Morphological, Photosynthetic and Dry Weight Accumulation Recovery Dynamics of Riparian Plant Distylium chinense after De-submergence in the Three Gorges Reservoir Region, China
Distylium chinense is a tree species that occurs in natural water-level- fluctuation area of the Three Gorges Reservoir region, China. The capacity for fast-growth recovery after de-submergence is important for establishment of riparian species in a water-level-fluctuation zone. To investigate whether D. chinense has recovery growth capacity in the artificial water-level-fluctuation zone, the seedlings of D. chinense were subjected to two treatments: (1) 120 seedlings un-submerged and watered daily as control (CK) and (2) 160 seedlings completely submerged with 2m water depth (Submergence, top of plants at 2m below water surface). Four submergence durations included 15, 30, 90 and 120 d with 60 d recovery growth after de-submergence. Morphological growth and photosynthesis were monitored continuously during 60 d of recovery following 15, 30, 90 and 120 d of complete submergence. The results showed: (1) the seedlings subjected to different submergence duration treatments started recovery growth after de-submergence and showed strong recovery capability; (2) the submergence treatment significantly inhibited the formation of epicormic shoots and new leaves of submerged seedlings on day 30 after flooding was initiated. After being returned to the control conditions, the 30- and 60-day seedlings showed similarly fast and strong recovery for the epicormic shoots and new leaf RGR (relative growth rate). The 90- and 120-day submerged seedlings displayed slow increases in the RGR of the epicormic shoots and new leaves, reaching maximal level on day 25 and 35, respectively; (3) the recovery patterns of dry weight accumulation of stems, leaves and roots coincided with the full recovery of the maximal photosynthetic rate and number of epicormic shoots and new leaves. The results showed that D. chinense has relatively high submergence-tolerant with the quiescence strategy conserving energy and carbohydrates by restraining growth. On the other hand, D. chinense responded with the quiescence strategy saving energy and resources during submergence, This could positively affect the survival and generation of new tissue after de-submergence. Thus, D. chinense should be considered to be as native pioneer tree species in the re-vegetation and restoration of water-level-fluctuation zone, and should be considered when attempting to create a more effective riparian buffer in Three Gorges Reservoir Region,China.
Distylium chinense Submergence Morphological recovery growth Photosynthetic capacity Biomass Three Gorges Reservoir region
X.L.Li C.Y.Luan J.Yang P.S.Mei T.Xu Y.P.Huang
Engineering Research Center of Eco-Environment in Three Gorges Reservoir Region, Ministry of Education, China Three Gorges University, Yichang 443002, China
国际会议
The 3rd Biennial ISRS Symposium Achieving Healthy and Viable Rivers (ISRS)第3届国际河流大会
北京
英文
22-31
2013-08-05（万方平台首次上网日期，不代表论文的发表时间）