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You searched for: Subject term environmental factors Remove constraint Subject term: environmental factors Subject term dry season Remove constraint Subject term: dry season Text availability Citation in PubAg Remove constraint Text availability: Citation in PubAg
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1. Competitive Interactions of the Striped Plateau Lizard (Sceloporus Virgatus) and the Tree Lizard (Urosaurus Ornatus)

Author:
David C. Smith
Source:
Ecology 1981 v.62 no.3 pp. 679-687
ISSN:
0012-9658
Subject:
Sceloporus; demography; dry season; elderly; environmental factors; females; lizards; males; meteorological data; mountains; plateaus; population density; survival rate; trees; yearlings; Arizona
Abstract:
... The effect of competition on the demography of two coexisting lizards, the striped plateau lizard (Sceloporus virgatus) and the tree lizard (Urosaurus onatus), was studied experimentally in the Chiricahua Mountains, Arizona, USA. Lizards were marked on six plots, and U. ornatus were removed from two plots, S. virgatus from two plots, and two plots were maintained as controls. Initial lizard popula ...
DOI:
10.2307/1937736

2. Annual Variation in Seedfall, Postdispersal Predation, and Recruitment of a Neotropical Tree

Author:
Eugene W. Schupp
Source:
Ecology 1990 v.71 no.2 pp. 504-515
ISSN:
0012-9658
Subject:
adults; dry season; environmental factors; germination; islands; population density; predators; probability; saplings; seed predation; seedling emergence; seedling production; seedlings; seeds; species recruitment; tropical forests; tropics; understory; Panama
Abstract:
... Knowledge of the dynamics of seed production and seedling recruitment of individual tree species is crucial for a complete understanding of tropical forest dynamics, yet multiyear studies on the seed and young seedling stages of tropical trees are virtually nonexistent. In a 4—yr study of the understory tree Faramea occidentalis on Barro Colorado Island, Panama, I quantified natural levels of viab ...
DOI:
10.2307/1940304

3. Fish Community Structure in Dry‐Season Stream Pools

Author:
Teresa A. Capone; James A. Kushlan
Source:
Ecology 1991 v.72 no.3 pp. 983-992
ISSN:
0012-9658
Subject:
canopy; cluster analysis; community structure; drainage; dry season; environmental factors; factor analysis; fish; fish communities; habitats; pH; prediction; rivers; species diversity; streams; Texas
Abstract:
... Fish assemblage patterns were examined in 40 dry—season pools in a hydrologically variable river drainage in northeast Texas, to test the hypothesis that fish assemblage structure is correlated with environmental gradients of habitat characteristics. The study focused on two questions: 1. Do discrete, indentifiable fish assemblage patterns exist? 2. If so, how are they related to environmental con ...
DOI:
10.2307/1940598

4. Importance of temperature and seed water content on the induction of imaginal polymorphism in Callosobruchus maculatus

Author:
Ouedraogo, P.A.; Monge, J.P.; Huignard, J.
Source:
Entomologia experimentalis et applicata 1991 v.59 no.1 pp. 59-66
ISSN:
0013-8703
Subject:
Callosobruchus maculatus; Vigna unguiculata; adults; dry season; environmental factors; flight; insects; larvae; seeds; temperature; water content; wet season; Niger
Abstract:
... Callosobruchus maculatus (F.) is a tropical insect (Coleoptera: Bruchidae) that develops in Vigna unguiculata (Walp) seeds. In this beetle, there are two distinct adult forms that differ in their morphology, physiology and behaviour, the flight form and the flightless form. The development of C. maculatus is analyzed in a traditional store in Niger. During the dry season, 6 to 7 generations of the ...
DOI:
10.1111/j.1570-7458.1991.tb01486.x

5. Processes Regulating Soil Emissions of NO and N^2O in a Seasonally Dry Tropical Forest

Author:
E. A. Davidson; P. A. Matson; P. M. Vitousek; R. Riley; K. Dunkin; G. Garcia-Mendez; J. M. Maass
Source:
Ecology 1993 v.74 no.1 pp. 130-139
ISSN:
0012-9658
Subject:
ammonium compounds; carbon dioxide; denitrification; denitrifying bacteria; dry season; environmental factors; field experimentation; gases; greenhouse gas emissions; mineralization; models; nitric oxide; nitrification; nitrites; nitrogen; nitrous oxide; soil water; tropical forests; wet season; Mexico
Abstract:
... While much is known about control of production of NO and N₂O by nitrifying and denitrifying bacteria at the cellular level, application of this knowledge to field studies has not yielded unifying concepts that are widely applicable and that foster understanding of global sources of these atmospheric trace gases. We applied a simple conceptual model to the investigation of sources of NO and N₂O an ...
DOI:
10.2307/1939508

6. Field Performance of Select Tepary Bean Germplasm in the Tropics

Author:
P. N. Miklas; J. C. Rosas; J. S. Beaver; L. Telek; G. F. Freytag
Source:
Crop science 1994 v.34 no.6 pp. 1639-1644
ISSN:
0011-183X
Subject:
dry season; Phaseolus acutifolius; germplasm; variety trials; seeds; protein content; tropics; environmental factors; crop yield; antinutritional factors; anthocyanidins; screening; Puerto Rico
Abstract:
... Dry edible bean (Phaseolus vulgaris L.), a staple food crop for many tropical countries, is not well adapted to the hot temperatures and low rainfall that prevail during the dry seasons. Cultivated tepary bean (Phaseolus acutifolius A. Gray var. latifolius Freeman), an edible small-seeded desert annual with extreme tolerance to drought, may be suited to dry-season production in the tropics. To tes ...
DOI:
10.2135/cropsci1994.0011183X003400060040x

7. Environmental and physiological regulation of transpiration in tropical forest gap species: the influence of boundary layer and hydraulic properties

Author:
Meinzer, F.C.; Goldstein, G.; Jackson, P.; Holbrook, N.M.; Gutierrez, M.V.; Cavelier, J.
Source:
Oecologia 1995 v.101 no.4 pp. 514-522
ISSN:
0029-8549
Subject:
dry season; pioneer species; tropical forests; leaf water potential; environmental factors; canopy gaps; stomata; leaf conductance
DOI:
10.1007/BF00329432

8. Factors affecting Locusta migratoria migratorioides egg development and survival in the Lake Chad basin outbreak area

Author:
Ackonor, J.B.; Vajime, C.K.
Source:
International journal of pest management 1995 v.41 no.2 pp. 87-96
ISSN:
0967-0874
Subject:
dry season; soil temperature; ova; soil water content; soil density; air temperature; edaphic factors; wet season; seasonal variation; Locusta migratoria; soil texture; soil pH; biological development; mortality; Nigeria; Cameroon
DOI:
10.1080/09670879509371929

9. Effects of Nutrients and Hydroperiod on Typha, Cladium, and Eleocharis: Implications for Everglades Restoration

Author:
S. Newman; J. B. Grace; J. W. Koebel
Source:
Ecological applications 1996 v.6 no.3 pp. 774-783
ISSN:
1051-0761
Subject:
Cladium mariscus subsp. jamaicense; Eleocharis; Typha domingensis; biogeography; biomass; dry season; environmental factors; growing season; leaves; life history; nitrogen; nutrient content; nutrients; phosphorus; shoots; soil; surface water; tanks; wet season
Abstract:
... The recent expansion of Typha domingensis (Typha) into areas of the Everglades previously dominated by Cladium jamaicense (Cladium) communities has led to competing hypotheses about the importance of nutrient concentration vs. hydroperiod in controlling the distribution of these species. In this study, experimental mixtures of Typha domingensis, Cladium jamaicense, and Eleocharis interstincta (Ele ...
DOI:
10.2307/2269482

10. Sexual maturation and ovarian activity in Rhammatocerus schistocercoides (Orthoptera: Acrididae), a pest grasshopper in the state of Mato Grosso in Brazil

Author:
Launois-Luong, M.; Lecoq, M.
Source:
Environmental entomology 1996 v.25 no.5 pp. 1045-1051
ISSN:
0046-225X
Subject:
Acrididae; sexual maturity; ovarian development; ovarioles; oocytes; vitellogenesis; oviposition; corpus luteum; seasonal development; dry season; wet season; environmental factors; Brazil
Abstract:
... Sexual maturation and ovarian activity were studied in Rhammatocerus schistocercoides (Rehn, 1906) under natural conditions in the state of Mato Grosso in Brazil, a recognized outbreak area of this species. The end of the dry season marks the onset of sexual maturation, which could be associated with the photoperiod but not with the arrival of the 1st rains. This means that sexual maturation, alth ...
DOI:
10.1093/ee/25.5.1045

11. Notes on the Ecology of a Natural Glossina austeni (Diptera: Glossinidae) Population in the Jozani Forest, Unguja Island of Zanzibar

Author:
Marc J. B. Vreysen; Issa S. Khamis
Source:
International journal of tropical insect science 1999 v.19 no.2-3 pp. 99-108
ISSN:
1742-7592
Subject:
Glossina austeni; breeding; dry season; environmental factors; females; forests; habitats; males; sex ratio; wet season; Zanzibar
Abstract:
... Studies were made of Glossina austeni captured with sticky panels during the dry and wet season in the northern and central part of the Jozani forest on the island of Unguja, Zanzibar. The density of the fly population was significantly higher in the northern part of the forest than in the central. Female and male daily catches remained stable in time in the northern part of the forest but the den ...
DOI:
10.1017/S1742758400019354

12. Alternative life cycle strategies in the West African reed frog Hyperolius nitidulus: the answer to an unpredictable environment?

Author:
Kathrin P. Lampert; Eduard K. Linsenmair
Source:
Oecologia 2002 v.130 no.3 pp. 364-372
ISSN:
0029-8549
Subject:
adults; dry season; eggs; environmental factors; estivation; females; frogs; males; rain; reproduction; risk; savannas; wet season
Abstract:
... The West African reed frog Hyperolius nitidulus, mainly known for its extraordinary aestivation behaviour and physiology, is able to vary its reproductive strategy in response to environmental conditions. We found indirect as well as direct evidence for individuals not following the generally assumed one year-one generation life cycle including an extended aestivation phase during the dry season, ...
DOI:
10.1007/s00442-001-0821-4

13. The effect of some ecological factors on the intestinal parasite loads of the Asian elephant (Elephas maximus) in southern India

Author:
T. N. C. Vidya; R. Sukumar
Source:
Journal of biosciences 2002 v.27 no.5 pp. 521-528
ISSN:
0250-5991
Subject:
Elephas maximus; body condition; dry season; eggs; environmental factors; feces; forests; habitats; herds; intestines; parasite load; parasites; temporal variation; wet season; India
Abstract:
... Some ecological factors that might potentially influence intestinal parasite loads in the Asian elephant (Elephas maximus Linn.) were investigated in the Nilgiris, southern India. Fresh dung samples from identified animals were analysed, and the number of eggs/g of dung used as an index of parasite load. Comparisons across seasons and habitats revealed that parasite loads were significantly higher ...
DOI:
10.1007/BF02705050

14. Effects of controlled seasonal breeding on reproductive performance traits of pastoral goat herds in northern Kenya

Author:
Hary, Ingo; Schwartz, Horst-Jurgen; King, John M.; Carles, Alan B.
Source:
Journal of arid environments 2003 v.55 no.3 pp. 555-579
ISSN:
0140-1963
Subject:
breeding; conception; dry season; environmental factors; fecundity; flocks; goats; herds; mortality; parturition; progeny; reproductive performance; reproductive traits; seasonal variation; statistical analysis; weaning; Kenya
Abstract:
... A systematic breeding programme in a herd of Small East African goats was initiated in Isiolo District, northern Kenya. The study was undertaken to assess the effect of controlled seasonal breeding on the biological productivity of pastoral goat flocks. This paper reports the results of statistical analyses of reproductive performance traits (conception, abortion, birth, prolificacy, fecundity and ...
DOI:
10.1016/S0140-1963(02)00269-0

15. Resource use conflicts: the future of the Kalahari ecosystem

Author:
Moleele, N.N.; Mainah, J.
Source:
Journal of arid environments 2003 v.54 no.2 pp. 405-423
ISSN:
0140-1963
Subject:
anthropogenic activities; cattle; conservation areas; data collection; dry season; ecosystems; environmental factors; forage quality; grasses; grazing; households; human settlements; land cover; land suitability; models; photographs; plant communities; resource management; species diversity; vegetation; zoning
Abstract:
... The Kalahari ecosystem is characterized by natural resource conflicts and land-use pressure resulting from intensification of human activities. This paper addresses three issues of concern associated with the Kalahari ecosystem resource management: (i) the major land-use/land cover shifts in the Kalahari ecosystem since 1970 and the resulting pattern in vegetation species composition, cover and de ...
DOI:
10.1006/jare.2002.1099

16. Surface‐water constraints on herbivore foraging in the kruger national park, south africa

Author:
Jessica V. Redfern; Rina Grant; Harry Biggs; Wayne M. Getz
Source:
Ecology 2003 v.84 no.8 pp. 2092-2107
ISSN:
0012-9658
Subject:
buffaloes; census data; data collection; digestive system; dry season; ecosystems; environmental factors; forage quality; herbivores; landscapes; national parks; nutrient requirements; population density; regression analysis; savannas; surface water; wildebeest; zebras; South Africa
Abstract:
... At a landscape scale, the combined influence of biotic and abiotic factors may determine the distribution patterns of large herbivores in African savanna ecosystems. Herbivores foraging in these ecosystems may become nutritionally stressed during an annual dry season when both forage quality and quantity are reduced. Additionally, the locations of water sources may impose a landscape‐scale constra ...
DOI:
10.1890/01-0625

17. Water use in a Grevillea robusta–maize overstorey agroforestry system in semi-arid Kenya

Author:
Lott, J.E.; Khan, A.A.H.; Black, C.R.; Ong, C.K.
Source:
Forest ecology and management 2003 v.180 no.1-3 pp. 45–59
ISSN:
0378-1127
Subject:
Grevillea robusta; Zea mays; agroforestry; biomass production; corn; crop losses; crop production; cropping systems; crops; dry season; environmental factors; leaf area; overstory; rain; sap flow; soil profiles; transpiration; trees; Kenya
Abstract:
... Novel approaches involving a combination of sap flow measurements of transpiration and allometric estimates of biomass production were used to determine seasonal water use by trees and crops in agroforestry systems. The results were used to test the hypothesis that agroforestry may improve productivity by capturing a greater proportion of annual rainfall than annual crops. Grevillea robusta A. Cun ...
DOI:
10.1016/S0378-1127(02)00603-5

18. Distribution and status of the hippopotamids in the Ivory Coast

Author:
Harald H. Roth; Bernd Hoppe-Dominik; Michael Mühlenberg; Bernd Steinhauer-Burkart; Frauke Fischer
Source:
African zoology 2004 v.39 no.2 pp. 211-224
ISSN:
2224-073X
Subject:
Hexaprotodon liberiensis; Hippopotamus amphibius; aerial surveys; coasts; conservation areas; dry season; environmental factors; estuaries; forest reserves; forestry; habitats; herds; home range; interviews; national parks; population density; questionnaires; rain forests; rivers; sympatry; wet season; Cote d'Ivoire
Abstract:
... The distribution and relative abundance of the common hippo (Hippopotamus amphibius) and the pygmy hippo (Hexaprotodon liberiensis) was studied in the Ivory Coast between 1978 and 1986 by questionnaire survey, interviews, local field investigations and aerial censuses. In addition, the size of the pygmy hippo population in the Tai Forest area was monitored between 1995 and 2001. At the time of the ...
DOI:
10.1080/15627020.2004.11657218

19. Seed bank dynamics and tree-fall gaps in a northwestern Mexican Quercus-Pinus forest

Author:
Arriaga Laura; Mercado Carmen
Source:
Journal of vegetation science 2004 v.15 no.5 pp. 661-668
ISSN:
1100-9233
Subject:
Asteraceae; Euphorbiaceae; Fabaceae; Lamiaceae; botanical composition; buried seeds; death; dry season; environmental factors; forests; germination; seasonal variation; soil; trees; wet season; Mexico
Abstract:
... Questions: How does the seed bank respond to different types of tree-fall gaps and seasonal variations? How does the soil seed bank influence recovery of the standing vegetation in the mature forest and tree-fall gaps?Location: 1800 - 2020 m a.s.l., Quercus-Pinus forest, Baja California Sur, Mexico.Methods: Seed size, species composition and germination were estimated under different environmental ...
DOI:
10.1658/1100-9233(2004)015[0661:SBDATG]2.0.CO;2

20. Water table salinity, rainfall and water use by umbrella pine trees (Pinus pinea L.)

Author:
Teobaldelli, M.; Mencuccini, M.; Piussi, P.
Source:
Plant ecology 2004 v.171 no.1-2 pp. 23-33
ISSN:
1385-0237
Subject:
Pinus pinea; coasts; drainage; dry season; electrical conductivity; environmental factors; freshwater; heat; high water table; hills; osmotic pressure; rain; salinity; sandy soils; sap; sap flow; seasonal variation; seawater; soil water movement; spring; summer; surface water; transpiration; trees; water potential; winter; Italy
Abstract:
... The interactions between environmental conditions, particularly precipitation and water table salinity and tree water use were studied at the pinewood of Alberese, a stand of umbrella pine (Pinus pinea L.) trees growing along the Southern coastline of Tuscany and characterised by a sandy soil and a high water table level (ranging between 1 and 2 m depth). Data on sap flow, measured by heat pulse, ...