Shade shelters increase survival and photosynthetic performance of oak transplants at abandoned fields in semi-arid climates

• Published in: Journal of forestry research 2013-03, Vol.24 (1), p.23-28
• Main Authors: González-Salvatierra, Claudia, Badano, Ernesto Iván, Flores, Joel, Rodas, Juan Pablo
• Format: Article
• Language: English
• Subjects: artificial shade; Biomedical and Life Sciences; chlorophyll; dry season; environmental factors; fluorescence; forest restoration; Forestry; Life Sciences; microirrigation; mortality; Original Paper; photosynthesis; Quercus; seedlings; semiarid zones; solar radiation; trees; water stress; 光合性能; 半干旱地区; 季节性干旱; 幼苗移植; 庇护所; 森林恢复; 橡木; 气候条件
• ISSN: 1007-662X; 1993-0607
• DOI: 10.1007/s11676-013-0321-5

Forest restorations conducted in semiarid, seasonally dry climates must deal with the intense drought stress that affects tree seedlings during the dry season. Although this water deficit is the most commonly invoked source of mortality for seedlings, several other environmental factors may also preclude survival of transplants. For instance, it has been widely reported that excessive light reduces the efficiency of the photosynthetic apparatus, hence decreasing plant survival, but most seedling transplants in deforested areas are conducted under these light conditions. This study is focused in determining whether excessive light affects the photosynthetic performance and survival of Quercus coccolobifolia, a Mexican oak species, when their seedlings are transplanted in semiarid deforested areas. Further, this study tests the possibility of using artificial shade shelters to improve the ecophysiological performance and survival of seedlings. Oak seedlings were transplanted under full sunlight conditions and beneath artificial shade shelters of two different colors： white and black. To reduce water stress, and hence isolate the effects of light treatments, a drip irrigation system was implemented at each experimental plot. Seedling survival was monitored weekly for 128 days and photosynthetic performance was assessed by measuring chlorophyll fluorescence at three opportunities during the experiment. Sun-exposed seedlings showed lower photosynthetic performance and survival rates than those beneath shelters of both colors. These results suggest that sunlight damage can reduce seedling survival when they are transplanted in exposed sites, and that shade shelters can improve the success of forest restoration programs in semiarid climates.