caa a22 4500 475751507 CHVBK 20180406123525.0 cr unu---uuuuu 170329e20000501xx s 000 0 eng 10.1023/A:1009835424490 doi (NATIONALLICENCE)springer-10.1023/A:1009835424490 Hartvigsen Gregg Department of Biology, 130 College Place, Syracuse University, 13210, Syracuse, NY, USA aut Competition between co-dominant plants of the Serengeti plains depends on competitor identity, water, and urine [Elektronische Daten] [Gregg Hartvigsen] Kyllinga nervosa (Steud.) and Sporobolus kentrophyllus (K. Schum.) are co-dominant plants of the Serengeti short-grass plains, Tanzania. The plains are characterized by seasonal and sporadic rainfall and currently support in excess of 1.5 million migratory ungulates. The interactive effect of simulated bovine urine and water availability were tested on the competitive interactions of these species in the laboratory. Sporobolus kentrophyllus was a superior competitor to K. nervosa over the tested treatment levels with respect to growth and reproductive effort. Sporobolus kentrophyllus exhibited rapid growth in response to urine addition, leading to a significant species × urine interaction while reduced growth by K. nervosa in response to low water availability explained the significant species × water interaction and is likely explained by K. nervosa's shallow root system. Kyllinga nervosa, however, appears to be more tolerant of low nitrogen conditions based on its similar growth with and without the urine treatment. The effect of intraspecific competition on total biomass was similar for S. kentrophyllus and K. nervosa. Competition resulted in increased size differences (asymmetry) for K. nervosa and for the interspecific competition treatments compared to the size differences observed for plants grown individually (in absence of competition). Total reproductive biomass was reduced most by competition with S. kentrophyllus, irrespective of target species. The water treatment did not influence reproduction while the urine treatment significantly increased reproductive biomass and interacted with target species, competitor species, and yielded a three-way urine × target × competitor species interaction. Results suggest that codominance of these two species in the Serengeti is regulated by water availability, nitrogen input from grazers, and local neighbor identity. Kluwer Academic Publishers, 2000 Coexistence nationallicence Interactive factors nationallicence Interspecific and intraspecific competition nationallicence Response to competition nationallicence Size asymmetry nationallicence Plant Ecology Kluwer Academic Publishers 148/1(2000-05-01), 31-41 1385-0237 148:1<31 2000 148 11258 https://doi.org/10.1023/A:1009835424490 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1009835424490 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Hartvigsen Gregg Department of Biology, 130 College Place, Syracuse University, 13210, Syracuse, NY, USA aut NATIONALLICENCE 773 0- Plant Ecology Kluwer Academic Publishers 148/1(2000-05-01), 31-41 1385-0237 148:1<31 2000 148 11258 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer