The impact of land use change on morphological and anatomical adaptations of Rhizophora species

Abstract

BACKGROUND AND OBJECTIVES: The ongoing destruction of mangrove forests highlights the urgent need for mitigation and control efforts. Indonesia, home to a rich diversity of mangrove species, has the potential to provide viable solutions to address this issue. The main objective of researchers is to maintain the existence of all species. It is crucial that research data support control and mitigation strategies to ensure efficient and optimal management of these ecosystems. Analyzing how a species responds to alterations in land use can yield significant understanding of its capacity for adaptation. The ability to adapt can be assessed by analyzing variations in leaf structure and anatomy. This study investigated the morphological and anatomical characteristics of three species in the Rhizophoraceae family: Rhizophora mucronata, Rhizophora apiculata, and Rhizophora stylosa, which thrive in three distinct mangrove ecosystems in North Sumatra Province. The purpose was to examine how effectively these species have modified their behaviors and characteristics in relation to shifts in their environmental conditions. This study sought sought to evaluate the extent to which these species have adjusted to the changing environmental conditions in their habitat located in North North Sumatra Province, Indonesia. METHODS: This study aimed to select sites that illustrated three unique land uses residential areas in Belawan Sub-District, healthy mangrove forests in Sitardas Village, and mangrove areas designated for fish pond activities in Percut Sei Tuan Sub-District. Observations were made on three mangrove species: Rhizophora apiculata Blume, Rhizophora mucronata Poir, and Rhizophora stylosa Griff, to assess how their leaf morphology and anatomy respond to changes in land use within their natural environments. Leaf samples were collected from three separate locations, ensuring that ten trees of each species were included at each site. Each tree had five branches, and from each branch, five healthy leaves were selected for measurement and analysis. Data were gathered on 12 distinct characters. The method of stomatal printing was used to prepare leaf material for the analysis of stomatal characteristics. Data were collected on seven characteristics. Stomatal density and stomatal index were measured across 15 units per leaf. The morphological and anatomical characteristics of Rhizophora apiculata, Rhizophora mucronata, and Rhizophora stylosa were statistically analyzed using Analysis of Variance. Furthermore, a principal component analysis graphic was utilized to depict the environmental parameters, emphasizing the differences observed among the sampling locations. FINDINGS: The results revealed that the varying land use conditions at each study site affected the three species of Rhizophora. Rhizophora stylosa was unable to grow at the Medan Belawan study site due to severe damage and pollution. In contrast, the other two sites, Percut Sei Tuan and Sitardas, are lightly polluted environments that are suitable for all three Rhizophora species. This finding demonstrates that certain Rhizophora species, specifically Rhizophora apiculata and Rhizophora mucronata, can thrive in habitat conditions and environmental factors that are unsuitable for Rhizophora stylosa. Furthermore, there were notable variations in the stomatal index among all three Rhizophora species. Rhizophora apiculata had a stomatal index of 19.69, Rhizophora mucronata had a value of 111.7, and Rhizophora stylosa had a value of 24.67. These variations may impact their efficiency in adapting to their respective environments. CONCLUSION: This study offers insight into how three Rhizophora species adapt to changes in land use. Each species demonstrates distinct adaptations influenced by various factors. The outcomes of this study will be instrumental in suggesting species that can effectively contribute to restoration initiatives within mangrove ecosystems.