• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 7
  • 3
  • 3
  • 2
  • Tagged with
  • 14
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Qualidade da água e identificação da comunidade fitoplanctônica de um viveiro de piscicultura utilizado para irrigação

Lachi, Giuliana Berchieri [UNESP] 30 June 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:27:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-06-30Bitstream added on 2014-06-13T20:56:22Z : No. of bitstreams: 1 lachi_gb_me_jabo.pdf: 215317 bytes, checksum: eb1819efbb518f65960adda7fbccbf9f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O estudo foi realizado em um viveiro de criação semi-intensiva de peixes do Centro de Aqüicultura da UNESP (CAUNESP) Jaboticabal, SP. O trabalho avaliou algumas variáveis limnológicas e fitoplâncton neste viveiro utilizado para irrigação. Foram analisados variáveis físicas e químicas (pH, oxigênio dissolvido, condutividade, temperatura, alcalinidade total, formas de carbono inorgânico, dureza, sólidos totais solúveis, demanda bioquímica de oxigênio, nitrito, nitrato, amônia, fósforo total e ortofosfato), clorofila-a e identificação dos organismos fitoplanctônicos. A temperatura sofreu influência direta das condições ambientais. A utilização deste viveiro para fins de irrigação deve ser reavaliado em função das condições de manejo e da presença de Cyanobacteria. Devido a distribuição em série em que o viveiro estudado esta incluído, provocou o aumento nas variáveis limnológicas, principalmente no período de engorda dos peixes. O manejo inadequado em piscicultura geralmente acelera o processo de eutrofização, deteriorando a qualidade da água, em função do manejo empregado principalmente, pela administração de altas doses de ração e fertilização (orgânica ou inorgânica). O objetivo do trabalho foi avaliar alguns aspectos bióticos e abióticos de um viveiro de piscicultura e sua relação direta na qualidade da água para uso múltiplo. / This study was carried out at one semi-intensive breeding fishpond at the UNESP (CAUNESP) Aquaculture Center, in Jaboticabal, SP. The study evaluated some limnological parameters and phytoplankton of a fishpond used to irrigation. The purpose of this work was to determine physical and chemical variables (pH, dissolved oxygen, conductivity, temperature, total alkalinity, forms of inorganic carbon, hardness, total solids soluble, biochemical oxygen demand, nitrite, nitrate, ammonia, total phosphorus, and orthophosphate), chlorophyll-a and phytoplankton organisms consist. The temperature was influenced directly by climatic conditions. The utilization of this fishpond as a source of irrigation must be revaluated in function of management conditions and the presence of Cyanobacteria. In function of set up sequentially, this fishpond study had favored a change in the limnological features, mainly in the grow-out fish period. The used of inappropriate management may eventually produce the eutrophication, and water quality degradation due to the higher rates of ration and fertilizer (organic or inorganic). The present work was conducted to evaluate the biotic and abiotic aspects in the water quality of fish pond with water flow and distributed sequentially and multiple use.
2

Qualidade da água e identificação da comunidade fitoplanctônica de um viveiro de piscicultura utilizado para irrigação /

Lachi, Giuliana Berchieri. January 2006 (has links)
Orientador: Lúcia Helena Sipaúba Tavares / Banca: Ely Nahas / Banca: Rose Meire Vidotti / Resumo: O estudo foi realizado em um viveiro de criação semi-intensiva de peixes do Centro de Aqüicultura da UNESP (CAUNESP) Jaboticabal, SP. O trabalho avaliou algumas variáveis limnológicas e fitoplâncton neste viveiro utilizado para irrigação. Foram analisados variáveis físicas e químicas (pH, oxigênio dissolvido, condutividade, temperatura, alcalinidade total, formas de carbono inorgânico, dureza, sólidos totais solúveis, demanda bioquímica de oxigênio, nitrito, nitrato, amônia, fósforo total e ortofosfato), clorofila-a e identificação dos organismos fitoplanctônicos. A temperatura sofreu influência direta das condições ambientais. A utilização deste viveiro para fins de irrigação deve ser reavaliado em função das condições de manejo e da presença de Cyanobacteria. Devido a distribuição em série em que o viveiro estudado esta incluído, provocou o aumento nas variáveis limnológicas, principalmente no período de engorda dos peixes. O manejo inadequado em piscicultura geralmente acelera o processo de eutrofização, deteriorando a qualidade da água, em função do manejo empregado principalmente, pela administração de altas doses de ração e fertilização (orgânica ou inorgânica). O objetivo do trabalho foi avaliar alguns aspectos bióticos e abióticos de um viveiro de piscicultura e sua relação direta na qualidade da água para uso múltiplo. / Abstract: This study was carried out at one semi-intensive breeding fishpond at the UNESP (CAUNESP) Aquaculture Center, in Jaboticabal, SP. The study evaluated some limnological parameters and phytoplankton of a fishpond used to irrigation. The purpose of this work was to determine physical and chemical variables (pH, dissolved oxygen, conductivity, temperature, total alkalinity, forms of inorganic carbon, hardness, total solids soluble, biochemical oxygen demand, nitrite, nitrate, ammonia, total phosphorus, and orthophosphate), chlorophyll-a and phytoplankton organisms consist. The temperature was influenced directly by climatic conditions. The utilization of this fishpond as a source of irrigation must be revaluated in function of management conditions and the presence of Cyanobacteria. In function of set up sequentially, this fishpond study had favored a change in the limnological features, mainly in the grow-out fish period. The used of inappropriate management may eventually produce the eutrophication, and water quality degradation due to the higher rates of ration and fertilizer (organic or inorganic). The present work was conducted to evaluate the biotic and abiotic aspects in the water quality of fish pond with water flow and distributed sequentially and multiple use. / Mestre
3

Rybník Svět - vývoj vybraných environmentálních faktorů v letech 2009 - 2010 / The pond Svět - the development of selected environmental factors in the years 2009-2010

JAKEŠOVÁ, Ludmila January 2011 (has links)
Fishpond Svět is one of the most prominent and attractive water bodies of Třeboň region. It is located close to Třeboň town, is is used for fish production and joined economic activities, as well as for recreation and sporting. To harmonize all the functions is the goal of the Rybářství Třeboň Co., owner of the fishpond, and local governement of Třeboň town. For revitalization of the fishpond, economic activities are harmonized in order to improve the water quality. The goal is provided via decreasing fish number, fertilizers and food, which resulted in decreasing numbers of cyanobacteria and algae in phytoplankton, especially during warm parts of years, when the troubles, for recretaion, are most. This measures are monitored by Inst. Botany Acad. Sci. via regular sampling and analysing NO2-, NO3-, tN, PO43-, tP, Cl- a NH4+ concentrations as well as temperature, Secchi desk depth and chlorophyll_a. I was participating in sampling and evaluation in period 2008-2010. Results of the monitoring are regularly presented in local press and internet home page of town Třeboň which is also covering the expenses of the project.
4

Posílení populace hohola severního (Bucephala clangula) pomocí umělých budek / Increasing of density of the goldeneye population (\kur{Bucephala clangula}) by using artificial nest boxes

SKLÁŘOVÁ, Kateřina January 2016 (has links)
In the autumn 2013 were set up 50 nest boxes for increasing of density of the Common Goldeneye population (Bucephala clangula) in Třeboň region. The main objectives of this study were to check the nest boxes after breeding season and analyse the results. These nest boxes were checked in the July 2014 and 2015. In the spring 2015 were set up 2 mobile scouting cameras to the selected nest boxes. There was also monitor the occurrence of the Common Goldeney on the Naděje fishpond system and Prátr fishpond system by counting. The Naděje fishpond system is created by 16 different sized fishponds and it is situated approximately 8.5 km to the south of the town Veselí nad Lužnicí. The Prátr fishpond system is situated approximately 1 km to the south of the town Třeboň and it is created by 9 fishponds. The monitor was realised in term from 17. 3. 2015 to 27. 7. 2015. The other species of water birds were also counted. In the year 2014 10 nest boxes were occupied and in the year 2015 17 nest boxes were occupied. The nest boxes which were located on the fishpond´s islands were preferred. Both of the mobile scouting cameras recorded European Pine Marten (Martes martes) devastating the nest. The Common Goldeneye was occurred on the both fishpond systems in 2015. In the year 2015 was observed the female of the Common Goldeneye with 8 ducklings on the Prátr fishpond system.
5

Biodiversity Study around Fishponds of Sihcao, Tainan City

Tang, Chen-hsien 03 September 2010 (has links)
Abstract Fishpond area of Sihcao, Tainan City, approximate 488 hectors, is a part of coastal wetlands of Taiwan. Fishponds can be found almost everywhere in the wetlands, readily forming a fragmented ecosystem. Previous studies on populations of small mammals in coastal wetlands of Taiwan are scarce. Disturbance types found in the study area include straying dogs, working farmers, tillaging of the fishponds, and typhoons, etc, which would probably reduce the abundance of small mammals. The resources such as shelter, vegetation coverage, insects and seeds would increase the abundance of small mammals. The seasonal changes of these environmental factors may in turn affect the population dynamics of small mammals. I monitored the monthly population fluctuation of small mammals and invertebrates in the fishpond habitats, 2008. Six species of small mammals and 106 species of invertebrates were found. The small mammal populations in the Hairy Beggar Ticks region were compared with those within the non-Hairy Beggar Ticks region. More small mammals were found in the Hairy Beggar Ticks region in the sampling period. The vegetation coverage of the former was higher than that of the latter. There was positive correlation between evenness of small mammals and temperature. No differences of the biodiversity of invertebrates were found between the regions in the year. Significant correlation existed between the sunshine duration and the richness of invertebrates. The correlation may be due to the change of photoperiod. There was no significant correlation between the richness of small mammals and that of invertebrates.
6

An evaluation of the information dissemination mechanisms for small scale subsistence farmers

Tire, Mpho 12 1900 (has links)
Thesis (MPhil (Information Science))--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: Rural communities depend on the use of natural resources surrounding them for their daily livelihoods. These communities have in the past lived off these resources amid the day-to-day natural threats that pose a threat to their environmental resources. These communities depend on tending the land and rearing livestock to provide for their day-to-day needs. The only period when these communities decide to sell what they have produced is when they have unexpected surpluses that were neither planned for and these are normally sold to derive extra income. Given the total dependence on the use of their natural resources as a means of their survival one would expect this group to be provided with relevant information and be kept abreast of developments in the sector to enable them to produce better and derive surpluses that will generate extra income. This is unfortunately not the prevailing arrangement, very often these communities are left on their own to fend for themselves using knowledge and practical experience that has been gained over the years. In other instances the nature of the information provided is in most cases such that it does not lend itself for easy use by a person who is either semi-literate or illiterate. For those who can read the information it is not always forthcoming or does not deal with the relevant local issues, and lack of supportive infrastructure also adds to the farmers ailing conditions. The kind of agricultural research as well as extension services provided to these farming communities is still lagging behind due to a number of factors, these include: poor interaction with the farmers in an effort to identify and prioritize their needs, high level of illiteracy, insufficient resources, low levels of income and a host of other related problems. Adomi et.al. (2003), in their study on crop farmers’ access to agricultural information in rural areas of Delta State Nigeria, also stress the importance of farmers having access to agricultural information if their agricultural efforts are to succeed. They further emphasize that farmers need to share knowledge and experience with farmers who operate under similar conditions, this will enable them to adapt and replicate experiences learnt from other farmers. Most importantly farmers need to be provided with information on access to credit and information from research institutions. The paper intends to look at challenges facing small-scale farmers in as far as information dissemination is concerned, appropriate techniques that can be applied to overcome these challenges and use lessons that have proved to work for countries operating under similar conditions. It is important to remember that farmers irrespective of their scale of operation, are managers in their own right, they are constantly facing challenges, are forced to make choices and decisions that will determine the future of their farming enterprise in the cut-throat competitive environment. The livelihoods of their families depend on these very decisions. Therefore providing timely, accurate, reliable and user-friendly information at affordable prices is their only hope for survival in the present free- market economy.
7

Vybrané aspekty hnízdní biologie potápky roháče (Podiceps cristatus) ve vztahu k prostředí / The selected aspects of nesting biology of Great Crested Grebe (Podiceps cristatus) in relation to environmental conditions

JEŽKOVÁ, Eva January 2014 (has links)
The aim of the thesis was the appraisal of Great Crested Grebe (Podiceps cristatus) nesting biology aspects in relation to environmental conditions. The research took 6 months from the 2nd of April to the 2nd of October in 2013 and was realised in the Naděje fishpond system on the ponds Víra, Láska, Skutek, Dobrá Vůle, Rod and Naděje. This fishpond system is situated in CHKO Třeboňsko nearby villages Frahelž and Klec and it consists of total of 15 ponds which are used for intensive fish farming, partly for breeding of Wild Ducks for hunting purposes. The counting of birds, active searching of nests and measuring parameters of nests and eggs were carried out during the work. The nests were found on ponds Naděje, Skutek and Láska. In 2013 18 nests were measured altogether. On the fishpond Naděje 8 nests were situated, on the fishpond Láska 4 nests and on the fishpond Skutek 6 nests altogether. 13 nests of the total were found on a free water surface and 5 nests were situated in the vegetations of the Great Reedmace (Typha latifolia) at a maximum distance of 1 m from the free water surface. In 2013 64 eggs were measured altogether. On the fishpond Naděje parameters of 33 eggs were obtained, on the fishpond Láska 17 eggs and on the fishpond Skutek 14 eggs were found altogether.
8

Colonisation d'un écosystème d'eau douce hétérogène, par un oiseau d'eau herbivore : le cygne tuberculé (Cygnus olor) dans les étangs piscicoles de Dombes / Colonization of heterogeneous aquatic ecosystems, by a herbivorous waterbird : the Mute swan (Cygnus olor) on Dombes fishponds

Gayet, Guillaume 15 December 2010 (has links)
Dans certains cas, la colonisation des zones humides par les espèces animales et végétales peut être une menace majeure pour la biodiversité. Il est donc primordial de mieux connaître l'écologie des espèces colonisatrices pour définir leurs relations avec le reste de l'écosystème. Nous avons étudié les conséquences de la colonisation relativement récente des étangs piscicoles français par le cygne tuberculé (Cygnus olor). Nous nous sommes intéressés à l'expression de cette colonisation dans l'espace par l'étude des processus de sélection de l'habitat. Nos résultats montrent que dans un paysage d'étangs, la répartition des cygnes tuberculés dépend à la fois de la configuration spatiale des étangs (aire isolement), des ressources disponibles et du statut de reproduction des cygnes tuberculés. Nous avons ensuite étudié les interactions entre le cygne tuberculé et les communautés animales et végétales des étangs. Sur les sites de cantonnement des couples, nous n'avons pas montré d'effet de la présence des cygnes tuberculés sur l'abondance des oiseaux d'eau, et aucune forme d'exclusion spatiale à l'échelle de l'étang. En revanche, les cygnes tuberculés peuvent générer une déplétion significative des herbiers de macrophytes aquatiques, suggérant des effets en cascade sur les autres communautés des étangs piscicoles. Comme toute perturbation générée par une espèce colonisatrice, celle associée à l'arrivée des cygnes doit néanmoins être replacée dans le contexte plus large des régimes de perturbations à l'oeuvre sur l'écosystème, ce qui importe particulièrement dans le cas d'écosystèmes aussi dépendants de l'activité humaine que les étangs piscicoles. / In some cases, wetland colonization by animals and plants may be a major threat to biodiversity. It is therefore crucial to better understand the ecology of colonizing species to assess their relationships with the other elements of ecosystems. We studied the consequences of the relatively recent colonization of French fishponds by mute swan (Cygnus olor). We especially considered how such colonization now translates into space, through the analysis of habitat selection processes. Our results show that swan distribution within a fishpond landscape depends on fishpond spatial configuration (area isolation), available resources as well as mute swan breeding status. We then analysed the relationships between mute swan and fishpond animal and plant communities. Where swan pair settle, we do not demonstrate any effect of swan presence on the abundance of other waterbirds, nor any spatial exclusion within fishponds. Conversely, mute swans can signif icantly deplete aquatic macrophyte beds, suggesting cascade effects on other fishpond communities are possible. Like any perturbation caused by a colonizing species, that associated with swan arrival however has to be considered in the broader context of perturbation regimes onto the ecosystem. This is especially crucial in ecosystems like fishponds, that are so much dependent upon human activity.
9

Analýza vybraných aspektů hnízdní biologie potápky roháče (Podiceps cristatus) / Analysis of selected aspects of the breeding biology of Great Crested Grebe (\kur{Podiceps cristatus})

MARKOVÁ, Kateřina January 2016 (has links)
The aim of the thesis was monitoring abundance and distribution of nests of Great Crested Grebe (Podiceps cristatus) during the season on the Naděje fishpond system. Further observation included factors that could affect nesting success of the Great Crested Grebe. Attention was concentrated on Wild Duck (Anas platyrhynchos) which is bred by man on the fishpond system and might negatively affect nesting success of Great Crested Grebe. Part of this study was the detailed observation of selected pairs during the nesting season by using camera traps. Temperature measurement in the nests was done by temperature data logger. The investigation was realized on the Naděje fishpond system near the village Frahelž. The research took place from the 14th of April to the 28th of October in 2015. In 2015 were found and investigated 37 nests on the Naděje fishpond system. On the fishpond Skutek were monitored 34 nest, on the fishpond Láska 2 nests and on the fishpond Rod only 1 nest. Majority nests (30) were found on a free surface and 7 nests were situated in the bushy vegetation. Parameters of 111 eggs were obtained altogether. On the fishpond Skutek were found 100 eggs, on fishpond Láska 8 eggs and in the only nest on fishpond Rod 3 eggs. Using the camera traps during the observation proved negative effect of wild duck on Great Crested Grebe nesting. The nest was destroyed group of wild duck. The maximum temperature in the nest reached 33,8 °C.
10

Floristický průzkum části povodí řeky Oslavy mezi obcemi Velké Meziříčí a Vaneč / Floristic research of part of catchment area of Oslava river between villages Velke Mezirici and Vanec

BORŮVKOVÁ, Zuzana January 2008 (has links)
The study deals with a description of vegetation of part of catchment area of Oslava river between villages Velke Mezirici and Vanec. The search had been realised during the vegetation seasons of the years 2006 and 2007. There are characterised geological-petrographical, soil, climatic, hydrographic ratios and basic phytogeographical characteristics of this area in the form of a search. Selected genera of the observed plants was characterised and their incidence is figured in the schematic maps of the area. There were found out 327 kinds of plants there. In the annex there are attached schematic maps with places of occurence of the plant genera and photographic documentation.

Page generated in 0.0564 seconds