The niche response surfaces of two macrophytes, Potamogeton pectinatus L. and Hydrilla verticillata (L.f.) Royle were characterized and an assessment was made of various methods used to estimate the annual net production of the macrophyte stand in Lake Nainital, (located at 1937 m in Central Himalaya). The niche response surface were characterized by plotting the biomass values of the macrophytes in relation to two variant: site (depth) and time (months). Although the niche response surfaces of the two macrophytes showed a broad overlap, they differed from each other in detail. Furthermore, individuals of the same species populations showed varying responses to variations in site and time in terms of growth phenology and amounts of biomass and productivity. In view of the inter- and intraspecies differences in growth responses to the gradients of site and time, the method of calculation which followed the biomass changes of each site separately and considered all the positive increments by all species gave the most accurate net primary productivity estimate of the macrophyte stand. © 1987.
Purohit, R., & Singh, S. P. (1987). Niche response surfaces and productivity estimates of macrophytes in lake nainital, Central Himalaya, India. Aquatic Botany, 29(1), 49–62. https://doi.org/10.1016/0304-3770(87)90028-3