Gas Exchange, Photochemical Efficiency, and Leaf Water Potential in Three Salix Species

Abstract

Gas exchange, photochemical efficiency, and leaf water potential (Ψ l ) of Salix matsudana (non-indigenous species), S. microstachya and S. gordejevii (indigenous species) were studied in Hunshandak Sandland, China. Ψ l of all the three species decreased from 06:00 to 12:00, and increased afterwards. S. matsudana showed higher values of Ψ l than others. Net photosynthetic rate (P N ) and stomatal conductance (g s ) of S. matsudana were the lowest among all, with the maximum P N at 10:00 being 75 % of that of S. gordejevii. Compared with the indigenous species, the non-indigenous S. matsudana had also lower transpiration rate (E) and water use efficiency (WUE). The values of F v /F m in all the species were lower from 06:00 to 14:00 than those after 14:00, indicating an obvious depression in photochemical efficiency of photosystem 2 in both non-indigenous and native species. However, it was much more depressed in S. matsudana, the non-indigenous tree. P N was positively correlated to g s and negatively related to Ψ l . The relationship between g s and vapour pressure difference (VPD) was exponential, while negative linear correlation was found between g s and Ψ l .

Ecophysiological Responses of Three Tree Species to a High-Altitude Environment in the Southeastern Tibetan Plateau

“…F v /F m of P. cathayana and U. pumila decreases to a lower level than that of S. longistamina at mid-day, but recovers almost completely at sunset, suggesting that photoinhibition in these species is a photoprotective mechanism accomplished through thermal dissipation of excess energy, as suggested by the mid-day increase of NPQ in both species [57]. Photoinhibition can be caused by photodamage not only to the photosynthetic apparatus but also to photoprotective mechanisms through thermal dissipation of excess energy [58]. In our study, F v /F m remains lower than 0.80 throughout the day, indicating that all three species are stressed by the high irradiance.…”

Intercambio gaseoso de dos clones de Paulownia elongata x fortunei al primer año de desarrollo vegetativo en tres sitios del centro-sur de Chile

“…Los resultados de este trabajo corroboran aquellos reportes donde se muestra que algunas especies de un mismo género o clones de una misma especie, pueden responder a las condiciones edafoclimáticas de cada sitio con intercambios gaseosos diferentes, presentando de esta manera diferentes respuestas de tolerancia ante una situación de estrés (Orlovic et al 1998, Yu 2001, Liu et al 2003, Ngugi et al 2003, como reflejo de la posible existencia de diferencias genéticas inter e intraespecíficas, esta última por su plasticidad a los sitios (Tsialtas et al 2001, Ponton et al 2002, Yin et al 2005.…”

“…Estas diferencias pueden observarse incluso entre especies del mismo género creciendo en las mismas condiciones edafoclimáticas (Orlovic et al 1998, Ngugi et al 2003. Por ejemplo, Liu et al (2003) detectaron diferencias en los parámetros de intercambio gaseoso en tres especies del género Salix establecidos en un sitio semiárido de China, donde S. matsudana Koidz., especie introducida, presentó a lo largo del día menores tasas de fotosíntesis y conductancia estomática que las especies nativas S. gordejevii Y.L. Chang & Skvortsov y S. microstachya Turz.…”

Qualitative and Quantitative Analysis of Five Bioactive Flavonoids in <i>Salix bordensis</i> Turcz. by HPLC-DAD and HPLC-ESI-MS

“…Previous studies have focused on the drought resistance, wind prevention, and sand fixation of Salix bordensis Turcz. [13]- [16]. Except for studies on the isolation and identification of ten compounds, including seven flavonoids by Luo et al [17] and Yang et al [18], systematic investigations on the phytochemistry of the components of Salix bordensis Turcz.…”