scholarly journals La vegetación de Calakmul, Campeche, México: clasificación, descripción y distribución

2017 ◽  
pp. 7 ◽  
Author(s):  
Esteban Martínez ◽  
Carlos Galindo-Leal

The Calakmul region, at the center of the Yucatan peninsula, contains the largest forested area of the Mexican tropics. Our objective is to provide the classification, description and spatial distribution of the plant communities of Calakmul region. In spite of the relatively lack of topographic features there is large spatial heterogeneity in the vegetation. Five plant associations are underlined because of their regional, national and world relevance: guayacán forest (Guaiacum sanctum), jobillo forest (Astronium graveolens), low deciduous forest, tall forest and mixed seasonally flooded forest. We discuss the main factors influencing the vegetation, including rainfall gradients, soil development, natural disturbances and anthropogenic factors. This study underscores the importance of using vegetation classification with enough detail to assess the representation and effectiveness of natural protected areas.

2021 ◽  
Vol 10 (1) ◽  
pp. 135-141
Author(s):  
Aleksey Vladimirovich Podolsky

The paper presents data on the ecology of two common species of reptiles in the Tambov Region: the sand lizard, Lacerta agilis Linnaeus, 1758, and the common grass snake, Natrix natrix (Linnaeus, 1758). The material was collected in the Michurinsky, Pervomaysky, Tambovsky and Inzhavinsky (on the territory of the Voroninsky State Nature Reserve) Districts of the Tambov Region during the 2019 field season. Field observations and accounting for the numbers of animals on the routes were carried out in the most typical biotopes for the study sites: in pine forest, deciduous forest, in steppe areas affected to varying degrees by anthropogenic transformation, in floodplains of rivers and along the shores of lakes and artificial reservoirs. Information on the following aspects of the ecology of these reptile species in the region is presented and discussed: habitat distribution and numbers, seasonal and diurnal activity, phenology of reproduction and development and the influence of anthropogenic factors. All materials obtained as a result of our own research are compared with the data of the literature sources cited in the paper. On the basis of wide distribution in the region, relatively high numbers and trends to synanthropy it is stated that the state of the populations of the sand lizard and common grass snake in the region in the present conditions is safe and special measures for their protection are not required.


2018 ◽  
Vol 22 (7) ◽  
pp. 4-10
Author(s):  
E.I. Pupyrev ◽  
G.A. Sambursky

Conduct a ranging of natural-climatic and anthropogenic factors. It is shown that the main factors of lake pollution by nutrients are natural-climatic factors, in particular, forest fires. An analysis of the regulatory framework has been carried out, it has been proposed to harmonize the phosphorus and nitrogen indicators with all-Russian standards. It is established that in the residential areas there is no water treatment to the normative indices. For each class of settlements presented possible technologies for wastewater treatment. The strategy of building of unified system of water disposal in the Central ecological zone of the Baikal natural territory is formulated.


Phytotaxa ◽  
2017 ◽  
Vol 307 (4) ◽  
pp. 278
Author(s):  
HÉCTOR M. M. HERNÁNDEZ ◽  
CARLOS GÓMEZ-HINOSTROSA

A new species of Calliandra (Leguminosae, Mimosoideae, tribe Ingeae) from a restricted locality of Campeche, Mexico is herein described and illustrated. The species appears to be closely related to C. molinae, a species from Honduras, El Salvador and Nicaragua, from which it may be distinguished by being allopatric, and by a more limited development of suberose bark in stems and branches, comparatively smaller leaflets, consistently glabrous leaflets and corollas, and by the scarcely villous pods. Calliandra mayana appears to be restricted to an extremely small seasonally flooded savannah surrounded by tropical deciduous forest and, based on IUCN criteria, it is provisionally considered Critically endangered.


2021 ◽  
Author(s):  
Soumya Dasgupta ◽  
Tapajit Bhattacharya ◽  
Prafulla Bhamburkar ◽  
Rahul Kaul

Tropical forests are complex systems with heterogenous community assemblages often threatened under conservation conflicts. Herbivory and disturbances affect the diversity and species assemblages within forest patches having different disturbance regimes. We studied the change in plant community composition and structure under a disturbance gradient in the tropical dry deciduous forest of the corridor area between Nagzira-Navegaon Tiger reserve of central India. We tested the hypothesis that the plant community will change along the proximity gradient from the human settlement depending on the anthropogenic stress. We sampled 183 nested quadrat plots to collect data on species abundance and various disturbance parameters. Density, diversity, and Importance Value Index were calculated from the collected data on species abundance and girth at breast height (GBH) of individual tree species. We did multivariate analysis to assess the changes in species assemblage along the disturbance gradients. We found 76% dissimilarity between the plant communities in the three disturbance gradients from near to far from the villages perpetrated by the difference in mean abundance of species like Tectona grandis, Terminalia sp, and Largerstroemia parviflora. The anthropogenic factors significantly influence the density and diversity of tree species and regeneration classes. We found the abundance of regeneration class increased along the distance from the villages. The study intensifies the need for proper management and conservative approach to preserve the minimum diversity of the forest patches for its structural and functional contiguity as a corridor in the central India's highly susceptible and intricate corridor framework.


2021 ◽  
Vol 28 (40) ◽  
pp. 55952-55966
Author(s):  
Merve Tunali ◽  
Alexandro André Radin ◽  
Selma Başıbüyük ◽  
Anwar Musah ◽  
Iuri Valerio Graciano Borges ◽  
...  

AbstractThis paper explores the main factors for mosquito-borne transmission of the Zika virus by focusing on environmental, anthropogenic, and social risks. A literature review was conducted bringing together related information from this genre of research from peer-reviewed publications. It was observed that environmental conditions, especially precipitation, humidity, and temperature, played a role in the transmission. Furthermore, anthropogenic factors including sanitation, urbanization, and environmental pollution promote the transmission by affecting the mosquito density. In addition, socioeconomic factors such as poverty as well as social inequality and low-quality housing have also an impact since these are social factors that limit access to certain facilities or infrastructure which, in turn, promote transmission when absent (e.g., piped water and screened windows). Finally, the paper presents short-, mid-, and long-term preventative solutions together with future perspectives. This is the first review exploring the effects of anthropogenic aspects on Zika transmission with a special emphasis in Brazil.


Author(s):  
M. Mleczko ◽  
M. Mroz ◽  
M. Fitrzyk

The aim of this study was to exploit fully polarimetric SAR data acquired during TanDEM-X – Science Phase (2014/2015) over herbaceous wetlands of the Biebrza National Park (BbNP) in North-Eastern Poland for mapping seasonally flooded grasslands and permanent natural vegetation associations. The main goal of this work was to estimate the advantage of fully polarimetric radar images (QuadPol) versus alternative polarization (AltPol) modes. The methodology consisted in processing of several data subsets through polarimetric decompositions of complex quad-pol datasets, classification of multitemporal backscattering images, complementing backscattering images with Shannon Entropy, exploitation of interferometric coherence from tandem operations. In each case the multidimensional stack of images has been classified using ISODATA unsupervised clustering algorithm. With 6 QUAD-POL TSX/TDX acquisitions it was possible to distinguish correctly 5 thematic classes related to their water regime: permanent water bodies, temporarily flooded areas, wet grasslands, dry grasslands and common reed. This last category was possible to distinguish from deciduous forest only with Yamaguchi 4 component decomposition. The interferometric coherence calculated for tandem pairs turned out not so efficient as expected for this wetland mapping.


Author(s):  
Л.В. Воронин ◽  
И.Я. Колесникова

Под влиянием антропогенных факторов в почве и сопряжённых с нею средах может происходить накопление опасных для человека (потенциально патогенных, аллергенных, микотоксичных) видов микроскопических грибов. Изучение этой группы микромицетов и явилось целью настоящей работы. Представлены результаты исследований, проведённых в 2011–2018 гг. в полевом стационарном опыте, заложенном на опытном поле ФГБОУ ВО Ярославская ГСХА, по изучению различных систем обработки почвы и систем удобрений. В 2014–2015 гг. дополнительно исследовали почву зоны перелеска, заросшей грунтовой дороги и леса по краю поля, которые представляют собой естественно сформировавшиеся растительные ассоциации. Многие из обнаруженных нами почвообитающих грибов как в естественных сообществах, так и в окультуренной почве, являются потенциально-патогенными видами, относящимися к III и IV группам по классификации санитарно-эпидемиологических правил СП 1.3.2322-08. Полученные результаты не выявили общих закономерностей распространения оппортунистических грибов в исследованной почве. Однако в целом большинство из них не имеют широкого распространения по частоте встречаемости и массовости. Исключением являются виды р. Aspergillus. Как аллергенные, в первую очередь, рассматриваются виды тёмноокрашенных родов Alternaria (A. alternata), Cladosporium (C. herbarum), а также рода Aspergillus (A. flavus, A. fumigatus, A. niger). По мнению ряда авторов, в настоящее время увеличилась распространённость сапротрофных видов грибов, способных продуцировать микотоксины и вызывать микотоксикозы и оппортунистические микозы. В связи с этим необходим постоянный мониторинг фитосанитарной ситуации в посевах сельскохозяйственных культур, тщательный микологический и микотоксикологический контроль сельскохозяйственной продукции, совершенствование видовой диагностики грибов. Under the influence of anthropogenic factors the accumulation of types of microscopic fungi that are dangerous for humans (potentially pathogenic, allergenic, mycotoxic) can occur in soil and its associated medium. The study of this group of micromycetes was the aim of this work. The results of the researches conducted in 2011–2018 in the stationary test laid down on the experimental field of the FSBEI HE Yaroslavl State Agricultural Academy to study various tillage systems and fertilizer systems are presented. In 2014–2015 the soil of the field woodland zone, overgrown dirt road and forest along the edge of the field which are naturally formed plant associations was additionally investigated. Many of the soil fungi found by us both in natural communities and in cultivated soil are potentially pathogenic species belonging to groups III and IV according to the classification of sanitary and epidemiological rules SP 1.3.2322-08. The results obtained did not reveal the general patterns of the spread of opportunistic fungi in the soil under investigation. However in general most of them are not widespread in frequency of occurrence and massive participation. An exception is the species g. Aspergillus. As allergenic, first of all species of the dark-colored genus Alternaria (A. alternata), Cladosporium (C. herbarum), and also the genus Aspergillus (A. flavus, A. fumigatus, A. niger) are considered. According to several authors the prevalence of saprotrophic species of fungi that can produce mycotoxins and cause mycotoxicoses and opportunistic mycoses has now increased. In this regard constant monitoring of the phytosanitary situation in agricultural crops, careful mycological and mycotoxicological control of agricultural products, improvement of the species diagnosis of fungi are necessary.


Author(s):  
M. Mleczko ◽  
M. Mroz ◽  
M. Fitrzyk

The aim of this study was to exploit fully polarimetric SAR data acquired during TanDEM-X – Science Phase (2014/2015) over herbaceous wetlands of the Biebrza National Park (BbNP) in North-Eastern Poland for mapping seasonally flooded grasslands and permanent natural vegetation associations. The main goal of this work was to estimate the advantage of fully polarimetric radar images (QuadPol) versus alternative polarization (AltPol) modes. The methodology consisted in processing of several data subsets through polarimetric decompositions of complex quad-pol datasets, classification of multitemporal backscattering images, complementing backscattering images with Shannon Entropy, exploitation of interferometric coherence from tandem operations. In each case the multidimensional stack of images has been classified using ISODATA unsupervised clustering algorithm. With 6 QUAD-POL TSX/TDX acquisitions it was possible to distinguish correctly 5 thematic classes related to their water regime: permanent water bodies, temporarily flooded areas, wet grasslands, dry grasslands and common reed. This last category was possible to distinguish from deciduous forest only with Yamaguchi 4 component decomposition. The interferometric coherence calculated for tandem pairs turned out not so efficient as expected for this wetland mapping.


1988 ◽  
Vol 235 (1280) ◽  
pp. 259-280 ◽  

The Morro de Fumaça, Município de Torixoreu, Mato Grosso, Brazil, is a low hill characteristic of a range of similar topographic features in the region. It shows a suite of representative and rapidly disappearing vegetation types together with their associated soils. The upper slopes are clothed in deciduous forest, which is followed downslope by a band of mesotrophic facies cerradão and then on the lower ground by more open cerrado. The parallel changes in soil pass from the shallow and frequently plinthitic lithosols over the summits and upper slopes to progressively deeper and more acidic soils over the footslope. The increasing impoverishment from upslope sites downwards is especially marked by the changes in the exchangeable calcium content. The vegetation survey was done by means of point-centred quarter transects and by quadrats. The tree species of the deciduous forest are listed. Both the forest and mesotrophic facies cerradão closely resemble in floristics, structure and soil characteristics those studied in the limited investigations available from other areas of Mato Grosso and elsewhere in Central Brazil. The soil data are derived from an initial reconnaissance survey, with soil profiles selected to represent the major changes in vegetation. Extremely little information exists on the deciduous forests of Brazil and the present communication provides information on this important and increasingly endangered type of vegetation.


2015 ◽  
Vol 76 (2) ◽  
pp. 168-179
Author(s):  
Janusz Krechowski ◽  
Katarzyna Piórek ◽  
Michał Falkowski ◽  
Marek Wierzba ◽  
Katarzyna Mikułowska

Abstract The ‘Mierzwice’ nature reserve (forest district 206b, c and d of the Sarnaki Forest Inspectorate), situated in the area of the Podlaski Przełom Bug Landscape Park, is one of the most valuable natural assets of the central Bug river valley. The 12.98 ha reserve was established in 2010 to aid protection of the stand of xerothermic vegetation and its surrounding deciduous forest. In total, eight plant associations were identified within the reserve: Geranio-Peucedanetum cervariae, Geranio-Anemonetum sylvestris, Geranio-Trifolietum alpestris, Trifolio medii-Agrimonietum, Rubo fruticosi-Prunetum, Rhamno-Cornetum sanguinei, Potentillo albae-Quercetum and Tilio cordatae-Carpinetum betuli. Furthermore, 23 protected and 31 endangered species were found in the reserve including the following examples: Cephalanthera rubra, Thesium ebracteatum, Cypripedium calceolus, Gentiana cruciata, Anemone sylvestris, Cimicifuga europaea, Viola rupestris, Crepis praemorsa, Asperula tinctoria, Stachys recta, Laserpitium latifolium. Over the last few years, a regression of the species diagnostic number for thermophilous oak forests and xerothermic grasslands has been observed as a result of succession and expansion of Calamagrostis epigejos. Active protection of xerothermic vegetation such as uprooting of trees and bushes, regular grazing or mowing has been suggested in order to prevent the expansion of Calamagrostis epigejos.


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