scholarly journals Seasonal dynamics of waterbirds from a relict wetland in the central Monte Desert, Argentina

2021 ◽  
Vol 16 (2) ◽  
pp. 333-349
Author(s):  
Ever Tallei ◽  
Analía Benavidez ◽  
Alejandro Schaaf ◽  
Pablo Isola ◽  
Marcelo Zanotti
Keyword(s):  
Environmental Changes ◽  
Integrated Management ◽  
Limited Resource ◽  
Taxonomic Diversity ◽  
Biological Indicators ◽  
Community Diversity ◽  
Monte Desert ◽  
Management Plans ◽  
Waterbird Assemblages ◽  
Diversity Profiles

Wetlands currently have high rates of degradation, with more than 70% lost globally. In the central Monte Desert, Argentina, they are a scarce and limited resource for the biodiversity which depends on them. Waterbirds have been used as biological indicators of wetlands because they respond to fluctuations in food resources and to environmental changes in the short term. Here we analyse the seasonal variations in the structure of the waterbird assemblage from a relict wetland in this region. We carried out censuses of waterbirds in a 6-year period (between 2009 and 2019) during the southern summer and winter. We recorded 1875 individuals of 33 species of waterbirds during the summer and 677 individuals of 29 species during the winter. The grouping patterns of the waterbird assemblages differed between seasons (R = 0.35; p < 0.01). Taxonomic diversity profiles showed greater diversity for all indexes (qD) during the summer. The guild of invertivorous and omnivorous waders had a greater abundance of individuals during the summer (p < 0.05) and, together with the surface-feeding herbivores, contributed to the 87% of the dissimilarity of the assemblages between seasons. Phoenicopterus chilensis was the only species registered as threatened with national and international extinction. Relict wetlands, such as Laguna del Viborón, still have attributes of community diversity and represent the last refuges for waterbirds of the central Monte Desert. The information gathered in this study will contribute to the guidelines for integrated management plans and monitoring programmes for the conservation of the wetland and its biodiversity.

scholarly journals A Study of Distributed Earth Observation Satellites Mission Scheduling Method Based on Game-Negotiation Mechanism

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6660
Author(s):  
Lihao Liu ◽  
Zhenghong Dong ◽  
Haoxiang Su ◽  
Dingzhan Yu
Keyword(s):  
Dynamic Scheduling ◽  
Environmental Changes ◽  
Search Algorithm ◽  
Integrated Management ◽  
Scheduling Algorithm ◽  
Earth Observation ◽  
Scheduling Problems ◽  
Satellite Systems ◽  
Earth Observation Satellites ◽  
Negotiation Mechanism

While monolithic giant earth observation satellites still have obvious advantages in regularity and accuracy, distributed satellite systems are providing increased flexibility, enhanced robustness, and improved responsiveness to structural and environmental changes. Due to increased system size and more complex applications, traditional centralized methods have difficulty in integrated management and rapid response needs of distributed systems. Aiming to efficient missions scheduling in distributed earth observation satellite systems, this paper addresses the problem through a networked game model based on a game-negotiation mechanism. In this model, each satellite is viewed as a “rational” player who continuously updates its own “action” through cooperation with neighbors until a Nash Equilibria is reached. To handle static and dynamic scheduling problems while cooperating with a distributed mission scheduling algorithm, we present an adaptive particle swarm optimization algorithm and adaptive tabu-search algorithm, respectively. Experimental results show that the proposed method can flexibly handle situations of different scales in static scheduling, and the performance of the algorithm will not decrease significantly as the problem scale increases; dynamic scheduling can be well accomplished with high observation payoff while maintaining the stability of the initial plan, which demonstrates the advantages of the proposed methods.

scholarly journals Vers une gestion intégrée des pâturages boisés – carte de visite du paysage jurassien | Towards an integrated management of the wooded pastures – typical of the Jura landscape

2011 ◽  
Vol 162 (3) ◽  
pp. 81-86
Author(s):  
Renaud Baumgartner
Keyword(s):  
Surface Area ◽  
Management System ◽  
Integrated Management ◽  
Leisure Activities ◽  
Cattle Grazing ◽  
Management Plan ◽  
Integrated Management System ◽  
Management Plans ◽  
Gestion Intégrée ◽  
The Creation

The wooded pastures arose from the colonisation of the valleys and high plateaux of the Jurassic Arc. They are the product of a mixed exploitation combining agricultural and silvicultural elements, and are dependent for their conservation on a form of management where a balance between cattle grazing and wood cutting is maintained. The abandon of farmland and fewer cattle at pasture in summer, the small returns from logging and the introduction of grants based on surface area of agriculturally used land (SAU) have together completely disturbed this balance. The necessity of an integrated management system which takes into account the interests of agriculture, silviculture, nature, landscape and leisure activities has led to the creation of interdisciplinary commissions on wooded pastures of the Bernese Jura and the Jurassic Arc. An Interreg IIIA project France-Switzerland has enabled the creation of a model integrated management plan. Due to the lack of funds from the Federal Office of Agriculture, the cantonal services promote the development of integrated management plans.

scholarly journals What are the main local drivers determining richness and fishery yields in tropical coastal fish assemblages?

2018 ◽  
Vol 35 ◽  
pp. 1-12
Author(s):  
Cynthia Diniz Souza ◽  
Vandick S. Batista ◽  
Nidia Noemi Fabré
Keyword(s):  
Wind Speed ◽  
Rainy Season ◽  
Fish Assemblages ◽  
Principal Component ◽  
Dry Season ◽  
Community Diversity ◽  
Tropical Species ◽  
Coastal Fish ◽  
Wide Range ◽  
Diversity Profiles

Seasonal ecological effects caused by temperature and photoperiod are typically considered minimal in the tropics. Nevertheless, annual climate cycles may still influence the distribution and abundance of tropical species. Here, we investigate whether seasonal patterns of precipitation and wind speed influence the structure of coastal fish assemblages and fishing yields in northeast Brazil. Research trips were conducted during the rainy and dry seasons using commercial boats and gear to sample the fish community. Diversity was analyzed using abundance Whittaker curves, diversity profiles and the Shannon index. Principal Component Analysis (PCA) was used to analyze associations between the abundance of species and various environmental variables related to seasonality. A total of 2,373 fish were collected, representing 73 species from 34 families – 20 of which were classified as both frequent and abundant. Species richness was greater and more equitable during the rainy season than the dry season – driven by changes in the precipitation rather than to wind speed. Species diversity profiles were slightly greater during the rainy season than the dry season, but this difference was not statistically significant. Using PCA was identified three groups of species: the first associated with wind speed, the second with precipitation, and the third with a wide range of sampling environments. This latter group was the largest and most ecologically heterogeneous. We conclude that tropical coastal fish assemblages are largely influenced by local variables, and seasonally mediated by annual changes related to precipitation intensity and wind speed, which in turn influences fishery yields.

scholarly journals Responses of Rhizosphere Fungal Communities to the Sewage Sludge Application into the Soil

2019 ◽  
Vol 7 (11) ◽  
pp. 505 ◽  
Author(s):  
Katarína Ondreičková ◽  
Marcela Gubišová ◽  
Michaela Piliarová ◽  
Miroslav Horník ◽  
Pavel Matušinský ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Fungal Community ◽  
18S Rdna ◽  
Mycorrhizal Fungi ◽  
Fungal Diversity ◽  
Municipal Wastewater ◽  
Environmental Changes ◽  
Community Diversity ◽  
Rdna Sequencing ◽  
Sludge Application

Due to the increasing sewage sludge production in the world and problems with its disposal, an application of sludge to the soil appears to be a suitable solution considering its fertilizer properties and ability to improve the soil physical conditions. On the other hand, the sludge may also contain undesirable and toxic substances. Since soil microorganisms are sensitive to environmental changes, they can be used as indicators of soil quality. In this study, we used sewage sludge (SS) from two municipal wastewater treatment plants (SS-A and SS-B) in the dose of 5 t/ha and 15 t/ha in order to determine possible changes in the fungal community diversity, especially arbuscular mycorrhizal fungi (AMF), in the rhizosphere of Arundo donax L. Rhizosphere samples were collected in summer and autumn for two consecutive years and the fungal diversity was examined using terminal restriction fragment length polymorphism and 18S rDNA sequencing. Fungal alpha diversity was more affected by SS-A than SS-B probably due to the higher heavy metal content. However, based on principal component analysis and ANOSIM, significant changes in overall fungal diversity were not observed. Simultaneously, 18S rDNA sequencing showed that more various fungal taxa were detected in the sample with sewage sludge than in the control. Glomus sp. as a representative of AMF was the most represented. Moreover, Funneliformis in both samples and Rhizophagus in control with Septoglomus in the sludge sample were other representatives of AMF. Our results indicate that the short-term sewage sludge application into the soil does not cause a shift in the fungal community composition.

scholarly journals Restructuring Integrated Watershed Management Models for the Federal Democratic Regime of Nepal

2019 ◽  
Vol 1 (1) ◽  
pp. 69-76
Author(s):  
Shambhu Paudel ◽  
Prabhat Pal ◽  
Harish Singh Dhami
Keyword(s):  
Watershed Management ◽  
Integrated Management ◽  
The United States ◽  
Management Plan ◽  
Federal States ◽  
Management Models ◽  
Management Plans ◽  
Legislative Framework ◽  
Administrative Units ◽  
Public Service Agencies

Recent political envision has redesigned the administrative units of Nepal into federal states with the aim of decentralizing the power to ensure the process of rapid sustainable development. As a consequence, all the public service agencies need to restructure their delivery units for achieving goals targeted by the newly adopted administrative regime plan. With the aim of recommending the best watershed management models for this changing context, this paper aims to review existing watershed management models applied in different continents like European union, African union and the United States where they have already adopted this watershed management plans into their federal states or countries union successfully. Although they are geographically distinct and economically advanced, the major approach adopted is a river basin approach with the clear legislative framework. This approach is highly succeeded between interstate (or between member countries) because of political or interstate commitments for the common pool resource water. Clear policies and commitments between member countries or interstate greatly improved the function of this mechanism. With the light of those experiences in the field of watershed management plan adopted in federal or union countries, river based integrated management plan balancing efforts between interstates seems best models in the world, and is also proposed for the new federal republic of Nepal.

scholarly journals A medium-spatial scale distribution pattern of Pseudoscorpionida (Arachnida) in a gradient of topography (altitude and inclination), soil factors, and litter in a central Amazonia forest reserve, Brazil

2006 ◽  
Vol 66 (3) ◽  
pp. 791-802 ◽  
Author(s):  
N. O. Aguiar ◽  
T. L. Gualberto ◽  
E. Franklin
Keyword(s):  
Spatial Scale ◽  
Environmental Changes ◽  
Biological Indicators ◽  
Predictor Variables ◽  
Generalist Predators ◽  
Soil Factors ◽  
Abundance And Diversity ◽  
The Stability ◽  
Clay Percentage ◽  
Trail System

In Amazonia, nothing is known about the distribution of the invertebrates on a medium-spatial scale pattern. In a trail system of 64 km² at Ducke Reserve, we sampled 72 transects using the hand-sorting method and Berlese-Tullgren extraction. The reserve possesses ecosystems of "terra-firme" forest and the trail system represents a gradient of topographic soil factors and vegetation, avoiding categorizations. Considering the abundance and diversity of Pseudoscorpionida, we investigated the relation of the community to environmental factors tested (topography, clay percentage, litter, and soil pH), to the two major drainage basins of the reserve, and if these invertebrates can be used as biological indicators to monitor changes. We registered two species for the first time in the reserve, increasing the known diversity to 17 species. The lack of correlation with the predictor variables and the large home range, indicate that pseudoscorpions are not good biological indicators in the reserve. As the eastern and western watersheds are not separate management units for the community, our results show that they are generalist predators. In spite of our results and lack of knowledge concerning their biology, life history and taxonomy, pseudoscorpions are cosmopolitan and easy to find and measure. Compared with previous studies in the reserve, they have a consistent pattern of abundance and diversity throughout the years showing the stability of the community which can be checked mainly by comparison with environmental changes that would occur in the reserve. An investigation on a medium-spatial scale pattern and over a long-term period including other habitats, and also other predictor variables, like humidity, the structure of the vegetation and canopy closure, will be necessary to reinforce the observed tendencies.

scholarly journals Assessing the Sensitivity of Riparian Algarrobo Dulce (Prosopis flexuosa DC) Radial Growth to Hydrological Changes

2016 ◽  
Vol 43 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Sergio Piraino ◽  
Fidel Alejandro Roig
Keyword(s):  
Radial Growth ◽  
Environmental Changes ◽  
Precipitation Amount ◽  
Summer Precipitation ◽  
Late Summer ◽  
Monte Desert ◽  
Hydrological Changes ◽  
Tightly Coupled ◽  
Prosopis Flexuosa ◽  
Ecological Importance

Abstract Ecotones, as for example riparian zones, have long interested ecologists, due to their potential role in generating species biodiversity and evolutionary novelty, as well as their sensitivity to environmental changes. Along riparian areas, vegetation is recognized for its ecological importance in several ecosystemic processes. In the Central Monte Desert (central-west Argentina), Prosopis flexuosa grows in territories characterized by a permanent access to water reservoirs, e.g. along riverbanks, where the species forms the classic gallery forests. Despite the ecosystemic role of the different Prosopis species distributed in arid lands, thus far no analysis has been conducted regarding the relation between their radial growth and hydrological changes, namely streamflow variability, in riparian settings. To fill this gap of knowledge, we performed a dendrochronological analysis considering several riparian P. flexuosa trees differing in their spatial position in relation to the riverbank. Pointer years, correlation function, and regression analyses show differences in the dendrohydrological signal of the studied species, probably function of tree distance from the river. In this sense, radial growth of trees distributed near the riverbank is tightly coupled to spring-summer (September to March) stream-flow variability, whereas for farthest trees the ring development is driven by a combination of winter and spring river discharge and late-summer precipitation amount. The presented results demonstrate the potentiality of P. flexuosa, and in a broader sense of the Prosopis genus, in dendrohydrological studies.

scholarly journals Таксономическое разнообразие диатомовых комплексов голоценовых донных отложений малых водоемов депрессии озера Имандра

2020 ◽  
Vol 12 (1) ◽  
pp. 41
Author(s):  
А.Л. Косова ◽  
Д.Б. Денисов ◽  
С.Б. Николаева
Keyword(s):  
Environmental Changes ◽  
Taxonomic Diversity ◽  
Western Coast ◽  
Diatom Algae ◽  
Tectonic Event ◽  
Algal Communities ◽  
The Holocene ◽  
Small Water ◽  
Murmansk Region ◽  
Diatom Complexes

A study of the taxonomic diversity of diatom algae in Holocene bottom sediments of two small water basins at the western coast of the lake Babinaskaya Imandra (Murmansk Region) has demonstrated the historical transformations of the species compositions of structures of diatom complexes associated with environmental changes in the Holocene. The water basins studied featured the predominance of the benthic and adhesive algae in the algal communities throughout the Holocene. The most drastic changes in the diatom complexes were associated with a tectonic event nearby the Imandra depression.

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