Literature type: Scientific
Journal: Environmental management
Volume: 54 , Pages: 1331–1341
DOI: 10.1007/s00267-014-0350-7
Language:
English
Full reference: Guan, L., Wen, L., Feng, D., Zhang, H., & Lei, G. 2014. Delayed flood recession in central Yangtze floodplains can cause significant food shortages for wintering geese: results of inundation experiment. Environmental management 54: 1331–1341 https://www.dx.doi.org/10.1007/s00267-014-0350-7
Keywords: Carex, Gompertz growth curve, flood regimes, Three Gorges Dam, China, lake–river relationship, habitat management
Abstract:
Carex meadows are critical habitat for wintering geese in the floodplains of the middle and lower reaches of Yangtze River, China. These meadows follow a growth cycle closely tied to the seasonal hydrological fluctuation: as water levels recede in the fall, exposed mudflats provide habitat for Carex spp. growth. The seasonal growth of Carex overlaps the arrival of wintering geese and provides an important food source for the migrants. Recent alterations to the Yangtze's hydrology, however, have disrupted the synchronous relationship between water levels, Carex growth and wintering geese at Dongting Lake. In October 2012, we carried out an outdoor mesocosm experiment to investigate potential impacts of delayed water recession on the germination and growth of Carex heterolepis, the dominant Carex species at Dongting Lake, to understand how changes in hydrology might impact wintering goose habitat. Results showed that the delayed flood recession exerted significant impact on the first growth cycle of Carex growth. Prolonged inundation significantly lowered the intrinsic growth rate (P = 0.03) and maximum growth rates (P = 0.02). It also took significantly longer time to reach the peak growth rate (P = 0.04 and 0.05 for number of shoot and biomass, respectively). As a result, biomass accumulation was reduced by 45, 62 and 90 % for 10-day, 20-day and 30-day inundation treatments, respectively. These results indicate a severe risk of food shortage for wintering geese when water recession delayed. This potential risk should be taken into consideration when operating any hydrological control structures that alter the flood regimes in Dongting Lake.
Literature type: Scientific
Journal: Journal of Ornithology
, Pages: online June 2013.
DOI: 10.1007/s10336-013-0979-7
Language:
English
Full reference: Wang, X., Zhang, Y., Zhao, M. Cao, L. & Fox, A.D. 2013. The benefits of being big: effects of body size on energy budgets of three wintering goose species grazing Carex beds in the Yangtze River floodplain, China. Journal of Ornithology : online June 2013. https://www.dx.doi.org/10.1007/s10336-013-0979-7
Keywords: energy budget, Yangtze River floodplain, erythropus, fabalis, serrirostris, Albifrons, wintering
Abstract:
Herbivores of different body size vary in food selection because of their different metabolic requirements and abilities to harvest and digest food. Compared with smaller grazers, larger ones require higher food quantity but can tolerate poorer quality. This divergence may also explain habitat partitioning in the distribution of closely related species. By estimating daily energy expenditure (based on observed activity budgets) and energy intake (using the indigestible marker method in food and faeces), we compared the field energy budgets of three wintering herbivorous goose species differing in body size feeding on the same Carex meadows. Throughout the winter, the larger Bean Geese Anser fabalis serrirostris and Greater White-fronted Geese Anser albifrons maintained positive energy budgets grazing lower quality Carex, in contrast to the smaller Lesser White-fronted Geese Anser erythropus which failed to do so and could only maintain positive energy budgets by grazing high-quality Alopecurus, Cynodon and Eleocharis. However, all three species failed to maintain positive energy balance and lost mass in midwinter. These results have important implications for explaining the divergent distribution patterns of these species on their wintering grounds in China.
Number of results: 2