Displaying publications 161 - 180 of 995 in total

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  1. Study on the chemical changes of Quercus acuttisima by Ganoderma lucidum cultivation after different years by FTIR analysis
    Zhang W, Chen X, Liu G, Jin G, Li Y, Li G, et al.
    Spectrochim Acta A Mol Biomol Spectrosc, 2022 Feb 05;266:120443.
    PMID: 34619507 DOI: 10.1016/j.saa.2021.120443
    The popularmedicinal mushroomGanodermalucidum was often cultivated by the natural-log. Generally the short log after cultivation were discarded and became pollutant. Rapid and less destructive method of analysis technical by Fourier Transform Infrared (FTIR) and Two-dimension Infrared (2DIR) correlation spectroscopy were selected to determine the composition changes of the logs after G.lucidum cultivation after first year to fifth year. The FTIR accumulated spectra formed without processed baseline showed the samples relied upon a sequenced increase of higher level than spectrum control Q (Q = Quercus acuttisima) from L + Q-5 (L = Lingzhi), L + Q-3, L + Q-1 to L + Q-2. The spectrum L + Q-4 has the optimum highest peak at box B, C and E from this lumped spectral view. The split spectra pinpointed on the fingerprint region of a sample begins from peak 1737 cm-1. ascribed C = O stretching vibration on acetyl and carboxyl hemicellulose group bonding gradually faded from L + Q-1 to L + Q-4 but appeared again on L + Q-5, possibly due to the degradation of hemicellulose. The absorption of peak around 1626 cm-1,1318 cm-1 and 781 cm-1 could be the characteristic absorption peak of calcium oxalate monohydrate. The correlation table indicated, most of the original structure of the building block of the wooden part was deteriorated and marked the lowest correlation value of the 4th year sample with control Q. The sudden changing pattern of 2nd derivative spectrum L + Q-3 to more flatten pattern spectrum L + Q-4 ascribed the changing contents of cellulose and hemicellulose included the lignin within one year during the G. lucidum cultivation. The 2DIR spectrum of the raw material sample precisely showed that the active site with red color was clustered with the area around 1800-1700 cm-1, 1450-800 cm-1 and 750-400 cm-1. In between, the range 1450-800 cm-1 was the most active cluster. Each of the sample showed the different sequence of autopeak comparison. This study has examined the impact of G. lucidum on the degradation of Q. acuttisima in term of their ecosystem life chain. The components of healthy Q. acuttisima wood including lignin, cellulose, hemicellulose and calcium oxalate monohydrate underwent changes after different years of G. lucidum cultivation.
    Matched MeSH terms: Ecosystem
  2. Structural and functional changes with depth in microbial communities in a tropical Malaysian peat swamp forest
    Jackson CR, Liew KC, Yule CM
    Microb Ecol, 2009 Apr;57(3):402-12.
    PMID: 18548182 DOI: 10.1007/s00248-008-9409-4
    Tropical peat swamp forests are important and endangered ecosystems, although little is known of their microbial diversity and ecology. We used molecular and enzymatic techniques to examine patterns in prokaryotic community structure and overall microbial activity at 0-, 10-, 20-, and 50-cm depths in sediments in a peat swamp forest in Malaysia. Denaturing gradient gel electrophoresis profiles of amplified 16S ribosomal ribonucleic acid (rRNA) gene fragments showed that different depths harbored different bacterial assemblages and that Archaea appeared to be limited to the deeper samples. Cloning and sequencing of longer 16S rRNA gene fragments suggested reduced microbial diversity in the deeper samples compared to the surface. Bacterial clone libraries were largely dominated by ribotypes affiliated with the Acidobacteria, which accounted for at least 27-54% of the sequences obtained. All of the sequenced representatives from the archaeal clone libraries were Crenarchaeota. Activities of microbial extracellular enzymes involved in carbon, nitrogen, and phosphorus cycling declined appreciably with depth, the only exception being peroxidase. These results show that tropical peat swamp forests are unusual systems with microbial assemblages dominated by members of the Acidobacteria and Crenarchaeota. Microbial communities show clear changes with depth, and most microbial activity is likely confined to populations in the upper few centimeters, the site of new leaf litter fall, rather than the deeper, older, peat layers.
    Matched MeSH terms: Ecosystem*
  3. Stream ecosystem integrity is impaired by logging and shifting agriculture in a global megadiversity center (Sarawak, Borneo)
    Jinggut T, Yule CM, Boyero L
    Sci Total Environ, 2012 Oct 15;437:83-90.
    PMID: 22922133 DOI: 10.1016/j.scitotenv.2012.07.062
    In common with most of Borneo, the Bakun region of Sarawak is currently subject to heavy deforestation mainly due to logging and, to a lesser extent, traditional slash-and-burn farming practices. This has the potential to affect stream ecosystems, which are integrators of environmental change in the surrounding terrestrial landscape. This study evaluated the effects of both types of deforestation by using functional and structural indicators (leaf litter decomposition rates and associated detritivores or 'shredders', respectively) to compare a fundamental ecosystem process, leaf litter decomposition, within logged, farmed and pristine streams. Slash-and-burn agricultural practices increased the overall rate of decomposition despite a decrease in shredder species richness (but not shredder abundance) due to increased microbial decomposition. In contrast, decomposition by microbes and invertebrates was slowed down in the logged streams, where shredders were less abundant and less species rich. This study suggests that shredder communities are less affected by traditional agricultural farming practices, while modern mechanized deforestation has an adverse effect on both shredder communities and leaf breakdown.
    Matched MeSH terms: Ecosystem*
  4. Fulltext Status of the undisturbed mangroves at Brunei Bay, East Malaysia: a preliminary assessment based on remote sensing and ground-truth observations
    Satyanarayana B, M Muslim A, Izzaty Horsali NA, Mat Zauki NA, Otero V, Nadzri MI, et al.
    PeerJ, 2018;6:e4397.
    PMID: 29479500 DOI: 10.7717/peerj.4397
    Brunei Bay, which receives freshwater discharge from four major rivers, namely Limbang, Sundar, Weston and Menumbok, hosts a luxuriant mangrove cover in East Malaysia. However, this relatively undisturbed mangrove forest has been less scientifically explored, especially in terms of vegetation structure, ecosystem services and functioning, and land-use/cover changes. In the present study, mangrove areal extent together with species composition and distribution at the four notified estuaries was evaluated through remote sensing (Advanced Land Observation Satellite-ALOS) and ground-truth (Point-Centred Quarter Method-PCQM) observations. As of 2010, the total mangrove cover was found to be ca. 35,183.74 ha, of which Weston and Menumbok occupied more than two-folds (58%), followed by Sundar (27%) and Limbang (15%). The medium resolution ALOS data were efficient for mapping dominant mangrove species such asNypa fruticans,Rhizophora apiculata,Sonneratia caseolaris,S. albaandXylocarpus granatumin the vicinity (accuracy: 80%). The PCQM estimates found a higher basal area at Limbang and Menumbok-suggestive of more mature vegetation, compared to Sundar and Weston. Mangrove stand structural complexity (derived from the complexity index) was also high in the order of Limbang > Menumbok > Sundar > Weston and supporting the perspective of less/undisturbed vegetation at two former locations. Both remote sensing and ground-truth observations have complementarily represented the distribution ofSonneratiaspp. as pioneer vegetation at shallow river mouths,N. fruticansin the areas of strong freshwater discharge,R. apiculatain the areas of strong neritic incursion andX. granatumat interior/elevated grounds. The results from this study would be able to serve as strong baseline data for future mangrove investigations at Brunei Bay, including for monitoring and management purposes locally at present.
    Matched MeSH terms: Ecosystem
  5. Spider (Araneae) predations on white-backed planthopper Sogatella furcifera in subtropical rice ecosystems, China
    Wang XQ, Wang GH, Zhu ZR, Tang QY, Hu Y, Qiao F, et al.
    Pest Manag Sci, 2017 Jun;73(6):1277-1286.
    PMID: 27739189 DOI: 10.1002/ps.4459
    BACKGROUND: Spiders are effective biological control agents in rice ecosystems, but the comparative study of predations among main spider species under field conditions has not been fully explored owing to a lack of practical methodology. In this study, more than 6000 spiders of dominant species were collected from subtropical rice ecosystems to compare their predations on Sogatella furcifera (Horváth) (white-backed planthopper, WBPH) using DNA-based gut content analysis.

    RESULTS: The positive rates for all spider taxa were closely related to prey densities, as well as their behaviors and niches. The relationships of positive rates to prey planthopper densities for Pardosa pseudoannulata (Böes. et Str.), Coleosoma octomaculata (Böes. et Str.), Tetragnatha maxillosa Thorell and Ummeliata insecticeps (Böes. et Str.) under field conditions could be described using saturated response curves. Quantitative comparisons of predations among the four spider species confirmed that P. pseudoannulata and C. octomaculata were more rapacious than U. insecticeps and T. maxillosa under field conditions. A comparison of ratio of spiders to WBPH and positive rates between fields revealed that biological control by spiders could be effectively integrated with variety resistance.

    CONCLUSION: Generalist spiders could follow up WBPH population timely, and assemblages of spiders coupled with variety resistance could effectively suppress WBPH population. © 2016 Society of Chemical Industry.

    Matched MeSH terms: Ecosystem
  6. Species richness of riparian vegetation after three decades of Kenyir dam establishment
    Shahimi S, Salam R, Salim JM, Ahmad A
    Data Brief, 2019 Aug;25:104045.
    PMID: 31194175 DOI: 10.1016/j.dib.2019.104045
    This data article is on riparian vegetation species richness in four different streams located in the Sultan Mahmud Hydroelectric dam, also known as Kenyir dam and commonly referred to as Tasik Kenyir, Terengganu. The dataset consists of three reservoir-island streams and the other is a small stream located on the mainland. A total of 41 families and 90 species of riparian plants were reported for the first time after 34 years of the establishment of the Sultan Mahmud Hydroelectric dam. Trees contributing 60% of the species recorded in this study and the others were non-tree species, including climbers, ferns, epiphyte, herbs, shrub, strangling trees and palms. Among the recorded riparian plant species, two are introduced which are Clidemia hirta and Mimosa pigra. The highest diversity of riparian plant found in the stream of Sungai Kiang, followed by Sungai Ikan and Sungai Saok with 46, 29 and 17 species respectively for the reservoir-island streams. The mainland stream, Sungai Siput recorded 37 species. These riparian plants provide important ecosystem services, among others soil stabilization, habitat and food for aquatic fauna and water filtration. In terms of plant utilization potential and values, 47 species are identified having medicinal value, 10 species with ornamental value and another 36 species are timber trees. Our study demonstrates that the riparian plants are closely linked to stream size with variability associated with types of stream systems. The data collected also demonstrates that the riparian plant community is at the seral stages of riparian forest. This is indicated by the increase in plant species richness as the vegetation gradually changes from riparian towards mature forest composition. To secure ecological functions of Tasik Kenyir riparian plant assemblages, particularly in stabilizing the lake's margin and riverbank, it is recommended that monitoring and legal protection may need to be imposed by local authority.
    Matched MeSH terms: Ecosystem
  7. Species of Triacanthinella Bychowsky & Nagibina, 1968 (Monogenea: Ancyrocephalidae) from triacanthid teleosts off Peninsular Malaysia, with a generic revision, amended diagnosis and key
    Lim LH, Gibson DI
    Syst Parasitol, 2008 Jul;70(3):191-213.
    PMID: 18535790 DOI: 10.1007/s11230-008-9137-7
    One new and four previously described species of Triacanthinella Bychowsky & Nagibina, 1968 (Monogenea) were collected from the tripodfishes Triacanthus biaculeatus and Tripodichthys blochii off Peninsular Malaysia. Triacanthinella lumutensis n. sp. from Tripodichthys blochii off Lumut, Selangor is similar to Triacanthinella principalis Bychowsky & Nagibina, 1968 in having morphologically similar types of haptoral sclerites and copulatory organ, but differs in possessing a longer copulatory tube. Also re-described are T. principalis Bychowsky & Nagibina, 1968, T. gracilis Bychowsky & Nagibina, 1968 and T. aspera Bychowsky & Nagibina, 1968 from both Triacanthus biaculeatus and Tripodichthys blochii, plus Triacanthinella longipenis Bychowsky & Nagibina, 1968 from Tripodichthys blochii and Triacanthinella tripathii Bychowsky & Nagibina, 1968 based on its type-material. In the new species, the filament loop of the anchors is associated with a sheath-like sclerite which envelops the anchor point. Such sclerites were also observed in the present specimens of Triacanthinella principalis, T. aspera, T. longipenis and T. gracilis but were not mentioned in the original descriptions. The generic diagnosis of Triacanthinella is amended and a key to the recognised species is presented. The specific names of two of the previously described species are emended from the neuter form to T. principalis and T. gracilis.
    Matched MeSH terms: Ecosystem
  8. Fulltext Species composition and invasion risks of alien ornamental freshwater fishes from pet stores in Klang Valley, Malaysia
    Saba AO, Ismail A, Zulkifli SZ, Halim MRA, Wahid NAA, Amal MNA
    Sci Rep, 2020 10 14;10(1):17205.
    PMID: 33057156 DOI: 10.1038/s41598-020-74168-9
    The ornamental fish trade has been considered as one of the most important routes of invasive alien fish introduction into native freshwater ecosystems. Therefore, the species composition and invasion risks of fish species from 60 freshwater fish pet stores in Klang Valley, Malaysia were studied. A checklist of taxa belonging to 18 orders, 53 families, and 251 species of alien fishes was documented. Fish Invasiveness Screening Test (FIST) showed that seven (30.43%), eight (34.78%) and eight (34.78%) species were considered to be high, medium and low invasion risks, respectively. After the calibration of the Fish Invasiveness Screening Kit (FISK) v2 using the Receiver Operating Characteristics, a threshold value of 17 for distinguishing between invasive and non-invasive fishes was identified. As a result, nine species (39.13%) were of high invasion risk. In this study, we found that non-native fishes dominated (85.66%) the freshwater ornamental trade in Klang Valley, while FISK is a more robust tool in assessing the risk of invasion, and for the most part, its outcome was commensurate with FIST. This study, for the first time, revealed the number of high-risk ornamental fish species that give an awareness of possible future invasion if unmonitored in Klang Valley, Malaysia.
    Matched MeSH terms: Ecosystem*
  9. Fulltext Species and Size Composition of Seahorses (Genus Hippocampus, Family Syngnathidae) in the Coastal Waters and Local Market of Kota Kinabalu, Sabah, Malaysia
    Shapawi R, Anyie AL, Hussien MA, Zuldin WH
    Trop Life Sci Res, 2015 Dec;26(2):1-13.
    PMID: 26868706 MyJurnal
    Seahorse diversity (genus Hippocampus, Family Syngnathidae), species identification, size composition and sexual dimorphism were studied from November 2012 to March 2013 in selected coastal waters around Kota Kinabalu, Sabah and the local market trade. Six species of seahorses were identified in the study: (1) Hippocampus barbouri, (2) Hippocampus comes, (3) Hippocampus kelloggi, (4) Hippocampus kuda, (5) Hippocampus spinosissimus and (6) Hippocampus trimaculatus. All six species were sold at the local market, and the dried seahorses were obtained mainly by local fishermen using trawl by-catch method and traded as traditional medicine, souvenirs and other uses. Four species were identified by direct samplings in various different habitats of Kota Kinabalu coastal waters: (1) H. barbouri, (2) H. comes, (3) H. kuda, and (4) H. spinosissimus. Based on the results, H. comes was the largest in size among the four fresh/live species found (mean standard length [SL]: 148.25±1.26 mm), whereas H. barbouri was the smallest species (mean SL: 129±7.81 mm). For the dried samples, H. kelloggi was the largest (mean SL: 245.25±14.55 mm) and H. barbouri was the smallest (mean SL: 127.21±10.01 mm). No significant difference (p>0.05) was observed between the lengths of males and females in every seahorse species, and there was no sexual size dimorphism in any of the species. The findings from the study are significant to provide baseline data for the conservation efforts of these unique marine teleost.
    Matched MeSH terms: Ecosystem
  10. Speciation and phylogeography of the Southeast Asian Anopheles sundaicus complex
    Dusfour I, Michaux JR, Harbach RE, Manguin S
    Infect Genet Evol, 2007 Jul;7(4):484-93.
    PMID: 17350896
    Anopheles sundaicus s.l. is a malaria vector in coastal areas of Southeast Asia. Previous studies showed at least four distinct species within the complex. The present study investigated the phylogeography and the status of A. sundaicus s.l. populations from Cambodia, Thailand, Malaysia and Indonesia with regard to A. sundaicus s.s. from Sarawak, Malaysian Borneo and A. epiroticus in Vietnam and Thailand. Three lineages recovered by analyses of Cyt-b and COI (mtDNA) confirmed the presence of A. sundaicus s.s. in Malaysian Borneo, the distribution of A. epiroticus from southern Vietnam to peninsular Malaysia, and recognised a distinct form in Indonesia that is named A. sundaicus E. The phylogenetic and demographic analyses suggest that the three species were separated during the Early Pleistocene (1.8-0.78 Myr) and experienced bottlenecks followed by a genetic expansion in more recent times. Based on the results and knowledge of the biogeography of the area, we hypothesise that the combination of cyclical island and refugium creation was the cause of lineage isolation and bottleneck events during the Pleistocene.
    Matched MeSH terms: Ecosystem
  11. Spatiotemporal trends and characteristics of microplastic contamination in a large river-dominated estuary
    Rakib MRJ, Al Nahian S, Madadi R, Haider SMB, De-la-Torre GE, Walker TR, et al.
    Environ Sci Process Impacts, 2023 May 25;25(5):929-940.
    PMID: 36939043 DOI: 10.1039/d3em00014a
    Microplastic (MP) pollution is a major global issue that poses serious threats to aquatic organisms. Although research on MP pollution has been extensive, the relationship between MPs and water quality parameters in estuarine water systems is unclear. This work studied the spatiotemporal distribution and characteristics of MPs in the Karnaphuli River estuary, Bangladesh. MP abundance was calculated by towing with a plankton net (300 μm mesh size) at three river gradients (up-, mid- and downstream) and the association between physicochemical parameters of water (temperature, pH, salinity, electrical conductivity, total dissolved solids, and dissolved oxygen) and MP distribution patterns was also investigated. Mean MP abundance in water was higher during the wet season (April) (4.33 ± 2.45 items per m3) compared to the dry season (September) (3.65 ± 2.54 items per m3). In descending order, the highest MP abundance was observed downstream (6.60 items per m3) > midstream (3.15 items per m3) > upstream (2.22 items per m3). pH during the wet season (April) and temperature during the dry season (September) were key physicochemical parameters that correlated with river MP abundance (r = -0.74 and 0.74 respectively). Indicating that if the Karnaphuli River water has low pH or high temperature, there is likely to be high MPs present in the water. Most MP particles were film-shaped, white in color, and 1-5 mm in size. Of the six polymers detected, polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), and cellulose were predominant, comprising roughly 17-19% each. These results can be used to model MP transport in the freshwater ecosystem of the Karnaphuli River estuary in Bangladesh to help develop future mitigation strategies.
    Matched MeSH terms: Ecosystem
  12. Spatio-temporal variation of microplastic along a rural to urban transition in a tropical river
    Chen HL, Gibbins CN, Selvam SB, Ting KN
    Environ Pollut, 2021 Nov 15;289:117895.
    PMID: 34364115 DOI: 10.1016/j.envpol.2021.117895
    Microplastic pollution is widely recognised as a global issue, posing risks to natural ecosystems and human health. The combination of rapid industrial and urban development and relatively limited environmental regulation in many tropical countries may increase the amount of microplastic entering rivers, but basic data on contamination levels are lacking. This is especially the case in tropical South East Asian countries. In this paper, the abundance, composition and spatio-temporal variation of microplastic in the Langat River, Malaysia, were assessed, and the relationship between microplastic concentration and river discharge was investigated. Water samples were collected over a 12-month period from 8 sampling sites on the Langat, extending from forested to heavily urbanised and industrial areas. All 508 water samples collected over this period contained microplastic; mean concentration across all sites and times was 4.39 particles/L but extended up to 90.00 particles/L in some urban tributaries. Most microplastics were secondary in origin, and dominated by fibres. Microplastic counts correlated directly with river discharge, and counts increased and decreased in response to changes in flow. A time-integrated assessment of the microplastic load conveyed by the Langat suggested that the river is typically (50 % of the time) delivering around 5 billion particles per day to the ocean. The positive correlation between the concentration of microplastics and suspended sediments in the Langat suggested that continuously logging turbidity sensors could be used to provide better estimates of microplastic loads and improve assessment of human and ecological health risks.
    Matched MeSH terms: Ecosystem
  13. Fulltext Spatio-temporal ecology of sympatric felids on Borneo. Evidence for resource partitioning?
    Hearn AJ, Cushman SA, Ross J, Goossens B, Hunter LTB, Macdonald DW
    PLoS One, 2018;13(7):e0200828.
    PMID: 30028844 DOI: 10.1371/journal.pone.0200828
    Niche differentiation, the partitioning of resources along one or more axes of a species' niche hyper-volume, is widely recognised as an important mechanism for sympatric species to reduce interspecific competition and predation risk, and thus facilitate co-existence. Resource partitioning may be facilitated by behavioural differentiation along three main niche dimensions: habitat, food and time. In this study, we investigate the extent to which these mechanisms can explain the coexistence of an assemblage of five sympatric felids in Borneo. Using multi-scale logistic regression, we show that Bornean felids exhibit differences in both their broad and fine-scale habitat use. We calculate temporal activity patterns and overlap between these species, and present evidence for temporal separation within this felid guild. Lastly, we conducted an all-subsets logistic regression to predict the occurrence of each felid species as a function of the co-occurrence of a large number of other species and showed that Bornean felids co-occurred with a range of other species, some of which could be candidate prey. Our study reveals apparent resource partitioning within the Bornean felid assemblage, operating along all three niche dimension axes. These results provide new insights into the ecology of these species and the broader community in which they live and also provide important information for conservation planning for this guild of predators.
    Matched MeSH terms: Ecosystem*
  14. Spatio-temporal changes in fractional vegetation cover and the driving forces during 2001-2020 in the northern slopes of the Tianshan Mountains, China
    He X, Zhang F, Cai Y, Tan ML, Chan NW
    Environ Sci Pollut Res Int, 2023 Jun;30(30):75511-75531.
    PMID: 37222898 DOI: 10.1007/s11356-023-27702-x
    This study aims to understand the factors and mechanisms influencing the spatio-temporal changes of fractional vegetation cover (FVC) in the northern slopes of the Tianshan Mountains. The MOD13Q1 product data between June and September (peak of plants growing) during the 2001-2020 period was incorporated into the pixel dichotomy model to calculate the vegetation cover changes. Then, the principal component analysis method was used to identify the primary driving factors affecting the change in vegetation cover from the natural, human, and economic perspectives. Finally, the partial correlation coefficients of FVC with temperature and precipitation were further calculated based on the pixel scale. The findings indicate that (1) FVC in the northern slopes of the Tianshan Mountains ranged from 0.37 to 0.47 during the 2001-2020 period, with an obvious inter-annual variation and an overall upward trend of about 0.4484/10 a. Although the vegetation cover had some changes over time, it was generally stable, and the area of strong variation only accounted for 0.58% of the total. (2) The five grades of vegetation cover were distributed spatially similarly, but the area-weighted gravity center for each vegetation class shifted significantly. The FVC under different land use/land cover types and elevations was obviously different, and as elevation increased, vegetation coverage presented a trend of a "∩"-shape change. (3) According to the results of principal component analysis, human activities, economic growth, and natural climate were the main driving factors that caused the changes in vegetation cover, and the cumulative contribution of the three reached 89.278%. In addition, when it came to climatic factors, precipitation had a greater driving force on the vegetation cover change, followed by temperature and sunshine hours. (4) Overall, precipitation and temperature were correlated positively with FVC, with the average correlation coefficient values of 0.089 and 0.135, respectively. Locally, the correlations vary greatly under different LULC and altitudes. This research can provide some scientific basis and reference for the vegetation evolution pattern and ecological civilization construction in the region.
    Matched MeSH terms: Ecosystem*
  15. Fulltext Spatial subsidies drive sweet spots of tropical marine biomass production
    Morais RA, Siqueira AC, Smallhorn-West PF, Bellwood DR
    PLoS Biol, 2021 Nov;19(11):e3001435.
    PMID: 34727097 DOI: 10.1371/journal.pbio.3001435
    Spatial subsidies increase local productivity and boost consumer abundance beyond the limits imposed by local resources. In marine ecosystems, deeper water and open ocean subsidies promote animal aggregations and enhance biomass that is critical for human harvesting. However, the scale of this phenomenon in tropical marine systems remains unknown. Here, we integrate a detailed assessment of biomass production in 3 key locations, spanning a major biodiversity and abundance gradient, with an ocean-scale dataset of fish counts to predict the extent and magnitude of plankton subsidies to fishes on coral reefs. We show that planktivorous fish-mediated spatial subsidies are widespread across the Indian and Pacific oceans and drive local spikes in biomass production that can lead to extreme productivity, up to 30 kg ha-1 day-1. Plankton subsidies form the basis of productivity "sweet spots" where planktivores provide more than 50% of the total fish production, more than all other trophic groups combined. These sweet spots operate at regional, site, and smaller local scales. By harvesting oceanic productivity, planktivores bypass spatial constraints imposed by local primary productivity, creating "oases" of tropical fish biomass that are accessible to humans.
    Matched MeSH terms: Ecosystem*
  16. Fulltext Spatial structure of seagrass suggests that size-dependent plant traits have a strong influence on the distribution and maintenance of tropical multispecies meadows
    Ooi JL, Van Niel KP, Kendrick GA, Holmes KW
    PLoS One, 2014;9(1):e86782.
    PMID: 24497978 DOI: 10.1371/journal.pone.0086782
    Seagrass species in the tropics occur in multispecies meadows. How these meadows are maintained through species co-existence and what their ecological drivers may be has been an overarching question in seagrass biogeography. In this study, we quantify the spatial structure of four co-existing species and infer potential ecological processes from these structures.
    Matched MeSH terms: Ecosystem*
  17. Fulltext Spatial scale changes the relationship between beta diversity, species richness and latitude
    Sreekar R, Katabuchi M, Nakamura A, Corlett RT, Slik JWF, Fletcher C, et al.
    R Soc Open Sci, 2018 Sep;5(9):181168.
    PMID: 30839691 DOI: 10.1098/rsos.181168
    The relationship between β-diversity and latitude still remains to be a core question in ecology because of the lack of consensus between studies. One hypothesis for the lack of consensus between studies is that spatial scale changes the relationship between latitude and β-diversity. Here, we test this hypothesis using tree data from 15 large-scale forest plots (greater than or equal to 15 ha, diameter at breast height ≥ 1 cm) across a latitudinal gradient (3-30o) in the Asia-Pacific region. We found that the observed β-diversity decreased with increasing latitude when sampling local tree communities at small spatial scale (grain size ≤0.1 ha), but the observed β-diversity did not change with latitude when sampling at large spatial scales (greater than or equal to 0.25 ha). Differences in latitudinal β-diversity gradients across spatial scales were caused by pooled species richness (γ-diversity), which influenced observed β-diversity values at small spatial scales, but not at large spatial scales. Therefore, spatial scale changes the relationship between β-diversity, γ-diversity and latitude, and improving sample representativeness avoids the γ-dependence of β-diversity.
    Matched MeSH terms: Ecosystem
  18. Spatial patterns in the distribution of tropical tree species
    Condit R, Ashton PS, Baker P, Bunyavejchewin S, Gunatilleke S, Gunatilleke N, et al.
    Science, 2000 May 26;288(5470):1414-8.
    PMID: 10827950
    Fully mapped tree census plots of large area, 25 to 52 hectares, have now been completed at six different sites in tropical forests, including dry deciduous to wet evergreen forest on two continents. One of the main goals of these plots has been to evaluate spatial patterns in tropical tree populations. Here the degree of aggregation in the distribution of 1768 tree species is examined based on the average density of conspecific trees in circular neighborhoods around each tree. When all individuals larger than 1 centimeter in stem diameter were included, nearly every species was more aggregated than a random distribution. Considering only larger trees (>/= 10 centimeters in diameter), the pattern persisted, with most species being more aggregated than random. Rare species were more aggregated than common species. All six forests were very similar in all the particulars of these results.
    Matched MeSH terms: Ecosystem*
  19. Spatial and temporal variations in Strombus canarium (Gastropoda: Strombidae) abundance at Merambong Seagrass Bed, Malaysia
    Zaidi Che Cob, Aziz Arshad, Japar Sidik Bujang, Mazlan Abd Ghaffar
    Sains Malaysiana, 2014;43:503-511.
    The abundance of marine benthic organisms often exhibits distinct distributional patterns, which is generally governed by many physical and biological factors specific to the habitat. In this study, the spatial and temporal variations in abundance of the dog conch, Strombus canarium Linnaeus 1758, a commercially important marine gastropod, was investigated. Assessment of conch abundance at Merambong seagrass bed, Malaysia, was conducted using a transect belt method. Sampling stations were randomly selected and environmental parameters associated with the habitat were recorded. The species showed distinct spatial distributional pattern. Conch densities were significantly higher in sheltered areas, mainly in mixed seagrass bed dominated by Halophila spp. and with high sediment organic content. The densities were relatively very low in areas dominated by the tape seagrass, Enhalus acoroides. The species studied also showed distinct temporal variation in abundance. The abundance value was seasonally varied with highest density recorded during the wet monsoon season (p<0.05). The densities were otherwise very low during the dry season, except for a slight peak in July. Since the conch is a very important fishery species within the Johor Straits and regulations on their harvesting is still lacking, this information would be very important for their sustainable management.
    Matched MeSH terms: Ecosystem
  20. Fulltext Spatial and temporal behavioural responses of wild cattle to tropical forest degradation
    Gardner PC, Goossens B, Goon Ee Wern J, Kretzschmar P, Bohm T, Vaughan IP
    PLoS One, 2018;13(4):e0195444.
    PMID: 29649279 DOI: 10.1371/journal.pone.0195444
    Identifying the consequences of tropical forest degradation is essential to mitigate its effects upon forest fauna. Large forest-dwelling mammals are often highly sensitive to environmental perturbation through processes such as fragmentation, simplification of habitat structure, and abiotic changes including increased temperatures where the canopy is cleared. Whilst previous work has focused upon species richness and rarity in logged forest, few look at spatial and temporal behavioural responses to forest degradation. Using camera traps, we explored the relationships between diel activity, behavioural expression, habitat use and ambient temperature to understand how the wild free-ranging Bornean banteng (Bos javanicus lowi) respond to logging and regeneration. Three secondary forests in Sabah, Malaysian Borneo were studied, varying in the time since last logging (6-23 years). A combination of generalised linear mixed models and generalised linear models were constructed using >36,000 trap-nights. Temperature had no significant effect on activity, however it varied markedly between forests, with the period of intense heat shortening as forest regeneration increased over the years. Bantengs regulated activity, with a reduction during the wet season in the most degraded forest (z = -2.6, Std. Error = 0.13, p = 0.01), and reductions during midday hours in forest with limited regeneration, however after >20 years of regrowth, activity was more consistent throughout the day. Foraging and use of open canopy areas dominated the activity budget when regeneration was limited. As regeneration advanced, this was replaced by greater investment in travelling and using a closed canopy. Forest degradation modifies the ambient temperature, and positively influences flooding and habitat availability during the wet season. Retention of a mosaic of mature forest patches within commercial forests could minimise these effects and also provide refuge, which is key to heat dissipation and the prevention of thermal stress, whilst retention of degraded forest could provide forage.
    Matched MeSH terms: Ecosystem
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