8 research outputs found
Land use effects on Ephemeroptera, Plecoptera, and Trichoptera (EPT) communities in RanauBeluran District, Sabah, Malaysia
Ephemeroptera, Plecoptera, and Trichoptera (EPT) are particularly sensitive and well suited as bioindicators for monitoring stream health. This study aims to investigate the EPT communities between disturbed and undisturbed areas of Ranau-Beluran District. Based on National Water Quality Standards of Malaysia, the sampled streams were categorized as Class I and II of water classes. Nonparametric MannWhitney test showed that only canopy cover was significantly different between disturbed and undisturbed sites. The sampled insects were dominated by Ephemeroptera (80.42%), followed by Plecoptera (14%) and Trichoptera order (5.58%). The Leptophlebiid family was the most abundant (44.82%). Family richness, the Simpson’s and Shannon-Weiner diversity indices all showed similar trends, EPT diversity being lower in disturbed sites. The diversity of EPT was strongly related to canopy cover
Diversity of aquatic macroinvertebrate assemblages and their functional feeding groups in the streams of Kota Marudu, Sabah.
Increasing human activities at Kota Marudu (an economic and agricultural hub of northern Sabah) affects water quality and related ecosystem services. However, the impacts of these human activities on the aquatic biological assemblages in tropical streams were poorly understood. Thus, the objective of this study was to determine the biological diversity and functional feeding groups of aquatic macroinvertebrate assemblages of some streams near different types of land use. Water samples and aquatic macroinvertebrates were collected from 6 streams, in 6 sampling trips. A total of 22994 individuals were identified with 136 genera and 17 orders corresponding to 3 main faunal phyla (Annelida, Mollusca, Arthropoda). Biodiversity indices and biotic indices showed significant spatial differentiation. The biodiversity of aquatic macroinvertebrate assemblages was highest at forested streams and lowest at streams from agricultural lands. In addition, the functional feeding groups also showed significant differences between the forested streams and human-disturbed rivers. Shredders and predators were more abundant in forested streams. In general, land use is an important factor influencing the structure of aquatic communities
Variable responses of individual species to tropical forest degradation
The functional stability of ecosystems depends greatly on interspecific differences in responses to environmental perturbation. However, responses to perturbation are not necessarily invariant among populations of the same species, so intraspecific variation in responses might also contribute. Such inter-population response diversity has recently been shown to occur spatially across species ranges, but we lack estimates of the extent to which individual populations across an entire community might have perturbation responses that vary through time. We assess this using 524 taxa that have been repeatedly surveyed for the effects of tropical forest logging at a focal landscape in Sabah, Malaysia. Just 39 % of taxa – all with non-significant responses to forest degradation – had invariant responses. All other taxa (61 %) showed significantly different responses to the same forest degradation gradient across surveys, with 6 % of taxa responding to forest degradation in opposite directions across multiple surveys. Individual surveys had low power (< 80 %) to determine the correct direction of response to forest degradation for one-fifth of all taxa. Recurrent rounds of logging disturbance increased the prevalence of intra-population response diversity, while uncontrollable environmental variation and/or turnover of intraspecific phenotypes generated variable responses in at least 44 % of taxa. Our results show that the responses of individual species to local environmental perturbations are remarkably flexible, likely providing an unrealised boost to the stability of disturbed habitats such as logged tropical forests
Thresholds for adding degraded tropical forest to the conservation estate
Logged and disturbed forests are often viewed as degraded and depauperate environments compared with primary forest. However, they are dynamic ecosystems1 that provide refugia for large amounts of biodiversity2,3, so we cannot afford to underestimate their conservation value4. Here we present empirically defined thresholds for categorizing the conservation value of logged forests, using one of the most comprehensive assessments of taxon responses to habitat degradation in any tropical forest environment. We analysed the impact of logging intensity on the individual occurrence patterns of 1,681 taxa belonging to 86 taxonomic orders and 126 functional groups in Sabah, Malaysia. Our results demonstrate the existence of two conservation-relevant thresholds. First, lightly logged forests (68%) of their biomass removed, and these are likely to require more expensive measures to recover their biodiversity value. Overall, our data confirm that primary forests are irreplaceable5, but they also reinforce the message that logged forests retain considerable conservation value that should not be overlooked
Thresholds for adding degraded tropical forest to the conservation estate
Logged and disturbed forests are often viewed as degraded and depauperate environments compared with primary forest. However, they are dynamic ecosystems1 that provide refugia for large amounts of biodiversity2,3, so we cannot afford to underestimate their conservation value4. Here we present empirically defined thresholds for categorizing the conservation value of logged forests, using one of the most comprehensive assessments of taxon responses to habitat degradation in any tropical forest environment. We analysed the impact of logging intensity on the individual occurrence patterns of 1,681 taxa belonging to 86 taxonomic orders and 126 functional groups in Sabah, Malaysia. Our results demonstrate the existence of two conservation-relevant thresholds. First, lightly logged forests (68%) of their biomass removed, and these are likely to require more expensive measures to recover their biodiversity value. Overall, our data confirm that primary forests are irreplaceable5, but they also reinforce the message that logged forests retain considerable conservation value that should not be overlooked
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Thresholds for adding degraded tropical forest to the conservation estate.
Acknowledgements: This study was supported by funding to the Stability of Altered Forest Ecosystems Project by the Sime Darby Foundation. Research permission and site access were provided by the Maliau Basin Management Committee, the Sabah Foundation, Benta Wawasan, Sabah Softwoods, the Innoprise Foundation, the Sabah Forestry Department and the Sabah Biodiversity Centre. R.M.E. is supported by the NOMIS Foundation. Data collection was financed by Australian Research Council grant DP140101541; Bat Conservation International; the British Council Newton-Ungku Omar Fund 216433953; British Ecological Society grant 3256/4035; the Cambridge Trust; the Cambridge University Commonwealth Fund; the Czech Science Foundation (14-32302S); the European Research Council (281986); the European Social Fund and the Czech Republic (CZ.1.07/2.3.00/20.0064); the Fundamental Research Grant Scheme (FRG0302-STWN-1/ 2011), Ministry of Higher Education, Malaysia; FFWS CZU (IGA number A_26_22); the Jardine Foundation; Malaysia Industry Group for High Technology (216433953); the Ministry of Education, Youth and Sports of the Czech Republic (INTER-TRANSFER LTT19018); the Panton Trust; the Primate Society of Great Britain; ProForest; Royal Society of London grant RG130793; the Sime Darby Foundation; the S. T. Lee Fund; the Sir Philip Reckitt Educational Trust; the Tim Whitmore Fund; the Universiti Malaysia Sabah; the University of East Anglia; the University of Kent; the University of Florida Institute of Food and Agricultural Sciences; UK Research and Innovation Natural Environment Research Council grants NE/H011307/1, NE/K016253/1, NE/K016407/1, NE/K016148/1, NE/K0106261/1, NE/K015377/1, NE/L002515/1, NE/L002582/1 and NE/P00363X/1 and studentship 1122589; the Varley Gradwell Travelling Fellowship; and the World Wildlife Fund for Nature. Data collection was supported by R. Adzhar, A. Afendy, N. Arumugam, S. Benedick, V. Bignet, S. Butler, K. Graves, H. E. Hah, H. Heroin, A. Kendall, H. H. Mahsol, D. Mann, J. Miller, S. Milne, J. Mumford, D. Norman, H. Rossleykho, D. Shapiro, K. Sieving, J. Sugau, B. Udell, B. E. Yahya and M. A. Zakaria.Logged and disturbed forests are often viewed as degraded and depauperate environments compared with primary forest. However, they are dynamic ecosystems1 that provide refugia for large amounts of biodiversity2,3, so we cannot afford to underestimate their conservation value4. Here we present empirically defined thresholds for categorizing the conservation value of logged forests, using one of the most comprehensive assessments of taxon responses to habitat degradation in any tropical forest environment. We analysed the impact of logging intensity on the individual occurrence patterns of 1,681 taxa belonging to 86 taxonomic orders and 126 functional groups in Sabah, Malaysia. Our results demonstrate the existence of two conservation-relevant thresholds. First, lightly logged forests (68%) of their biomass removed, and these are likely to require more expensive measures to recover their biodiversity value. Overall, our data confirm that primary forests are irreplaceable5, but they also reinforce the message that logged forests retain considerable conservation value that should not be overlooked
Risk for Major Bleeding in Patients Receiving Ticagrelor Compared With Aspirin After Transient Ischemic Attack or Acute Ischemic Stroke in the SOCRATES Study (Acute Stroke or Transient Ischemic Attack Treated With Aspirin or Ticagrelor and Patient Outcomes)
Abstract: Background: Patients with minor acute ischemic stroke or transient ischemic attack are at high risk for subsequent stroke, and more potent antiplatelet therapy in the acute setting is needed. However, the potential benefit of more intense antiplatelet therapy must be assessed in relation to the risk for major bleeding. The SOCRATES trial (Acute Stroke or Transient Ischemic Attack Treated With Aspirin or Ticagrelor and Patient Outcomes) was the first trial with ticagrelor in patients with acute ischemic stroke or transient ischemic attack in which the efficacy and safety of ticagrelor were compared with those of aspirin. The main safety objective was assessment of PLATO (Platelet Inhibition and Patient Outcomes)\u2013defined major bleeds on treatment, with special focus on intracranial hemorrhage (ICrH). Methods: An independent adjudication committee blinded to study treatment classified bleeds according to the PLATO, TIMI (Thrombolysis in Myocardial Infarction), and GUSTO (Global Use of Strategies to Open Occluded Coronary Arteries) definitions. The definitions of ICrH and major bleeding excluded cerebral microbleeds and asymptomatic hemorrhagic transformations of cerebral infarctions so that the definitions better discriminated important events in the acute stroke population. Results: A total of 13 130 of 13 199 randomized patients received at least 1 dose of study drug and were included in the safety analysis set. PLATO major bleeds occurred in 31 patients (0.5%) on ticagrelor and 38 patients (0.6%) on aspirin (hazard ratio, 0.83; 95% confidence interval, 0.52\u20131.34). The most common locations of major bleeds were intracranial and gastrointestinal. ICrH was reported in 12 patients (0.2%) on ticagrelor and 18 patients (0.3%) on aspirin. Thirteen of all 30 ICrHs (4 on ticagrelor and 9 on aspirin) were hemorrhagic strokes, and 4 (2 in each group) were symptomatic hemorrhagic transformations of brain infarctions. The ICrHs were spontaneous in 6 and 13, traumatic in 3 and 3, and procedural in 3 and 2 patients on ticagrelor and aspirin, respectively. In total, 9 fatal bleeds occurred on ticagrelor and 4 on aspirin. The composite of ICrH or fatal bleeding included 15 patients on ticagrelor and 18 on aspirin. Independently of bleeding classification, PLATO, TIMI, or GUSTO, the relative difference between treatments for major/severe bleeds was similar. Nonmajor bleeds were more common on ticagrelor. Conclusions: Antiplatelet therapy with ticagrelor in patients with acute ischemic stroke or transient ischemic attack showed a bleeding profile similar to that of aspirin for major bleeds. There were few ICrHs. Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01994720.Abstract: BACKGROUND: Patients with minor acute ischemic stroke or transient ischemic attack are at high risk for subsequent stroke, and more potent antiplatelet therapy in the acute setting is needed. However, the potential benefit of more intense antiplatelet therapy must be assessed in relation to the risk for major bleeding. The SOCRATES trial (Acute Stroke or Transient Ischemic Attack Treated With Aspirin or Ticagrelor and Patient Outcomes) was the first trial with ticagrelor in patients with acute ischemic stroke or transient ischemic attack in which the efficacy and safety of ticagrelor were compared with those of aspirin. The main safety objective was assessment of PLATO (Platelet Inhibition and Patient Outcomes)-defined major bleeds on treatment, with special focus on intracranial hemorrhage (ICrH). METHODS: An independent adjudication committee blinded to study treatment classified bleeds according to the PLATO, TIMI (Thrombolysis in Myocardial Infarction), and GUSTO (Global Use of Strategies to Open Occluded Coronary Arteries) definitions. The definitions of ICrH and major bleeding excluded cerebral microbleeds and asymptomatic hemorrhagic transformations of cerebral infarctions so that the definitions better discriminated important events in the acute stroke population. RESULTS: A total of 13 130 of 13 199 randomized patients received at least 1 dose of study drug and were included in the safety analysis set. PLATO major bleeds occurred in 31 patients (0.5%) on ticagrelor and 38 patients (0.6%) on aspirin (hazard ratio, 0.83; 95% confidence interval, 0.52-1.34). The most common locations of major bleeds were intracranial and gastrointestinal. ICrH was reported in 12 patients (0.2%) on ticagrelor and 18 patients (0.3%) on aspirin. Thirteen of all 30 ICrHs (4 on ticagrelor and 9 on aspirin) were hemorrhagic strokes, and 4 (2 in each group) were symptomatic hemorrhagic transformations of brain infarctions. The ICrHs were spontaneous in 6 and 13, traumatic in 3 and 3, and procedural in 3 and 2 patients on ticagrelor and aspirin, respectively. In total, 9 fatal bleeds occurred on ticagrelor and 4 on aspirin. The composite of ICrH or fatal bleeding included 15 patients on ticagrelor and 18 on aspirin. Independently of bleeding classification, PLATO, TIMI, or GUSTO, the relative difference between treatments for major/severe bleeds was similar. Nonmajor bleeds were more common on ticagrelor. CONCLUSIONS: Antiplatelet therapy with ticagrelor in patients with acute ischemic stroke or transient ischemic attack showed a bleeding profile similar to that of aspirin for major bleeds. There were few ICrHs