Trade-off strategy of leaf functional traits of desert halophyte Lycium ruthenicum in the lower reaches of Heihe River, Northwest China: response to soil moisture and salinity
KEYWORDS Soil salinity ·Soil water ·Desert halophyte ·Leaf functional traits ·Lycium ruthenicum 2 Abstract Abstract Background: Understanding salinity resistance and water utilization on shrub species is a challenge to the management and conservation of desert halophytes. Lycium ruthenicum Murr.with a significant soil and water conservation capacity, is one of the dominant shrubs and halophytes in the lower reaches of the Heihe River, Northwest China. In this paper, the effects of two depths (
... ts of two depths ( 0-40 and 40-80 cm) of soil salinities and water contents on the leaf functional traits of eight L. ruthenicum communities in different distances from the main channel were studied. Fourteen leaf water physiological and ecological stoichiometric traits were investigated, linking with soil factors to explain desert plant trade-off strategies. Results: Specific leaf volume (SLV), specific leaf area (SLA), leaf thickness (LT), nitrogen (N), C:N, C:P could serve as good indicators of drought and saline resistance. Low N, specific leaf area (SLA) indicated that the plant was located at the slow investment-return axis of the species resource utilization. Low C:N, C:P showed that L. ruthenicum had a defensive life history strategy at drought and salinity areas. The RDA results showed that 0-40 and 40-80 cm soil properties respectively explained 93.45% and 99.96% leaf traits variation. Soil water contents, HCO3had extremely positive correlation (P<0.01) with leaf functional traits. Shallow soil water contents significantly affects P, and deeper soil water contents significantly responds C and N; shallow soil salinity significantly affected LT, C and N contents, whereas deeper soil salinity significantly affected N and SLV. Conclusions: L. ruthenicum had a foliar resource acquisition and resource conservation trade-off with a defensive life history strategy in the area of drought and salinity. This finding provides baseline information to facilitate the management and restoration of arid-saline desert ecosystem. Background Green leaves collect and store nutrients to become the basis of terrestrial ecosystem function. Through many people's discussion, functional traits are defined as measurable morphological, physiological, and phenological properties that are related to individual adaptation , these three classification traits accordingly include specific leaf area (SLA), specific leaf volume (SLV), photosynthetic rate, plant height, seed mass, etc. Plant functional traits are a hot topic in current ecological research, aiming to clearly link the phenotypes and physiological changes of individual Declarations Authors' contributions SJL conceived and designed the experiments, revised the first draft; WG analyzed the data and wrote draft; HW and WG performed experiments; GQW and PXS guided writing and participated in the survey. All authors read and approved the final manuscript. Acknowledgements We are grateful to ZQ Li, KB Li, YL, JZ Chen for their help with fieldwork, to RL Zhao with lab work, and to Dr. LY for identifying plant species. Ethics approval and consent to participate There was no requirement to seek ethical approval to carry out the work described above. Consent for publication Not applicable.