in Yunnan Province, Southwest China. Soil microbial communities were assessed under four levels of disturbance with increasing levels of WUI: (i) none, undisturbed forest (control), (ii) light, naturally-regenerated Pinus kesiya Royle ex Gordon forest, (iii) intermediate, shrub and grassland communities formed through grazing, and (iv) severe, continuously managed coffee (Coffea arabica L.) plantations. With increasing WUI, the diversity of soil fungal and bacterial communities increased, while similarities in community composition decreased for fungi but increased for bacteria. Among fungal functional guilds, ectomycorrhizal fungi decreased significantly with increasing WUI, whereas saprotrophic fungi (undefined, wood, and soil saprotrophs) increased significantly. The species richness of woody plants remarkably affected fungal functional guilds. Ectomycorrhizal fungi interacted in a synergistic manner with the fungal network structure. Significantly affecting microorganismal network structure, WUI increases led to more homogeneous networks with less integration within modules within the microbial community. The WUI strongly altered hub identity and module composition in the microbial community. According to structural equation models, WUI had direct positive effects on soil fungal community composition via its effects on plant species richness. The diversity of bacterial and fungal communities and composition of bacterial communities were jointly regulated by the indirect effects of plant species richness and soil nutrients (including enzyme activity). Deterministic processes largely determined the composition of soil fungal and bacterial communities. This study highlights the importance of maintaining the diversity of soil fungal and bacterial communities despite changes in woodland use to sustain ecosystem functions. These results can be used to develop management practices in subtropical forests and help sustain plant and soil microbial diversity at levels sufficient to maintain long-term ecosystem function and services.

An Interannual Comparative Study on Ecosystem Carbon Exchange Characteristics in the Dinghushan Biosphere Reserve, a Dominant Subtropical Evergreen Forest Ecosystem.

Compared with other forest systems, research interest in the potential for a stronger ecosystem carbon sequestration of evergreen forests throughout subtropical China has greatly increased. The eddy covariance technique is widely employed to determine accurate forest-atmosphere carbon dioxide (CO2) flux, which is subsequently used to determine forest ecosystem carbon exchange characteristics. The Dinghushan Biosphere Reserve, a subtropical monsoon evergreen broad-leaved forest, is a suitable study area due to its warm and humid climate (compared with other regions within the same latitude), consequently playing a role in the carbon cycle in the region. For this study, we hypothesized that the forest land in this region generally acts as a carbon sink, and that its carbon sequestration capacity increases over time despite the influence of climatic factors. Here, we compared net CO2 flux data derived from the eddy covariance technique over an 8-year study window. Additionally, we ascertained the effects of various environmental factors on net CO2 flux, while also using the Michaelis–Menten model and a physiologically based process model to track and report on ecosystem carbon exchange characteristics. We observed seasonal trends in daily ecosystem flux, indicative of sensitivity to climatic factors, such as air temperature, precipitation, and sunlight. The carbon sequestration capacity of the region exhibited seasonal variability, increasing from October to March (−264 g C m−2 year−1, i.e., 48.4%) while weakening from April to September (−150 g C m−2 year−1, i.e., 40.4%) on average. The net ecosystem exchange (NEE) rate varied from −518 to −211 g C m−2 year−1; ecosystem respiration (Re) varied from 1,142 to 899 g C m−2 year−1; and gross primary production (GPP) varied from 1,552 to 1,254 g C m−2 year−1. This study found that even though the Dinghushan Biosphere Reserve generally acts as a carbon sink, its carbon sequestration capacity did not increase significantly throughout the study period. The techniques (models) used in this study are suitable for application in other ecosystems globally, which can aid in their management and conservation. Finally, the Dinghushan Biosphere Reserve is both an exemplary and a model forest system useful in exploring CO2 absorption and sequestration from the atmosphere.

Effects of Typhoon Mangkhut on a Monsoon Evergreen Broad-Leaved Forest Community in Dinghushan Nature Reserve, Lower Subtropical China

Sensitivity to climate change is one of the key features of the Dinghushan National Nature Reserve that is located in the lower subtropical China. Having faced typhoon Mangkhut in 2018, there emerged a need to study the effects that the typhoon had on the evergreen broad-leaved forest community in Dinghushan. The forest composition data for 2015, 2018, and 2020 was used in this study. The aim was to establish a scientific basis for the restoration of natural forests that have the ability to withstand strong weather phenomena such as typhoons and the hypothesis stated that typhoon Mangkhut had a long-term detrimental effect on the forest community in Dinghushan forest. The results showed that trees that have a DBH of less than 5 cm and a height of less than 2 m were more prone to damage during a severe weather events. In 2015, there was a total of 5,682 trees per hectare while in 2018 there was a total of 5,022 trees per hectare showing a decline in the number of trees per hectare of 660 due to the typhoon. Number of trees in each DBH class, height class, total above ground dry weight and average tree height was also lower in 2018 as compared to 2015 and 2020. The species abundance was also adversely affected with a loss of 672 species per hectare in 2018 compared to 2015. In 2020, about 83% of all trees had a DBH of less than 5 cm and an average height of 3.8 m making up a large proportion of trees that could be damaged if another storm occurred of similar or greater magnitude as the one that hit the region in 2018. Of interest was the forests remarkable ability to bounce back as there is an increase in biomass when 2018 is compared to 2020. The results support the hypothesis of the study. It is therefore of utmost importance that strategies be put in place to protect this ecosystem and others of a similar nature, by employing the use of natural forests that have great resilience against typhoons.

Vegetation and vascular plant diversity of Huzhou Island, Huizhou, China

Human activities have an increasingly severe impact on uninhabited islands. It is beneficial to monitor and protect the vegetation diversity of uninhabited islands to master the species composition and diversity of plant communities. The vascular plants and plant communities of Huzhou Island were investigated by sample plot method. The plant species diversity was analyzed. The results showed that there were 98 species of vascular plants belonging to 88 genera and 49 families in the island. Among them, tropical and subtropical families were dominant the island. The genera floristic distribution of vascular plants was mainly pantropic distribution and secondly old word tropic distribution.The vegetation in the island could be classified into 1 vegetation type (monsoon evergreen broad-leaved forest vegetation), 1 alliance (coastal hilly monsoon evergreen broad-leaved forest) and 2 associations (Ficus microcarpa and Eucalyptus urophylla - Myrtle). The change trend of community richness, evenness and diversity was consistent. This study can provide scientific data for resource protection and development of uninhabited island.

鼎湖山不同演替阶段森林土壤水分时空变异研究

PDF HTML阅读 XML下载 导出引用 引用提醒 鼎湖山不同演替阶段森林土壤水分时空变异研究 DOI: 10.5846/stxb201912022603 作者: 作者单位: 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（31600353，41430529）；广东省自然科学基金项目（2016A030310450）；广东省林业科技创新平台项目（2020-KYXM-09） Temporal and spatial variability of soil moisture in a forest succession series in Dinghushan Author: Affiliation: 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:土壤水分作为森林生态系统水分蓄库的主体，森林土壤水分储量及其时空动态与变异对揭示区域植被恢复与气候变化背景下的森林生态系统水文过程响应与服务功能变化机制具有重要意义。本研究以南亚热带地区典型森林植被演替序列马尾松人工林（Pinus massoniana coniferous forest，PF）-马尾松针阔叶混交林（mixed Pinus massoniana/broad-leaved forest，MF）-季风常绿阔叶林（monsoon evergreen broad-leaved forest，MEBF）为研究对象，依托中国生态系统研究网络森林样地建设与监测统一规范对鼎湖山森林生态系统定位站站区内分布的上述森林类型土壤水分的长期定位观测（2005-2015年），通过分析各演替阶段森林土壤不同土层（0-15、15-30、30-45、45-60、60-75和75-90 cm）土壤体积含水量观测数据，探究该区域森林植被恢复过程中的土壤水分变化及其时空变异。结果表明：在雨热同期且干湿季明显的南亚热带地区，鼎湖山森林土壤储水量及其时间动态受降雨量的影响显著，森林土壤层对降雨具有强烈的调蓄和稳定作用，伴随PF→MF→MEBF自然演替进程，调蓄水分能力逐步增强。林型间，由初期阶段PF到顶级群落MEBF，森林土壤水分储量逐渐提高，且演替后期林型相对于早期林型，土壤储水量均呈现为较小的年际与年内变幅。干、湿季而言，干季时林型间的土壤储水量差异大于湿季，干季时MEBF和MF土壤含水量分别是PF的1.33倍和1.11倍。从土壤含水量的干、湿季期间变异来看，不同林型各土层土壤含水量的变异系数大小均表现为干季大于湿季；垂直剖面方向上，突出表现为无论干湿季MEBF各层土壤含水量变异均比其他两种林型较为缓和，充分体现了MEBF优越的土壤水分时空调配能力。整体上，伴随PF→MF→MEBF自然演替进程，土壤水分储量及其稳定性逐步提升。 Abstract:Soil moisture is the main component of water storage in forest ecosystems. The soil water reserve of forests and its spatiotemporal dynamics and variations are of great significance for revealing the response of hydrological processes and the change mechanism of service functions in forest ecosystems under the background of regional vegetation restoration and climate change. In this study, we focused on the typical forests in lower subtropical China: a Pinus massoniana forest (PF), mixed Pinus massoniana/broad-leaved forest (MF), and monsoon evergreen broad-leaved forest (MEBF), which formed a natural successional sequence in this region. Based on the unified standards for the construction and monitoring of forest plots by the Chinese Ecosystem Research Network, long-term positioning observation of soil moisture in the above forest types of the Dinghushan Forest Ecosystem Research Station was conducted during the 2005-2015 period. Through analysis of the measured soil volumetric water content in different soil layers (0-15, 15-30, 30-45, 45-60, 60-75 and 75-90 cm) of the above mentioned forests at each stage of succession, the change in soil water storage and its spatiotemporal variation in the process of forest vegetation restoration in this region were explored. The data showed that in the southern subtropical regions with simultaneous rain and heat and distinct dry and wet seasons, soil water storage and its seasonal dynamics in Dinghushan were significantly affected by rainfall, and the soil layer had a strong regulatory and stabilizing effect on rainfall. With natural succession from the planted (PF) to the climax (MEBF) stage, the ability to regulate and store water gradually increased. Among forest types, from the initial stage (PF) to the top community (MEBF), the soil water storage of the forest ecosystem gradually increased, and compared with the early forest types, the soil water storage of late succession forest types showed small interannual and intra-annual variation. At a seasonal scale, the difference in soil water storage between forest types in the dry season was greater than that in the wet season. The soil water content of MEBF and MF in the dry season was 1.33 times and 1.11 times that of PF, respectively. According to the variation in the soil water content in dry and wet seasons, the coefficient of variation of the soil water content in each soil layer of the different forest types was greater in the dry season than in the wet season. In the vertical direction, this coefficient of variation highlighted that the variation in the soil water content in each layer of MEBF was more moderate than that in the other two forest types in both the dry and wet seasons, which reflected the superior water regulation ability of MEBF. On the whole, with natural succession from the planted (PF) to the climax (MEBF) forest, the soil water storage and its stability improved. 参考文献 相似文献 引证文献

Effects of long-term simulated acid rain on soil microbial community structure in a monsoon evergreen broad-leaved forest in southern China

Effects of long-term simulated acid rain on soil microbial community structure in a monsoon evergreen broad-leaved forest in southern China

Dynamics of community structure and bio-thermodynamic health of soil organisms following subtropical forest succession

Soil organisms play essential roles in maintaining multiple ecosystem processes, but our understanding of the dynamics of these communities during forest succession remains limited. In this study, the dynamics of soil organism communities were measured along a 3-step succession sequence of subtropical forests (i.e., a conifer forest, CF; a mixed conifer and broad-leaved forest, MF; and a monsoon evergreen broad-leaved forest, BF). The eco-exergy evaluation method was used as a complement to the classic community structure index system to reveal the holistic dynamics of the bio-thermodynamic health of soil organism communities in a forest succession series. Association between the self-organization of soil organisms, soil properties, and plant factors were explored through redundancy analyses (RDA). The results indicated that the biomass of soil microbes progressively increased in the dry season, from 0.75 g m−2 in CF to 1.75 g m−2 in BF. Microbial eco-exergy showed a similar pattern, while the community structure and the specific eco-exergy remained constant. Different trends for the seasons were observed for the soil fauna community, where the community biomass increased from 0.72 g m−2 to over 1.97 g m−2 in the dry season, but decreased from 3.94 g m−2 to 2.36 g m−2 in the wet season. Faunal eco-exergies followed a similar pattern. Consequently, the average annual biomass of the soil faunal community remained constant (2.17–2.39 g m−2) along the forest succession sequence, while the significant seasonal differences in both faunal biomass and eco-exergy observed at the early successional stage (CF) were insignificant in the middle and late forest successional stages (MF and BF). Both the dynamics of soil microbes and soil fauna were tightly correlated with tree biomass and with soil physicochemical properties, especially soil pH, moisture, total nitrogen, nitrate nitrogen, and organic matter content.