Abstract. Tolentino PJS, Navidad JRL, Angeles MD, Fernandez AP, Villanueva ELC, Obena RDR, Buot Jr IE. 2020. Review: Biodiversity of forests over limestone in Southeast Asia with emphasis on the Philippines. Biodiversitas 21: 1597-1613. A comprehensive review of literature was carried out to determine the status of plant and animal diversity on forests over limestone in Southeast Asia (SEA), particularly in the Philippines. Angiosperm records are available in Peninsular Malaysia (1216 spp.); West Java and Seram Indonesia (101 and 149 spp., respectively); Laos (135 spp.); Thailand and Myanmar (1 sp.); and Limestone areas in Vietnam. Pteridophytes were recorded in Malaysia (32 spp.) while Bryophytes are recorded in Peninsular Malaysia (59 spp.). In the Philippines, there are plant records in: Masbate (61 spp.); Isabela (169 spp. Pteridophytes); Bohol (12 spp.), and Samar forests over limestone (29 spp. palms and 20 spp. orchids). A floral assessment in Samar Island Natural Park (SINP) includes species (212 spp.) that can possibly be found but are not limited to karsts. New Philippine endemic species are also recorded in Cebu, Palawan, and Panay Island. There are animal records in SEA including Vietnam (Bats-36, Bird-1, and Langurs-5 spp.); Malaysia (Sciuridae-1, Bats-28, Birds-129, Reptiles-17, and Invertebrates-74 spp.); Thailand (Murids-12, Reptiles-11, and Amphibian-1 sp.); and Myanmar (Reptiles-15 spp.). Records in the Philippines include: Mammals (Bicol-9, Mt. Irid-24, Mt. Aruyan-1, and Cebu-1 species), and; Birds (Cebu-1 sp.). A terrestrial faunal assessment in SINP includes species (182 spp.) that can possibly be found but are not limited to karsts. Forests over limestone are still largely understudied and the potential of discovering species is high. Further research is critical to establish science-based initiatives and policies that will protect and conserve limestone ecosystem biodiversity while allowing the utilization of its biological resources at a sustainable level.

Abstract. Alcala AA, Delos Angeles MD, Buot Jr IE. 2019. Fern species diversity across various land use types of Mt. Makiling, Luzon Island, Philippines. Biodiversitas 20: 2437-2445. Mt. Makiling of Luzon Island, Philippines is home to many living organisms including ferns and fern allies which are one of the important understory vegetation in many forest communities and having various economic uses like food, medicine and ornamentation. This study identified fern species found in various land use types across the northeastern slope of Mt. Makiling, Los Baños, Philippines. The plot technique was employed using a 20x20 meter quadrat. Three (3) 5x2 subquadrats were randomly distributed within the established quadrat. Fern specimens were identified (sensu PPG, 2016) and measured. Samples were collected for herbarium voucher deposited in the PBDH. A total of 28 fern species with 22 genera from 14 families were found across land use types. Identified land use types were: i) Mahogany (341 m asl.); (ii) Agriculture (355 m asl.); (iii) Buffer zone (365 m asl.); (iv) Agroforest (368 m asl.); (v) Roadside (455 m asl.), and (vi) Forest (482 m asl.). The most represented fern families were found out to be Thelypteridaceae (5 spp), Dryopteridaceae (3 spp), Polypodiaceae (3 spp.), Pteridaceae (3 spp), Aspleniaceae (2 spp), Dennstaedtiaceae (2 spp), Selaginellaceae (2 spp.) and Tectariaceae (2 spp.). On the other hand the families Schizaeaceae, Lindsaeaceae, Davalliaceae, Nephrolepidaceae, and Marratiaceae are comprised of one species only. Pteris blumeana C. Agardh and Tectaria crenata Cav. were found only in buffer zone area. Dennstaedtia philippinensis Copel., Lygodium circinnatum (Burm. f.) Sw. and Microlepia sp., were found only in agroforest area; Sphaerostephanos unitus (L.) Holttum found only in agricultural; Bolbitis heteroclita (C. Presl) Ching and Microsorum membranifolium (R. Br.) Ching were found in roadside while Asplenium tenerum G. Forst. , Christella sp., Lindsaea fissa Copel. and Nephrolepis cordifolia (L.) C. Presl were found in forest area. Pneumatopteris nitidula (C. Presl) Holttum. is a dominant fern species found in agriculture and mahogany plantation area. There is a need to document fern species along with its population across land use types in order to utilize ferns as plant indicators due to their vulnerability to changes in environmental conditions. These results can shed light on the appropriate strategy for the conservation and management of ferns in Mt. Makiling.

This study presents the first checklist of the lesser known terrestrial biodiversity in forests over limestone karst of Calicoan Island in Guiuan Marine Reserve Protected Landscape and Seascape, Guiuan, Eastern Samar, Philippines. Plants and terrestrial vertebrate species in nine 20x20 m plots and 18 line transects were recorded and identified. A total of 60 bird, eight reptile, one amphibian, and six mammal species were recorded. Moreover, a total of 41 floral species were documented belonging to 17 plant families and 24 genera. Of the plant species recorded, 5 were shrubs and 35 were trees. This study reported a new locality record of the Philippine endemic tree species Hancea wenzeliana, and new island records for fauna such as Varanus samarensis and Cyrtodactylus sumuroi, among many others. To date, the present study is the only assessment of herpetofauna and mammals in Guiuan and represent new island records for most of these taxa in Calicoan Island. Among plants, Shorea negrosensis, Aquilaria cuminigiana and Wallaceodendron celebicum were identified to have a vulnerable conservation status based on their IUCN Red List and DENR-DAO 2017-11. These native and endemic plants can be used for reforestation programs in the area, and conserving biodiversity in general will be crucial to potential ecotourism programs.

The extensive forests over limestone of the Samar Island Natural Park (SINP) on Samar Island, Philippines harbour a rich variety of unique species. In this contribution, we describe and illustrate a new Loranthaceous mistletoe, endemic to Samar Island named Decaisnina tomentosa, representing the 12th member of the genus reported to the Philippines. This new species is similar to D. confertiflora (Merr.) Barlow with respect to the presence of shortly and densely off-white tomentose inflorescence and 6-merous flowers. However, it is unique amongst congeners in having tomentose and partially fused bracteoles which cover almost or entirely the ovary of individual flowers in the triads. To date, D. tomentosa seems to be restricted to the SINP and is only known from a handful of individuals. More studies are needed to properly assess the demography, host range, conservation status and phylogenetic position of this distinctive species of mistletoe.

Corybas Salisbury (1807: t. 83) comprises approximately 120 highly distinctive and diminutive terrestrial and lithophytic species widely distributed from India to the western Pacific (Pridgeon et al. 2001, Aldrich & Haggins 2008, Chung & Hsu 2008, Chantanaorrapint & Chantanaorrapint 2016, Govaerts et al. 2019). The Philippines has six Corybas species (Pelser et al., 2011): C. boholensis Tandang, Bustamante, Reyes & Lyon (2020a: 261), Bohol, Visayas;, C. circinatus Tandang &  Bustamante (2020b: 135), central Palawan; C. geminigibbus Smith (1927: 13), Mt. Victoria, Palawan; C. laceratus Williams (1937: 54), Rizal Prov., Luzon; C. merrillii (Ames) Ames (1908: 42), Mt. Mariveles, Luzon; and C. ramosianus Dransfield in Dransfield et al. (1986: 611), Ilocos Norte Prov., Luzon. Corybas is often overlooked and understudied owing to its diminutive size and ephemeral flowers (Tandang et al. 2020a), and ongoing explorations of the Philippine Archipelago have demonstrated the merit of this observation, with several species having been newly documented and described in recent years from areas that are known to have been botanized in the past.

The geographic location, climatic, and soil conditions of Samar Island render a mosaic of varied habitats which harbor numerous endemic, rare, and endangered species of plants. The island province is one of the centers of plant endemism in the Philippines. Included in this rich biodiversity of flora are members of genus Begonia of the family Begoniaceae. In 2018, researchers of the University of the Philippines found in the island three unknown Begonia species. With rhizomatous habits, persistent stipules, protandrous inflorescences, four-tepaled flowers, three winged capsules and bifid placenta, the three species are clearly members of Begonia section Baryandra. Studies of literature, herbarium specimens, and living plants support the recognition of the three new species: Begonia sohoton, Begonia tarangban and Begonia burabod.

Begonia normaaguilariae, a new Philippine Begonia species from the section Baryandra is described and illustrated herewith. It bears a superficial resemblance to B. biliranensis with a repand leaf margin, and obovoid anther shape. However, the new species is unique in reference to its conduplicate stipule, longer capsule pedicel length, and completely glabrous rhizome, petioles, and leaves. Begonia normaaguilariae was only recorded from the limestone forests of Samar Island Natural Park, Samar Island, Philippines. Following the Red List criteria of the IUCN Standards and Petitions Subcommittee, B. normaaguilariae is hereby proposed as Critically Endangered.

Studies regarding pteridophyte distribution on Mt. Makiling is scarce. A continuous documentation regarding this floral group, with emphasis on distribution, will contribute to the current listings and may contribute to the development of a conservation strategy to preserve the fern flora of Mt. Makiling. The plot technique method was employed along the altitudinal gradient of Mt. Makiling resulting to 10 sampling sites. In general, this study aims to determine the species richness of ferns along the altitudinal gradient on the northeastern slope of Mt. Makiling. Furthermore, specific objectives are as follows: a) to identify the different fern species along the altitudinal gradients of Mt. Makiling b) to determine the richness and diversity along the altitudinal gradients of these fern species and c) to determine the zonation pattern of fern vegetation along the altitudinal gradient. The study was conducted during the months of April and June which pertains to the dry season. The diversity and distribution of pteridophytes along the altitudinal gradient of the Northeastern slope of a secondary forest in Mt. Makiling were determined.  A total of 27 species belonging to 18 genera and 14 families were identified. There is an increasing trend in diversity along the altitudinal gradient. However at the 550 and 650 m.a.s.l. altitudes, there was a higher diversity in both seasons due to the presence of a running body of water as well as a rocky substrate providing favorable habitat for the ferns. There were three zones identified during the dry season using dendogram by average linkage clustering (i) Zone 1: 150-450masl; (ii) Zone 2: 550-750masl; (iii) Zone 3: 850-1050masl.   Keywords - Altitudinal zonation, ferns, pteridophytes, Mt. Makiling, tropical rainforests, Philippines