Temat: savanna - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Diversity and trophic structure of bird’s communities in Brazilian Savanna areas of the Cuiabá River basin
Autorzy:: Dario, Fabio Rossano
Sandrini, Marcos Paulo
Tematy:: Brazil
Savanna
avifauna
bird
ecology; Pokaż więcej
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/1031776.pdf Link otwiera się w nowym oknie
Opis:: We analyzed the differences in composition, richness, and abundance of birds in different forest fragments of the Brazilian Savanna in the Cuiabá River basin, Mato Grosso State, Brazil, and we demonstrated the variations in richness and abundance of birds between different trophic guilds. We used point counts to characterize the avifauna. Sampling was conducted in two seasons: summer and winter of 2018 in a total of 36 hours distributed in 108 samples. A total of 743 contacts were obtained belonging to 87 bird species distributed among 17 orders and 33 families and categorized in 16 trophic guilds. The omnivorous and insectivorous birds composed most of the community. For each species, we calculated the abundance index value that showed our study site had a large number of species with low index and few species with intermediate to high index compared to the pattern observed in other surveys. Our study area was characterized by high species diversity for both periods studied. The Shannon-Weaver diversity index for our study areas was 3.90 for the summer period and 3.77 for the winter period. Equitability was high, 0.82 for the summer period and 0.79 for the winter period, suggesting the number of species registered in our study site represented the maximum capacity the areas can shelter. Our results show that despite being a secondary and fragmented forest the study area was characterized by a diverse avian community. The ciliary forest studied that follows the Cuiabá River, although fragmented and isolated by extensive degraded areas and occupied by pastures and agricultural crops, they are important natural environments to maintain bird diversity.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Assessment of Soil Based Heavy Metals from Anthropogenic Activities in Kaduna Northern Guinea Savanna of Nigeria
Autorzy:: Sodimu, A. I.
Onwumere, G. B.
Yilwa, V. M.
Tematy:: Anthropogenic
Assessment
Heavy Metals
Northern Guinea Savanna
Soil Based; Pokaż więcej
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/1075622.pdf Link otwiera się w nowym oknie
Opis:: Soil based heavy metals resulting from anthropogenic activities in Kaduna Northern Guinea Savanna of Nigeria was assessed. Soil samples were collected at a depth of 15m with a soil auger using 50m × 50m plots laid in each of the four sites (ST1, ST2, ST3 and ST4) replicated three (3) times to make a total of twelve (12) plots. The assessment was done in two (2) seasons (wet season and dry season). Soil based heavy metals were carried out according to AOAC using atomic absorption spectrophotometer. The data collected were analyzed with descriptive statistic as well as Anova using SPSS package. Eleven (11) soil based heavy metals; V, Cr, Mn, Zn, Co, Ni, Cu, Br, Pb, Cd and Fe were revealed in each of the selected sites. There were significant differences (P<0.05) when concentration are compared between seasons within the sites. Higher soil heavy based metals were recorded in the wet season than the dry season in all the sites. The sites behind Kaduna Refinery and Petrochemical Company (KRPC) is significantly higher (P<0.05) in concentration than all other sites while the control (Kamaku National Park) has the least concentration (P<0.05). Pearson correlation showed a significant and positive association between soil based heavy metals and automobile / farming activities in wet season (R = 0.40**) and dry season (R = 0.95**) as well as in industrial / farming activities in wet season (R = 0.88**) and dry season (R = 0.94**) at 0.01 probability level. It is concluded that variation in the assessment of soil based heavy metals in the selected sites are influenced by anthropogenic activities (mainly agriculture and fossil fuel combustion) in the sites. It is recommended that there should be provision for licensing and registration of all major industrial polluters and monitoring their compliance with laid down standard; further research into anthropogenic air pollution and farming activities which leads to increase in soil based heavy metals especially in the Northern Guinea Savanna where there are limited research should be investigated.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Devastating Effect of Forest Degradation in Southern Guinea Savanna of Nigeria
Autorzy:: Buochuama, A.
Akande, O. A.
Buochuama, M. O.
Tematy:: Nigeria
devastating
ecological
forest degradation
guinea savanna; Pokaż więcej
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/1161466.pdf Link otwiera się w nowym oknie
Opis:: Forest degradation poses serious ecological consequences to the environment. Therefore, this research deals with the devastating effect of forest degradation in southern guineas savannah of Nigeria. In this study, about one hundred and twenty questionnaires (120) were used to collect data from a number of villages in Wawa community. Descriptive statistics was used in the data analysis. Construction, poverty, population increase, and farming were some of the sources of forest degradation in the study area. The consequences of forest degradation in the study area were erosion, desertification, wildlife habitat destruction and global warming/ climate change. The study noted that the solutions for curbing forest degradations include the following; agroforestry, creation of more forest reserves afforestation/ reforestation, implementation of forest laws and policies and public enlightenment on the consequences of forest degradation.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Hibiskus rhodanthus (Malvaceae) : an interesting plant species in Southeastern Africa
Autorzy:: Medwecka-Kornaś, Anna
Opis:: Hibiscus rhodanthus Gürke ex Schinz (Malvaceae) is a small plant with bright red flowers, herbaceous in the above-ground parts and permanently woody in the underground rootstock. It belongs to the ‘geoxylic suffrutices’, a group of pyrophytes. The author had an opportunity to observe H. rhodanthus in Zambia, Southeastern Africa. This paper contains information on the genus Hibiscus L., the morphology of the studied species, and the vegetation and climate of Zambia. Newly ascertained localities of H. rhodanthus are listed, and data on its occurrence on two permanent plots in tall-grass savanna near Lusaka are given. The above-ground parts of H. rhodanthus usually develop soon after burning of vegetation, mainly in the second part of the dry season. Flowers may occur first, then stems and leaves, in full development during the rainy season. The geographic distribution and theories of the origin of ‘geoxylic suffrutices’ are discussed.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 5.

Tytuł:: Performance of some forage rass species in the Southern Guinea Savannah agro-ecological zone in Nasarawa State of Nigeria
Autorzy:: Okwori, Abel Ibrahim
Abdulsalam, Mansur
Tematy:: Forage species
Nasarawa State
Performance
Southern Guinea Savanna; Pokaż więcej
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/1179173.pdf Link otwiera się w nowym oknie
Opis:: The absence of improved forage grass species in Nasarawa ecological zone has prompted a study to identify improved species for use. A potted screen house study was therfore conducted using four improved forage grass species obtained from the National Animal Production Research Institute (NAPRI) Shika near Zaria, Nigeria. The four forage species were thus sown into four soil types obtained from four locations in Nasarawa State arranged in a randomized complete block design. Records were taken for percent emergence, weekly growth rate and dry matter yields. The results indicated that there was significant differences in the percent emergence, weekly growth rate and dry matter yield.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Identifying Climatic Change Adaptations of Crops in Orinoco Basin Oxisols Through Study of Soil Water Availability
Autorzy:: Gallo, Oscar Javier
Loaiza-Úsuga, Juan Carlos
Rodríguez, Betty Jazmín Gutiérrez
Quiñones, Andres Javier Peña
Riobo, Jaime Humberto Bernal
Tematy:: soil moisture
savanna
water balance
climatic change
tropic environment; Pokaż więcej
Wydawca:: Polskie Towarzystwo Inżynierii Ekologicznej
Powiązania:: https://bibliotekanauki.pl/articles/59113880.pdf Link otwiera się w nowym oknie
Opis:: Crop yield variations in the Orinoquía region – Colombia, are primarily associated with extreme precipitation events. Therefore, studying crop water supplies under naturally variable climate conditions is fundamental in an actual climatic change context. Rainfall data collected in the Quenane sub-basin were analyzed to understand the soil water dynamics in the Orinoco catchment. The basin covers 179 km2 and consists of the piedmont landscape (Eastern Mountain Range) of the Villavicencio Municipality, Department of Meta. This study analyzes the rainfall variability using Pearson correlation analysis, the Mann-Kendall trend analysis, and soil water balance to determine the implications of these factors in crop performance at the basin scale. The results indicated that the spatial distribution of rainfall in the basin responds to a longitudinal average variation of precipitation and that this response is more accentuated (i.e., greater rainfall) toward the west of the basin. Despite the basin being located in the tropical zone, no evidence was found regarding the effect of the El Niño Southern Oscillation on rainfall patterns. Yet, the temporal analysis revealed some years with extreme rainfall values and high-uncertainty levels during transitions between wet and dry periods. During these transition periods, a greater potential for effects on farm yields exists due to the variable cumulative rainfall observed during recent years. The time series trend analysis revealed changes in rainfall patterns at different scales (weekly and yearly) and distribution based on the decrease of rainy days per week and year. This trend is much more accentuated during the second half of the year, generating uncertainty and reducing farm yields throughout the basin.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: The Impact of Gas Flaring from the Kaduna Refinery and Petrochemical Industry (KRPC) on Plant Diversity in Kaduna Northern Guinea Savanna Eco-Region of Nigeria
Autorzy:: Sodimu, A. I.
Yilwa, V. M.
Onwumere, G. B.
Tematy:: Eco region
Impact
Kaduna Refinery
Northern Guinea Savanna
Plant diversity; Pokaż więcej
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/1182487.pdf Link otwiera się w nowym oknie
Opis:: 50m x 50m plots were laid in each of the two (2) sites, replicated three (3) times to make a total of six (6) plots in all. The plants in all the sites were grouped into four (4) growth forms (trees, shrubs, herbs and grasses) which are evaluated using line transect method. The data were analyzed using student ‘t’ test and biodiversity index was calculated using Shannon Weiner method. The result showed that the population density and biodiversity index of the plant composition in the control site are more than that of the flare site from all the growth forms assessed due to combustion of fossil fuel and the heat generated from the flaring site. The mean of the plant species at the flare site is 663.00 and the control site is 1495.00. The standard deviation for the flare site is 4.32 and that of the control site is 2.51. The paired sample ‘t’ test correlation coefficient showed that there is strongly positive correlation efficient of 0.86 between plant diversity at the flare site and those at the control site. However, from the above analysis, it is concluded that there is statistically significant difference between plant species in the flare site and the control site (p<0.05) due to gas flaring that kills and suppress the growth of plants in the flare site. It is recommended that gas should be harnessed for use as liquefied natural gas. Government and NGOs should embark on an aggressive afforestation programme. Government should also enforce law against flaring, major industrial polluters and monitor their compliance with laid down standard.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Effects of Intra-Row Spacing of Pearl Millet (Pennisetum glaucum (L.) R. Br) and Cropping Systems on the Productivity of Soybean-Pearl Millet Intercropping System in a Southern Guinea Savanna Location, Nigeria. (Part I)
Autorzy:: Ijoyah, Michael Ojore
Hashin, Ishaya Kunzan
Geza, Richard Ter
Tematy:: Savanna
Southern Guinea
cropping systems
intra-row spacing
pearl millet
soybean; Pokaż więcej
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/1193958.pdf Link otwiera się w nowym oknie
Opis:: A field experiment was conducted from June to November, during the 2013 and 2014 cropping seasons at the Research Farm, University of Agriculture, Makurdi, Nigeria, to evaluate the effects of intra-row spacing of pearl millet and cropping systems on the productivity of soybean-pearl millet intercrop and to assess the yield advantages of the intercropping system. The experiment was a 3x4 factorial arrangement of treatments, fitted in a randomized complete block design (RCBD), replicated four times. The cropping systems (sole soybean, sole pearl millet and soybean-pearl millet intercrop) constituted the main plots, while the intra-row spacing of pearl millet (15 cm, 20 cm, 25 cm and 30 cm) into soybean were allocated to the subplots. Results of study showed that to maximize intercrop yields of soybean and pearl millet in a soybean-pearl millet intercrop, the optimal intra-row spacing for pearl millet is 30 cm. Intercropping soybean and pearl millet significantly (P ≤ 0.05) reduced yields of soybean (25.0 % and 22.2 % respectively, in years 2013 and 2014) and that of pearl millet (34.4 % and 33.3 % respectively, in years 2013 and 2014). Though, the highest land equivalent ratio (LER) values, highest land equivalent coefficient (LEC) values and lowest competitive ratio (CR) values were recorded for pearl millet sown into soybean at the intra-row spacing of 15 cm, however, highest aggressivity was obtained sowing pearl millet into soybean at the intra-row spacing of 25 cm, the level at which both crops dominated each other.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: The paleoecology of the Late Miocene mammals from the Optima Local Fauna of Oklahoma, USA
Autorzy:: Frederickson, Joseph A.
Cohen, Joshua E.
Engel, Michael H.
Hunt, Tyler C.
Wilbert, Greg A.
Castaneda, Olga S.
Czaplewski, Nicholas J.
Tematy:: Mammalia
grassland
tooth breakage
Neogene
North America
mesowear
savanna
stable isotopes; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/2216233.pdf Link otwiera się w nowym oknie
Opis:: The Optima Local Fauna represents an important glimpse into the ecological transition between savannah and grassland during the late Miocene (Hemphillian) of what is now the southcentral Great Plains of North America. Though dominated by horses, herbivores from the Optima are morphologically diverse, bearing adaptations for both browsing and grazing lifestyles. Likewise, the carnivorans show similar ranges of size and presumed dietary behavior. In this study, we used carbonate isotope, mesowear, and tooth breakage and wear analyses to investigate the dietary complexity of mammals from a single site collected by the Oklahoma Museum of Natural History. Seventeen taxa were analyzed, including five perissodactyls (Teleoceras hicksi, Dinohippus interpolatus, Neohipparion eurystyle, Nannippus ingenuus, and Astro hippus ansae), four artiodactyls (Texoceros guymonensis, Pediomeryx hemphillensis, Megatylopus matthewi, and Platy gonus sp.), a single proboscidean (Mammut sp.), two rodents (Dipoides indet. and Umbogaulus monodon), and five carni vorans (Agriotherium schneideri, Amphimachairodus coloradensis, Borophagus secundus, Eucyon davisi, Pliotaxi dea cf. nevadensis). Both stable isotope analysis and dental mesowear indicate a broad dietary partitioning occurred among the Optima herbivores, where the artiodactyls were identified as mixed feeders and the perissodactyls were recovered as grazers. In the carnivorans, the large felid Amphimachairodus coloradensis was a hypercarnivore with limited tooth breakage and an enriched δ13C signature, indicating low carcass utilization and a prey preference for horses. The canids had a more generalized diet, with B. secundus showing a greater proportional consumption of carcasses through a higher tooth breakage rate. The large ursid Agriotherium schneideri is here interpreted as an omnivore based on depleted δ13 C values. Overall, we found evidence for a diversity of dietary niches in both carnivores and herbivores during the late Hemphillian in Oklahoma, likely driven by the expansion of grasslands in the region.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Revisiting the Logistic Growth with Random Disturbances
Ponowna analiza modelu logistycznego z losowymi skokami
Autorzy:: Klimasara, Paweł
Tematy:: population dynamics
logistic growth
ecological modeling
savanna
savanna question
stationary density
piecewise deterministic markov processe
dynamika populacyjna
równanie logistyczne
modelowanie ekosystemów
sawanna
gęstość stacjonarna
kawałkami deterministyczne procesy Markova; Pokaż więcej
Wydawca:: Polskie Towarzystwo Matematyczne
Powiązania:: https://bibliotekanauki.pl/articles/953278.pdf Link otwiera się w nowym oknie
Opis:: Modele populacyjne oparte o równanie logistyczne wziaz sa popularne w modelowaniu ekosytemów i pozwalaja lepiej zrozumiec rózne zjawiska. W tym artykule rozwazamy prosty 1-wymiarowy model sawanny zaproponowany przez D’Odorico, Laio i Ridolfi’ego w pracy [5], który jest modelem współistnienia traw i drzew na sawannach indukowanego losowymi pozarami. Jednak zamiast wprowadzac ubytki biomasy spowodowane wystepowaniem pozarów bezposrednio do równan modelu, definiujemy odpowiedni proces stochastyczny. Nastepnie badamy go z wykorzystaniem teorii półgrup stochastycznych. Zasadniczym wynikiem jest twierdzenie 3.1 okreslajace, kiedy przedstawiony model moze opisywac stabilne współistnienie traw i drzew charakterystyczne dla sawann. Mianowicie przy spełnionym warunku (7) istnieje jedyny absolutnie ciagły rozkład stacjonarny biomasy drzew, do którego cały układ bedzie dazył, natomiast w sytuacji (8) taki rozkład nie istnieje. Powyzszy wynik mozna łatwo przeniesc na wyzsze wymiary i zastosowac np. w dwuwymiarowym modelu podanym w poprzedniej pracy (na ten temat) autora i Marty Tyran-Kaminskiej [7].
The logistic growth population model still can help explain ecological phenomena. We consider a simple 1-dimensional model of savanna introduced by D’Odorico, Laio, and Ridolfi [A probabilistic analysis of fire-induced tree-grass coexistence in savannas. The American Naturalist 167, 2006] which is in fact a model of tree-grass coexistence driven by stochastic fire. We provide an appropriate stochastic process for this model and study it using the stochastic semigroup theory. Finally, we give the condition inducing the existence of a unique stationary distribution of woody biomass.
Dostawca treści:: Biblioteka Nauki

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