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A. Cole Burton 《Biodiversity and Conservation》2012,21(12):3079-3094
Effective monitoring programs are required to understand and mitigate biodiversity declines, particularly in tropical ecosystems where conservation conflicts are severe yet ecological data are scarce. “Locally-based” monitoring has been advanced as an approach to improve biodiversity monitoring in developing countries, but the accuracy of data from many such programs has not been adequately assessed. I evaluated a long-term, patrol-based wildlife monitoring system in Mole National Park, Ghana, through comparison with camera trapping and an assessment of sampling error. I found that patrol observations underrepresented the park’s mammal community, recording only two-thirds as many species as camera traps over a common sampling period (2006–2008). Agreement between methods was reasonable for larger, diurnal and social species (e.g., larger ungulates and primates), but camera traps were more effective at detecting smaller, solitary and nocturnal species (particularly carnivores). Data from patrols and cameras corresponded for some spatial patterns of management interest (e.g., community turnover, edge effect on abundance) but differed for others (e.g., richness, edge effect on diversity). Long-term patrol observations were influenced by uneven sampling effort and considerable variation in replicate counts. Despite potential benefits of locally-based monitoring, these results suggest that data from this and similar programs may be subject to biases that complicate interpretation of wildlife population and community dynamics. Careful attention to monitoring objectives, methodological design and robust analysis is required if locally-based approaches are to satisfy an aim of reliable biodiversity monitoring, and there is a need for greater international support in the creation and maintenance of local monitoring capacity. 相似文献
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Ecological relationships between stream communities and spatial scale: implications for designing catchment-level monitoring programmes 总被引:5,自引:0,他引:5
RICHARD K. JOHNSON MIKE T. FURSE DANIEL HERING LEONARD SANDIN 《Freshwater Biology》2007,52(5):939-958
1. Stream communities are structured by factors acting over multiple spatial and temporal scales. Identifying what factors are driving spatial patterns in stream communities is a central aim of ecology.
2. Here we used two large European data sets of fish, invertebrates, macrophytes, benthic diatoms and environmental data in two stream groups (lowland and mountain) to determine the importance of variables at different spatial scales (geographical, regional, local) on community structure.
3. Both geographical position and ecoregion were selected first in canonical correspondence analysis (CCA), clearly showing the broad spatial gradients covered in the data set. Secondary predictors (after accounting for spatial and/or ecoregion effects) were similar between stream groups and among the four organism groups. In particular, conductivity and N concentration were strong predictors reflecting catchment land use.
4. Using partial CCA, we assessed the individual importance of the three spatial scales on the community structure of the four organism groups in the two stream groups. The majority of among-site variability (22–29%) was accounted for by local scale variables (e.g. water chemistry and substratum type), with regional and spatial variables accounting 11–13% and 5–6%, respectively. Our findings indicate that the four organism groups are responding similarly to the different levels of spatial scale, implying much redundancy which should be consider when implementing studies of bioassessment. 相似文献
2. Here we used two large European data sets of fish, invertebrates, macrophytes, benthic diatoms and environmental data in two stream groups (lowland and mountain) to determine the importance of variables at different spatial scales (geographical, regional, local) on community structure.
3. Both geographical position and ecoregion were selected first in canonical correspondence analysis (CCA), clearly showing the broad spatial gradients covered in the data set. Secondary predictors (after accounting for spatial and/or ecoregion effects) were similar between stream groups and among the four organism groups. In particular, conductivity and N concentration were strong predictors reflecting catchment land use.
4. Using partial CCA, we assessed the individual importance of the three spatial scales on the community structure of the four organism groups in the two stream groups. The majority of among-site variability (22–29%) was accounted for by local scale variables (e.g. water chemistry and substratum type), with regional and spatial variables accounting 11–13% and 5–6%, respectively. Our findings indicate that the four organism groups are responding similarly to the different levels of spatial scale, implying much redundancy which should be consider when implementing studies of bioassessment. 相似文献
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Studies on the response of wildlife to human disturbance generally focus on demographic changes or on physiological and behavioural modifications directly related to stress response. Yet fewer studies have explored whether the distribution of individual animals in response to human disturbance is influenced by temperament. Temperament represents the consistency of responses of individuals in reaction to novel or challenging situations. Individuals are thus assumed to express highly consistent behaviour-hormonal response under specific stress conditions. In this study, we investigate the relations between exploration, grooming-scanning continuum, emotionality, and docility of individual Eastern chipmunks (Tamias striatus) and location of their burrow respective to frequentation by humans. We then assess the relationship between cortisol accumulated in the hair and both temperament and frequentation by humans. Explorative or docile chipmunks were more common in frequented areas. Hair cortisol increased with docility, but was not related to human frequentation. These results indicate that temperament may cause animals to distribute themselves in a non-random way in response to human disturbance. Integrating temperament into studies of the stress response of wildlife to humans could therefore help us understand the impact of tourism on wildlife. 相似文献
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Howarth SJ Allison AE Grenier SG Cholewicki J McGill SM 《Journal of biomechanics》2004,37(8):1147-1154
Quantifying the stability of the spinal column offers a perspective on the effectiveness of the motor control strategy to ensure a stable spine--and minimize the risk of injury from experiencing an unstable event. There are essentially three energy based methods of calculating a stability index for the lumbar spine. All three methods involve mathematical manipulation of an 18 x 18 Hessian matrix. The purpose of this paper was to consider the mathematical implications for the three methods of determining a single stability index, and examine the effects of biological factors such as muscle activation in each of these methods. The first approach computes the Hessian's determinant and is thought to represent a more global or "average" perspective on stability. A second approach computes the smallest eigenvalue of the Hessian matrix to determine the weakest link of the spine. The final method determines an average critical stiffness difference for the spine and is intended to effectively determines how far a human spine is from instability, and allows comparison between tasks. This study shows that the same interpretation of stability is achieved via all three computational approaches--they agree as to whether the spine is stable or not. However they appear to differ in their sensitivity to the effect of muscle activation patterns. 相似文献
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CHRISTIAN K. FELD 《Freshwater Biology》2013,58(4):715-729
1. Although many studies have focussed on the effects of catchment land use on lotic systems, the importance of broad (catchment) and fine (segment/reach) scale effects on stream assemblages remain poorly understood. 2. Nine biological metrics for macrophytes (498 sites), benthic macroinvertebrates (491) and fish (478) of lowland and mountain streams in four ecoregions of France and Germany were related to catchment and riparian buffer land use using partial Redundancy Analysis and Boosted Regression Trees (BRTs). 3. Lotic fauna was better correlated (mean max., r = 0.450) than flora (r = 0.277) to both scales of land use: the strongest correlations were noted for mountain streams. BRTs revealed strong non‐linear relationships between mountain assemblage metrics and land use. Correlations increased with increasing buffer lengths, suggesting the importance of near‐stream land use on biotic assemblages. 4. Several metrics changed markedly between 10–20% (mountain ecoregions) and 40–45% (lowland) of arable land use, irrespective of the buffer size. At mountain sites with >10% catchment arable land use, metric values differed between sites with <30% and sites with >30% forest in the near‐stream riparian area. 5. These findings support the role of riparian land use in catchment management; however, differences between mountain and lowland ecoregions support the need for ecoregion‐specific management. 相似文献
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Edna Cabecinha Paul J. Van den Brink João Alexandre Cabral Rui Cortes Martinho Lourenço Miguel Ângelo Pardal 《Hydrobiologia》2009,628(1):27-45
Phytoplankton communities are structured by factors acting over temporal and spatial scales. Identifying which factors are
driving spatial patterns in aquatic communities is the central aim of ecology. In this study, data sets of phytoplankton communities
and environmental data of two Portuguese reservoirs types (lowland “riverine reservoirs” and higher altitude “artificial lake
reservoirs”) were used to determine the importance of environmental variables at different spatial (geographical, regional
and local) and time scales (seasons, years) on the community structure. In all the data sets, the multivariate ordination
technique Canonical Correspondence Analysis (CCA) showed that regional and local scales explained the majority (9–18% and
13–19%, respectively) of the taxa variance. However, for “riverine reservoirs”, time variables were more important, explaining 27% of the variability in phytoplankton
assemblages. Variance partitioning was used to assess the individual importance of the three spatial scales and time for the
community structure of the two reservoir types. The majority of among-site variability (5.9–21.4%) was accounted for by time
variables, with local, regional, and geographical scale variables accounting for 3.3–5.6%, 3.7–4.5% and 2.6–2.9%, respectively.
The effects of different spatial scales on phytoplankton communities were clearly interrelated; thus, implying that phytoplankton
assemblages are capable of detecting stress from catchment to site scales.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Handling editor: J. Padisak 相似文献
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A new system of monitoring remote wildlife via the Internet was developed. The system consists of a QuickTime streaming server with a digital PC camera and a recipient computer with monitoring software. Results of field experiments were fine. Wildlife (raccoon dogs and feral cats) inhabiting a forest remote from the observer were monitored and photographed automatically when detected. Data and frame rates were 35–300 kilobits per second and 3–14 frames per second, respectively, depending on the network traffic. This system is applicable wherever a broadband network is available and thus has great potential for ecological research. 相似文献
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Brinkhof MW Spycher BD Yiannoutsos C Weigel R Wood R Messou E Boulle A Egger M Sterne JA;International epidemiological Database to Evaluate AIDS 《PloS one》2010,5(11):e14149
Background
Evaluation of antiretroviral treatment (ART) programmes in sub-Saharan Africa is difficult because many patients are lost to follow-up. Outcomes in these patients are generally unknown but studies tracing patients have shown mortality to be high. We adjusted programme-level mortality in the first year of antiretroviral treatment (ART) for excess mortality in patients lost to follow-up.Methods and Findings
Treatment-naïve patients starting combination ART in five programmes in Côte d''Ivoire, Kenya, Malawi and South Africa were eligible. Patients whose last visit was at least nine months before the closure of the database were considered lost to follow-up. We filled missing survival times in these patients by multiple imputation, using estimates of mortality from studies that traced patients lost to follow-up. Data were analyzed using Weibull models, adjusting for age, sex, ART regimen, CD4 cell count, clinical stage and treatment programme. A total of 15,915 HIV-infected patients (median CD4 cell count 110 cells/µL, median age 35 years, 68% female) were included; 1,001 (6.3%) were known to have died and 1,285 (14.3%) were lost to follow-up in the first year of ART. Crude estimates of mortality at one year ranged from 5.7% (95% CI 4.9–6.5%) to 10.9% (9.6–12.4%) across the five programmes. Estimated mortality hazard ratios comparing patients lost to follow-up with those remaining in care ranged from 6 to 23. Adjusted estimates based on these hazard ratios ranged from 10.2% (8.9–11.6%) to 16.9% (15.0–19.1%), with relative increases in mortality ranging from 27% to 73% across programmes.Conclusions
Naïve survival analysis ignoring excess mortality in patients lost to follow-up may greatly underestimate overall mortality, and bias ART programme evaluations. Adjusted mortality estimates can be obtained based on excess mortality rates in patients lost to follow-up. 相似文献13.
Persistence and stability of macroinvertebrate communities in streams of Denali National Park, Alaska: implications for biological monitoring 总被引:3,自引:0,他引:3
1. Macroinvertebrate communities were studied from 1994 to 2001/2002 (except 1997) in six streams in Denali National Park, interior Alaska. All six streams were potential reference streams with no known impairment. 2. Abundance of individual taxa varied markedly from year to year. Overall, abundance decreased over the study period, particularly with respect to mayflies. Stonefly taxa showed lower persistence and were sometimes absent from a stream in any particular year. 3. Mean community persistence for the six streams, as measured by Jaccard's similarity coefficients between years, varied from 0.48 in the year pair 1999–2000 to 0.78 in 1998–99. Tattler Creek (a small stable stream) supported the most persistent macroinvertebrate community and Highway Pass Creek (a small, unstable creek) the least. Mean community persistence showed a significant relationship with mean winter snowfall (November to March) for the six streams. 4. The highest community compositional stability was found in Tattler Creek and the lowest in Highway Pass Creek, but stability varied markedly over time for the six streams, peaking in 1994–95 and reaching a minimum in 2000–01. Compositional stability was significantly related to the Pfankuch Index of channel stability. 5. The composition metrics % Chironomidae, % dominant taxa, %EPT, % Ephemeroptera and % Plecoptera, employed as part of the Alaska Stream Condition Index, varied over almost their entire range in these pristine streams across the 9 years of the study. 6. This study demonstrates the wide range of natural variation that occurs in benthic macroinvertebrate communities in these pristine central Alaskan streams, potentially limiting the applicability of composition metrics for the biological monitoring of water quality in these systems. 相似文献
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Burkina Faso, Mali and Niger are countries endemic for schistosomiasis, with a high predominance of Schistosoma haematobium. With the support of the Bill and Melinda Gates Foundation through the Schistosomiasis Control Initiative, national control programmes were launched in these countries in 2004. Here, we describe the progress of implementation for each programme and the challenges for maintaining sustainability for schistosomiasis control in these countries. 相似文献
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Analysis of proton release in oxygen binding by hemoglobin: implications for the cooperative mechanism 总被引:6,自引:0,他引:6
The relationship in hemoglobin between cooperativity (dependence of the Hill constant on pH0 and the Bohr effect (dependence of the mean oxygen affinity on pH) can be described by a statistical thermodynamic model [Szabo, A., & Karplus, M. (1972) J. Mol. Biol. 72, 163-197; Lee, A., & Karplus, M. (1983) Proc. Natl. Acad. Sci. U.S.A. 80, 7055-759]. In this model, salt bridges and other interactions serve to couple tertiary and quaternary structural changes. To test and refine the model, it is applied to the analysis of the pH dependence of the tetramer Adair constants corrected for statistical factors (K4i', i = 1-4). Attention is focused on the proton release of the first (delta H1+ = alpha log K41'/alpha pH) and last (delta H4+ = alpha log K44'/alpha pH) oxygenation steps, where K4i' are the Adair constants corrected for statistical factors. Measurements of delta H1+ and delta H4+ under carefully controlled conditions are reported, and good agreement between the model calculation and these experimental results is obtained. The salt bridges are found to be partially coupled to the ligation state in the deoxy quaternary structure; it is shown that a Monod-Wyman-Changeux-type model, in which the salt bridges are coupled only to quaternary structural change, is inconsistent with the data for delta H1. The significance of the present analysis for an evaluation of the Perutz mechanism [Perutz, M.F. (1970) Nature (London) 228, 726-734, 734-739] and other models for hemoglobin cooperativity is discussed. 相似文献
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Roberton SI Bell DJ Smith GJ Nicholls JM Chan KH Nguyen DT Tran PQ Streicher U Poon LL Chen H Horby P Guardo M Guan Y Peiris JS 《Proceedings. Biological sciences / The Royal Society》2006,273(1595):1729-1732
The Asian countries chronically infected with avian influenza A H5N1 are 'global hotspots' for biodiversity conservation in terms of species diversity, endemism and levels of threat. Since 2003, avian influenza A H5N1 viruses have naturally infected and killed a range of wild bird species, four felid species and a mustelid. Here, we report fatal disseminated H5N1 infection in a globally threatened viverrid, the Owston's civet, in Vietnam, highlighting the risk that avian influenza H5N1 poses to mammalian and avian biodiversity across its expanding geographic range. 相似文献
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Activated GTPases of the Rho family regulate a spectrum of functionally diverse downstream effectors, initiating a network of signal transduction pathways by interaction and activation of effector proteins. Although effectors are defined as proteins that selectively bind the GTP-bound state of the small GTPases, there have been also several indications for a nucleotide-independent binding mode. By characterizing the molecular mechanism of RhoA interaction with its effectors, we have determined the equilibrium dissociation constants of several Rho-binding domains of three different effector proteins (Rhotekin, ROCKI/ROK beta/p160ROCK, PRK1/PKNalpha where ROK is RhoA-binding kinase) for both RhoA.GDP and RhoA.GTP using fluorescence spectroscopy. In addition, we have identified two novel Rho-interacting domains in ROCKI, which bind RhoA with high affinity but not Cdc42 or Rac1. Our results, together with recent structural data, support the notion of multiple effector-binding sites in RhoA and strongly indicate a cooperative binding mechanism for PRK1 and ROCKI that may be the molecular basis of Rho-mediated effector activation. 相似文献
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ROLAND HAUSKNECHT ROMAN GULA BARTOSZ PIRGA RALPH KUEHN 《Molecular ecology resources》2007,7(2):208-212
Noninvasive samples are of increasing importance to study wild populations. In this study, we investigate the applicability of urine samples as the sole source of DNA for routine noninvasive genetic monitoring of wildlife using wolves (Canis lupus) as an example. Within the scope of a long‐term wolf population survey, we collected during winter snow tracking in Bieszczady Mountains, Poland 41 urine samples considered as utilizable for genetic analyses. DNA concentration was determined by quantitative real‐time polymerase chain reaction (qPCR) and six microsatellite loci were genotyped in threefold repeated genotyping experiments to assess the reliability of genetic analyses of urine. DNA concentration of 33 urine samples was successfully quantified and of 14 samples, we obtained congruent results for all analysed loci and all repeated genotyping experiments. The gender of urine samples was identified with a Y‐chromosome‐linked marker. Considering the high discovery rate of urine in conjunction with its genotype reliability, our study confirms that urine is a valuable source in noninvasive genetic monitoring. Additionally, preselection of samples via qPCR proved to be a powerful tool contributing to a beneficial cost‐value ratio of genetic analyses by minimizing genotyping errors. 相似文献