Seasonal Variation in Transpiration and Stomatal Conductance of Three Savanna Tree Species in Ruma National Park, Kenya
Authors:
- John Maina NyongesaJNJohn Maina Nyongesa
- Wycliff OronyiWOWycliff Oronyi
- Oyoo LawrenceOyoo Lawrence
- Ernest Kiplangat RonohERErnest Kiplangat Ronoh
- Lindsay Sikuku MwalatiLMLindsay Sikuku Mwalati
- Vincent SubaVSVincent Suba
- Leopody GayoLGLeopody Gayo
- Jacques NkengurutseJNJacques Nkengurutse
- Denis Ochuodho OtienoDODenis Ochuodho Otieno
- Yuelin LiYLYuelin Li
Open Access
Abstract
Understanding the seasonal regulation of transpiration and stomatal conductance is critical for evaluating plant water-use strategies in response to environmental variability. This study assessed these physiological traits in three dominant savanna tree species (Piliostigma thonningii (Schumach.) Milne-Redh., Combretum molle R.Br. ex G.Don, and Balanites aegyptiaca (L.) Delile) in Ruma National Park, Kenya. Measurements were taken during wet and dry seasons under varying canopy light conditions (light-exposed vs. shaded leaves) and soil moisture regimes. A randomized design with four treatments and three replicates was employed. Results showed significantly higher transpiration and stomatal conductance during wet seasons, especially in sunlit leaves (p < 0.05). P. thonningii exhibited the highest rates of transpiration (9 mmol m−2 s−1) and stomatal conductance (~2.2 mmol m−2 s−1) in light conditions, while B. aegyptiaca maintained consistently low values, reflecting a drought-tolerant strategy. C. molle demonstrated intermediate responses, suggesting a balance between water conservation and resource use. Despite seasonal trends, low R2 values indicated that internal physiological regulation outweighed the influence of external climatic drivers. These findings reveal species-specific water-use strategies and highlight the ecological significance of leaf-level responses to light and moisture availability in tropical savannas. The study provides valuable insights for forest management and climate-resilient restoration planning in water-limited ecosystems.Keywords
Funding Information
- National Natural Science Foundation of China (31961143023, 31670453, 2015/16)
- Jaramogi Oginga Odinga University of Science and Technology (JOOUST) Small Grants for Research (JSGR) (31961143023, 31670453, 2015/16)
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