TO THE METHOD OF DETERMINING THE LEAF AREA OF PLANTS OF THE FAMILY NYMPHAEACEAE SALISB.

Abstract

Leaf area is an important indicator that is closely related to the size of the assimilating surface, photosynthesis, respiration, transpiration, specific leaf area, and production. The purpose of this work is to obtain regression models for determining the leaf area of widespread hydrophytes – Nuphar lutea (L.) Smith and Nymphaea candida C. Presl. These plants have a high ecological valence and make a significant contribution to the overall productivity of reservoirs. Collection of floating leaves of water lilies was carried out in 2019 in the gulf of the Volga river in the Tver region (56°58'50.4", 37°27'45.2"). A total of 108 leaves of Nuphar lutea and 170 – Nymphaea candida were collected. Main parameters: the length of the leaf blade from the attachment point of the petiole to the tip (l1), the total length (l2) and width (w) of the leaf blade were measured with an accuracy of 0.1 cm. The actual leaf area was determined by a Planix 7 planimeter. Correlation and regression analyses were used to analyze the data. The growth of water lily leaves is uniform. Regression analysis revealed the dependence of the actual leaf area (LA) on morphometric indicators l1, l2, and w. For Nuphar lutea: LAN.l=2.12∙l11.81; LAN.l=0.64∙l21.95; LAN.l=0.93∙w2.05. For Nymphaea candida: LAN.c=3.88∙l11.79; LAN.c=0.85∙l21.94; LAN.c=0.93∙w1.96 The received power equation is fair from a biological point of view and correct with mathematical. They can be used in the field without causing damage to plant communities. This is a fast, reliable and cost-effective method. It allows you to monitor, assess the degree of overgrowth of reservoirs, predict the further development of communities, and allows you to conduct research on specially protected natural areas.