bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contrasting patterns of elevational zonation for birds and mammals in the Andes of southeastern Peru
Authors: Patterson Bruce D. , Stotz Douglas F. , Solari Sergio , Fitzpatrick John W. , Pacheco Victor 
Published: March 2003

Abstract. To determine the generality of avian diversity patterns, we investigated patterns of elevational zonation shown by birds and mammals along the eastern slope of the Andes Mountains in southeastern Peru. The strong environmental gradient sampled, entirely within Peru's Manu National Park and Biosphere Reserve, supports highly diverse faunas. Elevational distributions of 901 bird species, 129 bat species, and twenty‐eight species of native mice exhibit contrasting patterns in species richness, species composition, and species turnover. Birds and bats showed smooth declines of species richness with elevation, whereas the richness of mouse assemblages was unrelated to elevation. For all three groups, the greatest differences were between lowland and highland faunas, although cutoff points for this contrast varied among groups (≈ 500 m for birds, 750 m for bats, and 1000 m for mice). Differences in composition also separated bird and bat faunas on either side of c. 1400 m (the boundary between montance forest and cloud forest); for mice, this faunal transition may take place nearer to 2000 m. Bird and bat faunas lacked the more discrete zonations suggested for mouse assemblages, as indicated by elevational range profiles and nested subset analyses. Distinct highland assemblages are apparent in two‐dimensional histograms of range limits of birds and mice, but not for bats. Highland bat species occupy broader elevational ranges than lowland bat species, but for both birds and mice, species at intermediate elevations had the broadest amplitudes. Finally, clumping of range maxima and minima along the gradient identified zones of pronounced species turnover in each group, but these were generally not strongly associated with the locations of ecotones.Differences in zonation of these groups appear to reflect their different biological attributes and phylogenetic histories. Such differences obviously complicate discussions of ‘general’ diversity patterns, and limit the usefulness of birds to forecast or predict diversity patterns in other more poorly known groups—other groups may show elevated diversity and endemism in areas where avian diversity patterns appear unremarkable. The pronounced contrasts between bats and mice, and the generally intermediate character of avian patterns, suggest that future analyses might profitably partition birds into finer, more homogeneous groups of historically and/or ecologically similar species. Group differences in zonation may ultimately prove explicable with information on both species‐abundance patterns and resource distributions.
Island biogeography of the Japanese terrestrial mammal assemblages: an example of a relict fauna
Authors: Millien‐Parra Virginie , Jaeger Jean‐Jacques 
Published: March 2003

Summary AimThe aim of this paper is to provide a review of the biogeography of the terrestrial mammalian fauna from the Japanese islands. LocationThe Japanese archipelago is located off the eastern coast of Asia. It extends over a distance of approximately 2000 km in length, from north to south, and comprises more than 3900 islands of widely differing areas. MethodsThe list of the living and Quaternary mammalian fauna of Japan and its geographical distribution was compiled from various published works. Introduced species, marine mammals and bats were not considered in this study. Simpson and Jaccard indices were used to quantify the similarities between the fauna from twelve selected islands from the Japanese archipelago. Regression lines and Pearson correlation coefficients were used to describe the relations between species richness and various geographical factors of the islands, such as area or descriptors of isolation. Lastly, we used the method proposed by
Atmar & Patterson (1993) to measure the degree of nestedness of the Japanese terrestrial mammalian fauna. ResultsSpecies richness on islands is highly correlated with island size. However, this study reveals the importance of non‐equilibrium effects. At a large scale, the current distribution of mammals in Japan seems to be due to selective post‐glacial extinction processes. A large proportion of the Japanese mammals are endemic forms, and extinctions were not balanced by the colonization of species from the Asiatic mainland. In addition, we show the major role played by inter‐island dispersal processes, in particular from larger islands towards smaller ones, that are mainly effected by the presence of deep marine channels between islands. Main conclusionsThe present distribution of the terrestrial mammalian fauna from Japan is thus mainly the result of post‐glacial extinctions that were not compensated for by colonization of new species from the faunal Asiatic mainland source pool. However, this study emphasizes the importance of inter‐island dispersal processes.
Long distance migration of insects to a subantarctic island
Authors: Greenslade Penelope , Farrow Roger A , Smith Jeremy M. B. 
Published: March 2003

SummaryTransoceanic migration of four species of macrolepidoptera to subantarctic Macquarie Island has been detected in 7 out of 33 years during the period 1962–96 and is restricted to spring and autumn. Analyses of synoptic charts during the migration period show that autumn immigrants originated from New Zealand and comprised a single species of noctuid moth,Agrotis ipsilon (Walker). Spring immigrants originated from Australia and comprised two noctuids, Dasypodia selenophora Guenée and Persectania ewingii Westwood and a butterfly, Vanessa kershawi (McCoy). Autumn migrations were associated with depressions in the southern Tasman Sea. Spring migrations were associated with the eastward passage of prefrontal airflows ahead of cold fronts which extended from southern Australia to the west of Macquarie Island. In an analysis of one of these events, winds exceeded 30 ms−1 at 300 m altitude and could have transported migrants from Tasmania to Macquarie Island overnight in less than 10 h. Flight activity was assisted by the presence of a nocturnal temperature inversion that maintained upper air temperatures above 5 °C. The effect of potential global warming on the migration and colonization of Macquarie Island by insects is discussed.
Relationship between vegetation and environmental conditions in the northern Pantanal of Mato Grosso, Brazil
Authors: Zeilhofer Peter , Schessl Michael 
Published: March 2003

SummaryThis paper analyses the relationship between the distribution of tropical floodplain vegetation and environmental factors such as the soil types, their physical‐chemical properties and inundation dynamics in the northern Pantanal of Mato Grosso, Brazil. Fifty‐four soil profiles of the four principal geomorphologic units of the lowland were classified into twenty‐one units of the FAO‐UNESCO system and related to eight vegetation formations. Under the deciduous and semideciduous woodland and forest formations on flood free riverbanks and relict dunes Arenosols, Solonetz and Alisols dominate. Inundation forests grow on a large variety of soil groupings such as Alisols, Solonetz, Fluvisols, Gleysols and Cambisols, mainly on fluvial deposits. Under the grassland formations of periodically flooded spreadings and depressions Planosols, Acrisols, Alisols, Fluvisols, Arenosols and Cambisols were cored, while Gleysols are common on swamps bearing <ITALIC>Thalia geniculata or Cyperus giganteus</ITALIC>. Canonical Correspondence Analysis was applied to study the influence of monitored environmental factors on spatial distribution of vegetation formations. Water regime and soil texture were found to define the grassland‐forest boundaries as well as the transition between different grassland formations and between seasonal as well as evergreen forests.
How isolated are Pleistocene refugia? Results from a study on a relict woodrat population from the Mojave Desert, California
Authors: Smith Felisa A. , Matocq Marjorie D. , Melendez Karla F. , Ditto Amy M. , Kelly Patrick A. 
Published: March 2003

AbstractPleistocene vicariance is often invoked to explain the disjunct populations of animals in habitat refugia throughout the southwestern United States. The combined effects of small population size and isolation from the rest of the contiguous range are thought to result in genetic differentiation of relict organisms.Here, we describe a relict population of dusky‐footed woodrats (Neotoma fuscipesBaird) found in a pinyon‐juniper‐oak community in a small mountain range within the Mojave Desert. We compare morphological and genetic data for these individuals with two populations within the contiguous range, and with another species of woodrat (Neotoma lepida). We also examine the distributional overlap between contemporary oak species and dusky‐footed woodrats, and estimate the potential oak woodland habitat available during the late Quaternary.As expected, both the morphological and genetic analysis confirm that the relict population isN. fuscipes. Within the limitations of our data, we detect no evidence of differentiation. Instead, the relict population forms a paraphyletic group with the nearest population within the contiguous range. This may be explained by the combined influences of a shorter period of isolation and a greater effective population size than was originally expected.The linkage between contemporary oak and dusky‐footed woodrat distributions is very tight, reinforcing the idea of an obligate relationship between the two.We estimate that at ~8000 ybp, pinyon‐juniper‐oak woodlands may have covered ~53% of the central Mojave, forming large contiguous areas of habitat. Although considerably more fragmented, at present ~12% of the area consists of relict woodlands.Our results suggest that there may be numerous other woodrat refugia, with a relatively high degree of connectiveness between the larger ones. Animals within them may effectively function as a single metapopulation, buffering against occasional stochastic extinction events.
Cladistic biogeography of the Mexican transition zone
Authors: Marshall C. J. , Liebherr J. K. 
Published: March 2003

AbstractBiogeographic relationships among nine montane areas of endemism across the transition zone between North and South America are analysed cladistically based on phylogenetic hypotheses of thirty‐three resident monophyletic taxa of insects, fish, reptiles, and plants.Areas of endemism include the Arizona mountains (AZ), Sonoran Desert (SD), Sierra Madre Occidental (OCC), southern Sierra Madre Occidental (SOC), Sierra Madre Oriental (ORI), Sierra Transvolcanica (TRAN), Sierra Madre del Sur (SUR), Chiapan‐Guatemalan Highlands (CGH), and Talamancan Cordillera (TC).Area relationships are summarized using Brooks Parsimony Analysis and Assumption 0, with the former resulting in more defensible biogeographic hypotheses.Areas of endemism are dividable into two monophyletic groups; a northern group including AZ, SD, OCC, and ORI, and a southern group consisting of TC, CGH, TRAN, SUR, and the isolated southern regions of the Sierra Madre Occidental (SOC).The northern set of areas are characterized by recent, probably Pleistocene, isolation and prevalent widespread species, whereas the southerly areas probably diverged after Pliocene closure of the Panamanian isthmus.The southern areas are redundantly represented on many of the taxon‐area cladograms by endemic species, indicative of much higher levels of endemism in the Sierra Transvolcanica and further south.Use of a general area cladogram in such a transition zone permits explicit exploration of biogeographic patterns and establishes a predictive framework for taxonomy and conservation prioritization.
Biogeographic aspects of the distribution of bird species breeding in Québec’s peatlands
Authors: Calmé Sophie , Desrochers André 
Published: March 2003

AbstractAimThe state of peatlands in eastern Canada is of growing concern. This habitat is in decline due to urban sprawl, agriculture, forestry, and peat mining. Moreover, reduction and fragmentation have led to increasing isolation of remaining peatlands. We determined how bird species distribution in peatlands conforms to expectations drawn from island dynamics. We also determined the factors influencing the occurrence of 10 common peatland bird species, two of which rely mainly on peatlands for nesting in the study region.LocationWe sampled sixty‐three peatlands in southern Québec, Canada, within a landscape characterized by a mosaic of forest stands and farmland.MethodsWe sampled nesting bird populations within peatlands from 4 June to 14 July 1995, using both transect lines and fixed‐radius point counts. Each sampled peatland was characterized by area, vegetation structure (microhabitats), and isolation. We used multiple regression to test the relationship between bird species richness, peatland area, heterogeneity, microhabitat richness, and relative isolation, after correction for sampling effort. Relationships between bird species abundances and the variables the environmental variables were investigated with Canonical Correspondence Analyses. We calculated probabilities of occurrence of individual species in peatlands by logistic regression, with the same explanatory variables as mentioned previously.ResultsBird species richness was mainly explained by microhabitat richness, and to a lesser extent, by sampling effort. By contrast, the occurrence of more than half of the species was mainly explained by peatland microhabitat heterogeneity. Palm warblerDendroica palmarum(Gmelin) and upland sandpipersBartramia longicauda(Bechstein) were the only species less frequent in small and isolated peatlands than in other peatlands.Main conclusionsThe results for species richness support both the habitat diversity, and passive sampling hypotheses for patchy distribution of birds. By contrast, results from individual species emphasized the difference between factors affecting total species richness and individual species distribution. The distribution of palm warbler, the only species restricted to peatlands regionally, was consistent with expectations from island dynamics.
Fires and land‐cover change in the tropics:a remote sensing analysis at the landscape scale
Authors: Eva Hugh , Lambin Eric F. 
Published: March 2003

AbstractAimFires are an important landscape disturbance which interact in a complex way with land‐use and land‐cover change. The objective of this study is to understand the role of fires in vegetation‐cover change and, conversely, the role of land use as a controlling factor of fires.LocationThe study sites are located in Mato Grosso, Brazil, in Central Africa and on the border between Kenya and Tanzania.MethodsThe role of vegetation fire is addressed through a landscape‐scale analysis of the spatial association between maps of active fires and maps of land‐cover change derived from remote sensing data for the different sites in Africa and South America.ResultsThe empirical results of this study clearly support the idea that fires have widely varying impacts on land cover in savanna and forest ecosystems. Fires play different roles within the different components of landscape mosaics and at different times of the land‐cover change trajectory. The impact of fires on vegetation is mainly controlled by land use.ConclusionsThere is thus a need to consider the socioeconomic purpose of biomass burning and the context in which such activities are undertaken. In forest ecosystems, a statistically significant relationship exists between the occurrence of fires and forest‐cover changes. One could not conclude however, that fires are always the cause of the change in land cover, nor that fires are a reliable indicator of ‘hot spots’ of deforestation. Current low spatial resolution information on fire activity derived from remote sensing systems can be prone to inaccuracies due to a poor co‐location of fire with respect to land‐cover data, and temporal sampling problems affecting fire data.
Factors affecting the presence of the cool temperate rain forest tree myrtle beech (Nothofagus cunninghamii) in southern Australia: integrating climatic, terrain and disturbance predictors of distribution patterns
Authors: Lindenmayer D. B. , Mackey B. G. , Cunningham R. B. , Donnelly C. F. , Mullen I. C. , McCarthy M. A. , Gill A. M. 
Published: March 2003

AbstractAimThis study identified the factors influencing the presence, stocking rate and basal area of the southern Australian cool temperate rain forest tree myrtle beech (Nothofagus cunninghamii).LocationThis investigation was conducted in the montane ash forests of the Central Highlands of Victoria, south‐eastern Australia.MethodsThe occurrence ofN. cunninghamiiwas measured as part of field surveys of 474 sites (2844 plots) distributed widely throughout mountain ash (Eucalyptus regnans), alpine ash (E. delegatensis) and shining gum (E. nitens) forests. Statistical analysis was employed to examine relationships between the occurrence ofN. cunninghamiiand measured site attributes and interpolated and derived environmental variables.ResultsThe presence ofN. cunninghamiiwas significantly related to five variables: the age of the overstorey eucalypt stand, dominant species of overstorey eucalypt tree, topographic position in the landscape, slope and the estimated quantity of precipitation in the warmest quarter of the year.N. cunninghamiiwas more likely to occur in old growth eucalypt stands, in gullies and locations with high values for rainfall in the warmest quarter. In addition, there was an interaction between slope and dominant eucalypt tree species—in forests dominated byE. regnans,N. cunninghamiiwas more likely to occur on steep slopes whereas inE. nitensandE. delegatensis‐dominated stands,N. cunninghamiiwas more likely to occur on flatter terrain. Statistical modelling also showed a significant positive effect of slope on both the stocking rate and basal area of the species. The stocking rate ofN. cunninghamiialso was significantly higher in old growth eucalypt stands.Main conclusionsThe study demonstrated that the patterns of distribution ofN. cunninghamiimay be more complex than recognized previously and it illustrated the importance of multiple factors including climatic conditions, disturbance processes (as reflected through the age of the dominant overstorey eucalypt stands) and topography. Our work also shows there can be complex interactions between age cohorts of different tree species in the same stand—in this case, the dominant overstorey eucalypts and the understorey which includesN. cunninghamiistems.
Patterns of distribution for southern Australian marine echinoderms and decapods
Authors: O'Hara Timothy D. , Poore Gary C. B. 
Published: March 2003

AbstractAim To relate patterns of distribution of marine echinoderms and decapods around southern Australia to major ecological and historical factors.Location Shallow‐water (0–100 m) marine waters off southern Australia, south of 30° S.Methods (1) Record the presence/absence of known echinoderm and decapod species in cells ofc. 1° latitude and longitude, along the coast of southern mainland Australia and Tasmania. (2) Describe patterns in species composition, species richness and endemism through gradient analysis, ordination and cluster analysis. (3) Relate these patterns to distance and temperature gradients, the area of continental shelf, the average size of species range, and known historical factors.Results Species composition varied with both latitude and longitude. Species richness was relatively constant from east to west but graded with latitude from high in the warm‐temperate regions around Perth and Sydney to low in cool‐temperate southern Tasmania. Species richness was not related to the area of continental shelf or average species range size. Species turnover was not correlated with rates of temperature change. It was problematic to separate distance from temperature gradients, but there was evidence that the southern distribution limits of some species are related to minimum sea surface temperature. Within the taxonomic groups surveyed, evolutionary radiation has been largely limited to a few cosmopolitan species‐rich genera.Main conclusions There are historical as well as ecological hypotheses explaining the latitudinal gradient of marine species richness in southern Australia: (1) the continual invasion and speciation of species of tropical origin as Australia has split from Gondwana and drifted northward; (2) progressive extinction of some Gondwanan cool‐temperate species at the limits of their range; (3) low level of immigration of additional cool‐temperate species; and (4) somein situendemic speciation.
Forest plant species richness in small, fragmented mixed deciduous forest patches: the role of area, time and dispersal limitation
Authors: Jacquemyn Hans , Butaye Jan , Hermy Martin 
Published: March 2003

AimThe research aimed to investigate how plant species richness of small, fragmented forest patches changes over time. Also interactions between time and area were studied in relation to species richness. Finally, the relative importance of plant dispersal limitation on the process of species accumulation was examined by investigating how species were distributed within a regional landscape.LocationMixed deciduous forest patches in central Belgium.MethodsThe land use history of a region of 80 km2 was reconstructed using nine historical maps dating from 1775 to 1991. Within a central area of 42 km2, 241 forest patches were surveyed for presence/absence of 203 species predominantly occurring in forests. Aggregation of species within this region was estimated using a Monte Carlo simulation. Spatial and temporal patterns of species richness were investigated by both regression and analysis of variance (ANOVA).ResultsFifty‐one of 103 species showed significant spatial aggregation patterns, suggesting severe dispersal limitation. Species richness significantly increased with age. However, the effects of time on species richness could not be separated from area and area and time clearly interacted. Slopes of regression equations for species number on area and patch age were shown to be significantly interrelated.Main conclusionsArea and time cannot be treated independently as predictors of plant species richness. Dispersal proved to be important in structuring local forest plant community composition, contrary to most other studies that have investigated local forest plant community structure. The processes of forest succession and species accumulation are controlled by both local and regional processes. More studies focusing on the regional factors determining local community composition are needed in order to fully understand the process of forest plant community assembly.