Abstract:
:More than 500 species of the Poaceae are found in Kenya, East Africa. Eighteen of twenty-seven tribes are exclusively (except the Paniceae and Danthonieae) of the C3 photosynthetic type. A floristic analysis of low altitude grasslands suggests that nearly all species at these low altitudes are of the C4 photosynthetic type. At high altitudes, however, nearly all grasses are of the C3 photosynthetic type. Open grassland vegetation was sampled along a transect from arid low altitude sites to the top of Mt. Kenya in an attempt to document the general distributions of the photosynthetic types.The major tribes illustrated three general patterns of distribution. The C4 tribes Chlorideae, Eragrosteae, Sporoboleae, and Aristideae were abundant at low altitudes (or low indices of available soil moisture). The Paniceae and Andropogoneae were also exclusively C4 but were more common at intermediate altitudes. The C3 tribes Aveneae, Festuceae, and Agrostideae were found only at high altitudes. In these open grasslands there were no C3 species below 2,000 m and no C4 species above 3,000 m. The variation in δ13C of the live grass vegetation with altitude confirms these distributional patterns and suggests a sharp transition zone between these two photosynthetic types. The photosynthetic type accounts for broad distributions within the Poaceae but these distributions are further modified by characteristics which may be inherent in the tribal groups. Ecological and paleoecological significance of these patterns of distribution are discussed.
journal_name
Oecologiajournal_title
Oecologiaauthors
Tieszen LL,Senyimba MM,Imbamba SK,Troughton JHdoi
10.1007/BF00347910subject
Has Abstractpub_date
1979-01-01 00:00:00pages
337-350issue
3eissn
0029-8549issn
1432-1939pii
10.1007/BF00347910journal_volume
37pub_type
杂志文章相关文献
OECOLOGIA文献大全abstract::The ribulose-1,5-bis-phosphate (RBPC) 14CO2 fixation rate was measured at four different temperatures, 5°, 15°, 25° and 35° C, in three populations of Espeletia schultzii at different altitudes, 3100, 3550 and 4200 ma.s.l. The fixation rate increased with temperature increase in the populations studied. The population...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00317283
更新日期:1995-02-01 00:00:00
abstract::Assembly rules provide a useful framework for predicting patterns of community assembly under defined environmental conditions. Habitat created by canopy-forming algae (such as kelps) provides a promising system for identifying assembly rules because canopies typically have a large and predictable influence on underst...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-006-0389-0
更新日期:2006-06-01 00:00:00
abstract::The life history of Yucca glauca in the Great Plains was the subject of a four year field study. Data were incorporated in a stage transition model (based on rosette size) to explain how populations are maintained in spite of large regional and temporal variation in sexual reproductive success. Rosette size was found ...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00377060
更新日期:1986-06-01 00:00:00
abstract::The period between oviposition and the start of hatching varied from about 17 weeks at 3°C to about 1 week at 22°C, and the length of the hatching period varied from about 34 days at 3°C to about 3 days at 22°C. Regression equations are provided to estimate the lengths of both periods at all temperatures between 3°C a...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00345242
更新日期:1972-03-01 00:00:00
abstract::Organisms normally grow at a sub-maximal rate. After experiencing a period of arrested growth, individuals often show compensatory growth responses by modifying their life-history, behaviour and physiology. However, the strength of compensatory responses may vary across broad geographic scales as populations differ in...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-013-2754-0
更新日期:2014-01-01 00:00:00
abstract::In cloud forest at Monteverde, Costa Rica, two common treelets (Palicourea lasiorrachis and Cephaelis elata, both Rubiaceae) depend simultaneously on one hummingbird population (Lampornis calolaema) for pollination. Both species are distylous and self-incompatible. In laboratory experiments, we examined possible effec...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00377045
更新日期:1988-08-01 00:00:00
abstract::Decomposition of standing dead trees that were killed by fire was examined for 10 species in the Great Smoky Mountains National Park. The decrease in wood density as fire age increased was used to estimate decomposition rates. Quercus prinus had the fastest decay rate (11% yr-1) while Pinus virginiana had the slowest ...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00363839
更新日期:1982-02-01 00:00:00
abstract::Belowground processes in light gap openings are poorly understood, particularly in tropical forests. Fine roots in three zones of light gap openings and adjacent intact forest were regularly measured in buried bags and surface litter envelopes for 2 years. Fine root biomass does not vary significantly within gaps for ...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00317207
更新日期:1990-07-01 00:00:00
abstract::In this paper we test the influence of temperature and interference competition by dominant species on the foraging of subordinate species in Mediterranean ant communities. We have analyzed the changes in resource use by subordinate species in plots with different abundances of dominant ants, and in different periods ...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s004420050674
更新日期:1998-12-01 00:00:00
abstract::During summer, 1971, a massive outbreak of red tide resulted in defaunation of a previously characterized sandy, intertidal habitat in upper Old Tampa Bay, Tampa, Florida. Repopulation of the polychaete fauna was studied from August, 1971, to July, 1973. A transect composed of 4 stations running from just below mean h...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00344711
更新日期:1976-06-01 00:00:00
abstract::Correlations between environmental parameters and the distribution of four chromosomal taxa in the acridine grasshopperCaledia captiva (F.) have been analyzed. A bioclimate prediction system (BIOCLIM) was used as a model to determine their bioclimatic envelopes and to predict their probable geographic distributions, b...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00776409
更新日期:1988-05-01 00:00:00
abstract::The central mudminnow (Umbra limi) and yellow perch (Perca flavescens) are two species of fishes that commonly co-occur in small bog lakes in the Great Lakes region of North America. Both species are dietary generalists with a high degree of dietary overlap, and perch populations have been shown to have a strong negat...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00379865
更新日期:1985-05-01 00:00:00
abstract::To maximize fitness, many animals must trade off their need to forage efficiently against their need to avoid predators. We studied such a trade-off in four species of tits (Paridae) in a forest near Oxford, UK. During winter, tits form flocks which increase feeding efficiency and reduce predation risk. These flocks f...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s004420100713
更新日期:2001-10-01 00:00:00
abstract::Predation by invasive species is a major threat to the persistence of naïve prey. Typically, this negative effect is addressed by suppressing the population size of the invasive predator to a point where the predation pressure does not hinder the viability of the prey. However, this type of intervention may not be eff...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-020-04814-6
更新日期:2021-01-08 00:00:00
abstract::Caterpillars of Maculinea arion are obligate predators of the brood of Myrmica sabuleti ants. In the aboratory, caterpillars eat the largest available ant larvae, although eggs, small larvae and prepupae are also palatable. This is an efficient way to predate. It ensures that newly-adopted caterpillars consume the fin...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00317247
更新日期:1992-08-01 00:00:00
abstract::Size-limited predation is an important process during the development of many aquatic species, and mortality rates of early larval stages and small individuals can be particularly high. Structurally complex habitats can mediate predator-prey interactions and provide a potentially important mechanism for decreasing pre...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s004420050444
更新日期:1998-04-01 00:00:00
abstract::We tested several assumptions and predictions of host-quality-dependent sex allocation theory (Charnov et al. 1981) with data obtained for the parasitoid Metaphycus stanleyi Compere on its host, brown soft scale (Coccus hesperidum L.), in a California citrus grove and in the laboratory. Scales ceased growing after par...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s004420050616
更新日期:1998-10-01 00:00:00
abstract::Urbanization is a major challenge for biodiversity conservation, yet the evolutionary processes taking place in urbanized areas remain poorly known. Human activities in cities set new selective forces in motion which need to be investigated to predict the evolutionary responses of animal species living in urban areas....
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-013-2663-2
更新日期:2013-11-01 00:00:00
abstract::Understanding and explaining the causes of variation in food-chain length is a fundamental challenge for community ecology. The productive-space hypothesis, which suggests food-chain length is determined by the combination of local resource availability and ecosystem size, is central to this challenge. Two different a...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-007-0798-8
更新日期:2007-10-01 00:00:00
abstract::Increasing evidence has shown that nutrients and consumers interact to control primary productivity in natural systems, but how abiotic stress affects this interaction is unclear. Moreover, while herbivores can strongly impact zonation patterns in a variety of systems, there are few examples of this in salt marshes. W...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-009-1504-9
更新日期:2010-05-01 00:00:00
abstract::Many plant species currently exist in fragmented populations of different sizes, while they also experience unpredictable climatic fluctuation over time. However, we still understand little about how plant demography responds to such spatial and temporal environmental variability. We studied population dynamics of an ...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-009-1505-8
更新日期:2010-04-01 00:00:00
abstract::The isopod Sphaeroma terebrans, which bores into the prop roots of the red mangrove, Rhizophora mangle, can cause death and subsequent breakage of the inhabited root and, debatably, may reduce the support system of the tree. We examined whether different characteristics of a root or its physical setting, both of which...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s004420000619
更新日期:2001-05-01 00:00:00
abstract::Mimicry between rewarding and non-rewarding flowers within individuals has been accepted as a strategy favored by selection to deceive pollinators. It has been proposed that this mechanism relies on the exploitation of pollinator's sensory biases, but field evidence is still scarce. In this study, we describe the mech...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-012-2250-y
更新日期:2012-07-01 00:00:00
abstract::Seasonal changes in the Crassulacean Acid Metabolism (CAM) activity and growth characteristics of Opuntia humifusa Raf. were examined under midwest climatic conditions. Twenty-four hour studies were done at monthly intervals for two years, with diurnal changes in transpiration, gas exchange, and titratable acidity mon...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00540212
更新日期:1980-01-01 00:00:00
abstract::Atriplex sagittata is a heterocarpic species producing three types of fruits which differ in morphology and ecological properties. This study focused on variation in biomass allocation into particular fruit types under different density and fertilization levels. The reduction in total weight under stressful conditions...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s004420050761
更新日期:1999-04-01 00:00:00
abstract::Herbivores are thought to achieve adequate nutrition by consuming numerous species of plants or by occasionally consuming animal tissue. Although active selection of diverse foods is common in nature, the relationship between diet mixing and consumer fitness is poorly understood, especially in marine environments. We ...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s004420051012
更新日期:2000-05-01 00:00:00
abstract::At Bakers Hill, differential winter mortality of juvenile slowgrowing Amphibolurus ornatus is correlated with the incidence of frosts (Bradshaw, 1971). The present study shows that the probability an individual will spend the night in a refuge that is safe from the lethal effect of a frost is directly related to the i...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00349996
更新日期:1978-01-01 00:00:00
abstract::Plant species composition is changing across many landscapes, but it is unclear how these changes affect habitat quality for animals. We used functional diversity and community-weighted mean (CWM) trait values for four plant traits (litter N, P, lignin and soluble phenolics) to explore how changes in plant species com...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-013-2856-8
更新日期:2014-04-01 00:00:00
abstract::Severe droughts may alter the reproductive phenology of tropical tree species, but our understanding of these effects has been hampered by confounded variation in drought, light and other factors during natural drought events. We used a large-scale experimental reduction of throughfall in an eastern-central Amazon for...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-006-0507-z
更新日期:2006-11-01 00:00:00
abstract::Growth and reproduction of twoDaphnia species (Cladocera) from Lake Constance were measured experimentally in a through-flow laboratory system under different food conditions, in order to investigate the effect of food quality on zooplankton populations. The cryptomonadRhodomonas sp. and the diatomStephanodiscus hantz...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00634599
更新日期:1991-09-01 00:00:00