Kosrae Research Articles

A Tropical Freshwater Wetland: III. Direct Use Values and Other Goods and Services

Understanding the economic value of a wetland as well as how people perceive its role in providing goods and services can provide insight into the wetland's actual role and the kinds of policies needed to ensure sustainable use. On the island of Kosrae, Federated States of Micronesia, freshwater forested wetlands dominated by Terminalia carolinensis (hereafter called Terminalia) are often found just upslope from mangrove forests, which appear to be hydrologically connected to them. Many of these Terminalia forests have been converted into agroforests. A survey of 10% of the households on Kosrae showed that 89% owned some Terminalia land. Most grew taro, bananas, and sugar cane, either in or immediately adjacent to Terminalia forests. Most owned canoes constructed of Terminalia logs, and nearly half had harvested trees from these forests during the past year: 64% to clear land for agricultural purposes, 36% for building canoes, and 31% for other uses. Terminalia forests provided over $3.1 million worth of goods to Kosraeans, primarily from agricultural production. Approximately 2/3 of those surveyed understood that Terminalia grows best in a wetland setting. Most thought that Terminalia forests provide erosion protection and improve water quality. However, very few were cognizant of the ecological links between Terminalia and mangrove forests. Kosraeans attached little importance to the fact that Terminalia is endemic to the eastern Caroline Islands. If human dependence on these wetlands increases, the integrity of Terminalia forests, as well as adjacent mangrove forests, could be at risk.

Beyond Good Intentions: Combating Linguistic Genocide in Education

Scientific imperialism involves outsiders creating knowledge about dominated groups. This applies to the relationship between indigenous or minority children, parents, teachers and communities on the one hand, and dominant groups (schools, teachers/administrators, us as researchers) on the other hand. How can we as outsiders work together with other oppressed groups to overcome the legacy and consequences of linguistic and cultural genocide and, in the process, create new and liberating histories for us all? The article examines how scientific imperialism has contributed, and continues to contribute, to linguistic genocide in the education of indigenous and minority children and outlines some of the challenges and opportunities that people are faced with when trying to change the genocidal situation. New forms of linguistic genocide based on subtractive bilingualism, ‘free market’ economics, parental ‘consent’ and ‘good intentions’ can be more harmful to indigenous and minority children than overt attempts at extinguishing the language and culture, because they are more difficult to analyse. In subtractive language learning, a dominant or majority language is learned at the cost of the mother tongue. Subtractive teaching subtracts from the children’s linguistic repertoire (instead of adding to it). The children undergoing this type of education, or at least their children, are forcibly transferred to the dominant group linguistically and culturally, and the education can cause them mental and physical harm; both are defined as genocide in the United Nations Genocide Convention. The most decisive educational factor in causing negative statistics of indigenous ‘performance’ is the use of the wrong teaching language (together with lack of indigenous content, methods and ethos in schools). An additive approach to bilingualism based on long-term, mainly mother-tongue medium (MTM) education, can be employed to preserve and enrich indigenous and minority languages and cultures. In large-scale studies of educational models for minorities, the amount of education through the medium of the mother tongue is the strongest predictor of both children’s competence and gains in English, and of their school achievement. The final part of the article focuses on the struggle to combat linguistic genocide in education and its consequences on the island of Kosrae in Micronesia.

A Tropical Freshwater Wetland: I. Structure, Growth, and Regeneration

Forested wetlands dominated by Terminalia carolinensis are endemic to Micronesia but common only on the island of Kosrae, Federated States of Micronesia. On Kosrae, these forests occur on Nansepsep, Inkosr, and Sonahnpil soil types, which differ in degree of flooding and soil saturation. We compared forest structure, growth, nutrition, and regeneration on two sites each on Nansepsep and Inkosr soils and one site on the much less common Sonahnpil soil type. Terminalia tree sizes were similar on all three soil types, but forests differed in total basal area, species of smaller trees, and total plant species diversity. Terminalia regeneration was found only on the Inkosr soil type, which had the highest water table levels. Other Terminalia species are relatively light demanding, and T. carolinensis exhibited similar characteristics. It is therefore likely that Terminalia requires periodic, but perhaps naturally rare, stand-replacing disturbances (e.g., typhoons) in order to maintain its dominance, except on the wettest sites, where competition from other species is reduced. Terminalia swamps in the Nansepsep soil type appeared to be at the greatest risk of conversion to other uses, but swamps on all three types may face greater pressure as Kosrae's population increases and the island's infrastructure becomes more developed.

Phytosterolemia on the island of Kosrae: founder effect for a novel ABCG8 mutation results in high carrier rate and increased plasma plant sterol levels

Screening of 932 adults on the Pacific island of Kosrae for plasma plant sterol levels disclosed three subjects, two of them asymptomatic, with phytosterolemia. Sequencing the ATP binding cassette subfamily G member 8 (ABCG8) gene revealed a novel exon 2 mutation that causes a change in codon 24 from glutamine to histidine and a frame shift followed by a premature stop codon, precluding the formation of a functional ABCG8 protein. Genotyping of 1,090 Kosraens revealed 150 as carriers, a 13.8% carrier rate. DNA sequencing of 67 carriers revealed the same mutation as in the probands. In carriers, plasma campesterol and sitosterol levels were 55% and 30% higher, respectively, than in noncarriers. Moreover, compared with noncarriers, carriers showed 21% lower plasma levels of lathosterol, a surrogate marker for cholesterol biosynthesis. There was no difference between the groups in plasma total cholesterol, triglycerides, apolipoprotein B, or apolipoprotein A-I levels. In summary, on the island of Kosrae, a strong founder effect of a mutant ABCG8 allele results in a large number of carriers with increased plasma plant sterol levels and decreased lathosterol levels. The latter finding suggests that heterozygosity for a mutated ABCG8 allele results in a modest increase in dietary cholesterol absorption and a decrease in cholesterol biosynthesis.

Genome-wide scan in a large complex pedigree with predominantly male schizophrenics from the island of Kosrae: evidence for linkage to chromosome 2q.

It is widely accepted that founder populations hold promise for mapping loci for complex traits. However, the outcome of these mapping efforts will most likely depend on the individual demographic characteristics and historical circumstances surrounding the founding of a given genetic isolate. The 'ideal' features of a founder population are currently unknown. The Micronesian islandic population of Kosrae, one of the four islands comprising the Federated States of Micronesia (FSM), was founded by a small number of settlers and went through a secondary genetic 'bottleneck' in the mid-19th century. The potential for reduced etiological (genetic and environmental) heterogeneity, as well as the opportunity to ascertain extended and statistically powerful pedigrees makes the Kosraen population attractive for mapping schizophrenia susceptibility genes. Our exhaustive case ascertainment from this islandic population identified 32 patients who met DSM-IV criteria for schizophrenia or schizoaffective disorder. Three of these were siblings in one nuclear family, and 27 were from a single large and complex schizophrenia kindred that includes a total of 251 individuals. One of the most startling findings in our ascertained sample was the great difference in male and female disease rates. A genome-wide scan provided initial suggestive evidence for linkage to markers on chromosomes 1, 2, 3, 7, 13, 15, 19, and X. Follow-up multipoint analyses gave additional support for a region on 2q37 that includes a schizophrenia locus previously identified in another small genetic isolate, with a well-established recent genealogical history and a small number of founders, located on the eastern border of Finland. In addition to providing further support for a schizophrenia susceptibility locus at 2q37, our results highlight the analytic challenges associated with extremely large and complex pedigrees, as well as the limitations associated with genetic studies of complex traits in small islandic populations.

Genome-wide scan in a large complex pedigree with predominantly male schizophrenics from the island of Kosrae: evidence for linkage to chromosome 2q

Genome-wide scan in a large complex pedigree with predominantly male schizophrenics from the island of Kosrae: evidence for linkage to chromosome 2q

Factors limiting the intertidal distribution of the mangrove species Xylocarpus granatum.

The tree species Xylocarpus granatum is commonly described as occurring in the upper intertidal zone of mangrove forests, but mature trees are occasionally found at lower elevations. In the Utwe River basin, on the Pacific island of Kosrae, we investigated the relative importance of several biotic and abiotic factors that may control the intertidal distribution of X. granatum. Factors we evaluated included differential seed predation across the lower, mid, and upper intertidal zones and seedling responses to salinity, tidal flooding, and shade. Seed predation was 22.4% over the first 34 days and varied little among zones or in gaps versus under the forest canopy. By day 161, there were still no differences in seed mortality, but a significant difference was found in seedling establishment, with much greater establishment in the upper intertidal plots. X. granatum seedlings in a greenhouse experiment exhibited greater growth in freshwater than seedlings in 23 ppt salinity, which is typical of salinity levels found in the mid intertidal zone in our field study sites in Micronesia, where mature X. granatum trees are generally absent. Seedlings grown in 23 ppt salinity, however, exhibited few visible signs of stress associated with patterns in growth. Seedlings grown in a simulated tidal flooding treatment (with 23 ppt salinity) also showed few signs of stress. Growth declined dramatically under 80% shade cloths, but there were few interactions of shading with either 23 ppt salinity or simulated tidal flooding. Differential seed predation is not likely to be the primary factor responsible for the intertidal distribution of X. granatum on Kosrae. However, seedling tolerance of flooding or salinity may be more important, especially relative to a potential contribution to secondary stress mortality. Other factors may ultimately prove to be more critical, such as physiological effects of salinity on seed germination, effects of tides on seed dispersal and rooting, or differential herbivory on seedlings.

Organic Matter Dynamics on the Forest Floor of a Micronesian Mangrove Forest: An Investigation of Species Composition Shifts1

ABSTRACTSpecies composition shifts in mangrove forests may alter organic matter dynamics. The purpose of this study was to predict the effect of species replacements among mangrove trees on organic matter dynamics in a mangrove forest on the island of Kosrae, Federated States of Micronesia. We were particularly interested in elements of the carbon cycle that affect peat accumulation rates, organic matter exports to the estuary and coral reef systems, and soil microbiology. We compared organic matter production and decomposition rates among three mangrove species that commonly grow in similar hydrogeomorphic settings: Rhizophora apiculata BL, which is selectively harvested; Bruguiera gymnorrhiza, which may gradually replace Rhizophora; and Sonneratia alba, which is producing few mature fruits. Sonneratia had significantly higher rates of root production (estimated with ingrowth chambers) than Bruguiera or Rhizophora. Sonneratia foliage had significantly faster decomposition rates and significantly lower lignin:nitrogen ratios than Bruguiera foliage. Live root mass was positively correlated with ingrowth and soil carbon, although soil carbon and ingrowth were not significantly correlated with each other. Humic acid concentrations were significantly higher in Sonneratia rhizospheres than in either Bruguiera or Rhizophora rhizospheres and were positively correlated with root ingrowth. The species changes taking place on Kosrae are likely to result in lower rates of root production and foliage decomposition, and more refractory carbon pools in soil.

Candidate genes involved in cardiovascular risk factors by a family-based association study on the island of Kosrae, Federated States of Micronesia.

Altered plasma levels of lipids and lipoproteins, obesity, hypertension, and diabetes are major risk factors for atherosclerotic cardiovascular disease. To identify genes that affect these traits and disorders, we looked for association between markers in candidate genes (apolipoprotein AII (apo AII), apolipoprotein AI-CIII-AIV gene cluster (apo AI-CIII-AIV), apolipoprotein E (apo E), cholesteryl ester transfer protein (CETP), cholesterol 7alpha-hydroxylase (CYP7a), hepatic lipase (HL), and microsomal triglyceride transfer protein (MTP)) and known risk factors (triglycerides (Tg), total cholesterol (TC), apolipoprotein AI (apo AI), apolipoprotein AII (apo AII), apolipoprotein B (apo B), body mass index (BMI), blood pressure (BP), leptin, and fasting blood sugar (FBS) levels.) A total of 1,102 individuals from the Pacific island of Kosrae were genotyped for the following markers: Apo AII/MspI, Apo CIII/SstI, Apo AI/XmnI, Apo E/HhaI, CETP/TaqIB, CYP7a/BsaI, HL/DraI, and MTP/HhpI. After testing for population stratification, family-based association analysis was carried out. Novel associations found were: 1) the apo AII/MspI with apo AI and BP levels, 2) the CYP7a/BsaI with apo AI and BMI levels. We also confirmed the following associations: 1) the apo AII/MspI with Tg level; 2) the apo CIII/SstI with Tg, TC, and apo B levels; 3) the Apo E/HhaI E2, E3, and E4 alleles with TC, apo AI, and apo B levels; and 4) the CETP/TaqIB with apo AI level. We further confirmed the connection between the apo AII gene and Tg level by a nonparametric linkage analysis. We therefore conclude that many of these candidate genes may play a significant role in susceptibility to heart disease.

Rapid, independent evolution of flightlessness in four species of Pacific Island rails (Rallidae): an analysis based on mitochondrial sequence data

Flightless rails were once ubiquitous in the avifauna of Pacific oceanic islands. Most species have become extinct since human colonization of islands began about 2000 years ago. In this study, we use mitochondrial sequence data to estimate the phylogenetic relationships and ages of four species of flightless insular rails in the genus Porzana: palmeri, from Laysan Island in the Hawaiian archipelago; sandwichensis, from the island of Hawaii; monasa, from Kosrae Island in Micronesia; and atra, from Henderson Island in the Pitcairn group. Although all four species survived into historic times, all but atra are now extinct. The optimal trees show that palmeri is descended from Porzana pusilla, a volant crake distributed widely throughout the Old World. Porzana sandwichensis, P. monasa, and P. atra are each descended from the lineage leading to P.tabuensis, a volant rail widespread in northern and eastern Australia and on islands north to Micronesia and the Philippines and east through Polynesia. Loss of flight appears to have evolved rapidly in these insular rails, based on both sequence divergence values and data on the ages of the islands. In the case of the Laysan Rail (palmeri), divergences including loss of flight probably evolved in less than 125,000 years.

Organic Matter Dynamics on the Forest Floor of a Micronesian Mangrove Forest: An Investigation of Species Composition Shifts1

Species composition shifts in mangrove forests may alter organic matter dynamics. The purpose of this study was to predict the effect of species replacements among mangrove trees on organic matter dynamics in a mangrove forest on the island of Kosrae, Federated States of Micronesia. We were particularly interested in elements of the carbon cycle that affect peat accumulation rates, organic matter exports to the estuary and coral reef systems, and soil microbiology. We compared organic matter production and decomposition rates among three mangrove species that commonly grow in similar hydrogeomorphic settings: Rhizophora apiculata BL, which is selectively harvested; Bruguiera gymnorrhiza, which may gradually replace Rhizophora; and Sonneratia alba, which is producing few mature fruits. Sonneratia had significantly higher rates of root production (estimated with ingrowth chambers) than Bruguiera or Rhizophora. Sonneratia foliage had significantly faster decomposition rates and significantly lower lignin:nitrogen ratios than Bruguiera foliage. Live root mass was positively correlated with ingrowth and soil carbon, although soil carbon and ingrowth were not significantly correlated with each other. Humic acid concentrations were significantly higher in Sonneratia rhizospheres than in either Bruguiera or Rhizophora rhizospheres and were positively correlated with root ingrowth. The species changes taking place on Kosrae are likely to result in lower rates of root production and foliage decomposition, and more refractory carbon pools in soil.

Source water partitioning as a means of characterizing hydrologic function in mangroves

Mangrove ecosystems rely on seawater, rain-derived flow, and groundwater for hydrologic sustenance, flushing, and inflow of nutrients and sediments. The relative contribution of these source waters and their variability through time and space can provide key information concerning the hydrologic function of ecosystems. We used hydrologic tracers to partition source waters and trace their movements in the Enipoas stream, a river-dominated mangrove ecosystem on the island of Pohnpei, Federated States of Micronesia (FSM) and in the Yela watershed, an interior mangrove ecosystem on the island of Kosrae, FSM. The Enipoas site was characterized as a salt wedge estuary whose source water contributions alternated between predominantly seawater and rain-derived flow, depending on the tide. The source waters in the interior Yela site were also predominantly seawater and rain-derived flow, however the relative contribution of each was much more stable. The mean groundwatercontribution was 5% (SD 5 5.5) for the Enipoas site and 20% (SD 5 11.0) for the Yela site. Although a small contributor to flow, groundwater was a steady source of freshwater for both systems. Hydrologic linkages between mangroves and adjacent ecosystems were demonstrated by the temporal and spatial distribution of source waters.The 0.8 km Enipoas estuary, with its highly dynamic bi-directional flows, transported source waters along a hydrologic continuum comprised of coral reef, mangroves, and palm forest. In the interior mangroves of the Yela watershed, the presence of rain-derived flow and groundwater demonstrated a hydraulic connection between the mangroves and an upstream freshwater swamp. Interior mangroves with such linkages avoid stresses such as desiccation and heightened salinity, and thus are more productive than those with little or no freshwater flows.

Natural Resource Management: The Need for Interdisciplinary Collaboration

Human influence is now so pervasive that every ecosystem on Earth is being managed, whether intentionally or inadvertently. It is therefore imperative for scientists and managers to work together so that appropriate management regimes can be put in place wherever possible. However, it is not always clear what is appropriate, and the difficulties that often arise when scientists and managers work together can be even further compounded by the inclusion of lay stakeholders in the decision-making process. The expansion of interdisciplinary undergraduate and graduate programs would help both scientists and managers to deal more effectively with sociological issues and to understand how economic and demographic changes impact on natural resources. In addition, continuing education programs in these areas should be made available to established professionals to help them deal with new challenges. The concept of ecosystem services should be used to communicate the importance of various ecosystem components and processes to a broader audience. Consensus on a management regime can often be achieved through adaptive management. The process by which interdisciplinary collaboration can lead to new insights and research initiatives is exemplified by a resource management study on the island of Kosrae, Federated States of Micronesia. As a paradigm of natural resource management, microcosms like this small island community offer a unique opportunity for training and education.

Chemical Characterization of Micronesian Ceramics Through Instrumental Neutron Activation Analysis: A Preliminary Provenance Study

The development of exchange models from Pacific Islands' archaeological data is a major task facing Oceanic archaeologists. Chemical characterization of ceramics can assist provenance studies required for modelling past human interactions. This regional instrumental neutron activation analysis (INAA) conducted on ceramics collected from the Micronesian ceramic-producing islands of Belau, Chuuk, Guam, Kosrae, Pohnpei, and Yap allows us to form compositional groups and provenance ceramics from the coral islands of Fais, Satawal, and Ulithi. Different island contexts, which cause post-depositional chemical transformations in ceramic sherds, do not hinder the provenance assignments.

Patterns of natural and anthropogenic disturbance of the mangroves on the Pacific Island of Kosrae.

Mangroves in many parts of the world are subjected to frequent, large-scaledisturbances. A possible exception is Kosrae, Federated States of Micronesia(FSM), a small volcanic island in the west-central Pacific Ocean. Relativesea level has been stable for most of the last 1000 years and the last tropical cyclone to affect the island was in 1905. Many trees on Kosrae,especially individuals of the species Sonneratia alba, thereforeappear to die only after reaching advanced ages and exceptional sizes. Themost widespread anthropogenic disturbance is harvesting of trees for fuelwoodand poles, which is done selectively and generally creates small, dispersedgaps. Other forms of anthropogenic disturbance, such as modifications ofcoastal landforms, alterations of freshwater inflows road construction andconversion to residential or agricultural uses, are still relatively minorbut have led to some irreversible losses. The economy of Kosrae is basedto a large degree on income derived from a Compact of Free Association betweenthe FSM and the United States, an agreement that has an uncertain future.Many of the funding provisions of the Compact expire in 2001 and, if notrenewed, may have dramatic impacts on resource use. This in turn may leadto a much greater level of anthropogenic disturbance of what are now someof the world's most intact mangrove swamps.

Maximum Longevities of Rhizophora apiculata and R. mucronata Propagules

Maximum Longevities of Rhizophora apiculata and R. mucronata Propagules1 Judy Z. Drexler Abstract The longevity of viviparous mangrove seedlings (propagules) in seawater is a key factor determining their ability to survive dispersal both locally and across large expanses of ocean. The purpose of this experiment was to determine the maximum longevities of propagules from two common Pacific mangrove species: Rhizophora mucronata Lamk. and Rhizophora apiculata Bl. Propagules from each of these species were placed in outdoor tubs with continuously flowing seawater. The condition of each propagule was monitored until it sank or started to rot. Propagules were then planted to determine viability. After planting, 50% of R. apiculata propagules and 21% of R. mucronata propagules were viable. For both species, mortality of propagules was strongly related to the length of the floating interval. Maximum longevities for R. mucronata and R. apiculata propagules were 150 (median = 70) and 89 days (median = 7), respectively. Rhizophora mucronata propagules appeared to be better equipped for long-distance dispersal, yet had low survivorship that would decrease overall dispersal opportunities. In comparison, R. apiculata propagules had higher survivorship yet shorter longevity and, thus, appeared to be better equipped for shorter distance dispersal. Several Species of mangroves produce viviparous seedlings (propagules) that are buoyant and can disperse in seawater. The limits for such dispersal have long been the topic of speculation, especially among those seeking to explain the presence of closely related species in distant areas or the total absence of mangroves from suitable habitats (Guppy 1906, Ridley 1930, Tomlinson 1986, Duke 1992). One of the chief factors controlling the dispersal of viviparous mangroves is longevity, the number of days propagules remain buoyant and viable in seawater. Longevity of mangrove propagules varies between different species. Rhizophora mangle propagules can remain viable in laboratory vessels for over 12 months (Davis 1940) and can float throughout a 3-month period (Ellison 1996). Rhizophora harrisonii (now referred to as R. racemosa [pers. comm., N. Duke, Department of Botany, University of Queensland, St. Lucia, Australia]) and Pelliciera rhizophorae propagules are capable of regaining buoyancy after an initial sinking stage and can survive 3 months floating in seawater with no mortality (Rabinowitz 1978). Avicennia marina propagules may remain viable, either exposed by tides or totally submerged (in enclosures in the field), for up to 5 months during enforced dispersal (Clarke 1993). None of these studies, however, sought to determine the maximum longevities of propagules, which are essential for assessing long-distance dispersal capability. The aim of this experiment was to determine maximum longevities of propagules from two common Pacific mangrove species, Rhizophora mucronata Lamk. and Rhizophora apiculata Bl. Longevities of both species were [End Page 17] then used to compare their long-distance dispersal capabilities. Materials and Methods The island of Kosrae, Federated States of Micronesia (5° N, 163° E) was chosen for propagule collection because of the large, productive, and intact stands of both species that grow interspersed in mangrove forests in that location (Ewel et al. 1998). On 6-7 October 1997, mature R. apiculata and R. mucronata propagules were collected from trees within riverine populations on the northern and western parts of the island. Kosrae is a high volcanic island approximately 112 km2 in size that contains 1562 ha of mangroves represented by seven species (Whitesell et al. 1986). The watersheds sampled are relatively pristine, with only minimal impact from agricultural activities and logging. Average air temperature on Kosrae is approximately 27.4°C (Mueller-Dombois and Fosberg 1998), seawater temperature is approximately 28-30°C, and salinity outside the fringing reef is between 33.6 and 34.5 ppt (unpubl. data). After collection, propagules damaged from boring insects were discarded, so that maximum propagule longevities could be determined without confounding effects from herbivory. In total, 82 R. apiculata and 104 R. mucronata propagules were wrapped in moist newspaper, sealed in plastic bags, placed in sturdy cardboard boxes, and shipped overnight to Honolulu, Hawai'i, by air (this method has been used frequently for transporting mangrove propagules [pers. comm., Edward Proffitt, U.S. Geological Survey, National Wetlands Research Center, Lafayette, Louisiana]). On 8 October, each propagule was weighed, measured, and labeled. On the following day propagules were taken...

Epidemiology and Factor Analysis of Obesity, Type II Diabetes, Hypertension, and Dyslipidemia (Syndrome X) on the Island of Kosrae, Federated States of Micronesia

Objectives: Obesity, type II diabetes, hypertension, and dyslipidemia are major causes of morbidity and mortality throughout the world. Though these disorders often cluster in individuals and families and are collectively known as syndrome X, the basis for this aggregation is not well understood. To further understand the pathogenesis of syndrome X, a comprehensive epidemiological study was undertaken on the Pacific Island of Kosrae, Federated States of Micronesia (FSM). Methods: The entire adult (>20 years of age) population of Kosrae underwent a clinical evaluation that included a questionnaire that noted the participants’ sex, family data including listing of biological parents, siblings, and children, smoking status, village of residence, age and health status. The medical evaluation included: anthropometric measures (weight, height, waist, hip), serum chemistries (leptin, fasting blood sugar (FBS), insulin, total cholesterol (TC), triglycerides (TG), and apolipoproteins B and A-I (apo B and apo A-I) and blood pressure (BP) measurements. Results: Obesity (BMI ≥35) was found in 24%, diabetes (FBS ≥126 or 2-hour oral glucose tolerance test ≥200) in 12%, hypertension (SBP ≥140 or DBP ≥90) in 17%, and dyslipidemia (TC ≥240 or TG ≥200 or apo B ≥120 or apo A-I ≤88) in 20% of the population. Significant covariate effects after multivariate analysis were as follows: sex affected the frequency of all four disorders, parity affected the frequency of dyslipidemia, smoking affected the frequency of obesity and diabetes, village of residence affected the frequency of obesity, hypertension, and dyslipidemia, and age affected the frequency of all four disorders. Factor analysis identified four independent factors that explained 73% of the total variance of the entire data set: factor 1 (weight, waist, leptin, insulin, and TG), factor 2 (TC, TG, apo B, apo A-I, and insulin), factor 3 (systolic and diastolic BP, FBS, waist and weight), and factor 4 (apo A-I, TG, leptin, and weight). Conclusions: This population-based study on the Island of Kosrae suggests that syndrome X is a composite of 4 independent factors: obesity with diabetes and hypertriglyceridemia, combined hyperlipidemia with diabetes, hypertension with obesity and diabetes, and increased HDL-low TG with thinness and high leptin. Further studies to identify the genetic components of these factors as well as the individual traits are under way.

Downed wood in Micronesian mangrove forests

Dead, downed wood is an important component of upland forest and aquatic ecosystems, but its role in wetland ecosystems, including mangroves, is poorly understood. We measured downed wood in ten sites on the western Pacific islands of Kosrae, Pohnpei, and Yap, all located within the Federated States of Micronesia. Our goals were to examine patterns of variability in the quantity of downed wood in these mangrove ecosystems, provide a general characterization of downed wood in a region with no previously published accounts, and investigate the relationship between harvesting practices and the amount of downed wood. The overall mean volume of downed wood at our study sites was estimated to be 60.8 m3 ha−1 (20.9 t ha−1), which is greater than most published data for forested wetlands. There were significant differences among islands, with the sites on Kosrae (104.2 m3 ha−1) having a much greater mean volume of downed wood than those on Pohnpei (43.1 m3 ha−1) or Yap (35.1 m3 ha−1). Part of the difference among islands may be attributable to differences in stand age and structure, but the most important factor seems to be the greater amount of wood harvesting on Kosrae, coupled with a low efficiency of use of cut trees. Of a total of 45 cut trees examined on Kosrae, no wood had been removed from 18 (40%); these are believed to be trees cut down because other, more valuable, trees were caught on them as they were felled. Of the other 27 trees, only 24 to 42% of the stem volume (to a 10 cm top) was removed from the forest, the amount varying by species. The impacts of current harvesting practices are unknown but may include important effects on tree regeneration and the abundance and species composition of crab populations.

Mangrove Forests Supported by Peaty Habitats on Several Islands in the Western Pacific.

Six types of mangrove forests were distinguished on Kosrae Island (50°20’ N.L.; 163°00’ E.L.) and Pohnpei Island (6°55’ N.L.; 158°14’ E.L.) in Micronesia and Bohol Island (10°00’ N.L.; 124°30’ E.L.) in the Philippines based on phytosociological investigations. They are the Rhizophora stylosa forest on an inorganic habitat along the seaward fringe of a mangrove area, the Nypa fruticans thicket and the Barringtonia racemosa forest supported by clay deposits at the landward fringe of a mangrove region, and the Rhizophora apiculata-Avicennia marina forest, the Sonneratia alba-Bruguiera gymnorrhiza forest and the Xyrocarpus granatum-B. gymnorrhiza forest characteristically inhabiting peaty habitats. Accumulation of mangrove peat should be limited to a range corresponding to the upper half of the intertidal zone because mangrove forests themseves are restricted to this range. This range is estimated to be 75 cm or so in the areas investigated. A habitat with a peat layer equivalent to this range in thickness was usually found under the S. alba-B. gymnorrhiza forest. This type of forest is thought to have developed under the present, stable sea level condition through autogenic succession from the R. stylosa forest. On the other hand, a much thicker peat layer supporting the X. granatum-B. gymnorrhiza forest was found in the investigated area. Development of such a thick peat layer is assumed to have been proceeded by a rise in sea level, followed by filling up of the area with organic matter provided by the mangrove forest itself. Thus, this type of forest was considered to have been formed from the S. alba-B. gymnorrhiza forest through an autogenic process of succession in spite of the external effect of a rise in sea level.

Environmental Effects of Canopy Gap Formation in High‐Rainfall Mangrove Forests1

ABSTRACTThis study investigated the importance of gap formation in mangrove swamps on the island of Kosrae, Federated States of Micronesia, in order to understand better both natural processes of forest development and the effects of harvesting trees for firewood in these wetlands. Measurements were concentrated in seven plots located near four rivers: three in fringe zones and four in basin zones. Each plot was a cluster of five points and covered an area of ca 1.3 ha. From every point in each of the seven plots, the nearest canopy gap ≥10 m2 was located; 25 of the 35 gaps were formed by harvesting. Porewater salinity was significantly higher under the canopy in fringe mangrove forests than in basin mangrove forests. Although gaps were small (mean gap size = 158 m2; median gap size = 92 m2), soil temperatures were significantly higher in gaps of both zones. Soil redox potential was significantly lower and porewater salinity significantly higher in the gaps than under the canopy in the basin zone only. Higher porewater salinity may be attributed to high evaporation rates from the soil and high transpiration rates from trees surrounding gaps. There were significantly more seedlings in gaps than under the canopy only in the fringe zones. Although gap formation alters the soil environment of Kosraean mangrove swamps, high freshwater input may buffer these effects in basin mangrove swamps by reducing porewater salinity. Current harvesting rates do not appear to be changing canopy species composition, but large gaps, especially in mangrove forests in more arid areas, may lead to major changes.