#stand maturity

Abstract

Mount Katayagan, the tallest peak in the Agoo Mountain Range of the Province of La Union, Philippines, is a crucial yet understudied natural resource. This research addresses the biodiversity gap in non-protected areas like Mt. Katayagan, emphasizing its role as a watershed, supplying water for irrigation and households, and providing essential commodities such as fruits and timbers. Despite its ecological and economic significance, there is a lack of research on Mt. Katayagan’s biodiversity. This study aims to fill this gap by conducting a comprehensive flora assessment, identifying land cover types, forest formation, stand maturity and dominant upper canopy species. Using the “Terrestrial Ecosystem Biodiversity and Assessment Monitoring Manual,” the research reveals Mt. Katayagan’s predominantly closed forest with characteristics of a secondary-growth tropical moist deciduous forest. Pterocarpus indicus (narra) emerges as the dominant upper canopy species with an Importance Value of 20.85 percent. This research provides essential baseline data for environmental protection laws and emphasizes the urgent need for collaborative conservation efforts involving local communities, government bodies, and research institutions to safeguard Mt. Katayagan’s unique biodiversity.

Introduction

Biodiversity, the term for the variety of life forms and ecosystems on Earth, is crucial to the continuation of life and provides necessary ecosystem services (National Geographic Society, 2021). Since biodiversity is so important, there has been a global push to manage, conserve, and understand it. According to Diaz et al. (2019), a healthy, stable and resilient ecosystem is one that has a high level of biodiversity. At the 1992 Rio Earth Summit, the Convention on Biological Diversity emphasized the value of biodiversity and urged countries to give biodiversity management a priority (Tsiounami et al., 2020). The economic, ecological, recreational, cultural, and scientific dimensions of biodiversity’s importance all highlight how important it is to both environmental sustainability and human well-being (Australia State of the Environment, 2018). The need to thoroughly evaluate and manage biodiversity is increasing as human activities continue to have an impact on it. Unfortunately, a lot of locations that are being considered for development lack sufficient knowledge regarding biodiversity, which might have permanent consequences like habitat destruction and overexploitation (Paller, 2021).

This study focuses on two related topics in the nonprotected region of Mount Katayagan, Agoo, La Union, Philippines, in response to the need for thorough biodiversity surveys. First, over a 2 km transect line at Mount Katayagan, it seeks to identify the land cover types, forest formation, and stand maturity. Second, using the species with the highest Importance Value (IV), it seeks to determine which species is the most dominating in the upper canopy. This study fills in the gaps in laws like the Wildlife Resources Conservation and Protection Act of 2001 and the Philippine Environmental Impact Assessment System (PEIAS), which frequently encounter difficulties because of insufficient data on biodiversity (Convention on Biological Diversity, 2021; Republic Act 9147). This study is significant because it adds to the larger context of biodiversity protection by concentrating on the highest peak in the Agoo Mountain Range, Mount Katayagan. With a surface area of 41.03 hectares and an elevation of 250 meters above sea level, Mount Katayagan is significant both environmentally and commercially. Even though the mountain is significant, there aren't many thorough studies on its biodiversity, which makes it a perfect topic for investigation. Unprotected landscapes such as Mount Katayagan are susceptible to multiple dangers, highlighting the necessity of preservation in order to counteract the loss of biodiversity and tackle global problems (Kohler et al., 2009).

It is significant that vulnerable locations like Mount Katayagan receive little research attention because most studies that quantify biodiversity focus on protected regions. Since 2015, Mount Katayagan has drawn a lot of tourists from La Union because of its vital roles for the local community as well as its picturesque vistas. As a watershed, Mount Katayagan is essential to the towns of Agoo, Tubao, and Sto. Tomas' water supply for domestic use and irrigation. Communities that depend on agriculture benefit from the sloping topography's natural rainwater storage. In addition to its hydrological importance, the mountain provides free water to the locals and is an important supplier of goods like lumber and fruits (Eisma et al., 2015). As a result, by supporting conservation efforts and complying with existing regulatory frameworks, this study lays the groundwork for any future developments. By carefully examining land cover, forest formation, stand maturity, and upper canopy species, this study provides important information that is necessary for managing biodiversity and promoting sustainable development. The study follows the guidelines provided in the 2017 "Terrestrial Ecosystem Biodiversity and Assessment Monitoring Manual" published by the Biodiversity Management Bureau, with modifications made to meet the unique needs of Mount Katayagan in Agoo, La Union.