Woody plant communities in the Philippine teak forest landscape along Verde Island Passage, Batangas, Luzon, Philippines

Abstract

Abstract. Caringal AM, Buot IE Jr, Villanueva ELC. 2019. Woody plant communities in the Philippine teak forest landscape along Verde Island Passage, Batangas, Luzon, Philippines. Biodiversitas 20: 3189-3198. The study described the communities of woody plants in a semi-evergreen tropical forest dominated by endemic Philippine teak (Tectona philippinensis Benth. & Hook. f, Lamiaceae) and determined the local environmental factors affecting the distribution of dominant woody species across the Philippine teak forest (PTF) landscape. The Philippine teak is a Critically Endangered species according to the International Union for the Conservation of Nature (IUCN). Quantitative dominance analysis of arboreal vegetation data (basal area and relative dominance) from 24 (20m x 20m) sampling plots generated the cluster dendrogram, while Canonical Correspondence Analysis (CCA) was performed for 47 woody species and habitat-environment variables. As a result, four vegetation zones were named: (I) pure stand of Tectona philippinensis, (II) mixed T. philippinensis-Garuga floribunda-Terminalia polyantha, (III) mixed Celtis latifolia-T. philippinensis and (IV) mixed Tamarindus indica-Xylocarpus rumphii. These zones were governed more by physiographic (altitude ) and edaphic influences of predominantly agro-coastal landscapes. The environmental variables were essential in verifying not only the association of dominant tree flora in the local landscape but also provide insight for forest management zoning and the ecological requirements of the tree species for in-situ and ex-situ biodiversity conservation.

Vegetation structure of forests over limestone and its influencing environmental factors in Samar Island Natural Park, Philippines

“…Moreover, according to Freschet et al (2018), soil selects certain species based on functional traits and ultimately shapes the plant community in terms of species taxonomy (species composition, number of species) and trait distribution (plant characteristics: architectural, morphological, physiological, etc.). This has been demonstrated in studies on forest formations in the Philippines, where some soil nutrients were discovered to affect vegetation structure (Katabuchi et al 2012;Neri et al 2012;Peña-Claros et al 2012;Becknell and Powers 2014;De Jager et al 2015;Rodrigues et al 2016;Idowu et al 2020;Bañares-de-Dios et al 2022), which can be attributed to a variety of factors, including the complexity of karst forests (Sopsop and Buot 2013;Caringal et al 2019), such as SINP. Plants compete for soil resources, and the most competitive species are those that can capture these resources first (Liu et al 2014;Kim et al 2016;Kunstler et al 2016;Freschet et al 2018), thereby eliminating other competing species.…”

“…The unique geology of forests over limestone has afforded a rich biological diversity in this type of forest formation (Clements et al 2006), thus contributing to the megadiversity status of the Philippines (Mittermeier 1997). Various studies report the uniqueness of the forests over limestone flora and fauna in various localities in the country Buot 2009, 2010;Caringal et al 2019Caringal et al , 2020Caringal et al , 2021Lillo et al 2019Lillo et al , 2020aLillo et al , 2020bLillo et al , 2020cMalaki et al 2020aMalaki et al , 2020b. Incidentally, these studies made mention of several species under threat in this forest formation.…”

“…Unique biota could be answers to current problems related to food and medicine, among others. Equally significant studies regarding vegetation structure Okitsu 1998, 1999;Chanthavong and Buot 2017;Santiago and Buot 2018;Villanueva and Buot 2018;Caringal et al 2019) and the environmental factors affecting such characteristic structure in forests over limestone should be explored. Data sets will help understand environmental variables affecting vegetation structure hence, enhancing a better understanding of the dynamics of the landscape.…”

Some threatened woody plant species recorded from forests over limestone of the Philippines

“…Other forests over limestone were cited in available literature and included in the analysis (Figure 2). These are Cantipla forest (Cadiz & Buot 2009) and Mount Tabunan (Cadiz & Buot 2010) of Cebu City, Mount Lantoy of southern Cebu (Lillo et al 2019(Lillo et al , 2020(Lillo et al , 2021, and the coastal landscapes and seascapes of the Verde Island Passage, Batangas, southern Luzon (Caringal et al 2019(Caringal et al , 2021.…”

“…Another unique forest over limestone is found along Verde Island Passage, Batangas, Luzon Island where the endemic Philippine teak, Tectona philippinensis Benth. & Hook.f., is a dominant component (Caringal et al 2019(Caringal et al , 2021.…”