Orientador: Rafael Silva Oliveira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-20T07:23:50Z (GMT). No. of bitstreams: 1 DiMigueli_CaioOliveira_M.pdf: 2747069 bytes, checksum: d9c9a266d54797dc0c2753c7d1a10446 (MD5) Previous issue date: 2012 / Resumo: A disponibilidade de água é um importante fator determinante da distribuição de espécies vegetais em várias comunidades. Vários modelos climáticos preveem secas mais severas para regiões tropicais de altitude em decorrência do aumento na altitude média das camadas de nuvens orográficas que dão origem à neblina, o que poderá afetar a distribuição de espécies e de tipos vegetacionais da Floresta Atlântica nesses locais. Investiguei a diversidade de atributos hidráulicos de seis espécies de Floresta Nebular e quatro espécies de Campos de Altitude com o objetivo de entender as respostas de espécies desse tipo de vegetação a variações sazonais na disponibilidade de água. Optei por investigar atributos hidráulicos pois têm influência direta sobre as estratégias de uso de água pelas plantas em diferentes condições de disponibilidade desse recurso. Escolhi esses ecossistemas por co-ocorrerem em um topo de montanha e por apresentarem condições contrastantes quanto à seca ambiental, com diferentes níveis de exposição do solo às condições climáticas. Quantifiquei densidade da madeira, potenciais hídricos antes do amanhecer, às 10:00 h e mínimo diário e condutância estomática. Investiguei ainda a ocorrência nesses ecossistemas de relações negativas entre densidade da madeira e potenciais hídricos mínimos, já observadas em florestas tropicais secas e ambientes temperados. Verifiquei uma grande diversidade de valores de densidade da madeira nas espécies que estudei. As quatro espécies de Campos de Altitude apresentaram influência da demanda evaporativa da atmosfera sobre seus potenciais hídricos nos meses mais úmidos do estudo, o que é consistente com comportamento anisohídrico. Nesse tipo de estratégia, a condutância estomática se mantém inalterada frente a reduções nas disponibilidades de água do solo e da atmosfera, resultando em redução do potencial hídrico da planta. Nos meses mais secos essa influência foi menor, como se observa em plantas com comportamento isohídrico, que reduzem a condutância estomática e mantêm potenciais hídricos constantes frente ao aumento da seca ambiental. Dentre as espécies de floresta, apenas D. brasiliensis e Vernoniae sp. apresentaram comportamento isohídrico, as demais apresentaram comportamento anisohídrico. Com base nesses resultados faço a previsão que D. brasiliensis e Vernoniae sp. são as espécies mais vulneráveis à seca e podem apresentar maiores taxas de mortalidade por "privação de carbono", em decorrência do seu comportamento isohídrico. Em seguida, as espécies anisohídricas mais vulneráveis à seca são P. vellosiana, L. carassana e Miconia sp., em ordem decrescente de vulnerabilidade à cavitação. As espécies de Campos de Altitude são as mais resistentes à seca. A densidade da madeira só apresentou relação com o potencial hídrico mínimo sazonal quando analisei as espécies de Floresta Nebular e de Campos de Altitude em conjunto, e apresentou uma forte relação linear negativa com o potencial hídrico mínimo diário nas espécies de floresta. Esses resultados indicam que as relações entre esses atributos propostas na literatura parecem estar presentes nos ecossistemas que estudei / Abstract: Water availability is an important feature determining plant species distribution in several communities. Several climatic models predict harsher dry spells for high-altitude tropical regions due to the increase in the mean altitude of formation of the orographic cloud layer that originates fog, which can influence the distribution of species and vegetational types of the Atlantic Forest in these places. I have investigated the diversity of hydraulic traits of six Cloud Forest species and four High-altitude Grasslands species to understand the answers of species of this kind of vegetation to seasonal variations in water availability. I have choosen to investigate hydraulic traits because they have direct influence on the plant water use strategies under different conditions of availability of this resource. I have choosen these ecosystems because they co-occur in a mountain top and present contrasting conditions relative to environmental drought, with different exposure levels of the soil to climatic conditions. I have quantified wood density, pre-dawn, 10:00 o' clock and daily minimun water potentials and stomatal conductance. I have also investigated the occurrence in these ecosystems of negative relationships between wood density and minimun water potentials, that have been observed in tropical dry forests and in temperate environments. I found a very large diversity of wood density values in the species I have studied. The four High-altitude Grasslands species presented influence of atmospheric evaporative demand on their water potentials, consistent with anisohydric behaviour. In this strategy, stomatal conductance remains unaltered in face of reductions in soil and atmosphere water availabilities, resulting in reduction of plant water potential. In the wettest months this influence was smaller, as is seen in plants with isohydric behaviour, that reduce stomatal conductance and maintain constant water potentials in face of environmental drought intensification. Among the forest species, only D. brasiliensis and Vernoniae sp. presented isohydric behaviour, the remaining showing anisohydric behaviour. Based on these results I make the prediction that D. brasiliensis and Vernoniae sp. are the most drought vulnerable species and may present higher mortality rates by carbon starvation, due to their isohydric behaviour. Following these two species, the most drought vulnerable anisohydric species are P. vellosiana, L. carassana and Miconia sp., in decreasing order of vulnerability to cavitation. The High-altitude Grasslands species are the most resistant to drought. There was a correlation between wood density and minimun seasonal water potential only when I analised the Cloud Forest and the High-altitude grasslands species togheter. There was also a strong negative linear relationship between wood density and daily minimun water potential in the forest species. These results show that the relationships between these traits that are proposed in the literature appear to be present in the ecosystems I studied / Mestrado / Ecologia / Mestre em Ecologia

Kantzoner har en lång tradition i odlingslandskapet och används i dag som en miljöåtgärd som finansieras med ersättningar för att minska näringsläckage från åkrarna och bevara biologisk mångfald. Behovet av denna typ av åtgärder är en konsekvens av människans utnyttjande av naturen, där denna formats för att anpassa mänskliga behov med begränsad hänsyn för hur naturen påverkas av detta. Metoder för hållbar utveckling efterfrågas och med detta i åtanke tillägnas fokus i denna litteraturstudie kantzonernas potential att bidra med värden för både miljö och människa. Studien riktar sig mot möjligheten att skapa naturliga habitat där de mänskliga insatserna bidrar med positiva värden för naturen, samtidigt som hon kan ta del av de värden som produceras i kantzonen. Resultatet visar på att det finns en god möjlighet att producera biomassa samtidigt som produktionen i sig gynnar inbindningen av kol, minskar näringsläckage och ökar den biologiska mångfalden. Potentialen för kolinbindning beräknas vara 31% högre i gräsmarker jämfört med åkermark vilket genererar en möjlig kolinlagring på 95 ton/hektar. Kantzonerna kan även minska näringsläckagen då de uppmätts kunna bromsa 60-80% av det fosfor och 40-80% av det kvävet som passerar kantzonen. Vad gäller den biologiska mångfalden så kan kantzoner erbjuda habitat som kan härbärgera fler arter samt fler individer inom arterna.

European floodplain grasslands are characterized by periodic flooding and regular management, usually cutting and grazing as part of an agricultural system. Past losses and ecological degradation have been due largely to river regulation and either agricultural intensification or abandonment and have resulted in a substantial reduction in area across Europe. Nevertheless, the remaining resource supports considerable biodiversity and a high level of biological production. A better quantitative understanding of the functioning of these grasslands is required in order to establish effective conservation management within a sustainable land use system. The thesis examines the impact of key management factors on three important functional characteristics of the biodiversity of floodplain plant communities, namely plant diversity (measured by species diversity), cover (%) and primary production (above-ground biomass), on two floodplain grasslands of the River Trent, UK and a third on the the Luznice river, the Czech Republic. Field investigations of the effects of cutting, grazing, cessation of management, the influence of floodborne litter, and the impact of fertilizer nitrogen were undertaken over periods of between one and three seasons. These demonstrated that floodplain grassland plant communities are sensitive to variations in management and that impacts on communities are mediated particularly through effects on plant competition. Productive competitive species were encouraged both by abandonment and fertilizer application whereas cutting and grazing management, and the imposition of litter, favoured stress-tolerating perennials. Species diversity decreased both with high inputs of litter and additions of fertilizer. Plant community responses and competitive strategies of key species are discussed in the context of biodiversity conservation, ecological restoration and management of European floodplain grasslands.

Abstract In this thesis I studied responses of three biennial, monocarpic plants Erysimum strictum, Gentianella amarella, and G. campestris, to various aspects in resource availability (i.e. competition, mineral nutrition, neighbor removal) and environmental stress (early frost) at adult or rosette stages and how these effects are related to grazing tolerance. I also studied how manipulations in resource availability affected arbuscular mycorrhizal colonization of the roots. All three species were relatively tolerant to simulated grazing and in most cases plants were able to compensate quite well for minor biomass losses. According to the compensatory continuum hypothesis, tolerance is most pronounced in resource-rich conditions, but this was not always the case in the present experiments. Erysimum strictum compensated for defoliation at the rosette stage but the reproductive output of adult plants was reduced markedly in the next year. This reduction was strongest among fertilized plants. Moreover, apex removal at the adult stage resulted in overcompensation (i.e. clipped plants were more productive) but only in the absence of fertilization and in the presence of competition, which is against the compensatory continuum hypothesis. In E. strictum a potential cost of compensation appeared as delayed flowering and fruit maturation among clipped plants. However, in spite of early frost treatment clipped plants were still able to overcompensate. In Gentianella amarella and G. campestris, apex removal reduced growth and reproductive performance in most cases. Effects on root fungal parameters were positive or neutral. This pattern suggests that simulated above-ground herbivory tends to increase carbon limitation, and therefore regrowing shoots and the fungal symbionts may appear as alternative, competing sinks for the limited carbon reserves of the host plant. Both shoot architecture and resource availability modify the responses of the study plants to apical damage at both rosette and adult stages. In addition, different environmental stress factors affect success in compensatory growth.

The grasslands of South Africa are the foundation of commercial and subsistence agriculture yet they are being degraded at an alanning rate. The coastal grasslands of the Eastern Cape are no exception and they suffer added pressure of coastal resort development because of their proximity to an attractive coastline. In order to determine the degree of conservation necessary for any area it is essential to know what species occur there in order to determine if protection from habitat destruction is required. Four aims were defined for this studv. The initial aim was a phytogeographical classification of the grasslands in the coastal region west of the Kei River. This was done by vegetation sampling followed by computer based analysis with TWINSPAN. This analysis defined ten grassland associations. five being located in the area west of the Keiskamma River and five occurring east of it. The associations in the eastern half are termed mesic while those in the western balf are xeric. The second aim was to determine the presence of any underlying ecological gradients affecting the distribution of tbe associations. Indirect gradient analysis was carried out where samples are analysed irrespective of environmental factors. Direct gradient analysis was then carried out using scores per sample of various environmental factors. Environmental factors whicb migbt produce such gradients are both naturally-ocurring and man-induced. Natural factors which were recorded in the field include depth of soil at sample site, soil family, aspect and distance from the shore. An important factor is the land / sea interface. Natural factors analysed in the laboratory include soil pH. conductivity. percent organic matter, calcium, magnesium, phosphate and potassium. Man-induced factors are land use history e.g. Ploughing and grazing. Both direct and indirect gradient analysis were carried out with the computer based programme CANOCO. The third aim of the study was to determine the presence of any successional trends between the ten defined associations. This was done using several characteristics of the associations. Alpha and beta diversity were the first factors compared between associations. The percentage contribution of the Cyperaceae, Fabaceae, Asteraceae and Poaceae to each association was assessed and compared. The presence of various life forms of the species occurring in each association was determined together with the cover abundance of different classes of grass species. These results were then combined and analysed in the light of the results from CANOCO analvsis. They show that the mesic Themeda Iriandra - Anthospermum herhoceum, association which occurs closest to the shore and with the least disturbance is a depauperate form of the mesic climax Themeda triandra association. The mesic Hyparrhenia hirta - Dtheteropogon amplectens association may be a secondary grassland on account of phosphate and potassiun poor soils and land-use. The mesic Hyparrhenia hirta - Themedo triandra association is a slightly degraded form of the climax association due to grazing. The severely disturbed Stenotaphrum secundatum - C'entella coriacea association, which is located close to the shore, is a secondary grassland. Analysis of the xeric associations indicates a clearly defined ordination of associations on the basis of land-use. The Cynodon daclylon - Helictolrichon hirtulum and Sporobolis africanus - Setaria sphacelata associations which occur where ploughed lands have been left to lie fallow are secondary in nature. The Themeda triandra - Ehrharta calycina association is thought to be the closest representati ve of a climax xeric association but the presence of E. calycina indicates that some disturbance has occurred. The vegetation is subject to moderate grazing. The Cynodon dactylon - Ehrharla calycina and Diheleropogon filifolius - Ehrharla calycina associations are subject to varying intensities of trampling and grazing and are degraded forms of the Themeda triandra - Ehrharla calycina association. Because of tbe overriding influence of the land-use gradient separation along gradients of the remaining eight factors was limited. The effect of fire and temporal change in the mesic Themeda triandra and Hyparrhenia hirta - Themeeia trianda associations was assessed via long-term studies at Potter's Pass outside East London. The results show a quick response to burning with a return to 100% cover within six months by both associations. During spring the two associations could not be separated by either TWINSPAN or DECORANA. indicating a temporal shift from the Hyparrhenia hirta - Themeda triandra association to the Themeda triandra association. The fourth and final aim was to identify plants requiring protection from habitat destruction and to make recommendations for further conservation areas and management of the coastal grasslands. Through the collection and identification of as many plants as possible a species checklist was prepared and the status of each was determined through reference to the Red Data Book of threatened and endangered species. Kniphofia rooperi is vulnerable in the Cape and Euphorbia hupleuroides is considered rare in kwazulu-Natal. Ten species are endemic to the Cape and / or South Africa. The richness of the vegetation lies in the presence of species representative of the four major floras which converge in the eastern Cape. i.e. The Cape, NamaKarroo, Tongoland-Pondolaod floras and the Kalahari Highveld Regional Transitional Zone. Suggestions are made for the conservation of the grassland associations at various sites within the study area based on the present area conserved. Less than 2% of the coastline in the study area is conserved and it is felt that the area under conservation should be increased. Management suggestions based on the available literature are given for both farmed and conserved areas. There is a great potential for further studies on grassland dmamics within the areas surveyed. In terms of management, the grasslands require careful examination to determine the most effective season in which to burn if at all. As with most agricultural systems in South Africa. grazing strategies will benefit from further research. Any additional research on the dynamics of these grasslands can only be of benefit to the sustained utilisation of this vital resource.

Species possess characteristics that are considered adapted to burning and these allow them to outcompete species and dominate in fire prone environments. It has therefore been proposed that fire might have played a critical role in the observed expansion of the grasslands, during the late Miocene. The aim of this study was (i) to investigate whether plant response to fire was a result of physiology or (ii) whether it was due to phylogenetic history. This was achieved by doing a pair-wise comparison between Panicoideae (and Panicoideae) and non-Panicoideae (Danthonioideae and Aristidoideae) species. Pre-fire characteristics, that would enhance fire frequency and assist with plant recovery after burning, were compared across phylogenies and photosynthetic type. Post fire plant recovery was then followed in a field and pot comparison which examined the re-growth of the leaf canopy area, leaf mass, above-ground biomass and the cost of this to the below-ground biomass. The pre-fire characteristics showed both a photosynthetic and phylogenetic response. It was found that the species showed a greater canopy death during winter and had a lower moisture content than the species. These characteristics would potentially contribute towards a larger fuel load in the species. However, the comparison of the dead standing biomass at the end of winter and the below-ground biomass, showed a phylogenetic response with the Panicoideae having a proportionally larger dead standing biomass and below-ground biomass than the non-Panicoideae. These results suggest that not only did the Panicoideae have a larger potential fuel load but that they also shunted carbon below-ground, enabling a fast recovery after being burned. The post-fire results were more strongly determined by phylogeny than by photosynthetic type. The Panicoideae recovered faster and more completely than the non-Panicoideae grasses, possibly contributing to their success and expansion under conditions of increased fire frequency. Although recovery of the and Panicoideae were similar, frequently burnt grasslands are dominated by the Panicoideae. Hence, this dominance cannot be explained by differences in their fire responses and may be determined by the post-fire environmental conditions that potentially advantage species possessing the photosynthetic pathway. Panicoideae dominance is limited to mesic environments where fire is the likely driver of grassland expansion while more arid environments are dominated by non-Panicoideae species. Representative species from these non-Panicoid subfamilies showed poor recovery after fire. This suggests that factors other than fire were the likely drivers of these xeric grassland expansions. The ability of these subfamilies, and particularly the species, to cope with drought remains a likely selective mechanism that requires further research.

O florestamento dos campos do sul da América do Sul incluindo os campos do Pampa estão mudando a paisagem local e levando a mudanças nas populações de aves. O conhecimento sobre o efeito do florestamento sobre a avifauna dos campos do sul da América do Sul é bastante limitado à riqueza e composição de espécies. Além de preencher lacunas considerando diferentes índices para avaliar respostas das comunidades de aves ao florestamento dos campos (Capítulos 2 e 3), nesta tese nós também avaliamos se Áreas de Preservação Permanente localizadas dentro de plantações de eucalipto são funcionais para a avifauna local, fazendo uma comparação com áreas de campo pastejado (Capítulo 1). No capítulo 1 nós registramos uma diferença na composição de espécies entre as áreas devido principalmente às mudanças na altura e densidade da vegetação. Nos capítulos 2 e 3 nós avaliamos diferentes componentes da diversidade (taxonômica, filogenética e funcional) considerando possíveis efeitos do florestamento dos campos sobre estes Nossos resultados demonstram respostas diferenciadas entre os componentes, enquanto o florestamento leva a uma redução na diversidade taxonômica, diversidade filogenética e funcional não demonstram respostas negativas. No capítulo 2 no entanto, nós observamos que o florestamento dos campos conduz a uma perda de distintividade evolutiva, beneficiando desta forma linhagens que se diversificaram recentemente. No capítulo 3 apesar da redução na diversidade taxonômica não houve uma redução na diversidade funcional em áreas plantadas. Já a associação de alguns atributos funcionais com as áreas pós-corte, indica a plasticidade de algumas espécies que retornam para essas áreas logo após o corte dos plantios.De modo geral nossos resultados indicam que a manutenção de mosaicos de campo de diferentes alturas maximiza a biodiversidade local de aves e destaca a importância da proteção de áreas campestres. Além disso, vimos que considerar diferentes componentes da diversidade que incorporam informações sobre as espécies são importantes pois podem informar por exemplo, quantas extinções uma comunidade pode suportar até que funções importantes sejam perdidas, afetando assim a estabilidade dos ecossistemas. / The afforestation of southern grasslands of South America including the Pampa grasslands are changing the local landscape and leading to reduction of bird populations. Knowledge about the effect of afforestation on the avifauna of the southern South American grasslands is limited to richness and composition of species. In addition to filling gaps considering different indices to evaluate responses of the bird communities to the afforestation of the grasslands (Chapters 2 and 3), in this thesis we also evaluated whether Permanent Preservation Areas located within eucalyptus plantations are functional for the local avifauna, making a comparison with grazed grasslands areas (Chapter 1). In Chapter 1 we recorded a difference in species composition between areas due mainly to changes in height and density of vegetation. In chapters 2 and 3 we evaluated different components of diversity (taxonomic, phylogenetic, and functional), considering possible effects of grasslands afforestation on them. Our results demonstrate differentiated responses among components, while afforestation leads to a reduction in taxonomic diversity, phylogenetic and functional diversity do not demonstrate negative responses In chapter 2 however, we observe that grasslands afforestation leads to a loss of evolutionary distinctiveness, thus benefiting species that have diversified recently. In chapter 3, despite the reduction in taxonomic diversity, there was no reduction in functional diversity in planted areas. Furthermore, the association of some functional traits with the post-cut areas indicates the plasticity of some species that return to these areas soon after cut the plantations. In general our results indicate that the maintenance of grasslands mosaics of different heights maximize the local biodiversity of birds and highlight the importance of the protection of grasslands areas. In addition, we have seen that considering different components of diversity that incorporate information on species is important because they can tell, for example, how many extinctions a community can support until important functions are lost.

En av de naturtyper med flest antal växtarter i världen är hävdade gräsmarker som är präglade av traditionell skötsel. Denna naturtyp har minskat kraftigt i area och för att förhindra framtida artutdöenden är restaureringsåtgärder viktiga. Syftet med denna rapport var att med hjälp av vetenskapliga publikationer undersöka vilken effekt restaurering av före detta hävdade gräsmarker i norra och centrala Europa har på växtartrikedomen. Mer specifikt undersöktes effekten av olika restaureringsmetoder på totala antalet arter, arttätheten och artsammansättningen. Utöver detta undersöktes vilka faktorer som påverkar möjligheten till restaurering. Resultatet tyder på att restaurering med bete eller slåtter är mest framgångsrik av de olika undersökta metoderna. Restaurering med bete eller slåtter visade sig kunna ha en positiv effekt på totala antalet arter, arttätheten och artsammansättningen. Enbart rensning av träd och buskar var inte en långsiktigt hållbar metod för restaurering eller bevarandet av artrikedomen eller arter associerade med hävdade gräsmarker. Det finns många faktorer som påverkar möjligheten till restaurering och alla är inte entydiga. Något som kan vara intressant att vidare utforska är vilken betydelse de olika artrikedomsmåtten och artsammansättningen har för att kunna optimera restaureringsprojekt. Förutom att restaurering av hävdade gräsmarker både kan bidra till att utöka Natura 2000-nätverket och uppfylla de globala målen, ger det oss mängder med ekosystemtjänster och bevarande av kulturlandskap.

Semi-natural grasslands are amongst the most biodiverse ecosystems in Europe, though their importance they are experiencing a declining trend. To monitor and assess the health of these ecosystems is generally costly, personnel demanding and time-consuming. With satellite imagery and machine learning becoming more accessible, this can offer a cheap and effective way to gain ecological information about semi-natural grasslands.This thesis explores the possibilities to predict plant species richness in semi-natural grasslands with high resolution satellite imagery through machine learning. Five different machine learning models were employed with various subsets of spectral- and geographical features to see how they performed and why. The study area was in southern Sweden with satellite and survey data from the summer of 2019.Geographical features were the features that influenced the machine learning models most. This can be explained by the geographical spread of the semi-natural grasslands, as well as difficulties in finding correlations in the relatively noisy satellite data. The most important spectral features were found in the red edge- and the short-wave infrared spectrums. These spectrums represent leaf chlorophyll content and water content in vegetation, respectively. The most accurate machine learning model was Random Forest when it was trained using with all the spectral- and geographical features. The other models; Logistic Regression, Support Vector Machine, Voting Classifier and Neural Network, showed general inabilities to interpret feature subsets containing the spectral data.This thesis shows that with deeper knowledge about the satellite-biodiversity relationship and how to apply it with machine learning have the possibilities of cheaper, more efficient and standardized monitoring of ecologically valuable areas such as semi-natural grasslands.

Semi-natural grasslands are valuable ecosystems that have a high biodiversity. Unfortunately, a lot of this biodiversity is being lost as semi-natural grasslands are declining in both size and number. Restoration to reestablish semi-natural grasslands is often done by removing shrubs and trees and planting seeds. After this reinstalment of management such as mowing, and grazing is done to keep woody plants away. Grassland management and restoration have a proven positive effect on species richness and abundance regarding vascular plants. Yet little is known about the effects on insects and spiders. By reviewing scientific publications, I explored how insects and spiders are affected by management, as well as how local and landscape factors affect restoration. Grassland history and timing of restoration, as well as insect and spider’s dispersal ability, affects the possibility of a successful restoration. Larger habitats with good connectivity and surrounding supporting habitats are positive factors for viable insect and spider communities. By comparing different publications, some species benefit from intensive grazing and mowing, and some show a negative response. Long-term low to medium intensive management will favor a higher biodiversity compared to short-term intensive management. In conclusion, balancing conflicts and trade-offs is the real challenge when it comes to semi-natural grassland restoration. In general, to benefit as many insect and spider species as possible management should focus on variation in grass height and flower abundance. However, more research on how insect and spiders are affected by grassland restoration is something I believe would benefit future conservation projects.