A bacia do Rio Corumbataí é composta por um mosaico de ambientes, fortemente antropizado, com predominância de pastagens e plantações de cana-deaçúcar, além de florestas plantadas de eucalipto e fragmentos de floresta estacional semidecidual. Esta bacia, principal fonte de abastecimento de água da região metropolitana de Campinas, pode ser considerada como um modelo conveniente para o estudo da conservação da diversidade biológica. Subdivide-se em cinco sub-bacias, sendo que a maior, e que apresenta os maiores fragmentos florestais remanescentes, é a do Rio Passa-Cinco. Para verificar a diversidade e a abundância de espécies de mamíferos de médio e grande porte, bem como a utilização que fazem deste mosaico agroflorestal, foram realizados censos por meio de transectos, buscando-se todos os possíveis tipos de registro - diretos e indiretos - como observação direta, fezes, pegadas, arranhões e carcaças. Entre julho de 2003 e junho de 2004 foram percorridos 284,4 km ao todo, e registradas 25 espécies silvestres nativas e duas exóticas, além de seis espécies domésticas. Na floresta nativa foram registradas 23 espécies, no canavial 20, no eucaliptal 17 e nas áreas de pastagem 12. O estimador não-paramétrico Bootstrap calculou 25 espécies para a floresta nativa, 22 para o canavial, 18 para o eucalipto e 13 para o pasto, indicando que o esforço amostral não foi suficiente para a estabilização da curva de esforço. Os índices de Diversidade (H’ e 1/D), bem como Pielou (J’), mostraram ambientes similares, e o ajuste das curvas de distribuição de espécies ao modelo de séries logarítmicas mostra uma comunidade com uma estrutura composta por poucas espécies abundantes e muitas espécies raras. Quanto à freqüência de ocorrência e à abundância relativa nos quatro ambientes amostrados, as únicas espécies que apresentaram diferenças entre os ambientes foram o cachorro-do-mato (Cerdocyon thous) e a lebre européia (Lepus europaeus), ambas com hábitos generalistas, as duas com maior freqüência no canavial, e a lebre-européia também com maior abundância no canavial. Já em relação à comunidade de mamíferos como um todo, o pasto apareceu como o ambiente com menor riqueza de espécies e com o menor freqüência de ocorrência, enquanto que o canavial obteve a maior freqüência de ocorrência. A análise de correspondência mostrou sete espécies mais relacionadas à floresta nativa, cinco ao eucalipto e nove às áreas abertas (pastagem e canavial). Os resultados obtidos sugerem que a comunidade de mamíferos de médio e grande porte da Bacia do Rio Passa-Cinco é sujeita às modificações ambientais que a região vem sofrendo, e que as espécies de hábitos mais generalistas são as que estão conseguindo se manter com maior facilidade, devido, possivelmente, a seus menores requerimentos de habitat. / The Corumbataí river basin is a landscape with great human influence, with the most relevant agroecosystems of São Paulo. It has been used as one of the major water supplies for the metropolitan region of Campinas. This basin is formed by five subbasins, where the Passa-Cinco river basin is the largest, with the most native remaining fragments. This basin could be considered as a convenient model for the study of biodiversity conservation in agroecosystems. In order to evaluate the distribution and abundance of medium and large-sized mammals, 284,4 km of transects were censused from July 2003 to June 2004 in Semideciduous native forest, eucalyptus plantations, sugar-cane plantations and pastures. All possible records were recorded such as direct observation, faeces, tracks, scratches, and carcasses. I found 25 native species and two exotic species, besides six domestic species. On the native forest I recorded 23 species, on sugar cane 20, on eucalypt forest 17, and on the pasture areas 12. The diversity and the evenness index suggested that environments were similar, and the distribution species curve (Log-series model) showed few abundant and a majority of rare species. Crab-eating fox and European hare were the only species with differences among habitats in frequency of occurrence, and European hare was the only one with difference among habitats in relative abundance. The results suggested that this mammalian community has been influenced by the environmental alteration that this region has been suffering, and the current community is basically formed by generalist species what enhanced its adaptation to an anthropogenic landscape. In such conditions, current environmental laws should be enforced in order to improve forest conservation and mitigate the impacts of agriculture, paper industry, and livestock production.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-02-21T14:40:07Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Lígia Gomes Ferreira de Souza.pdf: 862040 bytes, checksum: 84b33fa4d8721af1d396e97801bddc15 (MD5) / Made available in DSpace on 2017-02-21T14:40:07Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Lígia Gomes Ferreira de Souza.pdf: 862040 bytes, checksum: 84b33fa4d8721af1d396e97801bddc15 (MD5) Previous issue date: 2016-02-25 / CNPq / A presença de rios sempre foi uma das condições primárias para o estabelecimento de grupos humanos, e as atividades destes grupos têm causado grande empobrecimento ambiental. Na caatinga, onde as características meteorológicas são consideradas extremas e o regime de chuvas é bastante irregular, a vegetação às margens dos rios encontra-se numa situação de perda de biodiversidade. Sendo assim, este estudo teve por objetivo gerar informações que contribuam em futuros projetos de recuperação de matas ciliares em regiões semiáridas através da avaliação do banco de sementes do solo de três localidades (Preservada, Intermediária e Degradada) submetidas a diferentes usos da terra em uma região de caatinga. Quarenta amostras de solo foram coletadas aleatoriamente em cada área, ao final das estações seca e chuvosa e avaliadas através do método de germinação. Ao final dos experimentos, 23.651 sementes viáveis foram observadas e 80,5% destas, germinaram durante o primeiro mês. Foram encontradas 89 espécies, onde 50 delas foram de herbáceas. As famílias que mais se destacaram foram Poaceae, Cyperaceae, Euphirbiaceae, Malvaceae, Fabaceae e Solanaceae. Maior densidade de sementes ocorreu ao final da estação seca, com a área Preservada apresentando uma densidade 3,7 vezes maior que a Intermediária. O índice de diversidade de Shannon apresentou comportamento decrescente e significativo para as áreas, da estação seca para a chuvosa. Sendo assim, o banco de sementes fornece principalmente espécies pioneiras, existindo uma limitação de espécies pertencentes aos estágios mais avançados. / The presence of rivers has always been one of the primary conditions for the establishment of human groups, and the activities of these groups have caused major environmental impoverishment. In the Caatinga, where the meteorological characteristics are considered extreme and rainfall patterns are very irregular, the vegetation along the riverbanks finds itself in a situation of loss of biodiversity. Thus, the objective of this study was to generate information which could contribute in future recovery projects of riparian forests in semi-arid regions by evaluating the soil seed bank of three locations (Preserved, Intermediate, Degraded) under different land uses in a caatinga region. Forty soil samples were collected randomly in each area at the end of the dry and rainy seasons and evaluated through the germination method. At the end of the experiments, 23,651 viable seeds were observed and 80.5% of these germinated during the first month. There were found 89 species, where 50 of them were of herbaceous found. Families who stood out were Poaceae, Cyperaceae, Euphirbiaceae, Malvaceae, Fabaceae and Solanaceae. The highest density of seeds occurred at the end of the dry season, with the Preserved area featuring a density 3.7 times greater than the Intermediary. The Shannon diversity index showed decreasing behavior and significant for the areas, from the dry season to the rainy season. Thus, the seed bank primarily provides pioneer species and there is a limitation of species belonging to the most advanced stages.

O aumento da concentração de CO2 na atmosfera nas últimas décadas e sua relação com o aquecimento global tem sido amplamente debatido nos meios acadêmicos. Paralelamente, o Brasil aparece como um dos grandes responsáveis pela emissão de gases estufa em decorrência do desmatamento. Buscando apoiar ações públicas, privadas e sociais e responder a questões ligadas ao papel de reflorestamentos mistos na absorção de carbono atmosférico e nas mudanças dos atributos do solo, este trabalho objetivou avaliar o estoque de carbono, o desenvolvimento florestal e os atributos edáficos em dois sistemas contrastantes de restauração florestal (Floresta Estacional Semidecidual). Foi analisado um experimento implantado em 1997, em Nitossolo Vermelho e Argissolo Vermelho-Amarelo, avaliando três tratamentos em blocos casualizados, com três repetições em cada sítio: Controle (regeneração natural), Baixa Diversidade (semeadura direta) e Alta Diversidade (plantio por mudas). Dois locais com Floresta Nativa serviram de referência para os atributos do solo. Na camada de 0-40 cm, o Nitossolo tem textura argilosa e boa fertilidade e o Argissolo é arenoso com média fertilidade. Os atributos físicos e químicos do solo apresentaram alterações entre 1998 e 2010, com diferenças entre a Floresta Nativa e os demais tratamentos. Para as duas áreas experimentais, a relação C:N e o carbono da biomassa microbiana dos solos nos modelos de restauração se assemelharam ao Floresta Nativa, indicando que as atuais condições favorecem a ciclagem de nutrientes. Apesar disto, para os atributos químicos do solo avaliados, as diferenças entre a Floresta Nativa e os demais tratamentos continuam a existir, mesmo após 10 anos da implantação, devendo ser gradativo o retorno da fertilidade à condição pré-existente, com influência dos plantios. Os modelos de reflorestamento tiveram diferença significativa quanto ao desenvolvimento florestal. Nos primeiros dez anos, além de incrementar os processos de sucessão natural, o sistema de Baixa Diversidade proporcionou uma maior e melhor edificação da estrutura horizontal e vertical que o de Alta Diversidade, refletida numa maior produção de biomassa seca. O desenvolvimento das árvores no Alta Diversidade foi favorecido em solo de boa fertilidade. Numa análise conjunta, os solos de boa e média fertilidade não se diferenciaram em termos de desenvolvimento arbóreo, que pode estar mais relacionado à alta competição com invasoras. A partir do décimo ano a produtividade primária líquida se estabilizou para o modelo de reflorestamento com baixa diversidade de espécies sobre o solo arenoso de média fertilidade, indicando a necessidade de intervenção. A biomassa arbórea em sítio de média fertilidade com baixa diversidade de espécies nativas se apresentou como um importante reservatório de carbono. Em solo argiloso de boa fertilidade o principal reservatório de carbono foi o abaixo do solo. O reflorestamento com baixa diversidade de espécies arbóreas mostrou um elevado potencial e capacidade de estoque de carbono em sistemas florestais, maior do que o reflorestamento com alta diversidade. Ambos os modelos/técnicas de restauração têm suas vantagens e desvantagens, as quais devem ser consideradas nos processos de mitigação do aquecimento global e da restauração da biodiversidade da Mata Atlântica em larga escala. / The increase of CO2 concentration in the atmosphere over the last decades and its relation to global warming has been largely documented by scientists. In parallel, deforestation in Brazil accounts for most emissions of greenhouse gases. Attempting to support public, private and social actions as well as to answer the questions concerning the role of mixed reforestation in the absorption of CO2 and changes of soil attributes, this study aimed to assess the carbon stock, forest development and soil changes in two different systems of forest restoration. We evaluated an experiment undertaken in 1997, in a red Alfisol and a red-yellow Ultisol, evaluating three treatments in a randomized block design with three replications in each site: Control (natural regeneration), Low Diversity (direct seeding) and High Diversity (seedlings). Two sites with Native Forest were used as reference for the soil attributes. In the first layer (0-40 cm) the Alfisol has a clay texture with good fertility and Ultisol is sandy with medium fertility. The physical and chemical soil properties showed changes from 1998 to 2010 and differences between the Native Forest and the other treatments were evident. For both experimental areas, the C:N ratio of soils in reforestation models is similar to that in the native forest. The increase in carbon in soil microbial biomass indicates that current conditions may favor the decomposition of soil organic matter. For the soil properties evaluated, the differences between the Native Forest and the other treatments still exist and leading to a gradual return of fertility to the pre-existing condition, influenced by plantations. The forestry development had significant differences among the reforestation models. In the first ten years, besides increasing the processes of natural succession, the lower diversity model provided a better horizontal and vertical structure than the high diversity model, reflected in increased biomass production. The development of trees in the high diversity model was favored in soil of good fertility. In a pooled analysis, the high and medium fertility soil do not differ in terms of tree development, which may be more related to weed competition. After the tenth year, the net primary production has stabilized in the low diversity restoration model on the medium fertility sandy soil, requiring management intervention. The tree biomass in the site of medium fertility with low diversity of native species is presented as a major carbon pool. In clayey soil of good fertility the main carbon pool is underground. Reforestation with low diversity of tree species has a high potential and capacity of carbon stocking in forest ecosystems, higher than that of high diversity reforestation model. Both models and restoration techniques have advantages and disadvantages, which should be considered in the process to mitigate global warming and to restore biodiversity of the Atlantic Forest on a larger scale.

Orientadores: Flávio Dias Passos, Fosca Pedini Leite / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-25T17:04:29Z (GMT). No. of bitstreams: 1 Fernandes_MarjorieCattaneo_M.pdf: 2191359 bytes, checksum: ec8782f154dd8bd30ae5def3636c426b (MD5) Previous issue date: 2014 / Resumo: As macroalgas associadas aos costões rochosos formam ambientes heterogêneos, que estão presentes em grandes áreas no ambiente marinho. São bem distribuídas na região entremarés e correspondem a um habitat favorável devido a sua complexidade estrutural, que está diretamente relacionada à diversidade de organismos associados a elas. Essa relação está provavelmente ligada à disponibilidade de refúgios e à capacidade de reter alimento. As macroalgas marinhas e sua fauna associada formam uma comunidade denominada fital. Os invertebrados são os principais animais associados às comunidades de fital, sendo a malacofauna bastante representativa neste sistema. No período de um ano realizaram-se quatro coletas de algas pardas Sargassum spp. em doze costões rochosos na região do Canal de São Sebastião, sendo seis na ilha de São Sebastião, e seis no continente, nos municípios de São Sebastião (5 costões) e Caraguatatuba (1 costão). Foram padronizados os números de frondes e a profundidade utilizada. O principal objetivo foi analisar a estrutura da comunidade de moluscos quanto à composição, a abundância e a riqueza de espécies, verificando se esses parâmetros diferiram entre ilha e continente. Foram registrados 15849 indivíduos, distribuídos em 72 espécies de moluscos, sendo 15 de Bivalvia e 57 de Gastropoda. As espécies com maior representatividade em relação ao número de indivíduos foram Bittiolum varium (Gastropoda), Eulithidium affine (Gastropoda), Pinctada imbricata (Bivalvia) e Mitrella dichroa (Gastropoda). A riqueza de espécies diferiu entre as localidades, 12 espécies de Bivalvia e 55 espécies de Gastropoda ocorreram na ilha somando 67 espécies e, 15 espécies de Bivalvia e 45 espécies de Gastropoda ocorreram no continente totalizando 60 espécies As curvas de rarefação também mostram que a comunidade de moluscos da ilha é mais rica que a do continente. O teste de escalonamento multidimensional não métrico demonstra um provável agrupamento entre as duas localidades, refletindo que pode haver diferenças na composição de espécies (ilha vs. continente), resultado sustentado pela análise de similaridade (R = 0,5333, p = 0,00415) e também representado pela Entropia de Renyi (? = 0). A porcentagem de similaridade indicou que as espécies que mais contribuem para a diferença entre ilha e continente são Eulithidium affine, Bittiolum varium, Pinctada imbricata, Mitrella dichroa e Anachis fenneli (Bray-Curtis 67,5%). Cerca de 50% dos gastrópodes são herbívoras ou carnívoras, e 20% dos bivalves são filtradores. As diferenças entre as comunidades de moluscos associados ao fital de ilha e continente podem ser atribuídas não somente à complexidade estrutural da alga parda, mas também à diversidade funcional entre algas e moluscos, à distribuição espacial devido aos fatores geográficos, às oscilações de temperaturas e chuvas, e fatores antropogênicos / Abstract: Macroalgae associated with rocky shores form heterogeneous environments, present in large areas in the marine habitat. They are well distributed in the intertidal region and correspond to a favorable habitat due to its structural complexity, which is directly related to the diversity of their associated organisms. This relationship is probably linked to the availability of refuges and the ability to retain food. The seaweeds and their associated fauna form a community called phytal. Invertebrates are the main animals in the phytal, the malacofauna being one of the most representative in this system. Along one year, samples of brown algae Sargassum spp. were collected in twelve rocky shores in the São Sebastião Channel region, six in the island of São Sebastião, and six in the continent , in the cities of São Sebastião (5 rock shores) and Caraguatatuba (1 rock shore). Numbers of fronds and depth used were standardized. The main objective was to analyze the structure of mollusc community through the composition, abundance and species richness, verifying if these parameters differ between island and continent. 15849 individuals were recorded, belonging to 72 species of molluscs, 15 from the Bivalvia and 57 from the Gastropoda. The species with the largest representation in relation to the number of individuals were Bittiolum varium (Gastropoda), Eulithidium affine (Gastropoda), Pinctada imbricata (Bivalvia) and Mitrella dichroa (Gastropoda). The species richness differed between localities, 12 species of Bivalvia and Gastropoda 55 species occurred in the island totaling 67 species, and 15 species of Bivalvia and 45 of Gastropoda species occurred in continent totalizing 60 species. Rarefaction curves also show that the community molluscs of the island is richer than that of the continent. The test metric multidimensional scaling shows a probable grouping of shores in two distinct localities, reflecting that there could be differences in species composition (vs island. Mainland), a result supported by the similarity analysis (R = 0.5333, p = 0.00415 ) and also represented by Renyi Entropy (? = 0). The percentage of similarity indicated that the species that contribute most to the difference between island and mainland are Eulithidium affine, Bittiolum varium, Pinctada imbricata, Mitrella dichroa and Anachis fenneli are the species that contribute most to the difference between island and continent (Bray-Curtis 67.5 %). About 50% of gastropods are herbivorous or carnivorous, and 20% of bivalves are filter feeders. The differences between the phytal communities in island and continent can be attributed not only to the structural complexity of algae, but also to the functional diversity between algae and molluscs, to the spatial distribution due to geographical factors, fluctuations in temperature and rainfall and anthropogenic factors / Mestrado / Ecologia / Mestra em Ecologia

Semi-natural grasslands with traditional management are known to be very species-rich, with many plant species strongly associated with the habitat. The last century’s decline of semi-natural grasslands, as a result of land use change and abandonment, has made the remaining semi-natural grassland a high concern for conservation. Since management can be costly and the available resources often are limited, it is important to use the most beneficial management method for preserving and enhancing the biodiversity. One semi-natural grassland type of certain interest around the Baltic region are coastal grasslands. In this study, I investigated vascular plant species occurrence in ten managed coastal grasslands located in the Stockholm archipelago. The effect of recent land-uplift and future sea level rise on the ten coastal grasslands were analyzed as well. A major part of all ten grasslands had been subjected to the process of isostatic land-uplift the past 100 years. Five of the grasslands were currently managed by grazing and the other five were managed by traditional mowing. There was no significant difference in alpha and gamma diversity between the two management types. Though, higher biodiversity values, such as more different species found in total, higher amount of species typically linked to meadows and pastures, less succession species and more red-listed species, were found in the traditionally mowed grasslands. Furthermore, a sea level rise with 40 cm the next 100 years in the region would lead to loss of plant species diversity in the investigated coastal grasslands. One major concern is the limited areas upwards on the coastal grasslands for species to migrate to in the future, which is expected to primarily affect species associated with meadows and pastures. The study highlights the importance of open and managed grassland areas further up the coastal grasslands for local species to migrate to, if the sea level would rise as predicted by future climate scenarios. Albeit weak the results of this study indicate that traditional mowing generates higher biodiversity values compared to grazing, hence it should be the preferred management method in coastal grasslands in the Stockholm archipelago.

A key challenge in biodiversity is: How many species are there on earth? This issue is especially acute in poorly surveyed regions with high diversity, particularly Southeast Asia that also experiences many limitations such as lack of funds, documents and experts. To help meet this challenge, I have developed a five-tiered approach for diversity measurement of freshwater fish for use in Thailand. This is: (1) the creation of a newly updated species inventory that uses existing data; (2) exploration of the patterns of species richness, endemism, and uniqueness; (3) estimation of the total species richness; (4) investigation of patterns of rarity; and (5) integration of this knowledge into conservation practice. The system should be applicable to other regions and other taxa where a similar challenge exists. My work shows that eight hundred and seventy-two species in 17 orders, 55 families and 255 genera of freshwater fishes, accounting for roughly 10% of the world's freshwater fish diversity, have been reported for Thailand to date. This number was derived from information in the museum collections, literature and all other available sources, including reports written in Thai as well as in English. During this work I uncovered many gaps in biodiversity information, in terms of taxonomic and spatial records, though some families and basins are better represented than others. Taxonomic uncertainty also continues to be a challenge for taxonomists and users. The high diversity of freshwater fishes in Thailand is the result of both high alpha (α) diversity (diversity within a particular locality) and beta (β) diversity (diversity differences between localities). I concluded that the substantial beta diversity I detected is associated with the geographical separation of the six river basins in Thailand. For example, the species composition of freshwater fishes in the Salween Basin dramatically differs from all other basins of Thailand. In contrast, the Chao Phraya Basin and the Mekong Basin contain the greatest number of shared species. Approximately 55% of species have a wide distribution range (being reported from more than two basins), whereas 45% are highly restricted within a single basin. Analyses using species richness estimators suggest that the figure of 872 species is an underestimate and that there may be between 1000 and 1300 fish species in Thailand, in other words an increase of between 14.7% and 49.1% over the list I compiled (which is itself an increase of 52.2% over the last report in 1997). Freshwater fish have become increasingly vulnerable to anthropogenic activities. Of the 872 Thai fish species, 6.8% and 15.1% are globally and nationally threatened, respectively. Nonetheless, a striking feature of the database is that the conservation status of the vast majority of species has not so far been assessed, either globally or nationally. Scientists and policy makers will find these results useful in appreciating the magnitude of the tasks involved in surveying, describing and conserving the country's freshwater fish biota. My work highlights localities and taxa where conservation is a priority and is thus an important resource for policy makers and conservation planners concerned with the management of freshwater fish in Thailand.

Abstract The area of traditionally managed semi-natural meadows is declining throughout Europe. Knowledge of how to restore their species richness is urgently needed. Community manipulations by means of grazing and mowing and, on the other hand, knowledge of species-level responses as well as the responses of functional plant groups to management may help in planning appropriate restoration tools. The restoration of species richness was studied in two community-level experiments: in a sheep grazing experiment and in a mowing experiment. Three species-level studies were conducted to test the compensatory capacity of monocarpic, herbaceous plants (Gentianella amarella, Erysimum strictum, Euphrasia stricta) to simulated herbivory (10–50% of stem being cut). The perennial Linaria vulgaris was used to study whether there is any benefit of clonal integration in the tolerance of simulated herbivory. This topic was studied in a growth experiment and a 13C tracer study. In both grazing and mowing experiments, small herbs gained more space, while the dominant tall herbs subsided. The species number increased by 30% on the grazed plots, but mowing did not affect species richness, probably indicating seed limitation. At sites of this kind, seed addition could be used to promote restoration. Functional plant groups appeared to be useful in predicting the effects of grazing on plant communities. Early season grazing and mowing seem to be proper management tools in overgrown/degraded meadows. In species-level studies, all the species had relatively good compensatory capacity to repair small damage. Overcompensation was observed in response to apical damage, especially when the growing conditions were favourable, supporting the compensatory continuum hypothesis. The studied monocarpic plant species may share a common unbranched growth form where incidental apical damage leads to activation of uninitialized meristems and slight overcompensation. These responses may represent consequences of adaptation to above-ground competition, rather than adaptation to predictable herbivory. In Linaria, damaged ramets were not supported, but the neighbouring ramets seemed to compete with each other for root resources. While growing in disturbed habitats, it is more profitable for this species to invest in new ramets. The present studies showed that, while the appearance and structure of a traditional grassland rich in small-growing herbs can be restored in five years, it is more difficult to increase species diversity by mere mowing or grazing. Knowledge of the tolerance of individual species for herbivory could provide useful information for planning management practices. More studies on the effects of different management tools on different meadow types are urgently needed for the maintenance of the diversity of these valuable environments. / Tiivistelmä Perinteisellä tavalla hoidettujen luonnonniittyjen pinta-ala vähenee kaikkialla Euroopassa. Tarvitsemme enemmän tietoa siitä, miten näiden elinympäristöjen lajiston monimuotoisuus voitaisiin turvata. Tietämys laidunnuksen ja niiton vaikutuksesta kasviyhteisöihin ja toisaalta yksittäisiin kasvilajeihin tai toiminnallisiin kasviryhmiin voi auttaa tehokkaiden hoito- ja ennallistamistapojen löytämisessä. Tässä työssä tutkittiin niittyjen lajirikkauden palauttamista kahdessa yhteisötason kokeessa: lammaslaidunkokeessa ja kokeessa, jossa eri niittotapojen vaikutuksia selvitettiin. Kolmessa lajitason kokeessa testattiin monokarppisten ruohokasvien (rantaukonnauris, horkkakatkero, ketosilmäruoho) kompensaatiokykyä simuloituun herbivoriaan (10–50 % varresta poistettiin). Monivuotista kannusruohoa käytettiin tutkittaessa onko klonaalisesta integraatiosta hyötyä herbivorian siedossa. Tätä selvitettiin kasvukokeella ja hiili-13-merkkiainekokeella. Sekä laidun- että niittokokeessa matalat ruohokasvit saivat kasvutilaa korkeiden ruohojen valta-aseman vähentyessä. Laidunnus lisäsi lajimäärää 30 % koealaa kohti, mutta niitto ei vaikuttanut lajirikkauteen. Molemmissa kokeissa kasviyhteisö oli luultavasti siemenrajoitteinen. Tällaisissa kohteissa siementen lisäystä voitaisiin käyttää ennallistamiskeinona. Toiminnalliset kasviryhmät olivat käyttökelpoisia ennustettaessa laidunnuksen vaikutuksia kasviyhteisöön. Aikaisin kasvukaudella tapahtuva niitto/laidunnus näyttää sopivalta hoitokeinolta umpeenkasvaneilla niityillä. Lajitason kokeissa kaikki tutkitut kasvilajit kykenivät melko hyvin kompensoimaan vähäisiä vaurioita. Ylikompensaatiota havaittiin vasteena kärkivaurioihin erityisesti, kun kasvuolot olivat edulliset. Tämä tuki ns. kompensaatiojatkumohypoteesiä. Tutkituilla lajeilla voi olla yhtenäinen haaraton kasvumuoto, jossa ajoittaiset kärkivauriot johtavat lepotilassa olevien silmujen aktivoitumiseen ja lievään ylikompensaatioon. Nämä vasteet voivat olla seurausta sopeutumisesta valokilpailuun pikemmin kuin sopeutumisesta ennustettavissa olevaan herbivoriaan. Kannusruoholla vaurioituneita versoja ei autettu, vaan kloonin sisällä versot näyttävät kilpailevan keskenään juuriresursseista. Koska laji kasvaa häirityillä paikoilla, sille näyttää olevan edullisempaa investoida uusiin versoihin. Tämä työ osoitti, että vaikka perinteisen matalakasvuisen lajirikkaan niityn ulkonäkö ja rakenne voidaan palauttaa viidessä vuodessa, on vaikeampaa lisätä lajirikkautta pelkän niiton tai laidunnuksen avulla. Tietämys yksittäisten kasvilajien vasteista biomassan menetykseen voi auttaa sopivien hoitotapojen suunnittelussa. Lisää kokeita eri hoitotapojen vaikutuksista ja eri niittytyypeillä tarvitaan pikaisesti näiden arvokkaiden elinympäristöjen monimuotoisuuden ylläpitämiseksi.

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La biodiversité marine et terrestre subit de multiples perturbations dues à la pression anthropique ainsi qu'au changement global, qui peuvent affecter la diversité spécifique et le fonctionnement des écosystèmes associés. Dans ce contexte, la cartographie des indices de diversité permet d'analyser les variations spatio-temporelles de la diversité spécifique, et d'identifier des régions à caractère prioritaire dans un cadre de gestion. Le premier objectif de cette thèse est d'évaluer la pertinence des deux approches disponibles pour la cartographie des indices de diversité, ici considérée sans la prise en compte de variables explicatives dans un modèle pour l'interpolation spatiale : (i) l'approche indirecte qui consiste à interpoler individuellement chaque espèce des assemblages échantillonnés, puis à calculer a posteriori l'indice de diversité sur l'ensemble de la zone étudiée, (ii) l'approche directe qui consiste à calculer a priori l'indice au niveau des assemblages, puis à l'interpoler sur l'ensemble de la zone d'étude. Nous montrons que les deux approches présentent des limites importantes pour cartographier rigoureusement les indices de diversité. En effet, d'une part l'approche indirecte est difficile à mettre en œuvre en pratique due à la forte proportion des espèces rares dans le milieu naturel (données zéro inflatées). D'autre part, le non-respect de la propriété mathématique de l'addivitié des indices rend l'approche directe non pertinente pour l'interpolation. Le second objectif de la thèse est d'étudier la variabilité spatio-temporelle de la diversité des assemblages de poissons démersaux en mer Méditerranée, région présentant un grand intérêt scientifique, de par sa forte diversité ainsi que des conditions environnementales et anthropiques contrastées qui s'y exercent. Une approche multi-composante et multi-échelle a été adoptée pour analyser un jeu de données constitué de 19 886 traits de chalut réalisés entre 10 à 800 m de profondeur dans le cadre des campagnes scientifiques annuelles MEDITS effectuées depuis 1994 dans la zone nord Méditerranéenne ainsi qu'en Algérie plus récemment. Nous montrons que la diversité des assemblages de poissons démersaux ne suit pas le gradient longitudinal traditionnellement attendu et/ou observé pour d'autres groupes faunistiques pour aucun des indices et échelles analysés. Néanmoins, nous avons identifié des hotspots de richesse spécifique à Malte, dans la zone Ibérique, et les mers Egée et Ionienne. En revanche, l'équitabilité, les divergences taxonomique, phylogénétique et fonctionnelle n'ont pas présentés de tels hotspots, mais se sont révélées spatialement hétérogènes au sein de chaque région. D'autre part toutes les composantes de la diversité étudiées sont stables au cours des deux dernières décennies. Ce travail apporte des éléments de connaissance essentiels dans cette zone pour la cartographie d'indices de diversité par de futurs modèles incluant des variables explicatives abiotiques et/ou biotiques qui, compte tenu de ce qui a été souligné par le premier volet de la thèse, constituerait une alternative pour l'interpolation spatiale des indices. Toutefois, des efforts restent nécessaires pour identifier et acquérir des données pertinentes à l'échelle de la zone d'étude sur les facteurs biotiques et abiotiques susceptibles d'influencer la distribution de la diversité des assemblages demersaux, par exemple, les interactions entre espèces, l'effort de pêche à partir des données Vessel Monitoring System. Dans l'ensemble, les résultats de cette thèse confirment la nécessité d'utiliser des indices complémentaires lors de l'élaboration des stratégies de suivi de la diversité et la localisation de zones prioritaires de protection, et a permis d'identifier des indices proxies pour suivre les poissons démersaux en Méditerranée. D'autre part, elle met en évidence les limites et le besoin d'avancées méthodologiques pour une cartographie pertinente des indices de diversité. / Increasing human pressures and global environmental change may severely affect species diversity and ecosystems? functioning. In this context, mapping diversity indices allows monitoring spatial and/or temporal variation in diversity, and helps identifying areas for effective conservation planning. The first objective of this thesis is to evaluate the relevance of using the two available diversity indices' mapping approaches without explanatory variables: i) the indirect approach interpolating each individual species distribution over the studied area, then computing a posteriori the diversity index, (ii) the community-level approach interpolating directly a diversity index over the studied area. We show that mapping index by interpolation methods used in the frame of direct or indirect approach suffers from two main limitations. Firstly, diversity indices are not additive making the direct approach irrelevant to use the direct approach. Secondly, many species in natural communities are scarce (i.e. zero inflated data) making difficult to apply the indirect approach. The second objective of this thesis is to study large spatio-temporal diversity of demersal fish assemblages in the Mediterranean Sea, an area of a particular scientific interest, both for its high diversity and direct human pressure in this region. A multi-component and multi-scale approach was applied to analyze a dataset of 19,886 hauls from 10 to 800 m depth performed annually during the last two decades by standardized scientific bottom trawl field surveys across the Mediterranean Sea, within the MEDITS program. We show that the diversity of demersal fish assemblages sampled by trawl do not follow the observed or expected decreasing longitudinal/latitudinal diversity gradients, for any of the indices and spatial scales analysed. However, we identified hotspots of species richness at both local and regional scales in the Iberian region, Malta, the Eastern Ionian and Aegean seas. In contrast, evenness as well as taxonomic, phylogenetic and functional divergences did not show regional hotspots. All studied diversity components remained stable over the last two decades. Finally, our analysis represents an essential step towards future studies focused on the drivers shaping demersal fish communities? diversity in the Mediterranean Sea using models that will include biotic and/or abiotic explanatory variables to map diversity indices. However, it will require identification and availability of accurate data of these variables at the scale of the Mediterranean Sea (e.g. species interactions, fishing effort from Vessel Monitoring System (VMS) data). Overall, our results highlight the need of using complementary diversity indices through different spatial scales when developing monitoring strategies and defining protected areas. They also identify suitable proxies to monitor demersal fish communities in the Mediterranean Sea. Moreover, this work underlines the main limits of approaches for mapping diversity indices, and the need of further developments in this field.

Habitat Evaluation Procedure data gathered at Ray Roberts Lake in 1989 and 1990 were analysed for temporal variability, observer variability and relationships between Habitat Units (HUs) and species density/diversity. observer variability within a group was analysed by cluster analysis and bootstrapping. Five out of 36 sites showed significant differences in Habitat Suitability Index (HSI) values within the group. A nonparametric Mann-Whitney test was used to analyze temporal variability. One of 6 sites showed a significant difference in HSI values between years. Using Spearman's Rank Correlation Coefficient, a correlation was found between indicator species density and HUs. No significant correlation was indicated between species diversity and HUs.