Abstract:
:Some factors influencing the species richness of West African fish communities were studied in a sample of 26 rivers using four habitat and hydrologic variables. Analysis of a larger sample of 39 rivers showed that species richness was positively related to area. A power function with an exponent of 0.32 gave the best fit. As the surface area used was that of the catchment area and not that (unknown) of the river, the biological significance of this relationship and the possibilities of comparison were limited. Ridge regression analysis and forward stepwise selection indicated that a model that explained ln(species richness) as a function of ln(mean annual discharge) and ln-(catchment surface area) was best, accounting for 90% of the variance of the dependent variable. The combination of surface area and discharge was presumed to act through the volume of water available for the fishes and habitat productivity. Habitat diversity, measured by the diversity of the terrestrial vegetation covering the catchment area, had no significant positive effect when surface area was used in the regression. Rivers ("islands") should have fewer species than tributaries of similar size since, for fishes within a river system ("continent"), there is free circulation between all its branches. The model derived from the river data underestimated the species richness of a sample of 11 tributaries. This was compatible with the hypothesis of higher population extinction rates in insular biotopes. The residuals of the linear model did not show random geographical distribution; the rivers in some areas had more species than expected. The possibility that historical factors, especially Quaternary climatic variations, might cause this distribution is discussed.
journal_name
Oecologiajournal_title
Oecologiaauthors
Hugueny Bdoi
10.1007/BF00388483subject
Has Abstractpub_date
1989-05-01 00:00:00pages
236-243issue
2eissn
0029-8549issn
1432-1939pii
10.1007/BF00388483journal_volume
79pub_type
杂志文章相关文献
OECOLOGIA文献大全abstract::The population ecology of Pardia tripunctana and Notocelia roborana, a bud- and a leaf-feeding tortricid respectively, on Rosa spp. was studied.Mortality factors of the egg and larval stages are low and density-independent.Pupal mortality in the soil is a regulatory mechanism: it compensates for density fluctuations, ...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00378920
更新日期:1985-02-01 00:00:00
abstract::Seasonal measurements of microclimatic conditions were compared to seasonal indices of leaf structural components and plant water relations in Prosopis glandulosa var. torryana. P. glandulosa had two short periods of leaf production which resulted in two distinct even aged cohorts of leaves. The two leaf cohorts (summ...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00399043
更新日期:1986-04-01 00:00:00
abstract::The photosynthetic responses of a range of trebouxioid lichens were investigated to determine whether variations in net assimilation rates shown by populations of the same species collected from different habitats could be correlated with adjustments in carbon-concentrating mechanism (CCM) activity. The activity of a ...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s004420050387
更新日期:1998-01-01 00:00:00
abstract::Alpine Trifolium species have high rates of symbiotic N2-fixation which may influence the abundance and growth of plant species growing near them. The potential for facilitative effects on plant abundance and growth in dry meadow alpine tundra of Niwot Ridge, Colo., characterized by low resource availability, was inve...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s004420050487
更新日期:1998-06-01 00:00:00
abstract::Soils of three Picea mariana-Cladina stellaris woodland sites, aged 2, 104 and 137 years after fire, were sampled at 3 cm intervals to 9 cm depth for soil microfungi. Mortierella, Mucor, Penicillium and Trichoderma were the most frequently isolated genera. The species composition of the microfungi remained much the sa...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00349986
更新日期:1978-01-01 00:00:00
abstract::1. The defecation behavior of the parasitoid larvae of Aleochara curtula in the Calliphora puparium was described. After occupation of the puparium the first-instar larva begins to defecate. With these excrements the larva closes the entry hole. Afterwards the first-instar larva as well as later the second-instar larv...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00345127
更新日期:1973-06-01 00:00:00
abstract::Two general approaches have usually been taken towards understanding the distributions and dynamics of localised species in heterogeneous landscapes, namely habitat characterisation and metapopulation dynamics. We show how habitat and metapopulation dynamics interact to generate a highly localised distribution of a bu...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s004420050957
更新日期:1999-12-01 00:00:00
abstract::Holling's (1992) proposition that discontinuities in biotic and abiotic processes generate structure in ecological systems is examined experimentally by imposing size-specific perturbations on marine sediment assemblages. Two kinds of perturbations were applied: organic enrichment and predation, each at two levels. Pe...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s004420050045
更新日期:2000-02-01 00:00:00
abstract::The parasitoids known to attack 191 phytophagous species of gall midges (Cecidomyiidae) were used to examine factors influencing parasitoid assemblage size. The number of parasitoid species a midge species supports was tested against nine variables describing geographical, biological and ecological attributes of hosts...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00377013
更新日期:1989-10-01 00:00:00
abstract::In the simultaneously hermaphroditic marine fish, Serranus subligarius, male role individuals are known to pair spawn, group spawn and streak spawn. While the effects of these common mating tactics on mating success in the male role have been well studied, their consequences for the reproductive success of the individ...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-012-2307-y
更新日期:2012-10-01 00:00:00
abstract::The population dynamics of Antarctic seabirds are influenced by variations in winter sea ice extent and persistence; however, the type of relationship differs according to the region and the demographic parameter considered. We used annual presence/absence data obtained from 1,138 individually marked birds to study th...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-009-1387-9
更新日期:2009-08-01 00:00:00
abstract::Animals with high metabolic rates are believed to have high rates of carbon and nitrogen isotopic incorporation. We hypothesized that (1) chronic exposure to cold, and hence an increase in metabolic rate, would increase the rate of isotopic incorporation of both 13C and 15N into red blood cells; and (2) that the rate ...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-005-0066-8
更新日期:2005-06-01 00:00:00
abstract::The impacts of disturbance on biodiversity and distributions have been studied in many systems. Yet, comparatively less is known about how lichens-obligate symbiotic organisms-respond to disturbance. Successful establishment and development of lichens require a minimum of two compatible yet usually unrelated species t...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-019-04413-0
更新日期:2019-06-01 00:00:00
abstract::Herbivore damage often deters pollinator visitation and many invasive plants in North America are pollinator-dependent. This has important implications for the biological control of invasive plants because it means that agents that deter pollinators may have a larger than expected impact on the plant. Yet interactions...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-013-2750-4
更新日期:2014-01-01 00:00:00
abstract::Mistletoes constitute instructive study cases with which to address the role of generalist consumers in the study of plant-animal interactions. Their ranges of safe sites for recruitment are among the most restricted of any plant; therefore, frugivores specializing in mistletoe have been considered almost indispensabl...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-014-3013-8
更新日期:2014-09-01 00:00:00
abstract:: In spite of recent theoretical interest, few field studies have addressed the links between individual behavioral decisions and population distribution. This work analyzes the foraging behavior of individuals and the spatial distribution of a population of blue tits (Parus caeruleus) just before the main breeding sea...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s004420050256
更新日期:1997-07-01 00:00:00
abstract::Indirect interactions among plant species mediated by frugivorous animals can be central to population and community dynamics, since the successful seed dispersal of species may depend on facilitative or competitive interactions with heterospecific plants. Yet, empirical evidence on these interactions is very scarce a...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-019-04434-9
更新日期:2019-07-01 00:00:00
abstract::Most aphids show cyclical parthenogenesis, have short generation times and complete several generations each season. Two hypotheses have been proposed to account for the adaptive seasonal trends observed in the reproductive strategies of aphids. Firstly, individuals of each generation modify their reproductive strateg...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s004420050422
更新日期:1998-03-01 00:00:00
abstract::We examined the manner in which animals adjust the proportion of energy allocated to growth and storage in response to food availability. We compared univariate growth and length-mass relationships between juvenile adders (Vipera berus) reared under two different feeding regimes. Animals in the low- and high-food expe...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00329041
更新日期:1996-12-01 00:00:00
abstract::The species composition of vesicular-arbuscular mycorrhizal (VAM) fungal communities changed during secondary succession of abandoned fields based on a field to forest chronosequence. Twenty-five VAM fungal species were identified. Seven species were clearly early successional and five species were clearly late succes...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00317600
更新日期:1991-05-01 00:00:00
abstract::Experimental studies were used to examine the mechanisms governing the distribution and abundance of two major patch types in unshaded reaches of Augusta Creek, Michigan (USA). One patch type is dominated by Cladophora glomerata, a macroalga potentially able to monopolize space, whereas the other type is comprised of ...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00317787
更新日期:1992-08-01 00:00:00
abstract::Two physiological races of the carabid beetle, Pterostichus nigrita, are compared. The larvae from the northern Scandinavian population (polar circle) develop faster in all temperature regimens, have a reduced mortality in lower temperatures and an increased growth rate in high temperatures compared with the central E...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00377589
更新日期:1975-03-01 00:00:00
abstract::To estimate the optimality of brood size, it is essential to study the effects of brood size manipulation on offspring survival and reproductive success. Moreover, testing the generality of the hypothesis of reproductive costs requires experimental data from a diversity of organisms. Here I present data on the growth,...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s004420050531
更新日期:1998-07-01 00:00:00
abstract::Pteromalus puparum is a gregarious parasitoid of many butterfly pupae. Adult size, mortality, and sex ratio of P. puparum, as a parasitoid of Papilio xuthus, were unit weight of the host. Effects of female size on fecundity, wing load, and longevity were also examined.The highest total weight of progeny from the host ...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00379463
更新日期:1985-12-01 00:00:00
abstract::Although many studies now examine how multiple factors influence the dynamics of herbivore populations, few studies explicitly attempt to document where and when each is important and how they vary and interact. In fact, how temporal variation in top-down (natural enemies) and bottom-up (host plant resources) factors ...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-002-1137-8
更新日期:2003-03-01 00:00:00
abstract::Human activities can have a suite of positive and negative effects on animals and thus can affect various life history parameters. Human presence and agricultural practice can be perceived as stressors to which animals react with the secretion of glucocorticoids. The acute short-term secretion of glucocorticoids is co...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-015-3318-2
更新日期:2015-09-01 00:00:00
abstract::Studies focused on how prey trade-off predation and starvation risk are prevalent in behavioral ecology. However, our current understanding of these trade-offs is limited in one key respect: we know little about the behavior of predators. In this study, we provide some of the first detailed information on temporal pat...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-006-0638-2
更新日期:2007-05-01 00:00:00
abstract::Interspecific competition is assumed to have a strong influence on the population dynamics of competing species, but is not easily demonstrated for mobile species in the wild. In the Florida Keys (USA), anecdotal observations have long pointed to an inverse relationship in abundance of two large decapod crustaceans fo...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-017-3844-1
更新日期:2017-05-01 00:00:00
abstract::Relatively few published food webs have included parasites, and in this study we examined the animal community in a stream across eight contiguous seasons to test how inclusion of helminth parasites alters the topology or structure of the food web. Food webs constructed for each season and analyzed using common binary...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-008-0999-9
更新日期:2008-06-01 00:00:00
abstract::Climate change effects on plants are expected to be primarily mediated through early life stage transitions. Snowfall variability, in particular, may have profound impacts on seedling recruitment, structuring plant populations and communities, especially in mid-latitude systems. These water-limited and frequently inva...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-014-3180-7
更新日期:2015-02-01 00:00:00