Displaying publications 161 - 180 of 650 in total

Abstract:
Sort:
  1. Sejarah awal Kepulauan Melayu: lima buah negeri warisan Sarawak yang hilang
    Sanib Said
    CREAM : Current Research in Malaysia (Penyelidikan Terkini di Malaysia), 2012;1(1):21-50.
    MyJurnal
    Sejarah awal negara Malaysia yang terdapat dalam pensejarahan Asia Tenggara telah menjadi sumber rujukan di peringkat sekolah dan juga universiti. Periode dari 100EU hingga 1400EU lazimnya mengandungi naratif ringkas mengenai kerajaan tua. Semenanjung Tanah Melayu mewarisi negeri-kerajaan tua Kataha (Kedah), Langkasuka, Panpan, Chihtu dan Baruas yang telah lama terdapat dalam buku sejarah. Bagaimanapun Sarawak kini tidak mewaris apa-apa sedangkan pesisir pantai Borneo di sebelah barat, selatan dan timur terdapat banyak negeri-kerajaan tua seperti Sambas, Mempawah, Pontianak, Landak, Sukadana, Sampit, Banjarmasin, Kutei, Pasri, Bolongan dan Brunei. Terdapat kekosongan dari segi masa dan ruang dalam pensejarahan negeri Sarawak kini. Kajian yang lebih teliti terhadap beberapa sumber primer peribumi di Arkipelago Melayu seperti Silsilah Raja-Raja Brunei dan karya Jawa, Nagarakertagama, telah membongkar beberapa toponim seperti Sarawak, Samarahan, Saribas, Kalaka dan Malanau yang kini merupakan pusat pentadbiran negeri itu. Sumber primer peribumi telah menyatakan bahawa toponim ini adalah negeri yang pernah menjadi jajahan takluk Majapahit selepas itu di bawah Brunei pula. Karangan ini tuba memaparkan naratif ringkas seperti pendekatan yang terdapat dalam pensejarahan Asia Tenggara dan Semenanjung Malaysia. Akhirnya karangan ini mencadangkan negeri kerajaan awal yang diwarisi oleh negeri Sarawak sekarang dinobatkan ke dalam buku sejarah kurikulum sejarah Negara.
    Matched MeSH terms: Borneo
  2. Fulltext Carbon stocks and fluxes in tropical lowland dipterocarp rainforests in Sabah, Malaysian Borneo
    Saner P, Loh YY, Ong RC, Hector A
    PLoS One, 2012;7(1):e29642.
    PMID: 22235319 DOI: 10.1371/journal.pone.0029642
    Deforestation in the tropics is an important source of carbon C release to the atmosphere. To provide a sound scientific base for efforts taken to reduce emissions from deforestation and degradation (REDD+) good estimates of C stocks and fluxes are important. We present components of the C balance for selectively logged lowland tropical dipterocarp rainforest in the Malua Forest Reserve of Sabah, Malaysian Borneo. Total organic C in this area was 167.9 Mg C ha⁻¹±3.8 (SD), including: Total aboveground (TAGC: 55%; 91.9 Mg C ha⁻¹±2.9 SEM) and belowground carbon in trees (TBGC: 10%; 16.5 Mg C ha⁻¹±0.5 SEM), deadwood (8%; 13.2 Mg C ha⁻¹±3.5 SEM) and soil organic matter (SOM: 24%; 39.6 Mg C ha⁻¹±0.9 SEM), understory vegetation (3%; 5.1 Mg C ha⁻¹±1.7 SEM), standing litter (<1%; 0.7 Mg C ha⁻¹±0.1 SEM) and fine root biomass (<1%; 0.9 Mg C ha⁻¹±0.1 SEM). Fluxes included litterfall, a proxy for leaf net primary productivity (4.9 Mg C ha⁻¹ yr⁻¹±0.1 SEM), and soil respiration, a measure for heterotrophic ecosystem respiration (28.6 Mg C ha⁻¹ yr⁻¹±1.2 SEM). The missing estimates necessary to close the C balance are wood net primary productivity and autotrophic respiration.Twenty-two years after logging TAGC stocks were 28% lower compared to unlogged forest (128 Mg C ha⁻¹±13.4 SEM); a combined weighted average mean reduction due to selective logging of -57.8 Mg C ha⁻¹ (with 95% CI -75.5 to -40.2). Based on the findings we conclude that selective logging decreased the dipterocarp stock by 55-66%. Silvicultural treatments may have the potential to accelerate the recovery of dipterocarp C stocks to pre-logging levels.
    Matched MeSH terms: Borneo
  3. Fulltext Borneocola (Zingiberaceae), a new genus from Borneo
    Sam YY, Takano A, Ibrahim H, Záveská E, Aziz F
    PhytoKeys, 2016.
    PMID: 28127243 DOI: 10.3897/phytokeys.75.9837
    A new genus from Borneo, Borneocola Y.Y.Sam, is described here. The genus currently contains eight species previously classified as members of the Scaphochlamys Baker. The finding is based on the results of the morphological and molecular studies of Scaphochlamys throughout its geographical range and its closely allied sister groups, Distichochlamys M.F.Newman and Myxochlamys A.Takano & Nagam. Borneocola is nested within the tribe Zingibereae and its monophyly is strongly supported by both ITS and matK sequence data. The genus is characterised by several thin, translucent and marcescent floral bracts, absence of coloured streaks on the labellum and capitate stigma with two dorsal knobs. The genus is distributed in northwest Borneo and all species are very rare and highly endemic.
    Matched MeSH terms: Borneo
  4. Fulltext Two variants of uterine leiomyoma in Malaysia's last Sumatran rhinoceros (Dicerorhinus sumatrensis)
    Salleh A, Zainuddin ZZ, Mohamed Tarmizi MR, Yap KC, Zamri-Saad M
    Vet Q, 2020 Dec;40(1):250-257.
    PMID: 33045934 DOI: 10.1080/01652176.2020.1836431
    Following its capture in March 2014, an adult female Sumatran rhinoceros frequently showed profuse vaginal bleeding. An ultrasonography suggested the presence of multiple reproductive lesions, including two uterine masses which were suspected to be leiomyomas. Soon after, an open pyometra was confirmed. Later in November 2019, the patient died and necropsy confirmed the presence of two uterine masses; one was located at the cervico-uterine junction and another in the uterine body, with pyometra, and cystic endometrial hyerplasia. Based on histological, special stains, and immunohistochemical examination, it was shown that one of the masses was composed of large, ovoid and polyhedral neoplastic mesenchymal cells with eosinophilic cytoplasm and a few binucleated cells surrounded by collagen fibres. It was tested positive for SMA and vimentin, while negative for desmin, cytokeratin AE1/AE3, EMA, CD34, and S100. The other mass was composed of mesenchymal cells undergoing myxoid degeneration as evidenced by the presence of glycosaminoglycan-rich matrix. It was tested positive for SMA, vimentin, partially positive for desmin, and negative for the other markers. With the aid of human medical nomenclature, these masses were diagnosed as epithelioid leiomyoma and myxoid leiomyoma, respectively. This report provides a clinical presentation, and histologic descriptions of the two variants of leiomyomas that have not been reported in veterinary medicine.
    Matched MeSH terms: Borneo
  5. [A case of leptospirosis infected in Borneo Island, Malaysia]
    Sakamoto M, Sagara H, Koizumi N, Watanabe H
    Kansenshogaku Zasshi, 2001 Dec;75(12):1057-61.
    PMID: 11806141
    We report a case of leptospirosis infected in Sabah, Borneo island, Malaysia. The case is 25-year-old male who had participated in the EcoChallenge Sabah 2000 Expedition Race, a multisport event held during August 20 to September 3, 2000 at various sites in Sabah in Malaysian Borneo. He developed a high fever and headache on September 7, and he was admitted to our hospital on September 9. On admission he also had conjunctivitis and myalgias. Laboratory findings on admission revealed leukocytosis with left shift, slightly elevated transaminase levels, high CRP levels and proteinuria. Plasmodium spp. were negative on blood smears, and no bacteria were isolated from blood and feces cultures. We performed the laboratory tests for leptospirosis, based on the information about the probable leptospirosis outbreak among athletes who participated in the EcoChallenge Race, however both Leptospira antigens and antibodies were negative at that time. We diagnosed leptospirosis clinically because he manifested persistent symptoms, and minocycline 100 mg b.i.d. was administered intravenously resulting in excellent efficacy. Serum antibody tests by microscopic agglutination test (MAT) at convalescent stage revealed significant increased antibodies against Leptospira interrogans serovar hebdomadis, and the diagnosis of leptospirosis was confirmed. Infectious diseases have been global and it is important to have information concerning worldwide infectious disease situations as much as possible for accurate diagnosis.
    Matched MeSH terms: Borneo
  6. Artocarpus (Moraceae)-gall midge pollination mutualism mediated by a male-flower parasitic fungus
    Sakai S, Kato M, Nagamasu H
    Am J Bot, 2000 Mar;87(3):440-5.
    PMID: 10719005
    A previously undescribed pollination system involving a monoecious tree species, Artocarpus integer (Moraceae), pollinator gall midges, and fungi is reported from a mixed dipterocarp forest in Sarawak, Borneo. The fungus Choanephora sp. (Choanephoraceae, Mucorales, Zygomycetes) infects male inflorescences of A. integer, and gall midges (Contarinia spp., Cecidomyiinae, Diptera) feed on the fungal mycelia and oviposit on the inflorescence. Their larvae also feed on the mycelia and pupate in the inflorescence. The gall midges are also attracted by female inflorescences lacking mycelia, probably due to a floral fragrance similar to that of male inflorescences. Because of the sticky pollen, dominance of Contarinia spp. in flower visitors, and pollen load observed on Contarinia spp. collected on both male and female inflorescences, Artocarpus integer is thought to be pollinated by the gall midges. Although several pathogenic fungi have been reported to have interactions with pollinators, this is the first report on a pollination mutualism in which a fungus plays an indispensable role. The pollination system described here suggests that we should be more aware of the roles fungi can play in pollinations.
    Matched MeSH terms: Borneo
  7. Three pollination guilds and variation in floral characteristics of Bornean gingers (Zingiberaceae and Costaceae)
    Sakai S, Kato M, Inoue T
    Am J Bot, 1999 May;86(5):646-58.
    PMID: 10330067
    The pollinators of 29 ginger species representing 11 genera in relation to certain floral morphological characteristics in a mixed-dipterocarp forest in Borneo were investigated. Among the 29 species studied, eight were pollinated by spiderhunters (Nectariniidae), 11 by medium-sized Amegilla bees (Anthophoridae), and ten by small halictid bees. These pollination guilds found in gingers in Sarawak are comparable to the pollination guilds of neotropical Zingiberales, i.e., hummingbird-, and euglossine-bee-pollinated guilds. Canonical discriminant analysis revealed that there were significant correlations between floral morphology and pollination guilds and suggests the importance of plant-pollinator interactions in the evolution of floral morphology. Most species in the three guilds were separated on the plot by the first and second canonical variables. Spiderhunter-pollinated flowers had longer floral tubes, while Amegilla-pollinated flowers had wider lips than the others, which function as a platform for the pollinators. Pistils and stamens of halictid-pollinated flowers were smaller than the others. The fact that gingers with diverse morphologies in a forest with high species diversity were grouped into only three pollination guilds and that the pollinators themselves showed low species diversity suggests that many species of rare understory plants have evolved without segregating pollinators in each pollination guild.
    Matched MeSH terms: Borneo
  8. A new pollination system: dung-beetle pollination discovered in Orchidantha inouei (Lowiaceae, Zingiberales) in Sarawak, Malaysia
    Sakai S, Inoue T
    Am J Bot, 1999 Jan;86(1):56-61.
    PMID: 21680345
    Lowiaceae, a family of the Zingiberales, comprise 11 species in the single genus Orchidantha. Here we present the first report on the pollination of Lowiaceae and describe a new system of dung-beetle pollination from Sarawak, Borneo. Orchidantha inouei has a zygomorphic flower located just above the ground. Observations revealed that the plant is visited frequently and is pollinated by scarabaeid dung beetles, mainly members of the genus Onthophagus. All four species of Onthophagus collected on O. inouei have also been caught using traps baited with dung or carrion in Borneo. Onthophagus was presumably attracted to the dung-like odor of the flower. Pollination of O. inouei is different from other examples of beetle pollination in that its flower provides neither reward nor protected space. Dung beetles are excellent at following a particular dung scent. Orchidantha is the only genus that includes species lacking floral nectar. It is interesting that this deception pollination using dung beetles was found in Zingiberales, in which all known species have mutual and specialized relationships with their long-distance, but costly, pollinators-bees, birds, and bats.
    Matched MeSH terms: Borneo
  9. The Distribution and Population Density of Bornean Tarsier, "Tarsius Bancanus Borneanus (Elliot)" in Secondary and Rehabilitated Forests of Universiti Putra Malaysia, Bintulu Sarawak Campus, Sarawak, Malaysia
    Sahimi HNM, Chubo JK, Top Mohd Tah MM, Saripuddin NB, Ab Rahim SS
    Trop Life Sci Res, 2018 Mar;29(1):139-154.
    PMID: 29644021 DOI: 10.21315/tlsr2018.29.1.10
    Tarsius bancanus borneanus was first reported by Elliot in 1990 which an endemic species that can be found on the Island of Borneo consisting of Sabah and Sarawak of Malaysia, Brunei Darussalam and Kalimantan, Indonesia. This sub-species has been listed as a totally protected animal under the Sarawak Wild Life Protection Ordinance (1998) and vulnerable by the International Union for Conservation of Nature (IUCN). The present study was conducted at Universiti Putra Malaysia Bintulu Campus (UPMKB), Sarawak from October 2014 till March 2015. Through mark and recapture sampling covering an area of 37 ha of secondary forest patches and 7.13 ha of rehabilitated forest, a total of 16 tarsiers were captured using mist nets while one tarsier was recapture. The population density was 38 individuals/km2 was captured using mist nets in the secondary forest while 28 individuals/km2 was recorded for the rehabilitated forest. Using the catch per unit effort (net hour) method, the average time for capturing tarsiers in the secondary forest patches was 26.6 net hour per animal and 30.0 net hour per animal in the rehabilitated forest. The presented results provides information on the presence of tarsiers in both the secondary and rehabilitated forests of UPMKB, Sarawak, Malaysia which underlines the conservation value of these forested areas.
    Matched MeSH terms: Borneo
  10. HISTOPLASMIN SENSITIVITY INVESTIGATION IN THE THIRD DIVISION OF SARAWAK, BORNEO
    SCHUMAN ND, MACKEY DM, SAFRIT HF
    Am. Rev. Respir. Dis., 1963 Aug;88:261-3.
    PMID: 14045234
    Matched MeSH terms: Borneo
  11. [ORGANIZATION OF A PSYCHIATRIC HEALTH SERVICE IN AN UNDERDEVELOPED COUNTRY OF SOUTHEAST ASIA (SARAWAK)]
    SCHMIDT KE
    Nervenarzt, 1963 Sep;34:397-401.
    PMID: 14163217
    Matched MeSH terms: Borneo
  12. Vocal acoustics in the endangered proboscis monkey (Nasalis larvatus)
    Röper KM, Scheumann M, Wiechert AB, Nathan S, Goossens B, Owren MJ, et al.
    Am J Primatol, 2014 Feb;76(2):192-201.
    PMID: 24123122 DOI: 10.1002/ajp.22221
    The endangered proboscis monkey (Nasalis larvatus) is a sexually highly dimorphic Old World primate endemic to the island of Borneo. Previous studies focused mainly on its ecology and behavior, but knowledge of its vocalizations is limited. The present study provides quantified information on vocal rate and on the vocal acoustics of the prominent calls of this species. We audio-recorded vocal behavior of 10 groups over two 4-month periods at the Lower Kinabatangan Wildlife Sanctuary in Sabah, Borneo. We observed monkeys and recorded calls in evening and morning sessions at sleeping trees along riverbanks. We found no differences in the vocal rate between evening and morning observation sessions. Based on multiparametric analysis, we identified acoustic features of the four common call-types "shrieks," "honks," "roars," and "brays." "Chorus" events were also noted in which multiple callers produced a mix of vocalizations. The four call-types were distinguishable based on a combination of fundamental frequency variation, call duration, and degree of voicing. Three of the call-types can be considered as "loud calls" and are therefore deemed promising candidates for non-invasive, vocalization-based monitoring of proboscis monkeys for conservation purposes.
    Matched MeSH terms: Borneo
  13. Fulltext Alternative futures for Borneo show the value of integrating economic and conservation targets across borders
    Runting RK, Meijaard E, Abram NK, Wells JA, Gaveau DL, Ancrenaz M, et al.
    Nat Commun, 2015 04 14;6:6819.
    PMID: 25871635 DOI: 10.1038/ncomms7819
    Balancing economic development with international commitments to protect biodiversity is a global challenge. Achieving this balance requires an understanding of the possible consequences of alternative future scenarios for a range of stakeholders. We employ an integrated economic and environmental planning approach to evaluate four alternative futures for the mega-diverse island of Borneo. We show what could be achieved if the three national jurisdictions of Borneo coordinate efforts to achieve their public policy targets and allow a partial reallocation of planned land uses. We reveal the potential for Borneo to simultaneously retain ∼50% of its land as forests, protect adequate habitat for the Bornean orangutan (Pongo pygmaeus) and Bornean elephant (Elephas maximus borneensis), and achieve an opportunity cost saving of over US$43 billion. Such coordination would depend on enhanced information sharing and reforms to land-use planning, which could be supported by the increasingly international nature of economies and conservation efforts.
    Matched MeSH terms: Borneo
  14. Fulltext A Taphonomic Study of Crocodylus porosus (Crocodylidae) and Tomistoma schlegelii (Gavialidae) Remains from Western Sarawak, Malaysian Borneo: Applications for Public Education
    Ruhana Hassan, Nur Fatimah Mohd Azizi, Muhammad Amirul Arib Md Adzhar, Mohd Izwan Zulaini Abdul Gani, Rambli Ahmad, Charles Leh Moi Ung
    Trends in Undergraduate Research, 2018;1(1):0-0.
    MyJurnal
    This study documented details of the dentitions, skulls and other skeletal remains of Crocodylus porosus and Tomistoma schlegelii, from western part of Sarawak, Malaysian Borneo. The remains of both reptiles were exhumed, followed by standard cleaning procedures and then detail morphological assessments were carried out accordingly. Both species show similar structure of vertebral columns, but T. schlegelii has the following unique structures: a long and narrower snout, D-shaped eye sockets, long and sharp pointed protruding quadratojugal bones, straight maxillae and dentary, a smooth surfaced skull, elongated triangular suborbital fenestrae, round shaped internal nares and visible supraoccipital from a dorsal view. C. porosus has heterodont dentition with blunt-pointed and irregular size of teeth whereas T. schlegelii has almost homodont dentition with sharp and similar size teeth. This is the first collection of teeth, skulls and other skeletal remains of both species obtained from Sarawak, and the materials have been used regularly to educate the public through science exhibitions, hoping they will spark the interests of young budding scientists to be involved in wildlife taphonomic studies in the future.
    Matched MeSH terms: Borneo
  15. Tuberculosis in Sabah
    Roy RN
    Med J Malaya, 1968 Mar;22(3):204-16.
    PMID: 4234357
    Matched MeSH terms: Borneo
  16. Fulltext Evolutionary pattern of Macaca fascicularis in Southeast Asia inferred using Y-chromosomal gene
    Rovie-Ryan JJ, Khan FAA, Abdullah MT
    BMC Ecol Evol, 2021 02 15;21(1):26.
    PMID: 33588750 DOI: 10.1186/s12862-021-01757-1
    BACKGROUND: We analyzed a combined segment (2032-bp) of the sex-determining region and the testis-specific protein of the Y-chromosome (Y-DNA) gene to clarify the gene flow and phylogenetic relationships of the long-tailed macaques (Macaca fascicularis) in Southeast Asia. Phylogenetic relationships were constructed using the maximum likelihood, Bayesian inference, and the median-joining network from a total of 164 adult male M. fascicularis from 62 localities in Malaysia, including sequences from the other regions from previous studies.

    RESULTS: Based on Y-DNA, we confirm the presence of two lineages of M. fascicularis: the Indochinese and Sundaic lineages. The Indochinese lineage is represented by M. fascicularis located northwards of the Surat Thani-Krabi depression region and is introgressed by the Macaca mulatta Y-DNA. The Sundaic lineage is free from such hybridization event, thus defined as the original carrier of the M. fascicularis Y-DNA. We further revealed that the Sundaic lineage differentiated into two forms: the insular and the continental forms. The insular form, which represents the ancestral form of M. fascicularis, consists of two haplotypes: a single homogenous haplotype occupying the island of Borneo, Philippines, and southern Sumatra; and the Javan haplotype. The more diverse continental form consists of 17 haplotypes in which a dominant haplotype was shared by individuals from southern Thai Peninsular (south of Surat Thani-Krabi depression), Peninsular Malaysia, and Sumatra. Uniquely, Sumatra contains both the continental and insular Y-DNA which can be explained by a secondary contact hypothesis.

    CONCLUSIONS: Overall, the findings in this study are important: (1) to help authority particularly in Malaysia on the population management activities including translocation and culling of conflict M. fascicularis, (2) to identify the unknown origin of captive M. fascicularis used in biomedical research, and; (3) the separation between the continental and insular forms warrants for the treatment as separate management units.

    Matched MeSH terms: Borneo
  17. Extensive sharing of mitochondrial COI and CYB haplotypes among reef-building staghorn corals (Acropora spp.) in Sabah, North Borneo
    Robert R, Rodrigues KF, Waheed Z, Kumar SV
    Mitochondrial DNA A DNA Mapp Seq Anal, 2019 01;30(1):16-23.
    PMID: 29521145 DOI: 10.1080/24701394.2018.1448080
    This study is aimed at establishing a baseline on the genetic diversity of the Acropora corals of Sabah, North Borneo based on variations in the partial COI and CYB nucleotide sequences. Comparison across 50 shallow-water Acropora morphospecies indicated that the low substitution rates in the two genes were due to negative selection and that rate heterogeneity between them was asymmetric. CYB appeared to have evolved faster than COI in the Acropora as indicated by differences in the rate of pairwise genetic distance, degrees of transition bias (Ts/Tv), synonymous-to-nonsynonymous rate ratio (dN/dS), and substitution patterns at the three codon positions. Despite the relatively high haplotype diversity (Hd), nucleotide diversity (π) of the haplotype datasets was low due to stringent purifying selection operating on the genes. Subsequently, we identified individual COI and CYB haplotypes that were each extensively shared across sympatrically and allopatrically distributed Indo-Pacific Acropora. These reciprocally common mtDNA types were suspected to be ancestral forms of the genes whereas other haplotypes have mostly evolved from autoapomorphic mutations which have not been fixed within the species even though they are selectively neutral. To our knowledge, this is the first report on DNA barcodes of Acropora species in North Borneo and this understanding will play an important role in the management and conservation of these important reef-building corals.
    Matched MeSH terms: Borneo
  18. Consolidated Checklist of Hard Corals of the Genus Acropora Oken, 1815 (Scleractinia: Acroporidae) in North Borneo, East Malaysia
    Robert R, Lee DJ, Rodrigues KF, Hussein MA, Waheed Z, Kumar SV
    Zootaxa, 2016 Nov 29;4200(2):zootaxa.4200.2.2.
    PMID: 27988618 DOI: 10.11646/zootaxa.4200.2.2
    Acropora is the most biologically diverse group of reef-building coral, and its richness peaks at the Indo-Malay-Philippine Archipelago, the centre of global coral reef biodiversity. In this paper, we describe the species richness of Acropora fauna of North Borneo, East Malaysia, based on review of literature and as corroborated by voucher specimens. Eighty-three species of Acropora are reported here; four species are literature based and 79 are supported by voucher specimens that were subsequently photographed. New records for North Borneo were recorded for 12 species, including Acropora suharsonoi Wallace 1994 that was previously thought to be confined to a few islands along Lombok Strait, Indonesia. The diversity of Acropora in North Borneo is comparable to that of Indonesia and the Philippines, despite the area's smaller reef areas. This further reinforces its inclusion as part the global hotspot of coral biodiversity.
    Matched MeSH terms: Borneo
  19. Major and persistent shifts in below-ground carbon dynamics and soil respiration following logging in tropical forests
    Riutta T, Kho LK, Teh YA, Ewers R, Majalap N, Malhi Y
    Glob Chang Biol, 2021 May;27(10):2225-2240.
    PMID: 33462919 DOI: 10.1111/gcb.15522
    Soil respiration is the largest carbon efflux from the terrestrial ecosystem to the atmosphere, and selective logging influences soil respiration via changes in abiotic (temperature, moisture) and biotic (biomass, productivity, quantity and quality of necromass inputs) drivers. Logged forests are a predominant feature of the tropical forest landscape, their area exceeding that of intact forest. We quantified both total and component (root, mycorrhiza, litter, and soil organic matter, SOM) soil respiration in logged (n = 5) and old-growth (n = 6) forest plots in Malaysian Borneo, a region which is a global hotspot for emission from forest degradation. We constructed a detailed below-ground carbon budget including organic carbon inputs into the system via litterfall and root turnover. Total soil respiration was significantly higher in logged forests than in old-growth forests (14.3 ± 0.23 and 12.7 ± 0.60 Mg C ha-1  year-1 , respectively, p = 0.037). This was mainly due to the higher SOM respiration in logged forests (55 ± 3.1% of the total respiration in logged forests vs. 50 ± 3.0% in old-growth forests). In old-growth forests, annual SOM respiration was equal to the organic carbon inputs into the soil (difference between SOM respiration and inputs 0.18 Mg C ha-1  year-1 , with 90% confidence intervals of -0.41 and 0.74 Mg C ha-1  year-1 ), indicating that the system is in equilibrium, while in logged forests SOM respiration exceeded the inputs by 4.2 Mg C ha-1  year-1 (90% CI of 3.6 and 4.9 Mg C ha-1  year-1 ), indicating that the soil is losing carbon. These results contribute towards understanding the impact of logging on below-ground carbon dynamics, which is one of the key uncertainties in estimating emissions from forest degradation. This study demonstrates how significant perturbation of the below-ground carbon balance, and consequent net soil carbon emissions, can persist for decades after a logging event in tropical forests.
    Matched MeSH terms: Borneo
  20. Logging disturbance shifts net primary productivity and its allocation in Bornean tropical forests
    Riutta T, Malhi Y, Kho LK, Marthews TR, Huaraca Huasco W, Khoo M, et al.
    Glob Chang Biol, 2018 07;24(7):2913-2928.
    PMID: 29364562 DOI: 10.1111/gcb.14068
    Tropical forests play a major role in the carbon cycle of the terrestrial biosphere. Recent field studies have provided detailed descriptions of the carbon cycle of mature tropical forests, but logged or secondary forests have received much less attention. Here, we report the first measures of total net primary productivity (NPP) and its allocation along a disturbance gradient from old-growth forests to moderately and heavily logged forests in Malaysian Borneo. We measured the main NPP components (woody, fine root and canopy NPP) in old-growth (n = 6) and logged (n = 5) 1 ha forest plots. Overall, the total NPP did not differ between old-growth and logged forest (13.5 ± 0.5 and 15.7 ± 1.5 Mg C ha-1  year-1 respectively). However, logged forests allocated significantly higher fraction into woody NPP at the expense of the canopy NPP (42% and 48% into woody and canopy NPP, respectively, in old-growth forest vs 66% and 23% in logged forest). When controlling for local stand structure, NPP in logged forest stands was 41% higher, and woody NPP was 150% higher than in old-growth stands with similar basal area, but this was offset by structure effects (higher gap frequency and absence of large trees in logged forest). This pattern was not driven by species turnover: the average woody NPP of all species groups within logged forest (pioneers, nonpioneers, species unique to logged plots and species shared with old-growth plots) was similar. Hence, below a threshold of very heavy disturbance, logged forests can exhibit higher NPP and higher allocation to wood; such shifts in carbon cycling persist for decades after the logging event. Given that the majority of tropical forest biome has experienced some degree of logging, our results demonstrate that logging can cause substantial shifts in carbon production and allocation in tropical forests.
    Matched MeSH terms: Borneo
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links