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141.
We used pitfall traps to sample ground beetles on sandbars along a small woodland stream and in the adjacent floodplain forest
(Oglethorpe Co., GA, USA). We captured a total of 1,477 ground beetles representing 41 species. Twenty-two species were exclusive
to sandbars, while eight were found only in the forested habitat. Ground beetles were captured in significantly greater numbers
from sandbars, especially Brachinus janthinipennis and Omophron americanum. The B. janthinipennis record represents a new state record for the species. This study demonstrates that many unique species can be found in specialized
microhabitats and emphasizes the need for biodiversity assessment surveys to include a wide range of these microhabitats within
a survey area. In addition, it appears that many generalist forest species might use sandbars seasonally to exploit available
resources.
The U.S. Government's right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged. 相似文献
142.
According to the intermediate disturbance hypothesis (IDH), species diversity should be higher at sites with intermediate
levels of disturbance. We tested this hypothesis using ground beetles (Coleoptera: Carabidae) collected in pitfall traps from
sites that varied in time since last disturbance. This successional gradient was embedded in an urban landscape near Montreal,
Quebec. We predicted that diversity in young forests and old fields would be higher than in agricultural fields and old forests.
Fifty-five species (2932 individuals) were found in 2003 and 46 species (2207 individuals) in 2004. In both years, species
richness was highest from traps placed in agricultural fields. We collected nine introduced species; these had higher catch
rates than the native species in both years (64.8% of total catch). When introduced species were removed from the Nonmetric
Multidimensional Scaling ordination analysis, the assemblages from agricultural fields were less distinct compared to those
of the other habitats, suggesting the introduced fauna is important in structuring carabid assemblages from the agricultural
fields. Introduced species may play a significant role in the community composition of ground beetles in urban landscapes,
and their influence may be the cause of the lack of support found for the IDH. 相似文献
143.
Carlos Fernandez Manuel San Andrés Miguel Angel Porcel Casilda Rodriguez Alvaro Alonso José Vicente Tarazona 《Soil & Sediment Contamination》2009,18(5):564-575
Ivermectin is a worldwide used antiparasitic compound acting against both endo- and ecto parasites of livestock. Ivermectin can reach the environment through the direct emission of dung from livestock on pasture and via manure application on agricultural lands. Due to its very high acute toxicity to many invertebrates, especially to D. magna, the excretion profile of ivermectin in dung after application is essential for assessing its potential effects on terrestrial and aquatic ecosystems. The aim of this article is to characterize the excretion profile, comparing plasma and dung levels, after a single subcutaneous dose to cattle, to be used in environmental risk assessment. The cumulative curve of excreted ivermectin was used to calculate the PEC dung in manure to be used as fertilizer. The potential hazard for dung fauna, aquatic and soil organism is presented through the combination of toxicity and excretion levels. Three hazard levels, offering the relevant information to veterinarians prescribing the drug, are presented. 相似文献
144.
Questions: What is the potential of sheep to serve as seed dispersers via ingestion and defecation in calcareous grasslands? Is the presence of viable seeds from dung correlated with specific seed traits? Location: Calcareous grasslands, South Limburg, the Netherlands/Belgium. Methods: Dung samples (n=24) from sheep were collected between September 2006 and November 2007 from five sites with Mesobromion plant communities, and communities of Nardo‐Galion saxatilis. Germinability and identity of seeds in the dung samples were ascertained from germination of seedlings under glasshouse conditions. Seed traits of species with viable seeds in dung were compared with those present in the local species pool. Results: Seventy‐two plant species from 23 plant families had viable seeds in sheep dung. The plant families encountered most frequently were Gramineae and Compositae. The most abundant and frequently recorded plant species in dung samples was Urtica dioica, accounting for >80% of the total number of seeds. Mean seed density in sheep dung was 0.8 seeds g?1 dry matter. Seeds with low seed mass and a high seed longevity index were over‐represented in dung. Viable seeds >2.5 mg were infrequent in the dung samples. Conclusions: We conclude that sheep are potentially important dispersers of plant species in Dutch calcareous grasslands. Although smaller seeds were relatively abundant in sheep dung, it cannot be excluded that this was mainly caused by differences in seed abundance. 相似文献
145.
Following the recent reclassification of the Palaeotropic xyleborine genera (Hulcr and Cognato in press), additional species are transferred to correct genera or synonymized based on analysis of their morphological characters. The following species are given new combinations: Debus amphicranoides (Hagedorn), comb. n., Debus birmanus (Eggers, 1930), comb. n., Debus dolosus (Blandford, 1896), comb. n., Debus eximius (Schedl, 1970), comb. n., Debus interponens (Schedl, 1954), comb. n., Debus robustipennis (Schedl, 1954), comb. n., Debus spinatus (Eggers, 1923), comb. n., Microperus alpha (Beeson, 1929), comb. n., Microperus corporaali (Eggers), comb. n., Microperus eucalyptica (Schedl, 1938), comb. n., Microperus nugax (Schedl, 1939), comb. n., Pseudowebbia percorthylus (Schedl, 1935), comb. n., Truncaudum circumcinctus (Schedl, 1941), comb. n.THE FOLLOWING SPECIES ARE SYNONYMIZED: Arixyleborus hirtipennis (Eggers), syn. n., with Arixyleborus puberulus (Blandford); Coptoborus palmeri (Hopkins), syn. n., with Debus emarginatus (Eichhoff); Coptoborus terminaliae (Hopkins), syn. n., with Debus emarginatus (Eichhoff); Cyclorhipidion polyodon (Eggers), syn. n., with Truncaudum agnatum (Eggers); Euwallacea artelaevis (Schedl), syn. n., with Planiculus bicolor (Blandford); Xyleborinus perminutissimus (Schedl), syn. n., with Xyleborinus perpusillus (Eggers); Xyleborus exesus Blandford, syn. n., with Debus emarginatus (Eichhoff); Xyleborus fulvulus (Schedl), syn. n., with Microperus corporaali (Eggers); Xyleborus marginicollis (Schedl), syn. n., with Diuncus justus (Schedl); Xyleborus shoreae Stebbing, syn. n., with Debus fallax (Eichhoff).THE FOLLOWING SPECIES ARE GIVEN NEW STATUS: Streptocranus superbus (Schedl, 1951), restored name; Webbia divisus Browne, 1972, restored name; Webbia penicillatus (Hagedorn, 1910), restored name. Genus Taphrodasus Wood (1980) is declared not valid. 相似文献
146.
David Sánchez-Fernández Pedro Abellán Andrés Mellado Josefa Velasco Andrés Millán 《Biodiversity and Conservation》2006,15(14):4507-4520
Water beetles were examined for use as potential biodiversity indicators in continental aquatic ecosystems in a semiarid Mediterranean
region, the Segura river basin (SE Spain). The indicator value of water beetles was investigated by examining the degree to
which their species richness patterns was correlated with other groups (Plecoptera, Trichoptera, Mollusca, Heteroptera and
Ephemeroptera), and the efficiency of water beetle area networks (selected by complementarity) in conserving overall groups
richness. The species richness patterns of Coleoptera, Ephemeroptera, Plecoptera and Trichoptera were significantly correlated
with the Remaining Richness value (RR), defined as the total number of species found at a site (of all six groups examined) minus the number of species belonging
to the considered indicator group. Area networks for Coleoptera selected by complementarity represented the highest RR percentage
(84.46%) and contained more than 78% species of each group. Furthermore, water beetles meet most of the criteria proposed
in the literature for choosing biodiversity indicator taxa. In our study, the correlation values and the percentage of species
represented by family, genus and species complementary networks were similar and we suggest that the higher taxa of water
beetles (genera or families) can be used as biodiversity surrogates for cost-effective practical surveys. 相似文献
147.
Fire frequency has significant effects on the biota of tallgrass prairie, including mammals, vascular plants and birds. Recent
concern has been expressed that widespread annual burning, sometimes in combination with heavy livestock grazing, negatively
impacts the biota of remaining prairie remnants. A common management recommendation, intended to address this problem, is
to create a landscape with a mosaic of different burn regimes. Pitfall trapping was used to investigate the impacts of fire
pattern on the diversity and species composition of ground beetles (Coleoptera: Carabidae) at Konza Prairie Biological Station
in eastern Kansas, USA. Trapping was conducted over three seasons in landscape units burned on average every 1, 4, or 20 years,
and in a fourth season across the available range of vegetative structure to assess the variability of the community within
the study system. In the fifth season communities were also followed immediately after two fire events to detect within-season
effects of fire and to study short-term patterns of post-disturbance community assembly. Fire frequency had comparatively
minimal effects on ground beetle diversity measures, and most numerically common species were observed widely across habitat
and management types. Fire frequency effects were manifested primarily in changes in abundance of common species. Colonization
of burned areas apparently did not occur from juxtaposed non-burned areas, but from underground or from long distances. While
these results suggest that widespread annual burning of tallgrass prairie remnants may not have dramatic effects on prairie
ground beetles, we urge caution regarding the application of these results to other taxa within tallgrass prairie. 相似文献
148.
Landscape genetics indicate recently increased habitat fragmentation in African forest‐associated chafers 下载免费PDF全文
Today, indigenous forests cover less than 0.6% of South Africa's land surface and are highly fragmented. Most forest relicts are very small and typically occur in fire‐protected gorges along the eastern Great Escarpment. Yet, they hold a unique and valuable fauna with high endemism and ancient phylogenetic lineages, fostered by long‐term climatic stability and complex microclimates. Despite numerous studies on southern African vegetation cover, the current state of knowledge about the natural extension of indigenous forests is rather fragmentary. We use an integrated approach of population‐level phylogeography and climatic niche modeling of forest‐associated chafer species to assess connectivity and extent of forest habitats since the last glacial maximum. Current and past species distribution models ascertained potential fluctuations of forest distribution and supported a much wider potential current extension of forests based on climatic data. Considerable genetic admixture of mitochondrial and nuclear DNA among many populations and an increase in mean population mutation rate in Extended Bayesian Skyline Plots of all species indicated more extended or better connected forests in the recent past (<5 kya). Genetic isolation of certain populations, as revealed by population differentiation statistics (), as well as landscape connectivity statistics and habitat succession scenarios suggests considerable loss of habitat connectivity. As major anthropogenic influence is likely, conservational actions need to be considered. 相似文献
149.
Persistence of the effect of frugivore identity on post‐dispersal seed fate: consequences for the assessment of functional redundancy 下载免费PDF全文
Ana Paula Lugon Marion Boutefeu Emilie Bovy Fernando Z. Vaz‐de‐Mello Marie‐Claude Huynen Mauro Galetti Laurence Culot 《Biotropica》2017,49(3):293-302
Large frugivores play an important role as seed dispersers and their extinction may affect plant regeneration. The consequences of such extinctions depend on the likelihood of other species being functionally redundant and on how post‐dispersal events are affected. We assess the functional redundancy of two seed dispersers of the Atlantic Forest, the muriqui (Brachyteles arachnoides) and the tapir (Tapirus terrestris) through the comparison of their seed dispersal quality, taking into account post‐dispersal events. We compare tapirs and muriquis for: (1) the dung beetle community associated with their feces; (2) the seed burial probability and burial depth by dung beetles; and (3) the seed mortality due to predators or other causes according to burial depth. We determine how seed burial affects seed dispersal effectiveness (SDE) and compare the dispersal quality of four plant species dispersed by these frugivores. Muriqui feces attract 16‐fold more dung beetles per gram of fecal matter and seeds experience 10.5‐fold more burial than seeds in tapir feces. In both feces types, seed mortality due to predation decreases with burial depth but seed mortality due to other causes increases. Total seed mortality differ within plant species according to the primary disperser. Therefore, the effect of seed burial on SDE varies according to the plant species, burial depth, and primary disperser. As tapirs and muriquis differently affect the seed fate, they are not functionally redundant. Since the effect of the primary disperser persists into the post‐dispersal events, we should consider the cascading effects of these processes when assessing functional redundancy. 相似文献
150.
Cryptosporidium oocysts were inoculated into fresh dung (∼1.2 × 104 oocysts per gram wet weight) and fed to dung beetles to assess the effect of dung burial by the dung beetle Bubas bison on the distribution of the oocysts in small cores of soil in the laboratory. The experiment consisted of five replicates of each of two treatments; controls (dung but no dung beetles) and the experimental treatment (inoculated dung and seven pairs of dung beetles). After 5 days, when approximately 90% of the dung was buried, the surface and buried dung was recovered and subsampled. The oocysts in the subsamples were recovered and enumerated using qPCR. Oocyst viability was evaluated using an assay based on the exclusion or inclusion of two fluorogenic vital dyes, 4′,6-diamidino-2-phenylindole (DAPI) and propidium iodide (PI). Results revealed that overall 13.7% of oocysts remained on the surface and 86.3% of oocysts were buried. The viability of oocysts in buried dung was only 10% compared to oocysts the surface dung (58%). Therefore, widespread dung burial by B. bison during the winter months could substantially reduce the numbers of Cryptosporidium oocysts available to be washed into waterways following winter rains. 相似文献