Displaying publications 1 - 20 of 445 in total

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  1. Zèches M, Mesbah K, Loukaci A, Richard B, Schaller H, Sévenet T, et al.
    Planta Med, 1995 Feb;61(1):97.
    PMID: 7701009
    Matched MeSH terms: Trees/chemistry*
  2. Zuleta D, Arellano G, McMahon SM, Aguilar S, Bunyavejchewin S, Castaño N, et al.
    Glob Chang Biol, 2023 Jun;29(12):3409-3420.
    PMID: 36938951 DOI: 10.1111/gcb.16687
    Accurate estimates of forest biomass stocks and fluxes are needed to quantify global carbon budgets and assess the response of forests to climate change. However, most forest inventories consider tree mortality as the only aboveground biomass (AGB) loss without accounting for losses via damage to living trees: branchfall, trunk breakage, and wood decay. Here, we use ~151,000 annual records of tree survival and structural completeness to compare AGB loss via damage to living trees to total AGB loss (mortality + damage) in seven tropical forests widely distributed across environmental conditions. We find that 42% (3.62 Mg ha-1  year-1 ; 95% confidence interval [CI] 2.36-5.25) of total AGB loss (8.72 Mg ha-1  year-1 ; CI 5.57-12.86) is due to damage to living trees. Total AGB loss was highly variable among forests, but these differences were mainly caused by site variability in damage-related AGB losses rather than by mortality-related AGB losses. We show that conventional forest inventories overestimate stand-level AGB stocks by 4% (1%-17% range across forests) because assume structurally complete trees, underestimate total AGB loss by 29% (6%-57% range across forests) due to overlooked damage-related AGB losses, and overestimate AGB loss via mortality by 22% (7%-80% range across forests) because of the assumption that trees are undamaged before dying. Our results indicate that forest carbon fluxes are higher than previously thought. Damage on living trees is an underappreciated component of the forest carbon cycle that is likely to become even more important as the frequency and severity of forest disturbances increase.
    Matched MeSH terms: Trees*
  3. Zohner CM, Mo L, Renner SS, Svenning JC, Vitasse Y, Benito BM, et al.
    Proc Natl Acad Sci U S A, 2020 06 02;117(22):12192-12200.
    PMID: 32393624 DOI: 10.1073/pnas.1920816117
    Late-spring frosts (LSFs) affect the performance of plants and animals across the world's temperate and boreal zones, but despite their ecological and economic impact on agriculture and forestry, the geographic distribution and evolutionary impact of these frost events are poorly understood. Here, we analyze LSFs between 1959 and 2017 and the resistance strategies of Northern Hemisphere woody species to infer trees' adaptations for minimizing frost damage to their leaves and to forecast forest vulnerability under the ongoing changes in frost frequencies. Trait values on leaf-out and leaf-freezing resistance come from up to 1,500 temperate and boreal woody species cultivated in common gardens. We find that areas in which LSFs are common, such as eastern North America, harbor tree species with cautious (late-leafing) leaf-out strategies. Areas in which LSFs used to be unlikely, such as broad-leaved forests and shrublands in Europe and Asia, instead harbor opportunistic tree species (quickly reacting to warming air temperatures). LSFs in the latter regions are currently increasing, and given species' innate resistance strategies, we estimate that ∼35% of the European and ∼26% of the Asian temperate forest area, but only ∼10% of the North American, will experience increasing late-frost damage in the future. Our findings reveal region-specific changes in the spring-frost risk that can inform decision-making in land management, forestry, agriculture, and insurance policy.
    Matched MeSH terms: Trees/growth & development*
  4. Zhou JN, Lin BR, Shen HF, Pu XM, Chen ZN, Feng JJ
    Plant Dis, 2012 May;96(5):760.
    PMID: 30727539 DOI: 10.1094/PDIS-11-11-0942
    Phalaenopsis orchids, originally from tropical Asia, are mainly planted in Thailand, Singapore, Malaysia, the Philippines, and Taiwan and have gained popularity from consumers all over the world. The cultivation area of Phalaenopsis orchids has been rising and large-scale bases have been established in mainland China, especially South China because of suitable environmental conditions. In September 2011, a soft rot of Phalaenopsis aphrodita was found in a Phalaenopsis planting base in Guangzhou with an incidence of ~15%. Infected plants initially showed water-soaked, pale-to-dark brown pinpoint spots on leaves that were sometimes surrounded by a yellow halo. Spots expanded rapidly with rising humidity and temperatures, and in a few days, severely extended over the blade with a light tan color and darker brown border. Lesions decayed with odorous fumes and tissues collapsed with inclusions exuding. The bacterium advanced to the stem and pedicle. Finally, leaves became papery dry and the pedicles lodged. Six diseased samples were collected, and bacteria were isolated from the edge of symptomatic tissues after sterilization in 0.3% NaOCl for 10 min, rinsing in sterile water three times, and placing on nutrient agar for culture. Twelve representative isolates were selected for further characterization. All strains were gram negative, grew at 37°C, were positive for indole production, and utilized malonate, glucose, and sucrose but not glucopyranoside, trehalose, or palatinose. Biolog identification (version 4.20.05, Hayward, CA) was performed and Pectobacterium chrysanthemi (SIM 0.868) was confirmed for the tested isolates (transfer to genus Dickeya). PCR was used to amplify the 16S rDNAgene with primers 27f and 1492r, dnaX gene with primers dnaXf and dnaXr (3), and gyrB gene with primers gyrBf (5'-GAAGGYAAAVTKCATCGTCAGG-3') and gyrB-r1 (5'-TCARATATCRATATTCGCYGCTTTC-3') designed on the basis of the published gyrB gene sequences of genus Dickeya. BLASTn was performed online, and phylogeny trees (100% bootstrap values) were created by means of MEGA 5.05 for these gene sequences, respectively. Results commonly showed that the representative tested strain, PA1, was most homologous to Dickeya dieffenbachiae with 98% identity for 16S rDNA(JN940859), 97% for dnaX (JN989971), and 96% for gyrB (JN971031). Thus, we recommend calling this isolate D. dieffenbachiae PA1. Pathogenicity tests were conducted by injecting 10 P. aphrodita seedlings with 100 μl of the bacterial suspension (1 × 108 CFU/ml) and another 10 were injected with 100 μl of sterile water as controls. Plants were inoculated in a greenhouse at 28 to 32°C and 90% relative humidity. Soft rot symptoms were observed after 2 days on the inoculated plants, but not on the control ones. The bacterium was isolated from the lesions and demonstrated identity to the inoculated plant by the 16S rDNA sequence comparison. Previously, similar diseases of P. amabilis were reported in Tangshan, Jiangsu, Zhejiang, and Wuhan and causal agents were identified as Erwinia spp. (2), Pseudomonas grimontii (1), E. chrysanthemi, and E. carotovora subsp. carovora (4). To our knowledge, this is the first report of D. dieffenbachiae causing soft rot disease on P. aphrodita in China. References: (1) X. L. Chu and B. Yang. Acta Phytopathol. Sin. 40:90, 2010. (2) Y. M. Li et al. J. Beijing Agric. Coll. 19:41, 2004. (3) M. Sławiak et al. Eur. J. Plant Pathol. 125:245, 2009. (4) Z. Y. Wu et al. J. Zhejiang For. Coll. 27:635, 2010.
    Matched MeSH terms: Trees
  5. Zhong Y, Chu C, Myers JA, Gilbert GS, Lutz JA, Stillhard J, et al.
    Nat Commun, 2021 May 25;12(1):3137.
    PMID: 34035260 DOI: 10.1038/s41467-021-23236-3
    Arbuscular mycorrhizal (AM) and ectomycorrhizal (EcM) associations are critical for host-tree performance. However, how mycorrhizal associations correlate with the latitudinal tree beta-diversity remains untested. Using a global dataset of 45 forest plots representing 2,804,270 trees across 3840 species, we test how AM and EcM trees contribute to total beta-diversity and its components (turnover and nestedness) of all trees. We find AM rather than EcM trees predominantly contribute to decreasing total beta-diversity and turnover and increasing nestedness with increasing latitude, probably because wide distributions of EcM trees do not generate strong compositional differences among localities. Environmental variables, especially temperature and precipitation, are strongly correlated with beta-diversity patterns for both AM trees and all trees rather than EcM trees. Results support our hypotheses that latitudinal beta-diversity patterns and environmental effects on these patterns are highly dependent on mycorrhizal types. Our findings highlight the importance of AM-dominated forests for conserving global forest biodiversity.
    Matched MeSH terms: Trees/microbiology; Trees/physiology*
  6. Zheng T, Mencuccini M, Abdul-Hamid H
    Physiol Plant, 2023;175(3):e13915.
    PMID: 37087558 DOI: 10.1111/ppl.13915
    Although a substantial body of evidence suggests that large and old trees have reduced metabolic levels, the search for the causes behind this observation has proved elusive. The strong coupling between age and size, commonly encountered in the field, precludes the isolation of the potential causes. We used standard propagation techniques (grafting and air-layering) to decouple the effects of size from those of age in affecting leaf structure, biochemistry and physiology of two broadleaved trees, Acer pseudoplatanus (a diffuse-porous species) and Fraxinus excelsior (a ring-porous species). The first year after establishment of the propagated plants, some of the measurements suggested the presence of age-related declines in metabolism, while other measurements either did not show any difference or suggested variability across treatments not associated with either age or size. During the second year after establishment, only one of the measured properties (specific leaf area) continued to show some evidence of an age-mediated decline (although much reduced compared to the field), whereas, for some properties (particularly for F. excelsior), even the opposite trend of age-related increases was apparent. We concluded that (1) our plants suffered from grafting shock during year 1 and they gradually recovered during year 2; (2) the results over 2 years do not support the statement that age directly mediates ageing in either species but instead suggest that size directly mediates ageing processes; and (3) neither shoots nor roots of A. pseudoplatanus showed any evidence of senescence.
    Matched MeSH terms: Trees/physiology
  7. Zakaria N, Tarmizi AA, Zuki MAM, Ahmad AB, Mamat MA, Abdullah MT
    Data Brief, 2020 Jun;30:105567.
    PMID: 32382599 DOI: 10.1016/j.dib.2020.105567
    This data article is about bats observed from fragmented forest understories interspaced by agricultural plantations, utility corridors, and man-made structures within rural areas of Setiu (Bukit Kesing Forest Reserve and Ladang Tayor TDM) and Hulu Terengganu (Pengkalan Utama and Sungai Buweh, Kenyir) that are situated in Terengganu state, Peninsular Malaysia. Surveys were conducted from October 2018 until January 2019. These bats were captured using harp traps and mist nets that were set 30 m apart across flyways, streams, rivers and less cluttered trees in the 50 m transect zones (identified at each site). All animals captured were distinguished by morphology and released at the same location it was caught. The data comprise of 15 species of bats from four family groups, namely Hipposideridae, Pteropodidae, Rhinolophidae and Vespertilionidae. The data were interpreted into weight-forearm length (W-FA) to inform about bats Body Condition Index (-0.25 to 0.25).
    Matched MeSH terms: Trees
  8. Zaini Hamzah, Che Yasmin Amirudin, Seh Datul Riduan, Ahmad Saat
    MyJurnal
    137 Cs is well known man-made radionuclide produced from nuclear industry. Nuclear weapon tests and nuclear accidents had contributed to presence of 137 Cs into the worldwide environment including Malaysia. It has spread out to the entire world through the air and water current. Since Cameron Highlands is located at high altitude, there is a better chance of the 137 Cs to settle down on the trees and later the soil underneath. In this study, the soil samples were taken at the slopes of two different tea plantation areas namely A and B. The soil samples were oven dried, ground, sieved and packed and sealed properly in plastic containers before measurement. Each plastic container contains around 450 g of sample. The measurement of 137 Cs activity concentration was done using HPGe detector gamma spectrometer. The spectrum was analyzed using Gamma Vision software to calculate the activity concentration of 137 Cs with energy peak of 661.66 keV. The activity concentration of 137 Cs found in the samples ranged from 0.23 to 1.90 and 0.11 to 3.01 Bq/kg for tea plantation A and tea plantation B, respectively. From the activity concentration of 137 Cs result, it was comparable to the others research regarding to 137 Cs in the soil around Asian.
    Matched MeSH terms: Trees
  9. Zainal Baharum, Abdah Md Akim, Roslida Abdul Hamid, Taufiq Yap Yun Hin, Rosmin Kasran
    Trop Life Sci Res, 2016;27(1):21-42.
    MyJurnal
    Plants have been a good source of therapeutic agents for thousands of years;
    an impressive number of modern drugs used for treating human diseases are derived from
    natural sources. The Theobroma cacao tree, or cocoa, has recently garnered increasing
    attention and become the subject of research due to its antioxidant properties, which are
    related to potential anti-cancer effects. In the past few years, identifying and developing
    active compounds or extracts from the cocoa bean that might exert anti-cancer effects
    have become an important area of health- and biomedicine-related research. This review
    provides an updated overview of T. cacao in terms of its potential anti-cancer compounds
    and their extraction, in vitro bioassay, purification, and identification. This article also
    discusses the advantages and disadvantages of the techniques described and reviews the
    processes for future perspectives of analytical methods from the viewpoint of anti-cancer
    compound discovery.
    Matched MeSH terms: Trees
  10. Yusuf SNA, Rahman AMA, Zakaria Z, Subbiah VK, Masnan MJ, Wahab Z
    Trop Life Sci Res, 2020 Jul;31(2):107-143.
    PMID: 32922671 DOI: 10.21315/tlsr2020.31.2.6
    Harumanis is one of the main signatures of Perlis with regards to its delightful taste, pleasant aroma and expensive price. Harumanis authenticity and productivity had become the remarks among the farmers, entrepreneurs, consumers and plant breeders due to the existence of morphological characteristics variation among the fruits and high production cost. Assessment of Harumanis morphological characteristics of natural population and different tree ages may represent a possible source of important characteristics for development and breeding purposes of Harumanis. The aim of this study is to evaluate the morphological variation of Harumanis collected from different location in Perlis and tree age. A total of 150 Harumanis fruits from 50 trees with three different stages of development (young, middle-aged and old) were characterised using 11 traits; 10 quantitative and one qualitative morphological trait. The ANOVA analyses in combination with Dunn's pairwise and Kruskal-Wallis multiple comparison test able to point out the existence of environmental factor and age influence towards the significant different of identified morphological traits except for Total Soluble Solid (TSS) and pulp percentage. Five clusters of 50 Harumanis accessions reflect a grouping pattern which not according to neither geographical region nor age. The result of Principal Component Analysis (PCA) using the first two principal components (PCs) provided a good approximation of the data explaining 84.09% of the total variance which majorly contributed by parameters of weight, fruit dimensional characteristics, peel percentage and hue angle, h. Preliminary screening of important morphological characteristics which contribute to the phenotypic diversity of Harumanis is successfully achieved. The findings can be employed by the plant breeders and farmers for the establishment of standard grading of Harumanis and advancement of breeding crop of Harumanis in future.
    Matched MeSH terms: Trees
  11. Yusah KM, Foster WA, Reynolds G, Fayle TM
    PeerJ, 2018;6:e4231.
    PMID: 29423344 DOI: 10.7717/peerj.4231
    Background: Competitive interactions in biological communities can be thought of as giving rise to "assembly rules" that dictate the species that are able to co-exist. Ant communities in tropical canopies often display a particular pattern, an "ant mosaic", in which competition between dominant ant species results in a patchwork of mutually exclusive territories. Although ant mosaics have been well-documented in plantation landscapes, their presence in pristine tropical forests remained contentious until recently. Here we assess presence of ant mosaics in a hitherto under-investigated forest stratum, the emergent trees of the high canopy in primary tropical rain forest, and explore how the strength of any ant mosaics is affected by spatial scale, time of day, and sampling method.

    Methods: To test whether these factors might impact the detection of ant mosaics in pristine habitats, we sampled ant communities from emergent trees, which rise above the highest canopy layers in lowland dipterocarp rain forests in North Borneo (38.8-60.2 m), using both baiting and insecticide fogging. Critically, we restricted sampling to only the canopy of each focal tree. For baiting, we carried out sampling during both the day and the night. We used null models of species co-occurrence to assess patterns of segregation at within-tree and between-tree scales.

    Results: The numerically dominant ant species on the emergent trees sampled formed a diverse community, with differences in the identity of dominant species between times of day and sampling methods. Between trees, we found patterns of ant species segregation consistent with the existence of ant mosaics using both methods. Within trees, fogged ants were segregated, while baited ants were segregated only at night.

    Discussion: We conclude that ant mosaics are present within the emergent trees of the high canopy of tropical rain forest in Malaysian Borneo, and that sampling technique, spatial scale, and time of day interact to determine observed patterns of segregation. Restricting sampling to only emergent trees reveals segregatory patterns not observed in ground-based studies, confirming previous observations of stronger segregation with increasing height in the canopy.

    Matched MeSH terms: Trees
  12. Yule CM, Lim YY, Lim TY
    Carbon Balance Manag, 2018 Feb 07;13(1):3.
    PMID: 29417248 DOI: 10.1186/s13021-018-0092-6
    BACKGROUND: Tropical peat swamp forests (TPSF) are globally significant carbon stores, sequestering carbon mainly as phenolic polymers and phenolic compounds (particularly as lignin and its derivatives) in peat layers, in plants, and in the acidic blackwaters. Previous studies show that TPSF plants have particularly high levels of phenolic compounds which inhibit the decomposition of organic matter and thus promote peat accumulation. The studies of phenolic compounds are thus crucial to further understand how TPSF function with respect to carbon sequestration. Here we present a study of cycling of phenolic compounds in five forests in Borneo differing in flooding and acidity, leaching of phenolic compounds from senescent Macaranga pruinosa leaves, and absorption of phenolics by M. pruinosa seedlings.

    RESULTS: The results of the study show that total phenolic content (TPC) in soil and leaves of three species of Macaranga were highest in TPSF followed by freshwater swamp forest and flooded limestone forest, then dry land sites. Highest TPC values were associated with acidity (in TPSF) and waterlogging (in flooded forests). Moreover, phenolic compounds are rapidly leached from fallen senescent leaves, and could be reabsorbed by tree roots and converted into more complex phenolics within the leaves.

    CONCLUSIONS: Extreme conditions-waterlogging and acidity-may facilitate uptake and synthesis of protective phenolic compounds which are essential for impeded decomposition of organic matter in TPSF. Conversely, the ongoing drainage and degradation of TPSF, particularly for conversion to oil palm plantations, reverses the conditions necessary for peat accretion and carbon sequestration.

    Matched MeSH terms: Trees
  13. Yee LK, Abbas Z, Jusoh MA, Yeow YK, Meng CE
    Sensors (Basel), 2011;11(4):4073-85.
    PMID: 22163837 DOI: 10.3390/s110404073
    This paper presents the development of a PC-based microwave five-port reflectometer for the determination of moisture content in oil palm fruits. The reflectometer was designed to measure both the magnitude and phase of the reflection coefficient of any passive microwave device. The stand-alone reflectometer consists of a PC, a microwave source, diode detectors and an analog to digital converter. All the measurement and data acquisition were done using Agilent VEE graphical programming software. The relectometer can be used with any reflection based microwave sensor. In this work, the application of the reflectometer as a useful instrument to determine the moisture content in oil palm fruits using monopole and coaxial sensors was demonstrated. Calibration equations between reflection coefficients and moisture content have been established for both sensors. The equation based on phase measurement of monopole sensor was found to be accurate within 5% in predicting moisture content in the fruits when compared to the conventional oven drying method.
    Matched MeSH terms: Trees/chemistry
  14. Yamashita S, Hattori T, Ohkubo T, Nakashizuka T
    Mycol. Res., 2009 Oct;113(Pt 10):1200-7.
    PMID: 19682573 DOI: 10.1016/j.mycres.2009.08.004
    The spatial distribution of basidiocarps provides much information on the dispersal abilities, habitat preferences, and inter- and intraspecific interactions of aphyllophoraceous fungi. To reveal the spatial distribution and resource utilization patterns of aphyllophoraceous fungi in Malaysia, we conducted field observations in a primary forest in 2006 and analyzed the relationships between the abundance of eight dominant fungal species and various environmental factors. The topographical characteristics were significantly patchily distributed at the 100-m scale, whereas woody debris and most fungal species were distributed randomly. Although the dominant fungal species differed among the decay classes and diameters of the woody debris, the abundance of a few dominant species was significantly correlated with environmental factors. Although the latter factors might affect the spatial distribution of these fungi, the effects appear to be so small that they would not create an aggregated distribution at a few 100-m scales.
    Matched MeSH terms: Trees/microbiology*
  15. Yamamoto S, Maruyama M
    Zookeys, 2013.
    PMID: 24146571 DOI: 10.3897/zookeys.336.5382
    Tetrasticta gnatha sp. n., collected under the bark of a rotten fallen tree in Peninsular Malaysia, is described. A habitus photograph, line drawings of diagnostic characters, and a diagnosis are provided. The new species is readily distinguished from all known congeners by having long mandibles, and long, curved maxillary palpi.
    Matched MeSH terms: Trees
  16. Yamada T, Yamada Y, Okuda T, Fletcher C
    Oecologia, 2013 Jul;172(3):713-24.
    PMID: 23183820 DOI: 10.1007/s00442-012-2529-z
    Differences in the density of conspecific tree individuals in response to environmental gradients are well documented for many tree species, but how such density differences are generated and maintained is poorly understood. We examined the segregation of six dipterocarp species among three soil types in the Pasoh tropical forest, Malaysia. We examined how individual performance and population dynamics changed across the soil types using 10-year demographic data to compare tree performance across soil types, and constructed population matrix models to analyze the population dynamics. Species showed only minor changes in mortality and juvenile growth across soil types, although recruitment differed greatly. Clear, interspecific demographic trade-offs between growth and mortality were found in all soil types. The relative trade-offs by a species did not differ substantially among the soil types. Population sizes were projected to remain stable in all soil types for all species with one exception. Our life-table response experiment demonstrated that the population dynamics of a species differed only subtly among soil types. Therefore, species with strong density differences across soil types do not necessarily differ greatly in their population dynamics across the soil types. In contrast, interspecific differences in population dynamics were large. The trade-off between mortality and growth led to a negative correlation between the contributions of mortality and growth to variations in the population growth rate (λ) and thus reduced their net contributions. Recruitment had little impact on the variation in λ. The combination of these factors resulted in little variation in λ among species.
    Matched MeSH terms: Trees/growth & development; Trees/physiology*
  17. Yamada K
    Zootaxa, 2014;3847(2):292-6.
    PMID: 25112341 DOI: 10.11646/zootaxa.3847.2.9
    Scoloposcelis seidaii sp. nov. is described from the Malay Peninsula based on a single specimen collected under the bark of a decaying tree. This discovery represents the first distribution record of the genus Scoloposcelis from Malaysia. Habitus photographs and diagnosis of S. parallela (Motschulsky, 1863) are provided for comparison with S. seidaii. 
    Matched MeSH terms: Trees
  18. Yahya MS, Syafiq M, Ashton-Butt A, Ghazali A, Asmah S, Azhar B
    Ecol Evol, 2017 08;7(16):6314-6325.
    PMID: 28861235 DOI: 10.1002/ece3.3205
    Monoculture farming is pervasive in industrial oil palm agriculture, including those RSPO plantations certified as sustainably managed. This farming practice does not promote the maintenance of farmland biodiversity. However, little scientific attention has been given to polyculture farming in oil palm production landscapes. Polyculture farming is likely to increase the floristic diversity and stand structural complexity that underpins biodiversity. Mist nets were used to sample birds at 120 smallholdings in Peninsular Malaysia. At each site, 12 vegetation structure characteristics were measured. We compared bird species richness, abundance, and composition between monoculture and polyculture smallholdings and used predictive models to examine the effects of habitat quality on avian biodiversity. Bird species richness was significantly greater in polyculture than that of monoculture smallholdings. The number of fallen and standing, dead oil palms were also important positive predictors of species richness. Bird abundance was also strongly increased by standing and dead oil palms and decreased with oil palm stand height. Our results indicate that polyculture farming can improve bird species richness in oil palm production landscapes. In addition, key habitat variables that are closely associated with farming practices, such as the removal of dead trees, should and can be managed by oil palm growers in order to promote biodiversity. To increase the sustainability of oil palm agriculture, it is imperative that stakeholders modify the way oil palms are currently planted and managed. Our findings can guide policy makers and certification bodies to promote oil palm production landscapes that will function more sustainably and increase existing biodiversity of oil palm landscapes.
    Matched MeSH terms: Trees
  19. Ya'cob Z, Takaoka H, Pramual P, Low VL, Sofian-Azirun M
    Acta Trop, 2016 Jan;153:57-63.
    PMID: 26476394 DOI: 10.1016/j.actatropica.2015.10.007
    To investigate the breeding habitat preference of black flies, a comprehensive black fly survey was conducted for the first time in Peninsular Malaysia. Preimaginal black flies (pupae and larvae) were collected manually from 180 stream points encompassing northern, southern, central and east coast of the Peninsular Malaysia. A total of 47 black fly species were recorded in this study. The predominant species were Simulium trangense (36.7%) and Simulium angulistylum (33.3%). Relatively common species were Simulium cheongi (29.4%), Simulium tani (25.6%), Simulium nobile (16.2%), Simulium sheilae (14.5%) and Simulium bishopi (10.6%). Principal Component Analysis (PCA) of all stream variables revealed four PCs that accounted for 69.3% of the total intersite variance. Regression analysis revealed that high species richness is associated with larger, deeper, faster and higher discharge streams with larger streambed particles, more riparian vegetation and low pH (F=22.7, d.f.=1, 173; P<0.001). Relationship between species occurrence of seven common species (present in >10% of the sampling sites) was assessed. Forward logistic regression analysis indicated that four species were significantly related to the stream variables. S. nobile and S. tani prefer large, fast flowing streams with higher pH, large streambed particles and riparian trees. S. bishopi was commonly found at high elevation with cooler stream, low conductivity, higher conductivity and more riparian trees. In contrast, S. sheilae was negatively correlated with PC-2, thus, this species commonly found at low elevation, warmer stream with low conductivity and less riparian trees. The results of this study are consistent with previous studies from other geographic regions, which indicated that both physical and chemical stream conditions are the key factors for black fly ecology.
    Matched MeSH terms: Trees
  20. Xu H, Detto M, Fang S, Chazdon RL, Li Y, Hau BCH, et al.
    Commun Biol, 2020 06 19;3(1):317.
    PMID: 32561898 DOI: 10.1038/s42003-020-1041-y
    Legumes provide an essential service to ecosystems by capturing nitrogen from the atmosphere and delivering it to the soil, where it may then be available to other plants. However, this facilitation by legumes has not been widely studied in global tropical forests. Demographic data from 11 large forest plots (16-60 ha) ranging from 5.25° S to 29.25° N latitude show that within forests, leguminous trees have a larger effect on neighbor diversity than non-legumes. Where soil nitrogen is high, most legume species have higher neighbor diversity than non-legumes. Where soil nitrogen is low, most legumes have lower neighbor diversity than non-legumes. No facilitation effect on neighbor basal area was observed in either high or low soil N conditions. The legume-soil nitrogen positive feedback that promotes tree diversity has both theoretical implications for understanding species coexistence in diverse forests, and practical implications for the utilization of legumes in forest restoration.
    Matched MeSH terms: Trees*
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