Leaf chlorophyll parameters and photosynthetic characteristic variations with stand age in a typical desert species (Haloxylon ammodendron)

Abstract

As a desert shrub, Haloxylon ammodendron combines ecological, economic, and social benefits and plays an important role in the ecological conservation of arid desert areas. Understanding its physiological characteristics and its mechanism of light energy utilization is important for the conservation and utilization of H. ammodendron. Therefore, we selected five stands (5-, 11-, 22-, 34-, and 46-year-old) of H. ammodendron as research objects in the study and measured their photosynthetic light response curves by a portable open photosynthesis system (Li-6400) with a red-blue light source (6400-02B). Then, we measured the leaf chlorophyll parameters in the laboratory, calculated the photosynthetic characteristics by using Ye Zipiao’s photosynthetic model, analyzed their variation patterns across stand ages, and explored the relationships between leaf chlorophyll parameters and photosynthetic characteristics. The results showed that leaf chlorophyll parameters and photosynthetic characteristics of H. ammodendron at different stand ages were significantly different. Chl content, Pnmax, and LUEmax of H. ammodendron were V-shaped with the increase of stand age. The 5-year-old H. ammodendron was in the rapid growth period, synthesized more Chl a+b content (8.47 mg g−1) only by using a narrower range of light, and the Pnmax and LUEmax were the highest with values of 36.21 μmol m−2 s−1 and 0.0344, respectively. For the 22-year-old H. ammodendron, due to environmental stress, the values of Chl a+b content, Pnmax, and LUEmax were the smallest and were 2.64 mg g−1, 25.73 μmol m−2 s−1, and 0.0264, respectively. For the older H. ammodendron, its Chl content, Pnmax, and LUEmax were not significantly different and tended to stabilize but were slightly higher than those of the middle-aged H. ammodendron. On the other hand, the other photosynthetic parameters did not show significant variation patterns with stand age, such as Rd, AQE, LSP, LCP, and IL-sat. In addition, we found that the relationships between Chl a+b content and Pnmax and between Chl a+b content and LUEmax were highly correlated, except for the older H. ammodendron. Thus, using leaf chlorophyll content as a proxy for photosynthetic capacity and light use efficiency should be considered with caution. This work will provide a scientific reference for the sustainable management of desert ecosystems and vegetation restoration in sandy areas.

Perfluorooctanesulfonic Acid Alters the Plant’s Phosphate Transport Gene Network and Exhibits Antagonistic Effects on the Phosphate Uptake

“…This is influenced by both nutrient conditions and environmental stresses. 53 The total chlorophyll contents of WT plants were found to be significantly lower under PFOS conditions compared to the pht1;8 mutant. This data indicated that the accumulation of PFOS in plants inhibits photosynthesis, thereby impacting overall growth, including a reduction in root length.…”

“…The quantity of chlorophyll largely determines the photosynthetic capacity of plants, which in turn affects their growth. This is influenced by both nutrient conditions and environmental stresses . The total chlorophyll contents of WT plants were found to be significantly lower under PFOS conditions compared to the pht1;8 mutant.…”

Insights into the multi-chromosomal mitochondrial genome structure of the xero-halophytic plant Haloxylon Ammodendron (C.A.Mey.) Bunge ex Fenzl

“…It is worth noting that proteins translated from edited RNAs could play a critical function in an environment change context, resulting in plant acclimatization and survival capabilities [ 49 ]. Indeed, H. ammodendron is well known for its remarkable tolerance to saline and dry environments [ 50 , 51 ].…”

Effects of groundwater depth on ecological stoichiometric characteristics of assimilated branches and soil of two desert plants

“…After long-term natural selection, they have shown strong adaptability to habitats, so they are important for wind control and sand control in the Gurbantunggut Desert ( Yue et al., 2020 ). Extensive research has been conducted on H. ammodendron and H. persicum , mainly focusing on the effects of environmental change (such as topographic change, precipitation change, and nitrogen addition) on their community structure, growth, development, physiological performance, and water use pattern ( Xu and Li, 2006 ; Hao and Li, 2022 ; Song et al., 2010 ; Wu et al., 2019b ; He et al., 2022 ; Qiang et al., 2022 ). However, little research has been conducted on the links between hydrological conditions and their ecological stoichiometry.…”