Stomatal dimensions of Laguncularia racemosa leaves in restored and degraded mangrove ecosystems

Abstract

ABSTRACT Mangrove leaves have adapted to effectively manage water conservation and regulate toxic saline conditions through the morphological characteristics of stomatal dimensions. The present study examines the stomatal dimensions of 120 Laguncularia racemosa leaves from both a degraded mangrove ecosystem and a restored mangrove ecosystem located along the Guyana coastline. Datasets were obtained during the wet and dry seasons using the nearest individual sampling method. The nail polish blotting technique, microscopy, and digital photography were used to obtain measurements of various stomatal dimensions, including guard cell length and width, pore length and width, circumference, surface area, stomatal frequency, density, index, and epidermal cell frequency. Our hypothesis is that there is significant variation in the stomatal dimensions of Laguncularia racemosa leaves as a function of mangrove ecosystem type and seasonal change. The results of this study confirmed this hypothesis as significant variations were observed in stomatal dimensions as a function of seasonal changes and mangrove ecosystem type. Statistically significant differences (p < 0.05, R > 0.70) were observed between the degraded ecosystem during the dry season and the restored ecosystem during the wet season, specifically regarding guard cell length and width, pore length and width, area, and circumference. Multiple regression analysis and PCA provide compelling evidence to support the existence of robust correlations between ecosystem types and stomatal dimensions. The results of our study indicate that the leaves of Laguncularia racemosa display certain small-scale adjustments that enable them to manage the stress factors present in different ecosystems and seasons.