scholarly journals Temporal Variability of Soil Reaction Among Surface and Near-Surface Horizons of Soils of Dissimilar Lithology in a Humid Tropical Environment

2021 ◽  
Vol 10 (1) ◽  
pp. 99-111
Author(s):  
Emmanuel Onweremadu ◽  
Bernadine Aririguzo ◽  
Nnaemeka Okoli ◽  
Isaiah Afangide

The study investigated changes in soil reaction among surface and near surface horizons of four soil groups as affected by wet and dry seasons in Southeastern Nigeria. A geological map of the area guided soil sampling. Free survey approach was used in locating soil profiles. Soil samples were collected based on horizon differentiation and samples were collected from the AB-horizon (near-surface) and the A-horizon (Surface). Routine laboratory analyses were conducted on these soil samples after sieving through a 2-mm sieve. Data were subjected to analysis of variance (ANOVA) using SAS Statistical Computer Package. There were significant (p<0.05) changes in soil reaction in A- and AB-horizons in the dry seasons of 2016 and 2017.  Similarly, in the wet season, soil pH varied significantly (p<0.05) in 2016 and 2017. Soil reaction significantly (p<0.05) differed in AB-horizons in both 2016 and 2017 irrespective of the season. All soil samples were acidic irrespective of lithologic material and season with pH values ranging from 4.20-5.60 and 3.31-5.42 in the A- and AB-horizons, respectively.

2002 ◽  
Vol 62 (2) ◽  
pp. 339-346 ◽  
Author(s):  
J. RAGUSA-NETTO

Figs are a remarkable food resource to frugivores, mainly in periods of general fruit scarcity. Ficus calyptroceras Miq. (Moraceae) is the only fig species in a type of dry forest in western Brazil. In this study I examined the fruiting pattern as well as fig consumption by birds in F. calyptroceras. Although rainfall was highly seasonal, fruiting was aseasonal, since the monthly proportion of fruiting trees ranged from 4% to 14% (N = 50 trees). I recorded 22 bird species feeding on figs. In the wet season 20 bird species ate figs, while in the dry season 13 did. Parrots were the most important consumers. This group removed 72% and 40% of the figs consumed in the wet and dry seasons, respectively. No bird species increases fig consumption from dry to wet season. However, a group of bird species assumed as seed dispersers largely increases fig consumption from wet to dry season, suggesting the importance of this resource in the period of fruit scarcity. The results of this study points out the remarkable role that F. calyptroceras plays to frugivorous birds, in such a dry forest, since its fruits were widely consumed and were available all year round.


2020 ◽  
pp. 175815592096320
Author(s):  
Alemayehu Shiferaw ◽  
Dereje Yazezew

The diversity, distribution, and relative abundance of avifauna were studied at and Around Ansas Dam, Debre Berhan Town, Ethiopia, from early September 2018 to early February 2019, covering both wet and dry seasons. Line transect technique was employed to study the diversity, abundance and distribution of birds species in the farmland site while total count employed on the dam. Data were collected in both wet and dry seasons from 6:30 to10:00 early morning and 15:30 to 18.00 late afternoon, when birds are more active. The data were analyzed with Shannon-Weiner Index, Simpson Index, Evenness Index, and relative abundance. A total of 45 bird species (35 in the dam and 22 in the farmland) belonging to nine orders and 21 families were recorded during the study period. Order Passeriformes (37.8%) followed by order Charadriformes (24.4%) were represented highest number. From all identified species at Ansas Dam and surrounding farmland, Abyssinian longclaw, Black-headed siskins, White-tailed swallow, Blue-winged goose, and Spot-breasted lapwing were endemic birds to Ethiopia. The highest Shannon diversity (H′ = 2.1) was recorded in dam during the dry season while the lowest (H′ = 1.78) was recorded during wet season in farmland. However, the Simpson diversity Index of avian species indicated relatively higher avian species diversity during the dry season in dam (D = 0.80) than farmland (D = 0.71) habitat. Evenness was highest in the dam (E = 0.65) and lowest in the farmland (E = 0.58) habitat. More avian species similarity (SI = 0.42) at farmland and dam habitat during the wet season but least similarity (SI = 0.2) was observed during the dry season. Most birds had scored rare in the ordinal scale while few species with abundant and uncommon ranks in both habitats and seasons. Conservation of the different charismatic bird species should be taken as an important component of wildlife management plan in the area.


Nematology ◽  
2009 ◽  
Vol 11 (1) ◽  
pp. 117-127 ◽  
Author(s):  
Johannes Hallmann ◽  
Tesfamariam Mekete ◽  
Richard Sikora ◽  
Sebastian Kiewnick

AbstractEndophytic bacteria were isolated from coffee roots in Ethiopia and identified by Fatty Acid Methyl Ester-Gas Chromatography (FAME-GC). A total of 201 and 114 endophytic bacteria were isolated and identified during the wet and dry seasons, respectively. The most abundant genera were Pseudomonas, Bacillus, Agrobacterium, Stenotrophomonas and Enterobacter. Population densities were higher during the wet season than the dry season ranging from 5.2 × 103 to 2.07 × 106 cfu (g fresh root weight)–1. Culture filtrates of the bacterial isolates showed nematicidal effects of between 38 and 98%. The most active strains were Agrobacterium radiobacter, Bacillus pumilus, B. brevis, B. megaterium, B. mycoides, B. licheniformis, Chryseobacterium balustinum, Cedecea davisae, Cytophaga johnsonae, Lactobacillus paracasei, Micrococcus luteus, M. halobius, Pseudomonas syringae and Stenotrophomonas maltophilia. Bacillus pumilus and B. mycoides were most effective in reducing the number of galls and egg masses caused by M. incognita by 33 and 39%, respectively.


1969 ◽  
Vol 93 (3-4) ◽  
pp. 207-221
Author(s):  
Matthew Ciomperlik ◽  
Chang Chi Chu ◽  
Jason Carlson ◽  
Marcus Richards ◽  
Thomas J. Henneberry

The insect populations in hot pepper, Capsicum chinense L. (Solanaceae), were surveyed in Georgetown, St. Vincent, during the 2004 wet and 2005 dry seasons. Modified white, blue, and yellow CC traps were used to capture insects in the plantings. Overall, 69 insect families were captured, 41 of which were captured during both the wet and dry seasons. During the wet season, the greatest numbers of individuals captured were from the Cecidomyiidae, Chironomidae, Chloropidae, Chrysomelidae, Cicadellidae, and Drosophilidae families. During the dry season, the greatest numbers of individuals captured were from Chrysomelidae and Cicadellidae families. The addition of dichlorvos as a killing agent and propylene glycol as an insect preservative to the CC traps increased the number and diversity of insects caught. Additionally, propylene glycol helped to preserve the specimens for taxonomic and genetic determinations. CC traps with yellow bases attracted more insect families than traps with white or blue bases. However, CC traps with blue bases caught more Lonchaeidae during both the wet and dry seasons, and more Tachinidae during the dry season. CC traps with white or yellow trap bases were equally attractive to insects in the families Aleyrodidae, Drosophilidae, Lauxaniidae, and Otitidae.


2011 ◽  
Vol 255-260 ◽  
pp. 3610-3614
Author(s):  
Ming Xia Chen ◽  
He Jian Zhu

The climatic zone is characterized by alternate wet and dry seasons along Fujian coast. The vertisols experience periodic swelling-shrinkage during alternate wet and dry seasons. 16 soil samples from different profiles (0~20cm depth, 20~40cm depth)were collected from different regions in the research area. The paper shows the swelling-shrinkage behavior along Fujian coast in terms of morphology, particle content and physical properties of vertisols, The structure of the soil profile varies with depth, while the profile horizonation is weak. Crack network is usually observed on the surface. In addition, this paper investigated the effect of wetting and drying on the expansive chatacteristics of the soil. The test results show that after each cycle, the height of the soil samples increased. This indicates that the swell-shrink behavior of vertisols is not completely reversible. The swelling-shrinkage characteristics of soils become greater with stickier texture. Compared to undisturbed soils, the swelling-shrinkage behavior of disturbed soils are greater.


1996 ◽  
Vol 23 (5) ◽  
pp. 547 ◽  
Author(s):  
M Evans

Home ranges and movement schedules of sympatric bridled nailtail wallabies, Onychogalea fraenata, and black-striped wallabies, Macropus dorsalis, were studied during wet and dry seasons by radio-tracking. Home ranges of black-striped wallabies (91 ha) were much larger than those of bridled nailtail wallabies (40 ha). Home-range size differed between sexes for bridled nailtail wallabies (males, 59 ha; females, 26 ha), but not for black-striped wallabies. Intraspecific seasonal differences in home-range size were not significant. All home ranges included diurnal shelter habitat, although the preferred type of shelter habitat was different for each species. Movement schedules differed significantly between wet and dry seasons for black-striped wallabies (which made a higher frequency of longer-distance movements during the dry season than during the wet season), but not for bridled nailtail wallabies.


2018 ◽  
Vol 18 (9) ◽  
pp. 6461-6482 ◽  
Author(s):  
Luiz A. T. Machado ◽  
Alan J. P. Calheiros ◽  
Thiago Biscaro ◽  
Scott Giangrande ◽  
Maria A. F. Silva Dias ◽  
...  

Abstract. This study provides an overview of precipitation processes and their sensitivities to environmental conditions in the Central Amazon Basin near Manaus during the GoAmazon2014/5 and ACRIDICON-CHUVA experiments. This study takes advantage of the numerous measurement platforms and instrument systems operating during both campaigns to sample cloud structure and environmental conditions during 2014 and 2015; the rainfall variability among seasons, aerosol loading, land surface type, and topography has been carefully characterized using these data. Differences between the wet and dry seasons were examined from a variety of perspectives. The rainfall rates distribution, total amount of rainfall, and raindrop size distribution (the mass-weighted mean diameter) were quantified over both seasons. The dry season generally exhibited higher rainfall rates than the wet season and included more intense rainfall periods. However, the cumulative rainfall during the wet season was 4 times greater than that during the total dry season rainfall, as shown in the total rainfall accumulation data. The typical size and life cycle of Amazon cloud clusters (observed by satellite) and rain cells (observed by radar) were examined, as were differences in these systems between the seasons. Moreover, monthly mean thermodynamic and dynamic variables were analysed using radiosondes to elucidate the differences in rainfall characteristics during the wet and dry seasons. The sensitivity of rainfall to atmospheric aerosol loading was discussed with regard to mass-weighted mean diameter and rain rate. This topic was evaluated only during the wet season due to the insignificant statistics of rainfall events for different aerosol loading ranges and the low frequency of precipitation events during the dry season. The impacts of aerosols on cloud droplet diameter varied based on droplet size. For the wet season, we observed no dependence between land surface type and rain rate. However, during the dry season, urban areas exhibited the largest rainfall rate tail distribution, and deforested regions exhibited the lowest mean rainfall rate. Airplane measurements were taken to characterize and contrast cloud microphysical properties and processes over forested and deforested regions. Vertical motion was not correlated with cloud droplet sizes, but cloud droplet concentration correlated linearly with vertical motion. Clouds over forested areas contained larger droplets than clouds over pastures at all altitudes. Finally, the connections between topography and rain rate were evaluated, with higher rainfall rates identified at higher elevations during the dry season.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Tewodros Kumssa ◽  
Afework Bekele

A study of the population status, habitat preference, and activity pattern of nonbreeding flamingos was carried out in Lakes Abijata, Shalla, and Chitu, part of the Great Rift Valley, Ethiopia, from 2011 to 2013. The current population status and habitat preference of flamingos in the area are still poorly known. Likewise, data on diurnal and seasonal activity pattern of the species are scarce and this leads to the misunderstanding of how Flamingos use local wetlands throughout the different seasons. Data regarding population size and activity pattern were gathered during the wet and dry seasons. Point-count method was used to estimate the population size. Behaviors were recorded using scan sampling techniques. A total of 53671 individuals representing two species of flamingo were counted during both wet and dry seasons from the three lakes. There were more flamingos during the dry season than the wet season in Lake Abijata contrary to Lakes Shalla and Chitu during the wet season. Lesser flamingos (Phoeniconaias minor) were the most abundant species comprising 95.39%, while Greater Flamingos (Phoenicopterus roseus) accounted for 4.61% of the total population. Lake Abijata is the major stronghold of Lesser Flamingos in the area. There was significant variation in the mean number of both species during the wet and dry season in the different study sites of the lake, respectively. The species were known to use varied habitats within the lakes. The Lesser Flamingo mainly preferred the shoreline and mudflat areas of the lakes. However, Greater Flamingo on several occasions showed preference to offshore area of the lakes. Seasonal average flock sizes were not similar between the species. There was a strong relationship between time allocated to each activity and time of day. Feeding activity varied among daylight hours and was higher in the evening (76.5%) and late morning (74.56%) and least during midday (54%). Some variations in activity breakdown were observed between time blocks and season. Conservation efforts in the park should include the wild flora and fauna not only of the land but also of the aquatic systems. The information in this study will be very useful for the future management of the species in the area.


1991 ◽  
Vol 18 (6) ◽  
pp. 761 ◽  
Author(s):  
DMJS Bowman ◽  
L Mcdonough

A grid of 447 cells (each 50x50 m) was set up in a wet monsoon rain forest on a gradual slope above the Adelaide River floodplain in the Australian Northern Territory. Surveys of pig (Sus scrofa) rooting were carried out at approximately 3-month intervals from November 1988 to September 1989. The pigs had only limited effects on the forest in both the wet and dry seasons. The seasonally flooded swamp communities (Melaleuca forest and sedgeland) were primarily exploited in the dry season; dryland communities ([Eucalyptus] and Lophostemon forests) were exploited during the wet season. Rainfall during the previous wet season may have influenced the pattern of rooting in the dryland forests. Rooting and ground cover were weakly positively related in 3 out of the 4 surveys.


2013 ◽  
Vol 11 (2) ◽  
pp. 57 ◽  
Author(s):  
Sukristiyonubowo Sukristiyonubowo ◽  
D. Gabriels ◽  
M. Verlooc

Terraced paddy field is not only important for rural food security, but also for trapping sediment in the slopping land. The aims of this research were to quantify the amount of incoming and outgoing sediments and to study sediment movement behavior during harrowing and fertilizing under traditional irrigation of terraced paddy field system. This study was carried out at Keji Village, Semarang District, Central Java during two cropping seasons, a wet season 2003/04 and a dry season 2004. A paddy field with eight terraces was selected. The terraces were flat, different in size and descending to the river. Sediment samples were taken at harrowing and fertilizing activities. The results indicated that at harrowing, outgoing sediment was higher than incoming both during the wet and the dry seasons. About 0.53 and 0.27 t ha-1 day-1 of soil were eroded during harrowing in the wet and the dry seasons, respectively. However, a week before and after fertilizing, both in the wet and the dry seasons, the amounts of incoming sediment were higher than the outgoing one. In the wet season, the amounts of incoming sediments were three to four times higher than the outgoing one, both a week before and after fertilizing. During the wet season, about 0.31 and 0.34 t ha-1 day-1 of sediment was yielded a week before and after fertilizing, respectively. During the dry season, the incoming sediments were ten times higher than the outgoing one. On an average the sediment yields were about 0.07 and 0.08 t ha-1 day-1 a week before and after fertilizing, respectively. Terraces having greater areas deposited more sediment than those with smaller sizes. During a week before and after first fertilizing, the total amounts of incoming sediments were 6.44 and 1.19 t ha-1 for the wet and dry seasons, while that of outgoing sediments were 1.89 and 0.14 t ha-1 for the wet and dry seasons, respectively. This indicates that terraced paddy fields are not only producing rice, but also providing environmental service in term of sediment trapping. This external service minimizes sedimentation in the downstream.<p> </p>


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