Abstract
Stable isotope analysis can be used to investigate water sources of plants because of no isotopic fractionation during water uptake by terrestrial plants.Ecosystems in the karst region of southwest China are very fragile due to the thin soil layer and intensive infiltration capacity of rock fracture,which result in a very limited amount of water storage for plant uptake.Water retention in the soil zone and shallow fractured rock zone(subcutaneous)is a key factor for plant growth.However,the source of water for plant growth in karst region remains unclear.Distinction of water sources taken by karst plants is a challenging task for botanists and hydrologists, and has important implications for ecosystem management.In this study,we selected 5dominant plant species grown in various micro-habitats in the Wangjiazhai catchment,a typical karst desertification area in Guizhou Province.The spatial heterogeneity of plant water sources at niche scale and the response of the heterogeneity to different karst rocky desertification degree were studied.Proportions of water sources for plant uptake were determined by theδD and δ18 O values of plant stem water,and the water taken from different soil layers and the subcutaneous zone.The following conclusions were drawn from the analysis:(1)TheδD andδ18 O values of soil water were significantly different among various micro-habitats,stony surface had the most positiveδD andδ18 O values,stony crevice had the most negativeδD andδ18 O values,the others had the mediumδD andδ18 O values.TheδD andδ18 O values of soil water were significantly different in soil profile and theδD andδ18 O values of soil water in the 0-10 cm layer were more positive than those in the 10-30 cm layer.(2)The plant species absorbed water from both soil layers and subcutaneous zone and these plant species extracted more water from soil layers than subcutaneous zone in rainy seasons in general.The proportion of plants water use from the subcutaneous zone decreased with increasing degree of karst rocky desertification.Pyracantha fortuneana,Rhamnus davurica and Viburnum utile in slight and non karst desertification grade extracted water from both soil layers and subcutaneous zone,while these plants only used water form soil layers in medium and severe grade,and Platycarya longipes and Carpinus pubescens in non karst desertification grade extracted water from both soil layers and subcutaneous zone,while these plants only used water form soil layers in slight grade,which is mainly due to various vegetation types,disturbance regimes,soil conditions and crack growth degree of rocks in different grades plots.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 7
Claim · model-written summary
The studied plants generally extracted more water from soil layers than from the subcutaneous zone in rainy seasons.
Verbatim
e0“The plant species absorbed water from both soil layers and subcutaneous zone and these plant species extracted more water from soil layers than subcutaneous zone in rainy seasons in general.”
Claim · model-written summary
Plant use of subcutaneous water decreased as karst desertification increased.
- Taxon
- plantsViridiplantaee0
- Outcome
- proportion of plants water use from the subcutaneous zonee0
- Direction
- decreasede0
- Setting
- karst rocky desertificatione0
Verbatim
e0“The proportion of plants water use from the subcutaneous zone decreased with increasing degree of karst rocky desertification.”
Claim · model-written summary
Pyracantha fortuneana used both soil and subcutaneous water in slight and non-desertified grades, but only soil water in medium and severe grades.
- Taxon
- Pyracantha fortuneana
Pyracantha fortuneanae0 - Outcome
- extracted water from both soil layers and subcutaneous zonee0
- Setting
- slight and non karst desertification gradee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Pyracantha fortuneana,Rhamnus davurica and Viburnum utile in slight and non karst desertification grade extracted water from both soil layers and subcutaneous zone,while these plants only used water form soil layers in medium and severe grade”
Claim · model-written summary
Rhamnus davurica used both soil and subcutaneous water in slight and non-desertified grades, but only soil water in medium and severe grades.
- Taxon
- Rhamnus davurica
Rhamnus davuricae0 - Outcome
- extracted water from both soil layers and subcutaneous zonee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Pyracantha fortuneana,Rhamnus davurica and Viburnum utile in slight and non karst desertification grade extracted water from both soil layers and subcutaneous zone,while these plants only used water form soil layers in medium and severe grade”
Claim · model-written summary
Viburnum utile used both soil and subcutaneous water in slight and non-desertified grades, but only soil water in medium and severe grades.
- Taxon
- Viburnum utile
Viburnum utilee0 - Outcome
- extracted water from both soil layers and subcutaneous zonee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Pyracantha fortuneana,Rhamnus davurica and Viburnum utile in slight and non karst desertification grade extracted water from both soil layers and subcutaneous zone,while these plants only used water form soil layers in medium and severe grade”
Claim · model-written summary
Platycarya longipes used both water sources in non-desertified grades but only soil water in slight grades.
- Taxon
- Platycarya longipesPlatycarya longipese0
- Outcome
- extracted water from both soil layers and subcutaneous zonee0
Verbatim
e0“Platycarya longipes and Carpinus pubescens in non karst desertification grade extracted water from both soil layers and subcutaneous zone,while these plants only used water form soil layers in slight grade”
Claim · model-written summary
Carpinus pubescens used both water sources in non-desertified grades but only soil water in slight grades.
- Taxon
- Carpinus pubescensCarpinus pubescense0
- Outcome
- extracted water from both soil layers and subcutaneous zonee0
Verbatim
e0“Platycarya longipes and Carpinus pubescens in non karst desertification grade extracted water from both soil layers and subcutaneous zone,while these plants only used water form soil layers in slight grade”