Yun-peng Nie

Chinese Academy of Sciences | CAS · Institute of Subtropical Agriculture

The driving forces of transpiration are not only atmospheric evaporation but also root zone water supply and stomatal regulation among species. However, the biophysiological drivers of transpiration remain incompletely understood in heterogeneous karst habitats. This study investigated the commonly coexisting tree species Mallotus philippensis and...

Groundwater flooding poses a significant yet often underestimated risk to urban development in flood-prone areas such as coastal zones, deltas, floodplains, and karst terrains. Unlike the immediate and visible effects of overland flooding caused by heavy rainfall or snowmelt, groundwater flooding develops slowly and can persist for prolonged period...

Tree transpiration dynamics and mechanisms in karst habitats are not fully understood due to the heterogeneous environmental features and complex species composition. Two common coexisting tree species, Mallotus philippensis and Celtis biondii , were examined in soil- and rock-dominated (SD and RD) karst habitats. Soil moisture, plant transpiration...

The southwestern region of China is the largest exposed karst area in the world and serves as an important ecological security barrier for the upstream of the Yangtze River and the Pearl River. The epikarst, formed by an interwoven network of dissolutional pores, is the core area of the karst critical zone. Water is the most active component that p...

Soils provide storage space for nutrients and water, which governs many hydrological processes and functions in the natural ecosystems. Due to the complex soil-rock structures and localized climate, soil thickness and stock vary distinctly in different karst areas in southwest China. The difficulties of soil detection and the non-transparent underg...

For many countries, karst aquifers are a significant source of potable water; thus, understanding their hydrogeological behavior is of great importance. However, in tectonically complex karst areas, knowledge of their hydrogeological behaviors has remained largely limited due to the high heterogeneity, often necessitating the use of costly and time...

Topographic positions can mediate subsurface water availability, but its effects on tree transpiration are controversial. In humid karst regions, climax forests are usually not limited by moisture supply, even at the summit, through absorbing water from deep layers. However, little is known on the transpiration pattern and its limiting factor on th...

Arbuscular mycorrhizal fungi (AMF) have been found to help plants adapt to water deficit conditions. However, it still lacks filed evidence on how AMF affect plant physiology and soil microbial communities under natural extreme drought events. Here, we conducted an AMF-inoculation and legume-intercropping (Medicago sativa) field experiment in a for...

Water ages in plant transpiration reveal important processes of water dynamics in soil‐plant‐atmosphere continuum, which is regulated by water variability and availability in both precipitation inputs and root zone. However, the impacts of climate patterns and rooting depth on water age dynamics in transpiration are inadequately investigated. In th...

Aims Slope position affects soil nutrients and plant diversity, thereby altering arbuscular mycorrhizal fungi (AMF) communities. However, the effect of slope position on the relationship between plant diversity, soil nutrients, and AMF communities remains unclear. Methods We characterized soil physicochemical properties, plant diversity, and the c...

Temperature is an important near-surface microclimate parameter that plays a key role in hydrological, ecological, and biogeochemical functions. However, the spatio-temporal distribution of temperature on the invisible and inaccessible soil-weathered bedrock continuum, wherein hydrothermal processes are most active, remains poorly understood. Tempe...

Epikarst, as a distinct layer of karst critical zone, plays a crucial role in water storage-transfer functions and biogeochemical processes. The epikarst thickness, which shows high spatial variability, is an important parameter that controls the dynamic characteristics of the water cycle. Due to the time-cost constraints in conventional field surv...

The use of plantations and natural restoration enhance vegetation coverage and contribute significantly to the hydrologic functions of degraded terrestrial ecosystems. Researchers have investigated the development and use of plantations, however, few studies looked at naturally-restored vegetation, especially for early successional areas. We applie...

Root-zone water storage is a core component of many hydrological systems, and a critical variable influencing water transport in the soil-vegetation-atmosphere continuum and biogeochemical processes. However, the dynamics of water bypass and replenishment in root-zone during precipitation infiltration processes have been rarely investigated. Here w...

Purpose Isotope-based root water uptake analysis usually involves cryogenic vacuum extraction (CVE) of water from soil and other water-holding materials, according to the assumption that no isotopic fractionation occurs during the related processes. Recently, a growing body of literature identified isotopic deviations that were caused by CVE. Howev...

The evaluation and quantification of aquifer structure in the Earth Critical Zones (CZ) are of great significance to the hydrological cycle and water resources management. 【Objective】However, the characterization of complex CZ structures at spatial scales remains a huge challenge. In this paper, research was conducted on a small karst dolomite wate...

Quantifying root-zone water replenishment (β) is essential to understanding how root-zone water is partitioned and released, and the associated residence time of water in Earth’s critical zone. However, dynamics of such water replenishments and mean residence time in karst environments remain poorly understood. In this study, stable isotope composi...

Plantations, as a form of vegetation restoration, play a critical role in the recent greening of the earth. However, the sustainability of the restored vegetation under precipitation changes has rarely been estimated, largely because of a lack of knowledge about the related plant water adaptation. In the current study, six tree species, including e...

Various water transmitting media are related to highly variable water source compositions, which limit the understanding of the aquifer structure and hydrological processes in a karst catchment. This study aims to understand the variation in water contribution by matrix, fissure, and conduit flows during storm and seasonal scales based on discharge...

Root access to bedrock water storage or groundwater is an important trait allowing plant survival in seasonally dry environments. However, the degree of coordination between water uptake depth, leaf‐level water‐use efficiency (WUEi) and water potential in drought‐prone plant communities is not well understood. We conducted a 135‐d rainfall exclusio...

Ecological restoration changes land cover types and management practices. However, understanding of their hydrological response is limited, especially in karst ecosystems, which are vulnerable to environmental changes. This study aimed to identify the spatial variability of the hydrological response in a mesoscale karst basin to climate change and...

Quantifying and understanding recharge behavior of aquifers in complex hydrogeological systems is challenging, which limits our ability to manage water resources in karstic areas. In this study, we analyzed the seasonal recharge sources and processes of a stream, an intermittent spring, and a perennial spring in a small dolomitic catchment. Weekly...

Coarse root systems provide a framework for water and nutrient absorption from the soil and play an important role in plant survival in harsh environments. However, the adaptions of plant roots in soil-limited environments with low water storage capacity and nutrient content needs to be better understood. The adaptation strategies of two common pla...

Determining the mechanism of rocky desertification by investigating the sediment transport process in carbonate aquifers with the great mixture of various karst conduit features presents severe difficulties. This study put its focus on the overlying soil entering the master small-scale surface karst negative (SSKN) feature, the tapering grike on li...

Highlights •Potential water sources for plant in rocky environment are hard to locate and sample. •They were separated into two water pools based on their hydrological differences. •Tree and shrub on a cliff-face were identified to rely on different water pools. •Linkage between plant water use and the two different water pools was built up.

裂隙发育的喀斯特出露基岩生境,虽无土层覆盖却能维持不同生活型植物的水分消耗.然而目前对该类生境植物的水分来源缺乏清晰认识.本研究以植物潜在水分来源相对简单的孤立出露基岩为例,聚焦遮雨(即剔除雨水对浅层水源的补给)1年后仍然生长旺盛的代表性植物种,同时以无遮雨处理样地(即始终接受降雨补给)的同种植物为对照,运用稳定性氢氧同位素技术,结合对植物水势的测定,综合分析了3种典型植物(落叶乔木菜豆树、落叶乔木紫弹树、常绿灌木四子海桐)的水分来源.结果表明: 在降水充沛的雨季,遮雨条件下3种植物均依赖与泉水同位素比率相近的深层水源,这是植物在遮雨1年后仍能正常生长的根本原因;遮雨菜豆树和四子海桐凌晨水势与自然植株无显著差异,表明植物未受水分胁迫,而紫弹树凌晨水势显著低于自然植株,表明其受一定程度的水分胁...

Precipitation in the karst regions of southwest China is plentiful, however, soils are shallow and highly permeable, which results in rapid transportation of surface water through a soil profile. Therefore, the presence and amount of water stress in a soil layer can be unpredictable. This study will investigate the soil water conditions on karst hi...

Core Ideas Macropores and cracks are preferential channels in karst depression and downslope locations Heterogeneity of soil property results in finger flow in karst mid‐ and upslope locations High K s and soil layering weaken preferential flow in mid‐ and upslope locations Preferential flow degree and infiltration rate can be independent in karst...

Questions Water source segregation among plant species has been widely observed in a variety of ecosystems. However, whether correlated segregation occurs at a community level and its relationship to successional stages has rarely been studied. Location Open shrubland, dense shrubland and secondary forest on adjacent rocky karst hill slopes, South...

Plant water use is an important component in the function of Earth's critical zone and this can be examined by decomposing isotope composition of xylem water into contributions from precipitation stored in shallow soil layers and deeper groundwater. The usual procedure for estimating the proportional use of groundwater by plants is to sample the is...

Habitats with different features such as soil depth and soil/rock conditions can provide favorable environments for species with different requirements, while anthropogenic disturbances normally exert additional effects on species composition. However, specific studies have rarely been conducted in the degraded karst regions of Southwest China desp...

This study focused on bedrock outcrops, a very common habitat in karst region of southwest China. To reveal the responses of plant transpiration to natural rainfall and continuous drought, two tree species typical to this habitat, Radermachera sinica and Triadica rotundifolia, were selected as test materials. A rainout shelter was used to simulate...

For tree species adapted to shallow soil environments, rooting strategies that efficiently explore rock fractures are important because soil water depletion occurs frequently. However, two questions: (a) to what extent shallow soil-adapted species rely on exploring rock fractures and (b) what outcomes result from drought stress, have rarely been te...

A unique but very common habitat, rocky outcrop in Karst region of southwest China was selected for this study. Sap flow patterns of two typical tree species (Radermachera sinica and Triadica rotundifolia) were analyzed by using the method of Granier's thermal dissipation probe (TDP). The results showed that sap flow density of both species exhibit...

Karst regions, which account for about 15% of the terrestrial surface area, are characterized by specific hydrogeological structure that different from most non-karst regions. Thus, many research methods that are used in non-karst regions cannot be directly used in karst regions. This issue is especially relevant to research on plant water sources....

Soil water movement is difficult to explain with event-scale approaches, especially in karst regions. This paper focuses on investigating seasonal recharge and mean residence time (MRT) of soil water based on temporal variation of stable isotopes (δD and δ¹⁸O) and a dispersion model (DM), and discussing their differences along a footslope and a dep...

Using stable isotope techniques, water sources and water use efficiencies of Eucalyptus urophylla ×E. grandis (exotic tree species) and Liquidambar formosana (native tree species, as a reference) were studied in a typical karst artificial forest, and the risk of drought stress of the plantation was discussed. The results showed that the isotope val...

Through in situ observation and indoor tests, the hydrochemical characteristics of a typical karst watershed at three different time scales (diurnal, single storm, and seasonal scales) from June 2013 to March 2014 were investigated, and their influencing factors were analyzed. The results showed that the diurnal variations of the hydrochemistry exh...

Soil saturated hydraulic conductivity (K s) is one of the most important parameters that determine soil water redistribution. However, it is little known in a karst area with thin, discontinuous, and rocky soils. The purpose of this paper was to investigate the spatial variability of K s and its influencing factors in a small karst catchment with h...

Nonlinear complexity is a characteristic of hydrologic processes. Using fewer model parameters is recommended to reduce error. This study investigates, and compares, the ability of gene expression programming (GEP) and artificial neural network (ANN) techniques in modeling ET0 by using fewer meteorological parameters in the karst area of northwest...

Soil and epikarst play an important role in the hydrological cycle in karst regions. This paper focuses on investigating the seasonal recharge and mean residence time (MRT) of soil water and epikarst water in a small karst catchment of southwest China. The deuterium contents in precipitation, creek, soil baseflow (direct recharge of the saturated s...

Saturated hydraulic conductivity (Ks) is one of the most important soil hydraulic parameters influencing hydrological processes. This paper aims to investigate the vertical distribution of Ks and to analyze its influencing factors in a small karst catchment in Southwest China. Ks was measured in 23 soil profiles for six soil horizons using a consta...

The karst region of southwest China is characterized by surface soils low in moisture and nutrients, low vegetation coverage and high microhabitat diversity. Knowledge of the temporal and spatial variability of surface soil moisture content is crucial for hydrological modeling and understanding soil water dynamics at different scales. This study ai...

Plant species growing in shallow-soil habitat are likely to experience water deficit especially in seasonally dry or arid regions. However, only scarce studies focused on their water-use strategies. The current study aimed to reveal water-use strategies of different species growing on continuous dolomite outcrops (a typical shallow-soil habitat) in...

A series of studies claimed that deep root development of plant established in karst regions was facilitated by fractured bedrock beneath the shallow soils; however, bedrock is not a uniform medium for root proliferation. We hypothesized plant species that survived in different karst habitats had some other rooting characteristics rather than deep...

Surface soil water-physical properties play a decisive role in the dynamics of deep soil water. Knowledge of their spatial variation is helpful in understanding the processes of rainfall infiltration and runoff generation, which will contribute to the reasonable utilization of soil water resources in mountainous areas. Based on a grid sampling sche...

Plant-water relation is an important part of eco-hydrological process. Its study scope has been greatly expanded with the improved research precision based on the application of stable isotope technique. However, water extraction of plant samples is time-consuming and laborious, which limits the application of this technology. In this study, we use...

The specific double hydrogeological structure increases the difficulty of study on hydrological processes in karst area. As an important input of water cycle in the basin, to study the seasonal variation of deuterium and oxygen-18 in precipitation and their influencing factors are necessary for discussing hydrological processes, such as origin of w...

In the seasonally dry karst region of Southwest China, woodland vegetation is frequently associated with rocky outcrops. We used stable isotope techniques to determine the water sources of two woody plant species (the semideciduous tree Rademachera sinica and the deciduous shrub Alchomea trewioides) across three surface types: continuous and isolat...

In karst regions, forests often grow on bedrock outcrops, however the water sources used by the forest vegetation are not known. This study aimed at investigating whether there were seasonal shifts (dry/wet season) of water sources for plants growing on the continuous dolostone outcrops, and comparing their differences with those growing on nearby...

This paper studied the profile distribution characters of 137Cs and soil organic carbon (SOC) on the Karst slopes and in the fissures in typical peak-cluster depression in Northwest Guangxi, aimed to approach the applicability of 137Cs method on Karst slopes and the implication of 37Cs for the characteristics of slope soil erosion. In all test prof...

Based on the measurements of the foliar δ13 C values of seven dominant plant species on the continuous rock outcrops and nearby soils on karst hill slopes of northwest Guangxi, China, this paper analyzed the differences in the foliar carbon isotope ratio of the plants in different habitats and different seasons. The foliar δ13 C values of test plan...

Plant water sources depend on the distribution of available water in the environment and the ability of plant to capture water. In dry season, plant transpiration demand often exceeds available water stored in soil in thin soil region, whether plants can maintain normal water loss depend on whether they can use water stored in weathered bedrock or...

Plant water source depends on the distribution of available water in the environment, and the capability of plants in capturing water. In dry season, the soil water in thin soil region cannot satisfy the demand of normal plant growth, and whether the plants can use the water stored in weathered bedrock is the key for them to maintain their normal w...

By using portable Li-6400 photosynthesis system, this paper studied the gas exchange in Radermachera sinica and Alchornea trewioides leaves in karst regions of Northwest Guangxi in rainy season (June, July, and August, 2009) and dry season (October, November, and December, 2009), and analyzed the relationships between leaf photosynthetic rate (Pn)...