• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • 1
  • 1
  • Tagged with
  • 4
  • 4
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 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

ArtrÃpodes de solo habitantes da caatinga sob manejo florestal (Fazenda Alvorada, SÃo GonÃalo do Amarante, CearÃ) / Arthropods soil population of caatinga under forest management (Farm Dawn are the, SÃo GonÃalo do Amarante, CearÃ)

Lilianne dos Santos Maia 11 February 2016 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / A Caatinga à a vegetaÃÃo predominante no semiÃrido Nordestino, caracterizada por plantas caducifÃlias que perdem suas folhas durante o perÃodo de estiagem. Uma das prÃticas que vem contribuindo para a perda da diversidade à a exploraÃÃo indiscriminada da vegetaÃÃo natural para produÃÃo de lenha, cujos efeitos sÃo devastadores, principalmente, no bioma que à considerado um dos mais frÃgeis. Visando a exploraÃÃo da madeira de forma legalizada e sustentÃvel, a partir de 2012 foram aprovados Planos de Manejo Florestal. Para garantir a sustentabilidade do Plano de Manejo Florestal se faz necessÃrio a realizaÃÃo de pesquisas que avaliem os possÃveis impactos sobre os artrÃpodes de solo, uma vez que esses organismos reagem rapidamente a qualquer alteraÃÃo ocorrida dentro de um ambiente. Diante do exposto o presente trabalho tem por objetivo relatar informaÃÃes sobre os principais grupos de organismos habitantes do solo (ArtrÃpodes de solo ou edÃficos), bem como o efeito do plano de Manejo florestal sobre organismos presentes em uma Ãrea do bioma Caatinga. Foram selecionadas cinco Ãreas que adotam Plano de Manejo Florestal em diferentes estÃgios de sucessÃo (T1- Ãrea sem ser explorada à seis meses; T2- Ãrea sem ser explorada à 2-3 anos; T3- Ãrea sem ser explorada à 5-6 anos; T4- Ãrea sem ser explorada à 10-11 anos e; Te- Testemunha representada pela Ãrea de reserva legal (NÃo explorada), onde foram instaladas quatro armadilhas âPitfallâ em cada Ãrea. A partir dos artrÃpodes coletados foram calculados os Ãndices ecolÃgicos: Shannon-Weaver (Hâ) e o Ãndice de Uniformidade de Pielou (e), a riqueza de espÃcies e utilizada a anÃlise multivariada - AnÃlise de Componentes Principais (ACP). Constatou-se a presenÃa de diversas espÃcies de artrÃpodes que foram agrupados à nÃvel de Ordem, sendo encontrados de sete à 14 grupos. Constatou-se ainda que Acari, Collembola, Formicidae e Diptera foram os grupos mais representativos em quantidade e que o ciclo de 10 anos de exploraÃÃo da Caatinga seguindo o Plano de Manejo Florestal contribuiu para restauraÃÃo do ecossistema / Caatinga is the predominant vegetation in semi-arid ortheast of Brasil, characterized by deciduous plants that lose their leaves during the dry season. One of the practices that have contributed to the loss of diversity is the indiscriminate exploitation of natural vegetation for fuel wood, the effects are devastating, especially in the biome that is considered one of the weakest. Aiming to logging legalized and sustainable manner, from 2012 were approved Forest Management Plans. To ensure the sustainability of the forest management plan is necessary to conduct research to assess the possible impacts on soil arthropods, as these organisms react quickly to any change within an environment. Given the above the present study aims to report information on the major groups of organisms inhabitants of the soil (soil Arthropods or edaphic), as well as the effect of forest management plan on organisms present in an area of Caatinga. They selected five areas that adopt Forest Management Plan in different stages of succession (T1-area without being exploited to six months; T2-area without being exploited to 2-3 years; T3-area without being exploited to 5-6 years; T4-area without being exploited for 10-11 years; Te-Control represented by legal reserve area (not exploited), where 'Pitfall' were set four traps in each area from the arthropod cological indices were calculated: Shannon-Weaver (H') and the Uniformity Index Pielou (e), the species richness and used multivariate analysis. -Principal Component analysis (PCA) found the presence of several species of arthropods that were grouped to Order level, and found seven to 14 groups. It was also found that Acari, Collembola, Formicidae and Diptera were the most representative groups in quantity and the cycle of 10 years of exploration Caatinga following the Forest Management Plan has ecosystem restoration.
2

Growth characteristics of fish species Gerres filamentosus (Cuvier, 1829) in coastal zone, Quang Binh province / Đặc điểm sinh trưởng của cá Móm gai dài Gerres filamentosus (Cuvier, 1829) ở vùng ven biển tỉnh Quảng Bình

Vo, Van Thiep, Tran, Thi Yen, Nguyen, Thi Huong Binh, Huynh, Ngoc Tam 08 December 2015 (has links) (PDF)
The research was conducted from October 2013 to March 2014 by using the method applied in the current ichthyology study by GV Nikolski, Pravdin IF, OF Xakun, NA Buskaia and Mai Dinh Yen. Fish samples were collected in the coastal area of Quang Binh province. The study results showed that Gerres filamentosus (Cuvier, 1829) had the length romf 52mm to 230mm, corresponding to the weight from 4g to 185g. The age structure of the fish was simple that consisted of four age groups (0+ - 3+), the annual growth rate was relatively fast, the growth equation following Von Bertalanffy was as: Lt = 234.4 x [1- e-0.35 (t + 0.996)], Wt = 373.4 x [1-e-0.0244 (t + 0.2388)] 3.0676. / Nghiên cứu được thực hiện từ tháng 10 năm 2013 đến tháng 3 năm 2014 bằng những phương pháp đang được áp dụng trong các nghiên cứu ngư loại hiện nay của G.V. Nikolski, I. F. Pravdin, O. F. Xakun, N. A. Buskaia và Mai Đình Yên, mẫu cá được thu tại vùng ven biển của tỉnh Quảng Bình. Kết quả nghiên cứu đã cho thấy cá Móm gai dài có chiều dài dao động từ 52mm – 230mm, tương ứng với khối lượng từ 4g – 185g. Cấu trúc tuổi cá Móm gai dài đơn giản, gồm 4 nhóm tuổi (0+ - 3+), tốc độ tăng trưởng hàng năm tương đối nhanh, phương trình sinh trưởng theo Von Bertalanffy có dạng Lt = 234,4 x [1-e-0,35(t + 0,996)], Wt = 373,4 x [1-e-0,0244(t + 0,2388)]3,0676.
3

Growth characteristics of fish species Gerres filamentosus (Cuvier, 1829) in coastal zone, Quang Binh province: Short communication

Vo, Van Thiep, Tran, Thi Yen, Nguyen, Thi Huong Binh, Huynh, Ngoc Tam 08 December 2015 (has links)
The research was conducted from October 2013 to March 2014 by using the method applied in the current ichthyology study by GV Nikolski, Pravdin IF, OF Xakun, NA Buskaia and Mai Dinh Yen. Fish samples were collected in the coastal area of Quang Binh province. The study results showed that Gerres filamentosus (Cuvier, 1829) had the length romf 52mm to 230mm, corresponding to the weight from 4g to 185g. The age structure of the fish was simple that consisted of four age groups (0+ - 3+), the annual growth rate was relatively fast, the growth equation following Von Bertalanffy was as: Lt = 234.4 x [1- e-0.35 (t + 0.996)], Wt = 373.4 x [1-e-0.0244 (t + 0.2388)] 3.0676. / Nghiên cứu được thực hiện từ tháng 10 năm 2013 đến tháng 3 năm 2014 bằng những phương pháp đang được áp dụng trong các nghiên cứu ngư loại hiện nay của G.V. Nikolski, I. F. Pravdin, O. F. Xakun, N. A. Buskaia và Mai Đình Yên, mẫu cá được thu tại vùng ven biển của tỉnh Quảng Bình. Kết quả nghiên cứu đã cho thấy cá Móm gai dài có chiều dài dao động từ 52mm – 230mm, tương ứng với khối lượng từ 4g – 185g. Cấu trúc tuổi cá Móm gai dài đơn giản, gồm 4 nhóm tuổi (0+ - 3+), tốc độ tăng trưởng hàng năm tương đối nhanh, phương trình sinh trưởng theo Von Bertalanffy có dạng Lt = 234,4 x [1-e-0,35(t + 0,996)], Wt = 373,4 x [1-e-0,0244(t + 0,2388)]3,0676.
4

La chasse aux trophées : menace ou alliée pour les espèces rares / Trophy hunting : threat or ally to rare species

Palazy, Lucille 12 February 2013 (has links)
La chasse aux trophées, type de chasse récréative dont l'objectif premier est de prélever un trophée d'intérêt, est un sujet très controversé. Cette activité est potentiellement génératrice d'un effet Allee anthropogénique (EAA). Ce processus démographique stipule que la valorisation de la rareté d'une espèce peut stimuler son exploitation et mener à son extinction. L'objectif de ce travail a été de tester le risque d'EAA dans la chasse aux trophées. Nous avons mis en évidence que les espèces rares ont une forte valeur économique dans la chasse aux trophées, quelque soit la taille du trophée, ce qui témoigne d'une demande forte pour ces espèces. Nous avons également montré que le nombre d'importations/exportations de trophées et le nombre de trophées de chasse enregistrés par le Safari Club International s'accroît pour les espèces les plus rares lorsque l'indice de rareté de l'espèce augmente. La chasse aux trophées sur les espèces rares a été proposée comme outil pour financer leur conservation. Cependant, nos résultats valident le risque d'EAA pour ces espèces. De plus, les chasseurs ne semblent pas motivés en priorité par la participation à la conservation de la vie sauvage et le peu de données disponibles sur les populations, la chasse illégale, la corruption et le manque de contrôle rendent possible l'exploitation non durable de ces ressources à forte valeur économique. Néanmoins, la vie sauvage doit apporter des bénéfices économiques pour motiver sa préservation. Ainsi, la chasse aux trophées des espèces rares peut être utilisée pour financer leur conservation mais certaines mesures sont à prendre au préalable pour prévenir leur surexploitation / Trophy hunting, which is a form of recreational hunting with the main objective of collecting a trophy of interest, is a controversial subject. This activity could potentially generate an anthropogenic Allee effect (AAE). This demographic process states that the valuation of rarity could drive rare species exploitation and even lead to their extinction. Our project aims at testing the potential for an AEE in trophy hunting. We demonstrate that rare species have a high financial value, regardless of the trophy size, indicating that there is a high demand for those species. We also show that the number of trophies traded internationally and the number of recorded trophies by the Safari Club International (one of the largest clubs for international trophy hunters in the USA) rises as the degree of rarity (as measured by a rarity index) increases. Trophy hunting of rare species has been proposed as a tool to fund their conservation. However, our results indicate that there is a risk of an AAE for rare species. Furthermore, the combined effects of trophy hunting, illegal hunting, corruption as well as the lack of population knowledge and of management controls have potential to result in the unsustainable exploitation of rare species of high financial value. Nonetheless, trophy hunting has potential to generate strong financial incentives that are necessary for wildlife preservation. Such incentives are only likely to be effective if strict measures are required and enforced to prevent overexploitation of rare trophy species

Page generated in 0.143 seconds