Alteration in isotopic composition of gross rainfall as it is being partitioned into throughfall and stemflow by xerophytic shrub canopies within water-limited arid desert ecosystems
| Autor: | Rui Hu, Ya-feng Zhang, Yan-xia Pan, Xin-ping Wang |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Canopy
China Biogeochemical cycle Environmental Engineering Stemflow 010504 meteorology & atmospheric sciences Rain ved/biology.organism_classification_rank.species Oxygen Isotopes 010501 environmental sciences 01 natural sciences Shrub Forest ecology Water Movements Environmental Chemistry Waste Management and Disposal 0105 earth and related environmental sciences Hydrology ved/biology Water Vegetation Deuterium Throughfall Pollution Arid Caragana Environmental science |
| Zdroj: | Science of The Total Environment. 692:631-639 |
| ISSN: | 0048-9697 |
| DOI: | 10.1016/j.scitotenv.2019.07.294 |
| Popis: | Isotopic composition of gross rainfall has been extensively used as a conservative tracer to track water movement and other hydrological processes in vegetated ecosystems. Recent studies from forest ecosystems, however, demonstrated that vegetation canopies can alter the isotopic composition of rainwater during rainfall partitioning into throughfall and stemflow, likely leading to errors and biases in aforementioned studies. No known studies, to date, had investigated this topic in shrub-dominated arid and semi-arid ecosystems where water is typically the driving factor in ecological, hydrological and biogeochemical processes. In this study, event-based gross rainfall, the throughfall and stemflow induced by shrubs of Caragana korshinskii were measured and samples were collected within a water-limited arid desert ecosystem of northern China, and their water stable isotopes (18O and 2H) were also analyzed in the laboratory. We mainly aimed to investigate whether there is an isotopic enrichment or depletion in stemflow and throughfall in comparison to gross rainfall, and to evaluate the possible underlying mechanisms. Our results indicated an enrichment of both isotopes in stemflow, while a general more depletion in throughfall than in gross rainfall, which is presumably affected by a combinative effects of canopy evaporation, isotopic exchange, and selective canopy storage. Deuterium excess of stemflow were found to be significantly higher (P |
| Databáze: | OpenAIRE |
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