Human activities, such as agricultural activity, housing construction, forest logging, etc., play an important role in vegetation changes. Any disturbance to the ecosystem by a severe change in landscape patterns may reduce the survival capacity of certain plant species. In recent years, many studies have used a geographic information system to establish spatial data on vegetation changes; this information includes both the plant species and their spatial structure. Therefore, the aim of this study is to investigate the trends and patterns of vegetation changes and the degree of correlation with the particular environmental features at Wangan Island and Chimei Island in the Penghu Islands, from 1979 to 2009. Both islands have very similar natural features, including geographic location, natural environment, and economic development, but the spatial structures of the land use type are different. The study makes use of geographic information systems, detrended correspondence analysis, canonical correspondence analysis and landscape ecological indicators as study tools. The results are expected to promote our understanding of the spatial distribution patterns of vegetation types and plant species. The results can be divided into three areas. First, both islands follow the same trend with regard to changes in land cover, but the rates of change are different. And the spatial structure of land use types affects the location of land cover types. Example, the centralized and decentralized villages both impact the distribution of the woodland. The mesh and ring road both impact the location of agricultural land. Second, the grassland plant species are correlated with the environmental factors, but the forest plant species are not. The major woodland specie is Leucaena leucocephala on both islands, whose physiological habits may reduce the degree of the correlation. Third, compared to the two islands, Chimei Island is more significant about that the vegetation types are correlated with the neighboring land use types. Finally, the plant species of the local vegetation types could be predicted by changes in the type of land use. In addition, this study has built a trend scheme of the spatial structure changes on Wangan Island and on Chimei Island, which can be used in the island¡¦s future environmental planning.

Monitoring and maintaining the health of coastal wetlands is a global concern. The greatest threat to coastal wetlands in the Great Lakes Basin are anthropogenic removal and enrichment. The coastal wetlands in Georgian Bay are relatively undisturbed by humans, but face disturbance caused by reduced annual water-level fluctuations. Since these wetlands are critical habitat for many fish, bird, amphibian, and reptile species, many efforts to accurately monitor and maintain their health have been put into place. Recently, these wetlands have been experiencing an abrupt (~1 m) transition to higher water levels, following 14 years of sustained lows, which allowed trees and shrubs to invade the meadow vegetation zone. This sustained water-level pattern has never occurred in this region before, offering the unique opportunity to study wetlands undergoing a transition, where areas of 10+ years of upland plant species growth was inundated and became part of the wetland habitat. This thesis first investigates how this change in water level affects the distribution of meadow, emergent, floating, and submerged vegetation both in physical space and area. The second chapter of this thesis presents long-term water quality, macrophyte, and fish community monitoring using ecological indices. Water quality and macrophyte indices are robust enough to monitor wetlands undergoing a transition; however, issues arise in the calculation of the wetland fish index, as the changes in macrophyte distribution described in Chapter 1 impact the ability to replicate community sampling using fyke nets. The research done throughout this thesis is highly beneficial in adding to the limited knowledge of key factors impacting macrophyte community shifting. This work also identifies water-level scenarios where managers must adjust sampling protocols to succeed in effectively sampling wetland fish communities. / Thesis / Master of Science (MSc) / The coastal wetlands in the Georgian Bay area are primarily threatened by human development and the removal of annual water-level fluctuations. From 1999-2013, the water level decreased and remained low. In 2014, the water level rose about 1 m, causing flooding of grass and trees that had grown in the meadow zone during the 14 years when the water level was low. The first goal of this thesis is to explain how and why all wetland plants are relocating during this period. The second goal is to make sure that common indicators of wetland health (water quality, plants, and fish) can still be used during a time when flooding of grasses and trees was occurring in wetlands. The findings in this thesis contribute to the ability to predict and understand how the plants will shift within a wetland during a time of flooding, as well as informing managers on appropriate sampling protocols.

Submitted by (edna.saturno@ufrpe.br) on 2017-02-14T14:20:14Z No. of bitstreams: 1 Ivo Thadeu Lira Mendonca.pdf: 906790 bytes, checksum: 20a8319a942fd0ff9acd8bcc2c266f8c (MD5) / Made available in DSpace on 2017-02-14T14:20:14Z (GMT). No. of bitstreams: 1 Ivo Thadeu Lira Mendonca.pdf: 906790 bytes, checksum: 20a8319a942fd0ff9acd8bcc2c266f8c (MD5) Previous issue date: 2009-02-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Opportunist species increase their population in detriment to others that previously participated in the assemblage, changing the ecosystem structure. Such changes can be used as ecological tools in pollutant sources monitoring, because they corroborate in the description of alterations of aquatic ecosystem trophic state. Therfore, this study aimed at surveying and characterizing the planktonic algae species of Boa Esperança Hydroelectric reservoir – PI/MA, Brazil, along its extension in different seasonal periods. Four quarterly surveys were carried out, between July 2006 and April 2007, in 17 sampling stations. The biological material was obtained through vertical tows along the euphotic zone. Algae ecological strategies and associations were defined and biotic indexes applied. 189 taxons were identified, distributed among Chlorophyta (94), Bacillariophyta (41), Cyanophyta (30), Euglenophyta (13), Dinophyta (4), Chrysophyta (3), Cryptophyta (3) and Xantophyta (1). The diversities and densities showed temporal differences, although tended to be longitudinally similar. The highest diversity was found in October 2006, 4,3 bit×org-1, in BOA 04, and the lowest was found in July 2006, 0,6 bit×org-1, in BOA 17, due the density of Aulacoseira granulata. The highest density was recorded in January 2007, 114,8×103 org×L-1, in BOA 17, and the lowest in April 2007, 1,4×103 org×L-1, in BOA 02. During the study, Cyanophyta and Aulacoseira granulata (Bacillariophyta) were the algal division and the species that presented the highest densities, respectively. The indexes indicated that the environment was, predominantly, mesotrophic during the year sessions. / Espécies oportunistas aumentam sua população em detrimento de outras que, outrora participavam da comunidade, mudando a estrutura populacional. Mudanças nessa estrutura podem ser utilizadas como ferramentas ecológicas em monitoramento de fontes poluidoras, pois corroboram na descrição de alterações do estado trófico em ecossistemas aquáticos. Sendo assim, objetivou-se inventariar e caracterizar as espécies de algas planctônicas do reservatório da Hidroelétrica de Boa Esperança, PI/MA, Brasil, ao longo de sua extensão e em diferentes períodos sazonais. Foram realizadas quatro coletas trimestrais, entre julho de 2006 e abril de 2007, em 17 estações amostrais. O material biológico foi obtido através de arrastos verticais ao longo da zona eufótica. Foram definidas as associações ecológicas e calculados índices bióticos. Foram identificados 189 táxons, distribuídos entre as Chlorophyta (94), Bacillariophyta (41), Cyanophyta (30), Euglenophyta (13), Dinophyta (4), Chrysophyta (3), Cryptophyta (3) e Xantophyta (1). As diversidades e densidades apresentaram diferenças entre os períodos de coleta, embora longitudinalmente tenham tendido à homogeneidade. A maior diversidade foi encontrada em outubro/06, 4,3 bit.org-1, em BOA 04, enquanto a menor em julho/06, 0,6 bit.org-1, em BOA 17, devido a densidade de Aulacoseira granulata. A maior densidade foi observada em janeiro/07, 114,8×103 org.L-1, em BOA 17, e a menor em abril/07, 1,4×103 org.L-1, em BOA. Durante o estudo, Cyanophyta e Aulacoseira granulata (Bacillariophyta) foram a divisão algal e a espécie que apresentaram as maiores densidades, respectivamente. Os índices aplicados indicaram que o ambiente encontra-se, predominantemente, mesotrófico nos diferentes períodos do ano.

Nematode communities in black pepper (Piper nigrum L.) agricultural soil in Thanh An, Binh Phuoc province, were investigated. Soil samples were collected in February 2012 at 9 selected sites belonging to 3 pepper groves. The structure of nematode communities and critical ecological indices were determined to estimate environmental status. 26 genera were found. Of those, plant parasitic nematodes such as Meloidogyne, Helicotylenchus, Hoplolaimus, Psilenchus, and Tylenchidae always appear with high frequency and density, whereas the carnivorous nematodes were rarely detected. The nematode density correlates to the concentration of the total organic matter which correlates closely to the (Ba + Fu) proportion showed by the regression equation y = 0.0223x + 1.6819 with R2 = 1. The ecological triangle model, but not the maturity index (MI), apparently showed the status and processes (decomposition and mineralization) which may be happening in the soils of areas studied. The first grove is rich in nutrient but stressed by chemicals. The second grove is stable, with no chemical stress, but has low nutrient contents. The third grove is affected by chemicals but to a lesser extent than the first one. / Các quần xã tuyến trùng trong hệ sinh thái đất trồng tiêu ở khu vực xã Thanh An, tỉnh Bình Phước được nghiên cứu. Các mẫu đất được thu nhận trong tháng hai năm 2012 tại 9 điểm thuộc 3 vườn tiêu. Cấu trúc quần xã tuyến trùng và các chỉ số sinh thái đã được xác định để qua đó đánh giá trạng thái môi trường. Tổng cộng có 26 giống tuyến trùng được tìm thấy. Trong đó, các loài tuyến trùng ký sinh thực vật như Meloidogyne, Helicotylenchus, Hoplolaimus, Psilenchus, và tuyến trùng ăn nấm Tylenchidae luôn xuất hiện với tần suất và mật độ cao, trong khi tuyến trùng ăn thịt lại hiếm khi được phát hiện. Mật độ tuyến trùng tương quan với lượng chất hữu cơ tổng số mà nó tương quan chặt chẽ với với tỉ lệ nhóm (Ba + Fu) được thể hiện ở phương trình hồi quy là y = 0.0223x + 1.6819 với R2 = 1. Mô hình tam giác sinh thái, nhưng không phải chỉ số tăng trưởng MI, thể hiện rõ trạng thái và các quá trình (sự phân hủy và sự khoáng hóa) có lẽ đang diễn ra trong đất của khu vực được nghiên cứu. Vườn thứ nhất thì giàu dinh dưỡng nhưng bị áp lực bởi hóa chất. Vườn thứ hai khá ổn định, không chịu áp lực hóa chất, nhưng hàm lượng dinh dưỡng rất kém. Vườn thứ ba bị tác động bởi hóa chất nhưng ở mức độ thấp hơn vườn thứ nhất.

Nematode communities in black pepper (Piper nigrum L.) agricultural soil in Thanh An, Binh Phuoc province, were investigated. Soil samples were collected in February 2012 at 9 selected sites belonging to 3 pepper groves. The structure of nematode communities and critical ecological indices were determined to estimate environmental status. 26 genera were found. Of those, plant parasitic nematodes such as Meloidogyne, Helicotylenchus, Hoplolaimus, Psilenchus, and Tylenchidae always appear with high frequency and density, whereas the carnivorous nematodes were rarely detected. The nematode density correlates to the concentration of the total organic matter which correlates closely to the (Ba + Fu) proportion showed by the regression equation y = 0.0223x + 1.6819 with R2 = 1. The ecological triangle model, but not the maturity index (MI), apparently showed the status and processes (decomposition and mineralization) which may be happening in the soils of areas studied. The first grove is rich in nutrient but stressed by chemicals. The second grove is stable, with no chemical stress, but has low nutrient contents. The third grove is affected by chemicals but to a lesser extent than the first one. / Các quần xã tuyến trùng trong hệ sinh thái đất trồng tiêu ở khu vực xã Thanh An, tỉnh Bình Phước được nghiên cứu. Các mẫu đất được thu nhận trong tháng hai năm 2012 tại 9 điểm thuộc 3 vườn tiêu. Cấu trúc quần xã tuyến trùng và các chỉ số sinh thái đã được xác định để qua đó đánh giá trạng thái môi trường. Tổng cộng có 26 giống tuyến trùng được tìm thấy. Trong đó, các loài tuyến trùng ký sinh thực vật như Meloidogyne, Helicotylenchus, Hoplolaimus, Psilenchus, và tuyến trùng ăn nấm Tylenchidae luôn xuất hiện với tần suất và mật độ cao, trong khi tuyến trùng ăn thịt lại hiếm khi được phát hiện. Mật độ tuyến trùng tương quan với lượng chất hữu cơ tổng số mà nó tương quan chặt chẽ với với tỉ lệ nhóm (Ba + Fu) được thể hiện ở phương trình hồi quy là y = 0.0223x + 1.6819 với R2 = 1. Mô hình tam giác sinh thái, nhưng không phải chỉ số tăng trưởng MI, thể hiện rõ trạng thái và các quá trình (sự phân hủy và sự khoáng hóa) có lẽ đang diễn ra trong đất của khu vực được nghiên cứu. Vườn thứ nhất thì giàu dinh dưỡng nhưng bị áp lực bởi hóa chất. Vườn thứ hai khá ổn định, không chịu áp lực hóa chất, nhưng hàm lượng dinh dưỡng rất kém. Vườn thứ ba bị tác động bởi hóa chất nhưng ở mức độ thấp hơn vườn thứ nhất.

The vegetation of the Nooitgedacht section of the Loskop Dam Nature Reserve resembles Bankenveld vegetation and differs from the other areas of the reserve. This study was undertaken to identify, classify, and describe the plant communities present on this section, and to determine their veld condition. The Braun-Blanquet approach was followed to classify the different plant communities. A total number of 170 sample plots (100m2) were placed in all homogeneous vegetation units in a randomly stratified basis. The Ecological Index Method (EIM) was used to determine the veld condition. Data were collected using the steppoint method and incorporated into the GRAZE model from where the veld condition was calculated. A minimum of 400 step points were surveyed in each community with more points in the larger communities. Plant community data was analysed using the JUICE software program. A total of 11 plant communities were identified. The overall veld condition score indicates the vegetation to be in a good condition, resulting in a high grazing capacity. / Environmental Sciences / M. Sc. (Nature Conservation)

The vegetation of the Nooitgedacht section of the Loskop Dam Nature Reserve resembles Bankenveld vegetation and differs from the other areas of the reserve. This study was undertaken to identify, classify, and describe the plant communities present on this section, and to determine their veld condition. The Braun-Blanquet approach was followed to classify the different plant communities. A total number of 170 sample plots (100m2) were placed in all homogeneous vegetation units in a randomly stratified basis. The Ecological Index Method (EIM) was used to determine the veld condition. Data were collected using the steppoint method and incorporated into the GRAZE model from where the veld condition was calculated. A minimum of 400 step points were surveyed in each community with more points in the larger communities. Plant community data was analysed using the JUICE software program. A total of 11 plant communities were identified. The overall veld condition score indicates the vegetation to be in a good condition, resulting in a high grazing capacity. / Environmental Sciences / M. Sc. (Nature Conservation)