Rainfall Interception Research Articles

Rainfall interception in temperate evergreen broadleaved forest and Japanese cypress plantation with abundant lower-layer vegetation in south-west Japan

ABSTRACT The interception of rainfall in conifer plantations has been intensively studied. However, research on broadleaved forests is limited, although the broadleaved forests dominate approximately half of forest area in Japan. Here, we compared the throughfall and stemflow of each vegetation layer to clarify interception in a naturally regenerated temperate evergreen broadleaved forest (lucidophyllous forest) and a Japanese cypress plantation over a three-year period. Both forests were approximately 100 years old and had abundant lower-layer vegetation. We found that approximately a quarter of rainfall was intercepted in both forests, although the half of that interception in the Japanese cypress plantation was owing to the abundant lower-layer vegetation. This indicated that the interception in the evergreen broadleaved forest was twice that of the Japanese cypress upper canopy. The well-developed layer structure in the evergreen broadleaved forest efficiently intercepted rainfall. From the point of view of water resource management, this study implies that both evergreen broadleaved forests and Japanese cypress plantations with abundant lower-layer vegetation can decrease the amount of water infiltrating soils.

On Canopy Rainfall Interception Modeling in a Eucalyptus Plantation

The interaction between the forest canopy and precipitation is a fundamental process for understanding the hydrological cycle in forests. Physical models have been applied to estimate canopy water interception, and their efficiency has been tested based on metrics used to assess hydrological models. For eucalyptus plantations in Brazil, more studies are needed on the canopy rainfall interception model. Thus, we calibrated the Gash model using two complete hydrological years of observation in a eucalyptus plantation in southeastern Brazil. The model’s parametrization was conducted using 17 trees individually in different planting spacings (3 m × 2 m, 3 m × 3 m, and 3 m × 5 m). The average values of the model’s parameters were taken to represent the forest, and the average parameters for each planting spacing were used to assess the model’s performance according to the planting spacings. We used NSE, KGE, and Pbias statistical metrics to assess the model’s performance. For individual trees and rainfall events, the model showed an average NSE and Pbias of 0.59 and 18.2%, respectively, meaning a “satisfactory” performance for eight trees and “poor” performance for nine trees. When the model was averaged for the entire forest and individual rainfall events were considered, the metrics were improved, being 0.643 for NSE and 8.2% for Pbias, indicating a “good” model performance, which was strengthened by an average KGE of 0.746. Regarding the model for the planting spacings, the best results were found for the 3.0 m × 2.0 m spacing (“a good performance”). For the other spacings, Pbias was higher than 15%, leading to inferior performance, but with the NSE and KGE compatible with “good” performance. The practical implications of our findings are significant, as they can be used to enhance the accuracy of models for a better understanding of the hydrological cycle in eucalyptus forests in Brazil, thereby contributing to more effective forest management and conservation.

Influence of Neltuma flexuosa and rainfall event on the germination of Leptochloa crinita and Pappophorum caespitosum in two different locations along a stress gradient in the central Monte desert

AbstractIn drylands, grass germination occurs after a large rainfall event. However, trees influence the water requirements for germination either by decreasing the rate of evaporation from soil surface or by interception rainfall with their canopy. The aim of this work was to evaluate the role of Neltuma flexuosa tree on the germination of Leptochloa crinita and Pappophorum caespitosum grasses in response to precipitation events of different sizes. The experiment was conducted in two locations within the Monte desert, Argentina: a semi‐arid location with an average annual precipitation of 345 mm and an arid location with an average annual precipitation of 156 mm. Six microsites were established under N. flexuosa canopies and six microsites in open areas at both locations. Within each microsite, 35 seeds of each grass species were exposed to precipitation events of varying sizes. This procedure was repeated 14 times across two growing seasons. Germinated seeds were counted in the laboratory. Generalized linear mixed models were then applied to evaluate the effects of accumulated precipitation and the microsite on the grass germination in both locations. Results showed that N. flexuosa did not influence the germination of either grass species in the arid location. However, in the semi‐arid location, N. flexuosa facilitated the germination of P. caespitosum only. Large precipitation events would act as an environmental signal for these perennial grasses, allowing them to germinate in favorable years regardless of the microsite or the location.

Uncertainty of canopy interception modeling in high-altitude Picea crassifolia forests of Semi-arid regions

The study of physically-based rainfall interception is crucial for comprehending the water balance within forest ecosystems and the contribution of vegetation to the hydrological cycle, particularly in arid/semi-arid ecosystems. Despite its importance, there is a lack of comprehensive sensitivity analysis and parameter optimization, resulting in uncertain or suboptimal predictive accuracy. To mitigate these shortcomings, this research involved the establishment and assessment of three quintessential forest canopy interception models namely, the power Návar model, the reformulated Gash model, and the Liu model, within semi-arid forest environments at two different elevations. A global sensitivity analysis conducted on the three physical models indicated that the canopy saturation point and the mean rainfall intensity required for canopy saturation were the parameters to which the reformulated Gash and Liu models were most sensitive when applied to high-altitude settings. Conversely, for the Návar model, the most sensitive parameters were the interception coefficient of the linear equation, and the parameters of the power equation k and c. The quantification indices of model sensitivity exert a certain influence on the ranking of parameter sensitivities. However, for models with a limited number of parameters, the impact of these results is constrained. Conversely, the identification and utilization of characteristics specific to the parameter tuning process can significantly enhance the efficiency of model calibration. The three models employed by the research institute have all demonstrated commendable performance in modeling the canopy interception process of subalpine P. crassifolia in arid, high-altitude regions, achieving a "good" rating with Nash-Sutcliffe Efficiency values exceeding 0.7. In practical applications, we recommend giving priority to the use of the Liu model. The findings of this study provide a reference for model selection, sensitivity analysis, parameter calibration, and model evaluation in the context of extensive canopy interception modeling in arid areas with significant altitudinal variation. This constitutes an important theoretical support for the refined modeling of hydrological processes in high-altitude forests within arid zones.

Forest cover lessens hurricane impacts on peak streamflow

AbstractCyclonic storms (i.e., hurricanes) are powerful disturbance events that often cause widespread forest damage. Storm‐related canopy damage reduces rainfall interception and evapotranspiration, but impacts on streamflow regimes are poorly understood. We quantify streamflow changes in Puerto Rico following Hurricane Maria in September 2017, and evaluate whether forest cover and storm‐related canopy damage account for the differences. Streams are particularly vulnerable to flooding in early post‐disturbance stages during hurricane season, so we focus on 3 months (Oct–Dec) following the hurricane. To discern changes in rainfall responses, we partitioned streamflow into baseflow and quickflow using a digital filter. We collected 2010–2017 streamflow and rainfall data from 18 watersheds and compared the relative magnitude of post‐ to pre‐hurricane double mass curve slopes of baseflow and quickflow volumes against rainfall. Several watersheds displayed higher post‐hurricane quickflow and baseflow, however, the response was variable. The magnitude of quickflow increase was greater in watersheds with high forest damage. Under the same level of relative damage, watersheds with low initial forest cover had greater quickflow increases than highly forested ones. Conversely, baseflow generally increased, but increases were greater in highly forested watersheds and smaller in highly damaged watersheds. These results suggest that post‐storm baseflow increases were due to recharge of hurricane‐related rainfall, as well as forest transpiration interruption and soil disturbance enhancing recharge of post‐hurricane rainfall, while increases to quickflow are related to loss of canopy rainfall interception and higher soil saturation decreasing infiltration. Our research demonstrates that forest damage from disturbance lowers quickflow and elevates baseflow in highly forested watersheds, and elevates quickflow and lowers baseflow in less‐forested watersheds. Less‐forested watersheds may be closer to the forest cover loss threshold needed to elicit a streamflow response following disturbance, suggesting higher flooding potential downstream, and a lower storm‐related forest disturbance threshold than in heavily forested watersheds.

Evaluation of evaporation methods for modelling rainfall interception in a dry tropical forest

Evaluation of evaporation methods for modelling rainfall interception in a dry tropical forest

Effect of rainfall interception and resting period on the soil seed bank

The ecosystems across the world are affected by diverse impacts of climate change. Climate change will also affect soil seed bank as the seed bank is determined by the plants that are above the ground. This study was conducted to determine whether rainfall interception and resting period will affect the soil seed bank or not. Rainfall interception was employed as main plot treatment at four different levels—namely, 15%, 30%, 60%, and 0%—and the main plot treatments were each replicated five times using the rainout shelters arranged as main plot treatments in a split-plot experimental design. The main plots are 49 m2 (7 m × 7 m) in size and were covered by metal frame structures with V-shaped clear acrylic bands on top without ultraviolet filter, and these plots were sub-divided into two sub-plots to determine the effect of resting periods (70 and 90 days). The soil samples were 8 cm in diameter and 20 cm in depth (1,005 cm3). We used seed emergence method rather than seed separation method to determine the soil seed bank due to the very small size of some seeds for some species. The 60% rainfall interception resulted in significantly high forb densities at both resting periods. The forb densities decreased by 32 and 35% at 15% and 30%, while they increased by 195% at 60% rainfall interception compared to 0% rainfall interception at 70-day resting period. Resting period significantly affected grass densities at 60% rainfall as the densities were higher at 70- than 90-day resting period. At 90-day resting period, grass densities were significantly higher at 0% rainfall interception than the rest of the treatments, while the grass densities were significantly lower at 60% rainfall interception. The 60% rainfall interception resulted in significantly (p< 0.05) higher total densities (forbs and grass) in both resting periods. Total density increased by 2.9% and 143.48% at 15% and 60% rainfall interception, respectively. Our results show that drought has a negative effect on grass soil seed bank, while it improves the forbs soil seed bank. Furthermore, the resting period has no significant effects on soil seed bank in grasslands.

Effect of spatial differentiation of Pinus massoniana canopy branches and leaves on rainfall interception – an example from Changting County

ABSTRACT The spatial differentiation of forest canopy branches and leaves affects rainfall interception. However, the scientific expression of the spatial differentiation of forest canopy branches and leaves has not been clarified, and revealing the effect of spatial differentiation of branches and leaves of the vertical structure of the forest canopy on rainfall interception is difficult. Using the Pinus massoniana planted in Changting County, China, as the research object, this study quantified the spatial differentiation of canopy branches and leaves in a hierarchical manner by combining the unmanned aerial vehicle (UAV) three-dimensional point cloud model with the landscape metrics and further simulated the interception mechanism of Pinus massoniana forest canopy on rainfall of different intensities by constructing the principal component regression model. The results showed that the spatial differentiation of canopy branches and leaves in different strata responds differently to different rainfall intensities.

Estimation of the leaf area index in a decline spruce forest in the Western Tatra Mountains for determination of rainfall interception

Estimation of the leaf area index in a decline spruce forest in the Western Tatra Mountains for determination of rainfall interception

Aboveground biomass determines canopy rainfall interception loss in Semiarid Grassland Communities

AbstractCanopy rainfall interception is one key hydrological process, affecting rainwater redistribution and effectiveness in semiarid regions. Canopy rainfall interception loss is jointly influenced by meteorology, vegetation and topography. The canopy water storage capacity (S), rainfall interception depth (Im) and ratio (I%) and vegetation characteristics, together with topographic factors of three grassland communities (dominated by Bothriochloa ischaemum, Lespedeza davurica and Artemisia gmelinii, respectively) were investigated on the Loess Plateau of China during the main growing season (June to September). Results showed that Im ranged from 0.55 to 0.89 mm and I% ranged from 6.14% to 12.1%, with the maximum values occurring in August for three communities, and A. gmelinii community had the largest Im (0.89 mm) and I% (12.1%). The Im and I% were positively correlated with aboveground biomass (AGB), coverage (Cov), leaf area index (LAI), community‐weighted mean height (CWMH) and altitude (Alt), but negatively correlated with slope degree and rainfall intensity (RI). Hierarchical partitioning analysis (HPA) showed that AGB had the highest contribution for Im (20.3%), while Alt had the highest contribution for I% (18.2%). The regression models based on forward selection could effectively predict the values of Im (R2 = 0.802, RMSE = 0.049) and I% (R2 = 0.546, RMSE = 1.434). Topographic factors (altitude, slope degree and aspect) indirectly influenced both Im and I% by modulating vegetation characteristics (AGB, Cov, etc.). All these indicated that aboveground biomass mainly determines grassland community rainfall interception loss in the semiarid Loess Plateau.

Rainfall interception by leaf litters: What happens with fallen leaves of different types and mixing degrees under simulated rainfall?

As a crucial component within the vertical structure of the forests, leaf litter plays a significant role in the hydrological effects of the forest ecosystem. Studying the impact of different types of leaf litter combinations on the hydrological performance, as well as understanding how the ratio of leaf types in the litter layer influences it, are crucial for achieving a deeper comprehension of the role of the litter layer in forest hydrological processes. The objectives of this study were to determine the rainfall interception characteristics of single leaf litters with different types (Pinus massoniana, Cinnamomum camphora and Magnolia grandiflora) and mixing degrees (P. massoniana × C. camphora, P. massoniana × M. grandiflora, and C. camphora × M. grandiflora, with mixing ratios of 1:3, 1:1, and 3:1) under various slope gradients (0°, 5° and 25°). The results showed that with varying combinations of leaf litters and different mixing degrees, there existed certain disparities in runoff mitigation efficiency. In particular, the response time of the P. massoniana × M. grandiflora to rainfall gradually advanced as the proportion of P. massoniana increased. The maximum and minimum interception capacity of the leaf litters were both highest for C. camphora, and minimum interception capacity of the mixed litters of P. massoniana × C. camphora decreased with an increasing proportion of P. massoniana. When C. camphora accounted for a larger proportion in the mixed litters of C. camphora × M. grandiflora, the minimum interception capacity was larger. In the combination of P. massonian × C. camphora, the proportion of infiltration flow was the highest when the mixing ratio was 1:1, while that of slope and lateral flow was the lowest. On the sloped land, the infiltration flow of P. massoniana × M. grandiflora increased with the increasing proportion of P. massoniana, while the slope flow was opposite. Mixtures of litters affect the accumulation spatial structure of the litter layer, consequently altering the interception and redistribution characteristics of rainfall. The research provides a reliable foundation for objectively assessing the water transfer mechanism and conservation function of the litter layer.

Deciphering global patterns of forest canopy rainfall interception (FCRI): A synthesis of geographical, forest species, and methodological influences

Forest canopy rainfall interception (FRCI) is an essential hydrological process that governs water and biogeochemical cycles in forest ecosystems. Identifying patterns and relationships of FCRI using a systematic review is key to improving our knowledge supporting new experiment research, modeling, and application. In this meta-analysis, we aimed to delineate the canopy interception (CI), throughfall (TF), and stemflow (SF) concerning geographical and forest variables and experimental methodologies. We leveraged peer-reviewed 170 articles across 234 sites globally, extracting TF, CI, SF, geographical, forest, and experimental aspects. We applied multivariate statistical procedures to discern the principal influences on TF, CI, and SF and examined their multicollinearity. In addition, we developed Generalized Linear Models (GLM) for CI and TF. Global TF experiments indicate that the predominant rainfall devices, number of sample trees, number of events, and monitoring length are 10–20 devices (81% fixed), 3–6 trees, 30–50 events, and 10–30 months. Predominant global values of TF, CI, and SF are 70–80% (median = 73%), 20%–30% (median = 23.9%), and <1.0% (median = 1.87%), respectively. Global models of CI and TF were responsive to T, LAI, and D (respectively, R2adj of 0.196** and 0.206**). Temperate forests mirrored the global model (R2adj of 0.274** and 0.31**, respectively). The Subtropical CI model was fitted based on P and DBH (R2adj = 0.245*), and the TF model was based on E, D, and LAI (R2adj = 0.532**); the Mediterranean CI model was based on T, Basal, and LAI (R2adj = 0.45*), while TF was based on P, Basal, and LAI (R2adj = 0.671**). The Tropical CI model was based on T and H (R2adj = 0.396*), and the TF model, LAI, and P (R2adj = 0.35*). This meta-analysis underscores the importance of comprehending the hydrological processes in forested areas as they are pivotal in mitigating climate change impacts.

Rainfall interception by urban trees: Event characteristics and tree morphological traits

AbstractThe rapid expansion of impermeable surfaces in cities has a major impact on urban hydrology by reducing rainwater infiltration and increasing runoff rates and peaks. The use of urban trees as stormwater management tools is gaining recognition for their potential to mitigate flood risk and provide additional ecosystem services. We conducted an in‐situ field experiment to measure throughfall on Norway maple (Acer platanoides) and small‐leaved lime (Tilia cordata) to assess the interception capacity of solitary urban trees under different degrees of surface sealing in the city of Freiburg, Germany. We examined the relationships between rainfall characteristics, tree morphological traits, and the interception behaviour, analysing eight trees per species over 76 recorded rainfall events from April to September 2021. Average interception values were higher for small‐leaved lime trees (70.3% ± 6.6%) than for Norway maple (54.8% ± 10.3%) surpassing those in typical forested environments. The average interception loss of all recorded events was 2.6 ± 0.6 mm for Norway maple and 3.7 ± 0.3 mm for small‐leaved lime. For both tree species, significant linear correlations were found between the relative interception and factors such as rainfall depths, the leaf area index (LAI), and the plant area index (PAI) (adj. R2 &gt;0.45). Unlike Norway maple, small‐leaved lime demonstrated significant relationships between several tree morphological parameters and interception (adj. R2 &gt;0.43). The LAI of both species significantly decreased with the increasing degree of surface sealing, which in turn affected interception rates. Our results enhance the understanding of the interception process by solitary trees in urban contexts and enables the parameterization of interception rates using measurable properties. To develop a comprehensive database for modelling parameters and aid urban planners in stormwater management, further field experiments involving various tree species are essential.

Response time of soil moisture to rain in a vineyard with permanent cover

The time elapsed between the moments of maximum rainfall intensity and maximum soil moisture, known as peak to peak (P2P), is part of the hydrological response of the soil, but literature has missed this metric in any woody crop. In a vineyard with permanent vegetation cover (humid climatic conditions), the influence of two cultivars (Agudelo and Blanco Legítimo) and two zones (rows and inter-row areas) on the values of soil moisture response time, absolute change in moisture (ΔS) and P2P was evaluated for 118 rainfall events in three soil layers. 12 capacitance probes and a weather station were used, and data measured every 15 min. A positive response (ΔS > 0) was observed in 79 %, 73 % and 67 % of all events at soil depth of 5, 15 and 25 cm, decreasing ΔS with increasing soil depth. Differences of ΔS were significant among layers, but not among cultivars and zones. The maximum ΔS occurred at 15 cm, while the minimum was observed at 25 cm. No response was evident when specific thresholds were not reached: rainfall depth (0.60 mm event−1), maximum intensity (1.20 mm h−1) or duration (30 min). Topsoil conditions –high rainfall interception by the dense cover and high soil organic matter content– influenced the results at 5 cm. Rain parameters correlated well with ΔS, but weak with the response time and P2P. P2P occurred earlier in the rows than between the rows, especially at 15 cm. Shorter P2P appeared in Agudelo, with significant differences in the rows at 5 cm. P2P differed significantly among layers, increasing P2P with soil depth. Similar ΔS values appeared in Spring and Autumn, and were significantly different than those in Summer, but P2P did not differ significantly among seasons. Therefore, the magnitude and timing of the soil hydrological response were independent processes.

Interspecies variation in plant surface water storage capacity in alpine meadows: Prediction based on plant ecological strategies

Rainfall interception by vegetation is essential in precipitation redistribution within ecosystems and greatly affects water services. However, the patterns of interspecies variation in plant surface water storage (PWS) remain unclear, which greatly limits our understanding of the relationship between species composition and vegetation rainfall interception. Thus, we aimed to examine whether the plant ecological strategy, which is an internal driving force and comprehensive characteristic of plant traits, can serve as a PWS predictor. The PWS of thirty-nine common plant species in natural, degraded, and restored alpine meadows within the Ruoergai wetland was compared, and the variability in PWS between these species was examined from both plant trait and ecological strategy perspectives. The results showed that PWS per plant (IWSC) ranged from 0.12 to 9.32 mL plant−1, and PWS based on projected area (PSCI) and fresh weight (PMS) ranged from 0.01 to 0.94 mm and 0.11 to 1.29 g g−1, respectively. The PSCI was comparatively lower in Cyperaceae, whereas the PMS was relatively lower in Polygonaceae, and Poaceae. The correlations between PWS and multidimensional plant traits are complex for predicting PWS but can be clarified by considering plant ecological strategies. Further regression analysis revealed that as an evolutionary representation of the crucially related plant traits, plant competition significantly positively affected both IWSC and PSCI, and stress tolerance obviously negatively affected these two parameters (P < 0.05). The correlation between plant strategy and PSCI implied that the increased dominance of competitive species in alpine meadows may intensify interception loss, thereby hindering rainfall allocation to soil and exacerbating water scarcity.

Modelling rainfall interception losses of three plantations in the Loess Plateau

AbstractThe forest canopy affects the water entering the forest ecosystem by intercepting rainfall. This is especially pertinent in forests that depend on rainfall for their ecological water needs, quantifying and simulating interception losses provide critical insights into their ecological hydrological processes. In the semi‐arid areas of the Loess Plateau, afforestation has become an effective ecological restoration measure. However, the rainfall interception process of these plantations is still unclear. To quantify and model the canopy interception of these plantations, we conducted a two‐year rainfall redistribution measurement experiment in three typical plantations, including a deciduous broadleaf plantation (Robinia pseudoacacia) and two evergreen coniferous plantations (Platycladus orientalis and Pinus tabuliformis). Based on this, the revised Gash model was used to simulate their interception losses, and the model applicability across varying rainfall types was further compared and verified. The experiment clarified the rainfall redistribution in the three plantations, and the proportions of throughfall to gross rainfall in Robinia pseudoacacia, Platycladus orientalis, and Pinus tabuliformis were 84.8%, 70.4%, and 75.6%; corresponding, the stemflow proportions were 2.0%, 2.2%, and 1.8%; the interception losses were 13.2%, 27.4%, and 22.6%, respectively. The dominant rainfall pattern during the experiment was characterized by low‐amounts, moderate‐intensity, and short‐duration, during which the highest interception proportions across the three plantations were observed. We used the Penman‐Monteith equation and the regression method, respectively, to estimate the canopy average evaporation rate of the revised Gash model, finding that the latter provides a closer match to the measured cumulative interception (NSE &gt;0.7). When simulating interception under the three rainfall patterns, the model with the regression method better simulated the cumulative interception and event‐scale interception for Platycladus orientalis and Pinus tabuliformis plantations under the dominant rainfall pattern. The results contribute valuable information to assess the impact of forest rainfall interception on regional hydrologic processes.

Introducing Pour Points: Characteristics and Hydrological Significance of a Rainfall‐Concentrating Mechanism in a Water‐Limited Woodland Ecosystem

AbstractThe interception of rainfall by plant canopies alters the depth and spatial distribution of water arriving at the soil surface, and thus the location, volume, and depth of infiltration. Mechanisms like stemflow are known to concentrate rainfall and route it deep into the soil, yet other mechanisms of flow concentration are poorly understood. This study characterizes pour points, formed by the detachment of water flowing under a branch, using a combination of field observations in Western Australian banksia woodlands and rainfall simulation experiments on Banksia menziesii branches. We aim to establish the hydrological significance of pour points in a water‐limited woodland ecosystem, along with the features of the canopy structure and rainfall that influence pour point formation and fluxes. Pour points were common in the woodland and could be identified by visually inspecting trees. Throughfall depths at pour points were up to 15 times greater than rainfall and generally comparable to or greater than stemflow. Soil water content beneath pour points was greater than in adjacent controls, with 20%–30% of the seasonal rainfall volume infiltrated into the top 1 m of soil beneath pour points, compared to 5% in controls. Rainfall simulations showed that pour points amplified the spatial heterogeneity of throughfall, violating assumptions used to close the water balance. The simulation experiments demonstrated that pour point fluxes depend on the interaction of branch angle and foliation for a given branch architecture. Pour points can play a significant part in the water balance, depending on their density and rainfall concentration ability.

Severe degradation and artificial restoration diversely drive runoff and sediment processes in alpine meadows

Artificial grassland is considered an effective measure for restoring severely degraded grassland in alpine areas and has been widely applied on the Qinghai-Tibetan Plateau. However, the specific effects of artificial restoration and degradation on slope runoff and sediment yield are still poorly understood. In this study, we investigated the effects of artificial restoration and degradation on the runoff sediment process in three areas: an alpine meadow (AM), a severely degraded alpine meadow (BL), and a degraded alpine meadow that was restored by artificial grassland (AG). Our findings revealed that the runoff in AG was significantly lower than that in both AM and BL, with reductions by 95.59% and 88.40%, respectively. The sediment yield in AG was significantly reduced, with reductions by 21.77% and 90.54% compared to AM and BL, respectively. Nevertheless, the sediment concentration in AG was 27.22 and 3.26 times higher than that in AM and BL, respectively. Our study provides clear evidence that plant and soil properties play a crucial role in driving soil erosion processes in both AG and BL. Specifically, artificial grassland was effective in inhibiting runoff and sediment yield. This inhibition was attributed to the modification of soil conditions and the interception of rainfall, which were facilitated by the recovery of vegetation coverage and the increased input of organic matter. These findings have significant implications for the artificial restoration of degraded alpine meadows and soil erosion prevention efforts on the Qinghai-Tibetan Plateau.

Enhancing global rainfall interception loss estimation through vegetation structure modeling

Accurate estimates of rainfall interception loss are crucial for modeling the water balance of forested areas. However, considerable regional variability exists in the interception process, and much uncertainty remains. This study enhances the estimation of rainfall interception loss at the global scale by integrating remote sensing products into the parameterization of Gash’s analytical model. We refer to this enhanced configuration as the Global Interception Model (GIM). High-resolution satellite imagery was used to derive vegetation indices and spectral reflectance, which were then employed in linear regression models to estimate canopy cover fraction (c) and vegetation water storage capacity (Sv). Their importance in ecological processes, and land and water resource management, makes the modeling of these parameters of particular interest. The other two parameters required to run the Gash model, namely the mean rainfall and evaporation rates under saturated canopy conditions, were obtained via the integration of MWSEP and ERA5-Land meteorological products. Modeling performance was evaluated using in situ measurements and gridded datasets. GIM estimates exhibited a superior performance statistic when compared to PMLv2 and GLEAMv3.7a. Our results demonstrate the high potential of this approach for improving the accuracy of rainfall interception loss estimates from local to global scales.

Impacts of re-vegetation on soil water dynamics in a semiarid region of Northwest China

Understanding how vegetation (shrub) cover in drylands affects local-to-regional soil water dynamics and associated water balances is of immense importance because of the abundance of afforestation projects worldwide. Vegetation's role in the control of soil water presents a particular challenge to soil water storage (SWS) management in the drylands of China. To address this knowledge gap, we conducted a two-year study in the Mu Us Desert of northwest China. The study involved the acquisition of in-situ soil water measurements within the first 180 cm of soil at three sand dune sites characterized by their differences in % shrub cover. The sand dunes varied from a vegetation-free, bare-ground sand dune site (BF) and two partly vegetated sites, one with medium-level (40 %) and another with high shrub cover (80 %; MF and HF, respectively). Results revealed that the site with the high shrub cover (HF) suffered a net reduction in soil water content (SWC) by up to 32.7 and 39.8 % in the shallow and deep subsoil (0–100 and 100–180 cm), respectively, when compared to corresponding changes at the BF site. Soil water content was shown to be largely influenced by site properties, namely shrub biomass and litter density (p < 0.05). Due to aboveground vegetation and rainfall interception by the litter, 32.2 mm of effective rainfall was reduced to the soil for every 10 %-increase in shrub cover. Bands of soil water depletion during the dry year did not fully recover during the following wet year, resulting in the development of a dried soil layer with an average SWC of 4.6–7.8 %. Increased evapotranspiration (ETtotal) led to a decrease in SWS and relative extractable soil water (REW), which caused ETtotal at HF to be lower than the rate observed at MF. These findings highlight the need for improvements in current restoration strategies, meant at striking a balance between vegetation restoration and SWC by developing optimal plant-community cover and mosaicked vegetation systems.