Pacific-Asia Biodiversity Transect Research Articles

Survey of Endemic, Native, and Invasive Vertebrates in the Sovi Basin, Fiji, 2003–2015

The Sovi Basin is a site within the Pacific-Asia Biodiversity Transect (PABITRA) network. It is located in Naitasiri Province, Viti Levu, and represents the largest area of undisturbed lowland forest within the Fiji Islands. It is considered to be one of the most biologically diverse areas within the Polynesia-Micronesia biodiversity hot spot. Four intensive surveys conducted between 2003 and 2015 assessed vertebrate fauna within the Sovi Basin. The study confirmed the biological importance of the site when compared with other locations within Fiji: 85%, 50%, 39%, and 38% of the Viti Levu fauna of birds, mammals, herpetofauna, and ichthyofauna were recorded during the surveys, respectively. In addition to the rich native and endemic fauna, invasive species were recorded (mongoose, feral pigs, black rats, red-vented bulbuls, tilapia, and cane toads), the impact of which is completely unknown. Further monitoring and possible management of these invasive species is needed to ensure that the Sovi Basin is appropriately managed for nature conservation. In addition, emerging threats such as a proposed mining scheme and agricultural activities are discussed in relation to the ecological integrity of the site for conservation purposes.

Freshwater ichthyofauna of the Pacific-Asia Biodiversity Transect (PABITRA) Gateway in Viti Levu, Fiji

The freshwater ichthyofauna of the Fiji islands remained poorly documented before the establishment of the Pacific-Asia Biodiversity Transect (PABITRA) network. The PABITRA approach assesses biodiversity along ocean-to-mountain transects and promotes sustainable land use on islands across the Pacific. Multiple surveys of freshwater fish species along the Viti Levu PABITRA transect have contributed six new occurrence records and one new species to the known freshwater fishes of Fiji since 2002. In total, 21 indigenous species of fish (9% endemic) from 10 families and no introduced fishes were found in the three PABITRA sites. Diversity was highest (16 species) at Savura forest reserve and decreased further inland into Sovi and Wabu. The assemblage found is dominated by highly migratory species (95%) that traverse the different aquatic habitats (marine, estuarine, lowland and upland streams) covered by the PABITRA transect. This high degree of connectivity highlights several growing issues affecting aquatic fauna on the high island of Viti Levu. The reduction in forest cover along the gateway transects, especially in the terminal reaches, and infrastructure development such as dams and weirs have deleterious effects on the migration routes of the Fijian ichthyofauna. Several species collected are important food sources and have cultural totemic importance to local inhabitants along the vertical transect. This paper documents the ichthyofauna of the Fiji gateway transect, ecological characteristics of this assemblage, IUCN Redlist conservation assessment status and highlights factors affecting the fragility and resilience of these communities, particularly focusing on the importance of life-history patterns and watershed conditions.

A Proposed PABITRA Study Area on Lauru Island, Western Solomon Islands

The island of Lauru (Choiseul) in the western Solomon Islands is a high (up to 1,060 m) mixed volcanic and limestone uplifted island, located between 6.5° and 7.5° S latitude and 156.5° and 157.5° E longitude. The central part of the island is suggested for inclusion in the Pacific-Asia Biodiversity Transect (PABITRA) system. The proposed area consists of the north-central coast, Mount Barokasa (850 m), Mount Maetabe (1,060 m), and the primary watershed systems that drain these mountains and the central plateau between them. Some of the concerns and expectations of traditional land owners and the Solomon Islands government are considered. These play important roles in any research activity and will be central to the success or failure of the project. The Solomon Islands, Lauru, and the specific study area are briefly described with synopses of previous research and current, preliminary research activities. Preliminary species checklists are given for plants and vertebrates in the area. Initially we propose to establish two transects, each passing through two biomes suitable for comparisons with similar biomes in other PABITRA sites: the tropical montane cloud forest of Mount Maetabe (the highest point in the island), and the lowland rain forests, between 200 and 500 m in elevation to the southwest of Susuka at the base of Mount Barokasa. The two proposed transects will stretch through two different watersheds, one of which has had traditional agriculture practiced in the coastal strand area and the other of which has had traditional agriculture practiced in the lowland forest of midelevations. A research agenda is proposed that will help achieve key objectives of developing local research capacity and internal biodiversity management systems while conserving traditional knowledge.

The PABITRA Project: Island Landscapes Under Global Change

ABSTRACT The Pacific-Asia Biodiversity Transect (PABITRA) is a network of the Ecosystem Division in the Pacific Science Association's Task Force on Biodiversity. The PABITRA project seeks to develop a network of ocean-to-mountain transects on islands across the Pacific to test hypotheses about biodiversity and promote sustainable use of island ecosystems under the influence of global change. A specific objective of PABITRA was to establish an ocean-to-mountain transect in Fiji with major involvement of the resident islanders. Along this transect, a number of biodiversity study sites were to be selected for further research. The transect was established during two consecutive field workshops, from 18 November to 3 December 2002. Involved were 25 University of the South Pacific (USP) students, eight local faculty including Fiji Government and nongovernmental organization officials, and seven overseas collaborators. The outcome was documented in a 69-page illustrated report issued by the USP Institute of App...

Complementing PABITRA High-Island Studies by Examining Terrestrial Plant Diversity on Atolls

The Pacific-Asia Biodiversity Transect (PABITRA) studies are based on a network of high-island biodiversity sites. These sites are structurally and historically complex. The majority of Pacific islands, in contrast, are low atolls with a common and simple flora and structure. As a result, atolls may serve as controls that may provide a way to assess impact of the upland high-island ecosystems on coastal regions of Pacific islands. Atoll studies can complement the PABITRA network because the gateway sites are near each other or separated from one another by one or more atolls. Such an addition will enhance interpretation of high-island ecosystems and their coastal zones because ecosystem surveys can be conducted quickly and accurately in atoll environments. We present results from quantitative studies of plant diversity from seven islets at Ailinginae Atoll in the northern Marshall Islands and discuss the value of this methodology as a way to enhance interpretation of the PABITRA data.

A Framework for Socioeconomic Valuation of Biodiversity in the PABITRA Focal Sites in Fiji

In Fiji, one of the underlying causes of historical and current losses of biodiversity has been lack of recognition of the value of many biological resources. The Pacific-Asia Biodiversity Transect (PABITRA) project provides an opportunity for integration of social and economic valuation of biodiversity. This is critical for any decision relating to management and conservation of biodiversity resources. Socioeconomic valuation of biodiversity can assist communities and policy makers to better understand the net benefits of managing and conserving biodiversity. This paper presents a framework that can be applied for valuing the socioeconomic attributes of biodiversity in the PABITRA focal sites. This framework has two components. First is the quantitative method of valuation. For this, environmental economics can be applied, in particular the use of nonmarket valuation methods. Second is the qualitative method. This is based on application of participatory economic valuation methods. This second method of eliciting economic values incorporates institutional, social, and cultural activities and equity issues at the village or community levels.

Botanical Studies within the PABITRA Wet-Zone Transect, Viti Levu, Fiji

ABSTRACT Botanical studies along mountain-to-sea transects are a key component of the Pacific-Asia Biodiversity Transect (PABITRA) project. For the Fiji PABITRA Wet-Zone Transect, it is suggested that four basic categories of biodiversity data (species inventory, plant community description, ecological data on the species and community level, and long-term monitoring) be collected within the seven biodiversity study sites (Mt. Tomaniivi/Wabu, Monasavu, Sovi Basin, Waisoi, Waibau, Savura, and Nasoata/Valolo Islands) covering an elevational gradient from sea level to 1,300 m. Currently, Sovi and Waibau are without data, except for vegetation descriptions based on aerial photographs. However, data from baseline surveys is now available for Sovi. Most of the data available on Mt. Tomaniivi/Wabu and Savura are extrapolated from collections and studies in adjacent areas, but in both areas data collection has recently begun. Only Waisoi and Nasoata/Valolo have species checklists and descriptions of the various p...

Survey Techniques for Freshwater Streams on Oceanic Islands: Important Design Considerations for the PABITRA Project

Fundamental differences in life history patterns of most indigenous freshwater stream species on oceanic islands and freshwater species in continental stream systems require important differences in design of appropriate aquatic survey methodologies. As an example of these issues, use of Instream Flow Incremental Methodology (IFIM) and the Index of Biotic Integrity (IBI) for describing island stream conditions are examined. Designed mainly for identifying optimal flow for salmonid fishes in the western United States, IFIM is difficult to apply to Hawaiian streams because of frequent flash floods in the Islands and because of the inherent difficulty of relating observed fish densities to total usable habitat in island streams. IBIs have been applied widely on the United States mainland as a technique for determining the health of a stream and aiding in stream fish conservation and management. Recently, there has been an attempt to establish an IBI for Hawaiian streams. Application of this technique to oceanic island streams raises a number of serious questions about the IBI's validity for use in Hawaiian streams. Potential problems are inherent in the basic assumptions of the IBI. They result in unintended consequences when applied to oceanic island streams; examples include erroneously attributing naturally occurring differences in observed fish assemblages to human-induced environmental change, not accommodating differences in closed and open system dynamics linked to life cycles of indigenous stream species, and not understanding implications of low-diversity environments typical of remote oceanic islands. Past research on Hawaiian streams supports use of appropriate survey and analysis techniques such as those developed for the Pacific-Asia Biodiversity Transect (PABITRA) for use among islands of the tropical Pacific.

Botanical Diversity at Savura, a Lowland Rain Forest Site along the PABITRA Gateway Transect, Viti Levu, Fiji

Savura is one of the seven focal sites of the Pacific-Asia Biodiversity Transect (PABITRA) Gateway Transect in Fiji. The site is composed of tropical lowland rain forest located in southeastern Viti Levu and consists of two adjacent watershed reserves, the Savura Forest Reserve and the Vago Forest Reserve. A total of 560 indigenous species (52% endemic) of vascular plants is recorded for this focal site. Savura has been chosen for the establishment of a large permanent plot of 12 ha following the methods proposed by the Centre of Tropical Forest Science (CTFS). This involves the recording of name, diameter at breast height (DBH), and precise location of every tree with 1 cm or more DBH. A total of 5,494 individuals with a total basal area of 2,752 m2 was recorded in the first 6,000 m2 of this CTFS/PABITRA permanent plot. The Myristicaceae (species of the genus Myristica) was the dominant family in numbers of individuals (14.4%) and basal area (35.6%). Tree ferns (Cyatheaceae [8.2% of individuals, 14.6% basal area]) and the Clusiaceae (8.6% of individuals, 12.8% basal area) are other major components. After this initial census, subsequent censuses will be carried out every 5 yr and should give insights on spatial dynamics, recruitment and mortality, and long-term changes in populations of tree species.

Kava Cultivation, Native Species Conservation, and Integrated Watershed Resource Management on Pohnpei Island

For many centuries, the kava plant, Piper methysticum, a series of sterile clones of a truly wild Piper species, has been used in several high islands in remote Oceania, including Pohnpei in the Federated States of Micronesia. Until modern times, its use on all of these islands was largely restricted to chiefly, priestly, and medicinal use. Because of colonial suppression and/or the use of other nonindigenous psychoactive drugs, its use was abandoned on some of these islands. On other islands, such as Pohnpei, its use has increased greatly, with substantial changes in rank, gender, motivation, time, and place. This steep rise in its use has resulted in a large increase in its cultivation. On Pohnpei, intensification of cropping in upland environments is largely responsible for more than 70% loss of the remaining native, tropical rain forest since 1975. This impact and other human activities endanger the unique upland biodiversity of this remote tropical island. Recent historical trends in forest exploitation, threats to biodiversity, and watershed disturbance on Pohnpei are discussed in this paper. The Watershed Conservation Plan and management benefits of the proposed Pacific-Asia Biodiversity Transect (PABITRA) are emphasized with permanent plot establishment for long-term monitoring.

The Kahana Valley Ahupua'a, a PABITRA Study Site on O'ahu, Hawaiian Islands

The acronym PABITRA stands for Pacific-Asia Biodiversity Transect, a network of island sites and conservation professionals collaborating throughout the Pacific-Asia region. An ideal PABITRA site is a broad landscape transect from sea to summit. Such a landscape is Kahana Valley on Windward O'ahu. Kahana Valley served during prior centuries as an ahupua'a, a Polynesian unit of land management that integrated the three biological resource zones, the upland forests, the agriculturally used land below, and the coastal zone, into a sustainable human support system. Results of terrestrial biodiversity surveys, as begun with a vegetation/environment study and a paleoecological investigation, are presented in relation to historical land use and sea level changes. In spite of the many former human-induced modifications of the Kahana Valley landscape, the natural structure and function of its ecosystems are well preserved. The distribution patterns of vegetation can be interpreted in terms of Hawaiian ecological zones in combination with the valley's precipitation, topography, stream system, and archaeological features. Currently, efforts are under way to restore the Kahana State Park (recently renamed Ahupua'a 'O Kahana State Park) as a functional ahupua'a. In addition, focused collaborative research can yield helpful information for further restoration and integrated management of the Kahana ahupua'a as a historic Hawaiian Heritage Site.

Plant discoveries from PABITRA-related exploration in Papua New Guinea

Abstract Unlike many of the archipelagic stations comprising the Pacific-Asia Biodiversity Transect (PABITRA) network, the flora of Papua New Guinea (PNG) is exceedingly speciose and in a remarkable state of preservation. Sites targeted for PABITRA action in PNG are unexplored or have only very limited botanical documentation. Vegetation sampling under such a combination of circumstances is highly problematic, particularly with respect to identification of sterile material from plot enumerations. The country team has thus pursued a study plan based on intensive collection and taxonomic evaluation, conducted prior to establishment of transects. Sterile vouchers can be determined to an acceptable level of confidence when matched to fertile specimens obtained from comprehensive exploration. Substantial numbers of new taxa are being revealed by the PABITRA assessments as a collateral benefit of this procedure. The following narrative summarizes the discoveries which have resulted from ongoing investigations in poorly known environments, and discusses some implications for future floristic work in Papuasia.

Biological surveys – new perspectives in the Pacific

Abstract Biological surveys have provided a wealth of data to advance the understanding, use and management of natural resources and were important in the establishment and development of museums of natural history. Museums, which hold billions of specimens worldwide, are now important repositories of biodiversity data. In the Pacific, the Bishop Museum has combined research and collections activities into the Hawaii Biological Survey and is integrating and synthesizing more than four million specimen records from Hawaii into an information system to guide future research and survey priorities. This has helped highlight the conservation importance of Hawaii and stimulate further research on Hawaii's biota. The Museum is now in the process of developing a Pacific Biological Survey and is working with a variety of partners to link all museum data – more than 22 million specimens – with other biodiversity and ecosystem data under the auspices of the Biological Resources Division of the U.S. Geological Survey, as part of IBOY, to create a Pacific Basin Information Node (PBIN). This effort is also linked to the development of a Pacific-Asia Biodiversity Transect Network (PABITRA) through DIVERSITAS to advance the understanding and management of island ecosystems.

Forest vegetation across the tropical Pacific: A biogeographically complex region with many analogous environments

The tropical realm of the Pacific contains many islands with closely similar (analogous) environmental settings. Due to the `filter effect' of the ocean, these are occupied by historically different species assemblages. This results in a unique biogeographic complexity not found in any of the continental tropical regions. The paper presents a hierarchical approach to the study of vegetation in analogous environments with data illustrated by a series of diagrams. It begins with differentiating island types and climatic zones. Then it focuses on Pacific-wide biomes, thereafter on island landscape profiles, and finally, on stand-level profiles as a method to compare forest structure and composition among islands in analogous environments at the scale of releves. The conclusions emphasize the urgent need for intensifying conservation-oriented research and capacity building in all island countries of the Pacific (not only Hawaii) to protect their indigenous biodiversities for sustainable uses and the health of their ecosystems. Attention is also drawn to the scientific advantage of using the Pacific-Asia Biodiversity Transect (PABITRA) Network, since it connects the island areas across biogeographic boundaries in form of an experimental design. This design refers to analogous island environments filled with different sets of biodiversities, which follow a trend of impoverishment with indigenous founder species from west to east.