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81.
Butterfly,seedling, sapling and tree diversity and composition in a fire‐affected Bornean rainforest
DANIEL F. R. CLEARY ALDRIANTO PRIADJATI BAMBANG K. SURYOKUSUMO STEPH B. J. MENKEN 《Austral ecology》2006,31(1):46-57
Abstract: Fire‐affected forests are becoming an increasingly important component of tropical landscapes. The impact of wildfires on rainforest communities is, however, poorly understood. In this study the density, species richness and community composition of seedlings, saplings, trees and butterflies were assessed in unburned and burned forest following the 1997/98 El Niño Southern Oscillation burn event in East Kalimantan, Indonesia. More than half a year after the fires, sapling and tree densities in the burned forest were only 2.5% and 38.8%, respectively, of those in adjacent unburned forest. Rarefied species richness and Shannon's H’ were higher in unburned forest than burned forest for all groups but only significantly so for seedlings. There were no significant differences in evenness between unburned and burned forest. Matrix regression and Akaike's information criterion (AIC) revealed that the best explanatory models of similarity included both burning and the distance between sample plots indicating that both deterministic processes (related to burning) and dispersal driven stochastic processes structure post‐disturbance rainforest assemblages. Burning though explained substantially more variation in seedling assemblage structure whereas distance was a more important explanatory variable for trees and butterflies. The results indicate that butterfly assemblages in burned forest were primarily derived from adjacent unburned rainforest, exceptions being species of grass‐feeders such as Orsotriaena medus that are normally found in open, disturbed areas, whereas burned forest seedling assemblages were dominated by typical pioneer genera, such as various Macaranga species that were absent or rare in unburned forest. Tree assemblages in the burned forest were represented by a subset of fire‐resistant species, such as Eusideroxylon zwageri and remnant dominant species from the unburned forest. 相似文献
82.
83.
SIN‐YEON KIM ANA SANZ‐AGUILAR EDUARDO MÍNGUEZ DANIEL ORO 《Biological journal of the Linnean Society. Linnean Society of London》2012,106(2):439-446
The evolutionary potential in the timing of recruitment and reproduction may be crucial for the ability of populations to buffer against environmental changes, allowing them to avoid unfavourable breeding conditions. The evolution of a trait in a local population is determined by its heritability and selection. In the present study, we performed pedigree‐based quantitative genetic analyses for two life‐history traits (recruiting age and laying date) using population data of the storm petrel over an 18‐year period in two adjacent breeding colonies (only 150 m apart) that share the same environmental conditions. In both traits, natal colony effect was the main source of the phenotypic variation among individuals, and cohort variance for recruitment age and additive genetic variance for laying date were natal colony‐specific. We found significant heritability only in laying date and, more specifically, only in birds born in one of the colonies. The difference in genetic variance between the colonies was statistically significant. Interestingly, selection on earlier breeding birds was detected only in the colony in which heritable variation in laying date was found. Therefore, local evolvability for a life‐history trait may vary within a unexpectedly small spatial scale, through the diversifying natural selection and insulating gene flow. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106 , 439–446. 相似文献
84.
DANIEL APOLÔNIO SILVA DE OLIVEIRA WILFRIDA DECRAEMER OLEKSANDER HOLOVACHOV JAY BURR IRMA TANDINGAN DE LEY PAUL DE LEY TOM MOENS SOFIE DERYCKE 《Zoological Journal of the Linnean Society》2012,164(1):18-35
Nematode diversity may seriously be underestimated when taking into account cryptic speciation. Thoracostoma trachygaster is commonly found in kelp holdfasts along the California coastline and was recently shown to consist of at least two distinct molecular clades (I and II). Here, we provide detailed morphological analysis of both clades, based on measurements taken from video vouchers of respectively eight and 16 individuals from the previous study, as well as 80 newly collected specimens from four Californian beaches. The latter were vouchered, measured, and then subjected to molecular analyses of the mitochondrial cytochrome oxidase c subunit I (COI) gene, and the ribosomal D2D3 and internal transcribed spacer (ITS) regions. This integrative approach shows that the three molecular clades are phylogenetically and morphologically distinct species, but a combination of morphological characters is needed to distinguish them. Two new species, Thoracostoma fatimae sp. nov. and Thoracostoma igniferum sp. nov. , are identified and described. The spicule length of T. fatimae sp. nov. is significantly shorter than that of T. trachygaster. Thoracostoma igniferum sp. nov. can be distinguished by the irregular posterior edge of the cephalic capsule and the two internal subdorsal tropis‐like projections in the wall of the cephalic capsule, which are lacking in T. fatimae sp. nov. and T. trachygaster. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 164 , 18–35. 相似文献
85.
THOMAS E. HAMER DANIEL E. VARLAND TRENT L. MCDONALD DOUGLAS MEEKINS 《The Journal of wildlife management》2008,72(4):983-993
Abstract: The marbled murrelet (Brachyramphus marmoratus) is a small Pacific seabird with a breeding range that extends from the Aleutian Islands to central California. Throughout most of its breeding range, it uses mature and old-growth coniferous forests as nesting habitat. Although most murrelets seem to nest within 60 km of the coast, occupied nesting habitat has been identified as far as 84 km from the ocean in Washington state. Due to the extensive inland distances within which birds are known to breed, the area requiring surveys to identify breeding sites can be enormous. Therefore, the standard 2-year survey protocol can be expensive and time-consuming for forest management agencies and companies to administer. We developed a logistic regression model to determine whether a suite of forest structural characteristics could be used to reliably predict occupancy of a forest patch by marbled murrelets. We tested the performance of the final model using cross-validation procedures and a sample of independent sites. We used 50 sites surveyed for marbled murrelets to estimate the model, and 48 independent sites were available to test model performance. All 50 sites were on private forestland owned by Rayonier located in the western lowlands of Olympic Peninsula within the Sitka spruce and western hemlock transition zones. We sampled forest habitat at each site, and we collected information on 15 explanatory variables. The best-fitting logistic regression model contained variables that measured number of canopy layers (P<0.001, approx. F test) and mistletoe (Arceuthobium sp.) abundance (P = 0.031, approx. F test). The model misclassified 2 of 33 (94% correct) unoccupied sites as occupied using a classification cut-off (c) of c=0.25. In the other direction, under cross-validation the final model misclassified 2 of 17 (88% correct) occupied sites as unoccupied. On a test of the model against an independent sample, using a classification cut-off value of c = 0.25, the final model correctly classified 36 of 48 sites (75% correct). The final model misclassified 3 of 31 occupied sites as unoccupied (90% correct). Use of predictive models could greatly reduce the amount of forest that requires surveys by screening out those sites with little probability of use and by focusing remaining effort on higher probability sites, resulting in a higher likelihood of identifying occupied sites and thereby more efficiently conserving marbled murrelet nesting habitat. 相似文献
86.
87.
The Role of Exchange in Productive Specialization 总被引:1,自引:0,他引:1
Nomadic pastoralists are specialists in complex systems of land use. Their own productive strategies are dependent in large part upon the conversion rates of their products to imported items from other sectors of a larger economy. Changes in these conversion rates are likely to arise for a number of reasons; pastoralists respond to such changes in various ways, depending upon their past histories and current conditions. The case of the Yörük, specialized pastoralists of southeastern Turkey, is used to illustrate this process of changing productive strategies. Generalizations are sought concerning the ways in which large systems of land use become more or less specialized through time, in terms of the consequences of shifting exchange conditions for the productive strategies of component households. [economic anthropology, pastoralism, complex society, interpopulation exchange] 相似文献
88.
89.
CHRISTIAN M. TOBIAS DANIEL M. HAYDEN PAUL TWIGG GAUTAM SARATH 《Molecular ecology resources》2006,6(1):185-187
Switchgrass is a large, North American, perennial grass that is being evaluated as a potential energy crop. There is a need to assess genetic diversity in stored accessions and in remaining native stands to assist breeding and conservation efforts. Marker development will also be necessary for genetic linkage mapping. Toward this end, 32 switchgrass genic di‐, tri‐ and tetranucleotide repeat microsatellites were identified from expressed sequence tags (ESTs). These microsatellites were used to screen individuals from two different named cultivars. The markers displayed a high level of polymorphism consistent with the tetraploid, allogamous behaviour of the cultivars tested. 相似文献
90.
DANIEL J. C. KRONAUER JÜRGEN GADAU JACOBUS J. BOOMSMA 《Molecular ecology resources》2007,7(4):688-690
Here we describe 12 polymorphic microsatellite loci that were cloned and characterized for three species of army ants: the North American Neivamyrmex nigrescens, and the Asian Aenictus laeviceps and Aenictus dentatus. Observed and expected heterozygosities ranged from 0.37 to 0.97 (mean 0.70), and from 0.48 to 0.95 (mean 0.72), respectively. We observed 2–30 (mean 12) alleles per locus. These new genetic markers will be useful for studies of overall population structure and the complex pedigrees in colonies of army ants. 相似文献