Publications by authors named "Wenhua Xiang"

Climate warming is projected to affect hydrological cycle in forest ecosystems and makes the forest-water relationship more controversial. Currently, planted forests are gaining more public attention due to their role in carbon sequestration and wood production relative to natural forests. However, little is known about how the global patterns and drivers of water yield and water-use efficiency (WUE) differ between planted and natural forests.

View Article and Find Full Text PDF

Transpiration is a key process that couples the land-atmosphere exchange of water and carbon, and its maximum water transport ability affects plant productivity. Functional traits significantly influence the maximum transpiration rate; however, which factor plays the dominant role remains unknown. SAPFLUXNET dataset, which includes sap flux density of diverse species worldwide, provides fundamental data to test the importance of photosynthetic and hydraulic traits on maximum tree-level sap flux density (J).

View Article and Find Full Text PDF

Leaf carbon isotope composition (δC) provides an integrative record on the carbon and water balance of plants over long periods. Photosynthetic ability and hydraulic traits which are highly associated with stomatal behavior could affect leaf δC. Association between photosynthetic ability and leaf δC has been examined, however, how hydraulic traits influence leaf δC has not been fully understood.

View Article and Find Full Text PDF

Thinning is a widely-used management practice to reduce tree competition and improve wood production and quality in forest plantations. Thinning affects the soil ecosystem by changing the microclimate and plant growth, as well as litter inputs above and belowground, with all the resulting consequences for microbial communities and functions. Although many case studies have been carried out, a comprehensive understanding of the thinning effects on soil properties and microbial communities and functions in plantations remains to be explored.

View Article and Find Full Text PDF

Microplastic threats to biodiversity, health and ecological safety are adding to concern worldwide, but the real impacts on the functioning of organisms and ecosystems are obscure owing to their inert characteristics. Here we investigated the long-lasting ecological effects of six prevalent microplastic types: polyethylene (PE), polypropylene (PP), polyamide (PA), polystyrene (PS), polyethylene terephthalate (PET), and polyvinyl chloride (PVC) on soil bacteria at a 2 % (w/w) level. Due to the inertia and lack of available nitrogen of these microplastics, their effects on bacteriome tended to converge after one year and were strongly different from their short-term effects.

View Article and Find Full Text PDF

and are commonly used to explain the mechanisms of natural community assembly. However, considerable uncertainty remains regarding the relative importance of different ecological processes in shaping forest communities. Functional traits and phylogeny provide important information about plant environmental adaptation strategies and evolutionary history and promise a better mechanistic and predictive understanding of community assembly.

View Article and Find Full Text PDF

Data capturing multiple axes of tree size and shape, such as a tree's stem diameter, height and crown size, underpin a wide range of ecological research-from developing and testing theory on forest structure and dynamics, to estimating forest carbon stocks and their uncertainties, and integrating remote sensing imagery into forest monitoring programmes. However, these data can be surprisingly hard to come by, particularly for certain regions of the world and for specific taxonomic groups, posing a real barrier to progress in these fields. To overcome this challenge, we developed the Tallo database, a collection of 498,838 georeferenced and taxonomically standardized records of individual trees for which stem diameter, height and/or crown radius have been measured.

View Article and Find Full Text PDF

Afforestation is an effective method to increase carbon (C) sinks and address climate change. It is crucial to understand how the stand growth affects C sequestration capacity, especially when the trade-offs with timber production from plantations have not been fully examined. We used a chronosequence approach to estimate C storage in Chinese fir (Cunninghamia lanceolata (Lamb.

View Article and Find Full Text PDF

Background: Forest ecosystems play an important role in carbon sequestration, climate change mitigation, and achieving China's target to become carbon (C) neutral by 2060. However, changes in C storage and net primary production (NPP) in natural secondary forests stemming from tree growth and future climate change have not yet been investigated in subtropical areas in China. Here, we used data from 290 inventory plots in four secondary forests [evergreen broad-leaved forest (EBF), deciduous and evergreen broad-leaved mixed forest (DEF), deciduous broad-leaved forest (DBF), and coniferous and broad-leaved mixed forest (CDF)] at different restoration stages and run a hybrid model (TRIPLEX 1.

View Article and Find Full Text PDF

Drought events lead to depressions in gross primary productivity (GPP) of forest ecosystems. Photosynthetic and hydraulic traits are important factors governing GPP variation. However, how these functional traits affect GPP responses to drought has not been well understood.

View Article and Find Full Text PDF

Total solar radiation is an important factor affecting carbon exchange in forest ecosystem. In order to understand the effects of radiation change on carbon exchange in Chinese fir plantation, long-term monitoring data of carbon dioxide flux and meteorological factors measured by open eddy covariance system and meteorological gradient observation system were used in this study. The clearness index () was used to represent the condition of solar radiation.

View Article and Find Full Text PDF

Primary or secondary forests around the world are increasingly being converted into plantations. Soil microorganisms are critical for all biogeochemical processes in ecosystems, but the effects of forest conversion on microbial communities and their functioning remain unclear. Here, we conducted a meta-analysis to quantify the impacts that converting forests to plantations has on soil microbial communities and functioning as well as on the associated plant and soil properties.

View Article and Find Full Text PDF

Establishing forest plantations is an important solution to the growing conflict between an increasing human population and mounting pressure to protect the natural forests, as plantations also harbor great potential for providing multiple ecosystem services (ESs). However, because of the trade-offs between multiple ESs and the conflicts between different stakeholders, the sustainable management of plantations has been exceedingly challenging. Especially in recent years, with China's emphasis on ecological civilization construction and sustainable development, forestry departments have begun to focus on long-term ecological benefits, which conflict with farmers' attention to short-term economic gains.

View Article and Find Full Text PDF

Rocky desertification is a process of soil erosion and vegetation destruction. On the surface, the landscape of rocky desertification is similar to that of desertification, which has a negative impact on the social and economic development of Southwest China. To clarify the influence of soil properties on plant diversity in rocky desertification areas, three grades of rocky desertification in Southwest Hunan Province were selected: light rocky desertification (LRD), moderate rocky desertification (MRD) and intense rocky desertification (IRD).

View Article and Find Full Text PDF

Fine root production accounts for a large proportion of net primary production (NPP) in forest ecosystems that is highly responsive to environmental and biotic changes. The underlying mechanisms of the relationship between tree species richness and fine root production have not been fully examined. Here we hypothesized that: (i) the relationship between aboveground species richness and fine root production could be attributable to belowground spatial resource partitioning; (ii) either symmetrical or asymmetrical root proliferation to obtain nutrients leads to increased fine root production; and (iii) stand density affects the relationship between species richness and fine root production.

View Article and Find Full Text PDF

Rapid response of uni- and multicellular organisms to environmental changes and their own growth is achieved through a series of molecular mechanisms, often involving modification of macromolecules, including nucleic acids, proteins and lipids. The ADP-ribosylation process has ability to modify these different macromolecules in cells, and is closely related to the biological processes, such as DNA replication, transcription, signal transduction, cell division, stress, microbial aging and pathogenesis. In addition, tRNA plays an essential role in the regulation of gene expression, as effector molecules, no-load tRNA affects the overall gene expression level of cells under some nutritional stress.

View Article and Find Full Text PDF

Atmospheric nitrogen (N) deposition affects the greenhouse gas (GHG) balance of ecosystems through the net atmospheric CO exchange and the emission of non-CO GHGs (CH and NO). We quantified the effects of N deposition on biomass increment, soil organic carbon (SOC), and NO and CH fluxes and, ultimately, the net GHG budget at ecosystem level of a Moso bamboo forest in China. Nitrogen addition significantly increased woody biomass increment and SOC decomposition, increased NO emission, and reduced soil CH uptake.

View Article and Find Full Text PDF

To quantify and assess the processes underlying community assembly and driving tree species abundance distributions(SADs) with spatial scale variation in two typical subtropical secondary forests in Dashanchong state-owned forest farm, two 1-ha permanent study plots (100-m × 100-m) were established. We selected four diversity indices including species richness, Shannon-Wiener, Simpson and Pielou, and relative importance values to quantify community assembly and biodiversity. Empirical cumulative distribution and species accumulation curves were utilized to describe the SADs of two forests communities trees.

View Article and Find Full Text PDF

Subtropical broadleaved forests play a crucial role in supporting terrestrial ecosystem functions, but little is known about their belowground soil fungal communities despite that they have central functions in C, N, and P cycles. This study investigated the structures and identified the drivers of soil fungal communities in subtropical deciduous and evergreen broadleaved forests, using high-throughput sequencing and FUNGuild for fungal identification and assignment to the trophic guild. Fungal richness was much higher in the deciduous than in the evergreen forest.

View Article and Find Full Text PDF

Biodiversity experiments have shown that species loss reduces ecosystem functioning in grassland. To test whether this result can be extrapolated to forests, the main contributors to terrestrial primary productivity, requires large-scale experiments. We manipulated tree species richness by planting more than 150,000 trees in plots with 1 to 16 species.

View Article and Find Full Text PDF

Background: Mixed forests are believed to enhance ecosystem functioning and sustainability due to complementary resource use, environmental benefits and improved soil properties. The facilitation between different species may induce overyielding. Meanwhile, the species-specific fine root foraging strategies and tradeoffs would determine the structure and dynamics of plant communities.

View Article and Find Full Text PDF

This study investigated seasonal patterns in stoichiometric ratios, nutrient resorption characteristics, and nutrient use strategies of dominant tree species at three successional stages in subtropical China, which have not been fully understood. Fresh leaf and leaf litterfall samples were collected in growing and nongrowing seasons for determining the concentrations of carbon (C), nitrogen (N), and phosphorus (P). Then, stoichiometric ratios (i.

View Article and Find Full Text PDF

Wood density (WD) is not only an important parameter to estimate aboveground biomass but also an indicator of timber quality and plant adaptation strategies to stressful conditions (i.e., windthrow, pests, and pathogens).

View Article and Find Full Text PDF

Forests contain one of the world's largest carbon (C) pools and represent opportunities for cost-effective climate change mitigation through programmes such as the United Nations-led "Reducing Emissions from Deforestation and Forest Degradation" Programme (REDD). Generic estimates for the conversion of forest biomass into C stock are not sufficiently accurate for assessing the utility of harvesting forest to offset carbon dioxide emissions, currently under consideration by the REDD Programme. We examined the variation in C concentration among tree species and tree functional types (classified based on leaf morphological and phenological traits) in a subtropical forest and evaluated the effects of these variations on stand-level estimations of C stock.

View Article and Find Full Text PDF

Methane (CH ) emissions from tropical wetlands contribute 60%-80% of global natural wetland CH emissions. Decreased wetland CH emissions can act as a negative feedback mechanism for future climate warming and vice versa. The impact of the El Niño-Southern Oscillation (ENSO) on CH emissions from wetlands remains poorly quantified at both regional and global scales, and El Niño events are expected to become more severe based on climate models' projections.

View Article and Find Full Text PDF