Abstract
Generally, plant species with shorter leaf longevity maintain a positive carbon balance by decreasing leaf mass per area (LMA) and increasing photosynthesis. However, plants at high elevations need to increase LMA against environmental stresses. Therefore, plants need to increase both LMA and photosynthesis at high elevations. To examine how deciduous plants maintain a positive carbon balance at high elevations, photosynthesis and related leaf traits for deciduous broad-leaved tree Betula ermanii were measured at three elevations. LMA was greater at middle and high elevations than at low elevation. Leaf δ13C was greater at higher elevations, and positively correlated with LMA, indicating greater long-term deficiency of CO2 in leaves at higher elevations. However, the Ci/Ca ratio at photosynthetic measurement was not low at high elevations. Nitrogen content per leaf mass and stomatal conductance were greater at higher elevations. Photosynthetic rates and photosynthetic nitrogen use efficiency (PNUE) did not differ among the three elevations. Photosynthetic rate showed a strong positive correlation with stomatal conductance on a leaf area basis (R2 = 0.83, P B. ermanii compensates the deficiency of CO2 in leaves at high elevation by increasing stomatal conductance, and maintains photosynthesis and PNUE at high elevation as much as at low elevation.
Highlights
IntroductionLeaf longevity of deciduous plant species decreases at higher elevations because
Nitrogen contents per leaf mass and leaf area were greater at high elevation than at middle and low elevations (Tukey HSD test, P < 0.05, Figure 1(b), Figure 1(c))
leaf mass per area (LMA) and the nitrogen content per leaf mass were high at high elevation, and nitrogen allocation ratios to chlorophyll a and b showed no elevational differences. 4.2
Summary
Leaf longevity of deciduous plant species decreases at higher elevations because. The photosynthetic rate is expected to be greater and LMA smaller for deciduous plant species at higher elevations because leaf longevity is shorter at higher elevations. Environmental stresses, such as strong wind, low temperature and UV-B, increase at high elevations [6]. Plants need to make tough leaves with high LMA at higher elevations, even though their leaf longevity is short. Whether deciduous plant species increase both LMA and photosynthesis at high elevations and how a positive carbon balance is maintained there have not been clarified
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
