bioclimatic zone
Recently Published Documents


TOTAL DOCUMENTS

30
(FIVE YEARS 20)

H-INDEX

5
(FIVE YEARS 2)

2021 ◽  
Vol 15 (12) ◽  
pp. e0009990
Author(s):  
Ali Bouattour ◽  
Amine Amri ◽  
Jaber Amine Belkhiria ◽  
Adel Rhim ◽  
Ons Fezaa ◽  
...  

Background Discovered by Nicolle and Comte in 1908 in Tunisia, Leishmania infantum is an intracellular protozoan responsible for zoonotic canine leishmaniosis (CanL) and zoonotic human visceral leishmaniasis (HVL). It is endemic in several regions of the world, including Tunisia, with dogs considered as the main domestic reservoir. The geographic expansion of canine leishmaniosis (CanL) has been linked to global environmental changes that have affected the density and the distribution of its sand fly vectors. Methodology/Principal findings In this study, a cross-sectional epidemiological survey on CanL was carried out in 8 localities in 8 bioclimatic areas of Tunisia. Blood samples were taken from 317 dogs after clinical examination. Collected sera were tested by indirect fluorescent antibody test (IFAT; 1:80) for the presence of anti-Leishmania infantum antibodies. The overall seroprevalence was 58.3% (185/317). Among positive dogs, only 16.7% showed clinical signs suggestive of leishmaniosis. Seroprevalence rates varied from 6.8% to 84.6% and from 28% to 66% by bioclimatic zone and age group, respectively. Serological positivity was not statistically associated with gender. The presence of Leishmania DNA in blood, using PCR, revealed 21.2% (64/302) prevalence in dogs, which varied by bioclimatic zone (7.3% to 31%) and age group (7% to 25%). The entomological survey carried out in the studied localities showed 16 species of the two genera (Phlebotomus and Sergentomyia). P. perniciosus, P. papatasi, and P. perfiliewi were the most dominant species with relative abundances of 34.7%, 25% and 20.4%, respectively. Conclusions/Significance The present report suggests a significant increase of CanL in all bioclimatic areas in Tunisia and confirms the ongoing spread of the infection of dogs to the country’s arid zone. Such an expansion of infection in dog population could be attributed to ecological, agronomic, social and climatic factors that affect the presence and density of the phlebotomine vectors.


Author(s):  
Anatolii Smaliychuk ◽  
Ivan Kruhlov ◽  
Oleg Chaskovskyi ◽  
Ganna Smaliychuk ◽  
Volodymyr Bilanyuk

Ecosystems provide multiple services for humans. Among them, a group of supporting and regulating ecosystem services is often less recognized by people as benefit and has been less studied by researchers. Amid various manifestations of climate change, more attention has been paid to particular subset of this group of services called climate regulating. Despite these there still few quantitative studies in this field. Trying to fill this research gap we conducted a study aimed at exploration of relation between climate regulating ecosystem services and their spatial determinants in the forest landscape within Ukrainian Carpathians. For that we chose the territory within Rakhiv and Tsiachiv districts in Transcarpathian region which represents all diversity of forest mountain ecosystems. For this study we used information on land surface temperature (LST) extracted from Landsat 8 thermal band for summer season of 2015. In order to account for vertical thermal gradient in mountains the LST data underwent normalization and in further analysis a dependent variable we employed normalized LST (nLST). Set of independent variables included geomorphometric indicators (altitude, slope, aspect, TPI) and data on forest cover (disturbance, density, dominant species, and disturbance in the neighborhood). For key study area of Velykyi watershed of 4059 ha we additionally used data on forest biomass and tree age. In general, all forest ecosystems in present research have been divided into three distinct classes – “natural”, “disturbed” and “other” forests. Using boosted regression trees method we built three statistical models for each of the forest classes called “global” models. Also we developed 12 “local” models that showed the link between nLST and analyzed independent variables within each altitudinal bioclimatic zone with considering also forest class. Three separate statistical models have been built for each of the forest classes for key study area. Our results suggest that both maximum and mean values of nLST within particular altitudinal bioclimatic zone are the lowest in “natural” forests and the highest in “disturbed” ones.. The statistical model performance based on the variance explained indicator ranged from 32 to 74 %, whilst for models for key study area it was between 77 and 89 %. The set of influential variables for different forest classes varied substantially, but the most often they included aspect, forest density and elevation despite of normalization applied before. In models created for class “disturbed” forests between 19 and 35 % of all explained variance has been contributed by variable indicating time of disturbance. In “local” models for class “natural” forests we revealed gradual decrease of influence of the geomorphometric indicators (elevation, slope, and TPI) when move from warmer to cooler altitudinal zones while for topographic aspect and forest density the trends were just the opposite. In case of key study area a wood stock and tree age variables along with elevation and aspect were amongst the most influential ones. We can conclude that depending on the state of naturalness of forest ecosystems they have different climate regulating potential which might be severely depleted by human and natural disturbances. Keywords: forest landscape, ecosystem services, remote sensing, climate regulation, climate change, Landsat satellite images, Ukrainian Carpathians.


Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2289
Author(s):  
Ronald D. Porley ◽  
Vladimir Fedosov ◽  
Vítězslav Plášek ◽  
Alina Fedorova

A new genus is described to accommodate Neodicranella hamulosa, a novel species resolved in the family Aongstroemiaceae, from the Monchiquense district in SW Portugal. Characterized by its small size, erect spreading to subsecund non-sheathing leaves, plane bistratose leaf margins, and rhizoidal gemmae with slightly protruberant cells, it differs from all other European Dicranellaceae in the uniquely patterned distal peristome segments with backward-pointing papillae resembling hooked barbs. The species appears to be endemic to the sub-Mediterranean bioclimatic zone, in wooded biomes where humidity remains relatively high throughout the year. Morphological and molecular data strongly support the singularity of this new taxon. The species is illustrated by photomicrographs and SEM, and its ecology and conservation are discussed.


2021 ◽  
pp. 14-34
Author(s):  
Olivier J. Walther ◽  
Denis Retaillé

This chapter examines the geographical meaning of the Sahel and its spatial dynamics. Unlike other approaches that define the Sahel as a bioclimatic zone or as an ungoverned area, it shows that the Sahel is primarily a space of circulation in which uncertainty has historically been overcome by mobility. The first section discusses how precolonial empires relied on a network of markets and cities that facilitated trade and social relationships across the region and beyond. The second section explores changing regional mobility patterns precipitated by colonial powers and the new approach they developed to control networks and flows. The third section discusses the contradiction between the mobile strategies adopted by local herders, farmers, and traders in the Sahel and the territorial development initiatives of modern states and international donors. Particular attention is paid in the last section to how the Sahel was progressively redefined through a security lens.


Nitrogen ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 332-346
Author(s):  
Auges Gatabazi ◽  
Barend Juan Vorster ◽  
Mireille Asanzi Mvondo-She ◽  
Edgar Mangwende ◽  
Robert Mangani ◽  
...  

South African soils generally lack native Bradyrhizobium strains that nodulate and fix atmospheric nitrogen (N2) in soybeans (Glycine max L.). It is therefore very important to inoculate soybeans with products that contain effective Bradyrhizobium strains as active ingredients. In this study, a field experiment was conducted on two bioclimatic zones in South Africa during the 2019/2020 season to assess the effect of Bradyrhizobium japonicum strain WB74 inoculant formulation on nitrogen fixation, growth and yield improvement in soybeans. The first bioclimatic zone was characterized by a sandy clay loam soil, whereas the second bioclimatic zone has a sandy loam soil. The results showed that inoculation of soybeans with both peat and liquid formulations of Bradyrhizobium japonicum WB74 increased nitrogen uptake, which resulted in yield increase. The amount of N fixed was measured as 15N isotopes and increased with all treatments compared to the uninoculated control in both liquid and peat inoculant formulations. In bioclimatic zone A, slightly better results were obtained using the liquid formulation (1.79 t ha−1 for liquid compared to 1.75 t ha−1 for peat treatments), while peat formulations performed better in bioclimatic zone B (1.75 t ha−1 for peat compared to 1.71 t ha−1 for liquid treatments). In both areas higher yields were obtained with the formulations used in this study compared to the registered standards (treatment T3). The findings in this study provide vital information in the development and application of formulated microbial inoculants for sustainable agriculture in South Africa.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Valérie Andrieu-Ponel ◽  
Pierre Rochette ◽  
François Demory ◽  
Hülya Alçiçek ◽  
Nicolas Boulbes ◽  
...  

AbstractCereals are a central resource for the human diet and are traditionally assumed to have evolved from wild grasses at the onset of the Neolithic under the pressure of agriculture. Here we demonstrate that cereals may have a significantly longer and more diverse lineage, based on the study of a 0–2.3 Ma, 601 m long sedimentary core from Lake Acıgöl (South-West Anatolia). Pollen characteristic of cereals is abundant throughout the sedimentary sequence. The presence of large lakes within this arid bioclimatic zone led to the concentration of large herbivore herds, as indicated by the continuous occurrence of coprophilous fungi spores in the record. Our hypothesis is that the effects of overgrazing on soils and herbaceous stratum, during this long period, led to genetic modifications of the Poaceae taxa and to the appearance of proto-cereals. The simultaneous presence of hominins is attested as early as about 1.4 Ma in the lake vicinity, and 1.8 Ma in Georgia and Levant. These ancient hominins probably benefited from the availability of these proto-cereals, rich in nutrients, as well as various other edible plants, opening the way, in this region of the Middle East, to a process of domestication, which reached its full development during the Neolithic.


Parasite ◽  
2021 ◽  
Vol 28 ◽  
pp. 44
Author(s):  
Khawla Elati ◽  
Faten Bouaicha ◽  
Mokhtar Dhibi ◽  
Boubaker Ben Smida ◽  
Moez Mhadhbi ◽  
...  

In this study, we report the results of a survey of Hyalomma ticks infesting one-humped camels in southern Tunisia. Examinations were conducted every second or third month on 406 camels in Tataouine district from April 2018 to October 2019. A total of 1902 ticks belonging to the genus Hyalomma were collected. The ticks were identified as adult H. impeltatum (41.1%; n = 782), H. dromedarii (32.9%; n = 626), H. excavatum (25.9%; n = 493), and H. marginatum for a single specimen. Although the camels were infested by ticks throughout the year, the highest overall infestation prevalence was observed in April 2018 (p < 0.01). The overall infestation intensity varied between 2.7 and 7.4 ticks/animal. There were no statistically significant differences in tick infestation prevalence based on age categories of the camels, and the overall infestation prevalence was between 82.7% and 97.4%. Female camels were significantly more infested with ticks (88.3%) than males (65.5%) (p < 0.01). The infestation prevalence of camels varied significantly according to the region where sampling took place (p < 0.01), but no correlations were found with abiotic factors. The preferred attachment sites for adult Hyalomma ticks were the sternum (38.3%; n = 729/1902), around the anus (36.2%; n = 689/1902), udder (18.4%; n = 350/1902), and inner thigh (6.9%; n = 132/1902). Morphological classification of ticks was corroborated by sequencing the cytochrome c oxidase I (Cox1) and 16S rDNA genes, and these sequences were also used to infer phylogenetic relationships. A single H. dromedarii seemed to be a natural hybrid with H. rufipes. More attention should be devoted by the veterinary services to the infestation of camels by ticks.


2020 ◽  
Vol 14 (8) ◽  
pp. 2903-2927
Author(s):  
Jhonn Logbo ◽  
Paul Yedomonhan ◽  
Brice Tente ◽  
Akpovi Akoegninou

Cette étude a permis de déterminer la distribution et les habitats potentiels de Newbouldia laevis et de Dracaena arborea dans les zones bioclimatiques du Bénin en vue de leur gestion durable. Trente relevés phytosociologiques ont été effectués dans les formations végétales. La matrice obtenue a permis de discriminer les forêts sacrées (74 genres ; 46 familles ; Richesse spécifique=130 ; H=5,92 bits; R=0,97) des champs/jachères (42 genres ; 28 familles ; Richesse spécifique =69; H=3,40 bits; R=0,62). Les densités moyennes de tiges sont passées en forêts sacrées de 64 à 31 et à 0 tiges.ha-1; puis de 28 à 16 tiges.ha-1 dans les champs/jachères chez D. arborea. Chez N. laevis, ces densités sont passées de 30 à 15 puis à 09 tiges.ha-1 en forêts sacrées et de 89 à 56 et à 13 tiges.ha-1 dans les champs/jachères respectivement en zones guinéo-congolaise, soudano-guinéenne et soudanienne. Les phanérophytes et les espèces guinéo-congolaises sont les plus dominants. D. arborea et N. laevis se conservent mieux respectivement en forêts sacrées et en champs/jachères. Leur introduction dans les programmes de reboisement et la protection de leurs habitats potentiels seraient un atout pour leur meilleure conservation et contribueront à formuler des recommandations soutenues pour leur valorisation au Bénin.Mots clés : Bénin, Distribution, Zones bioclimatiques, Newbouldia laevis, Dracaena arborea.   English Title: Distribution and habitats of Newbouldia laevis (P.Beauv.) Seemann ex Bureau and Dracaena arborea (Willd.) Link in the bioclimatic zones of BeninThis study carried out in the three bioclimatic zones of Benin aims to determine the potential habitats and the geographic distributions of Newbouldia laevis and Dracaena arborea, two anthropophilic agroforestry species in order to conserve them sustainably. Thirty phytosociological surveys were sampled and the matrix gotten was subjected to an analysis of the adjusted correspondences (DCA) to discriminate the sacred forests with great diversity (Rf = 130; H = 5.92; R = 0.97) of the fields/fallows of medium diversity (Rf = 69; H = 3.40; R = 0.62) and balanced. The average densities of stems went from 64, 31 and 0 stems.ha-1 in D. arborea to 30, 15 and 09 stems.ha-1 in N. laevis in sacred forests and in fields/fallows from 28, 16 and 0 stems.ha-1 in D. arborea at 89, 56 and 13 stems.ha-1 in N. laevis respectively in guinean-congolese, sudano-guinean and sudanian zones. Phanerophytes constitute 85% of the average recovery in number and occupation of space. Guinean-congolese species are dominant and have a wide distribution spectrum. D. arborea and N. laevis keep better in sacred forests and fields / fallows respectively. The protection of potential habitats and the introduction of species into national reforestation programs as a priority would be an asset for better conservation.Keywords : Benin, Distribution, bioclimatic zone, Newbouldia laevis, Dracaena arborea.    


Climate ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 136
Author(s):  
Dol Raj Luitel ◽  
Pramod K. Jha ◽  
Mohan Siwakoti ◽  
Madan Lall Shrestha ◽  
Rangaswamy Munniappan

The Chitwan Annapurna Landscape (CHAL) is the central part of the Himalayas and covers all bioclimatic zones with major endemism of flora, unique agro-biodiversity, environmental, cultural and socio-economic importance. Not much is known about temperature and precipitation trends along the different bioclimatic zones nor how changes in these parameters might impact the whole natural process, including biodiversity and ecosystems, in the CHAL. Analysis of daily temperature and precipitation time series data (1970–2019) was carried out in seven bioclimatic zones extending from lowland Terai to the higher Himalayas. The non-parametric Mann-Kendall test was applied to determine the trends, which were quantified by Sen’s slope. Annual and decade interval average temperature, precipitation trends, and lapse rate were analyzed in each bioclimatic zone. In the seven bioclimatic zones, precipitation showed a mixed pattern of decreasing and increasing trends (four bioclimatic zones showed a decreasing and three bioclimatic zones an increasing trend). Precipitation did not show any particular trend at decade intervals but the pattern of rainfall decreases after 2000AD. The average annual temperature at different bioclimatic zones clearly indicates that temperature at higher elevations is increasing significantly more than at lower elevations. In lower tropical bioclimatic zone (LTBZ), upper tropical bioclimatic zone (UTBZ), lower subtropical bioclimatic zone (LSBZ), upper subtropical bioclimatic zone (USBZ), and temperate bioclimatic zone (TBZ), the average temperature increased by 0.022, 0.030, 0.036, 0.042 and 0.051 °C/year, respectively. The decade level temperature scenario revealed that the hottest decade was from 1999–2009 and average decade level increases of temperature at different bioclimatic zones ranges from 0.2 to 0.27 °C /decade. The average temperature and precipitation was found clearly different from one bioclimatic zone to other. This is the first time that bioclimatic zone level precipitation and temperature trends have been analyzed for the CHAL. The rate of additional temperature rise at higher altitudes compared to lower elevations meets the requirements to mitigate climate change in different bioclimatic zones in a different ways. This information would be fundamental to safeguarding vulnerable communities, ecosystem and relevant climate-sensitive sectors from the impact of climate change through formulation of sector-wise climate change adaptation strategies and improving the livelihood of rural communities.


Author(s):  
Dol Raj Luitel ◽  
Pramod Kumar Jha ◽  
Mohan Siwakot ◽  
Madan Lall Shrestha ◽  
Rangaswamy Munniappan

Abstract Depending upon altitudinal gradient in the Himalayas, the rate of climate change varies from lowland to upland. The Chitwan Annapurna Landscape (CHAL) is the central part of the Himalayas and covers all bioclimatic zones. Analysis of time series data (1970-2019) of temperature and precipitation was carried out in seven bioclimatic zones extending from lowland Terai to higher Himalayas. The non-parametric Mann-Kendall test was applied to determine the trend, which was quantified by Sen&rsquo;s slope. Annual and decade interval average temperature, precipitation trends, and lapse rate were analyzed in each bioclimatic zone. Out of seven bioclimatic zones, four zones showed a decreasing precipitation trend (lower tropical, upper tropical, upper subtropical, and alpine bioclimatic zones)at the rate of 1.8, 1.98, 2.06, and 1.80 mm/year, and in lower sub-tropical, temperate, and lower subalpine bioclimatic zones, increasing at the rate of 0.45, 1.81 and 1.28mm/year, respectively. Precipitation did not show any particular trend at decade intervals. The average annual temperature at different bioclimatic zones clearly indicates that temperature at higher elevations is significantly increasing more than at lower elevations. In lower tropical bioclimatic zone (LTBZ), upper tropical bioclimatic zone(UTBZ), lower subtropical bioclimatic zone (LSBZ), upper subtropical bioclimatic zone(USBZ), and temperate bioclimatic zone(TBZ), the average temperature increased by 0.022, 0.030, 0.036, 0.042 and 0.051oC/year, respectively. The decade level temperature scenario revealed that the hottest decade was from 1999-2009. The average temperature was found as 24.1, 21.8, 19.7, 17.5, and 13.3oC in LTBZ, UTBZ, LSBZ, USBZ, and TBZ, respectively, and the average annual precipitation in LTBZ, UTBZ, LSBZ, USBZ, TBZ, LBZ, and ABZ was 2002.1, 2613.1, 2223.9, 3146.9, 1447.2, 952.1, and 361.7mm/year, respectively, in CHAL. With the impact of climate change site and region-specific, this information highlights the need to mitigate climate change in different bioclimatic zones.


Sign in / Sign up

Export Citation Format

Share Document