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  • 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.
161

Plant-herbivore-predator communities and grassland management intensity - Implications for biodiversity conservation practices on local and landscape scales

Rothenwöhrer, Christoph 19 March 2012 (has links)
No description available.
162

História natural e interação flores-besouros em espécies de Cerrado / Natural history and flower-beetle interactions in Cerrado species

Hipolito Ferreira Paulino Neto 11 September 2009 (has links)
Interações planta-animal, tais como polinização, são a chave de processos ecológicos in muitas comunidades terrestres. O estudo de quem interage com quem é uma importante ferramenta para se entender os processos ecológicos e evolucionários. Em algumas comunidades tropicais, mais de um quarto de todas as espécies de planta pode ser polinizado por besouros. Eles são um grupo de inseto muito antigo e diversificado e eles interagem com angiospermas desde o período de suas origens e princípio da diversificação. Adicionalmente, a interação entre besouros e recursos florais provém singular oportunidade para se avaliar a complexidade de interações e a possibilidade de generalização como a tendência para plantas para usar uma enorme proporção da fauna de besouros visitantes como polinizadores, ou especialização com plantas usando uma proporção relativamente pequena da fauna disponível de visitantes como polinizadores. A distribuição espacial de espécies vegetais tem sido considerada um importante componente na determinação de interações planta-animal, sendo esperado que muitos padrões observados nestes sistemas resultem de variações na distribuição de recursos vegetais. A disponibilidade de recursos florais apresenta variações espaço-temporais que podem influenciar a eficiência dos polinizadores do ponto de vista quantitativo, pela freqüência de ocorrência da interação, ou qualitativo pela contribuição dada ao sucesso reprodutivo das espécies. Os principais objetivos da presente tese foram: 1) descrever a história natural e interação flores besouros em espécies de Cerrado em relação à heterogeneidade espaço-temporal da distribuição de recursos entre fitofisionomias localizadas na Estação Ecológica de Itirapina (EEI) e em área de Cerradão pertencente ao Instituto Arruda Botelho (22º12- 22º10S e 47º55- 47º57W, respectivamente) durante dois anos consecutivos; 2) verificar o padrão local de distribuição de flores e besouros em quatro fitofisionomias de cerrado estudadas; 3) caracterizar a nível de comunidade os padrões de interações observados na comunidade composta por besouros associados a flores; 4) finalmente, compreender detalhadamente um dos diversos sistemas de interação besouros-plantas registrados na área de estudo. Escolhemos o sistema de interação de D. furfuracea-besouros com o objetivo de descrever sua fenologia de floração e frutificação e seu sistema reprodutivo, verificando se há limitação polínica e de recursos. Também foi avaliada a função e o efeito dos visitantes florais sobre o sistema reprodutivo. Uma alta proporção de espécies de plantas tem suas flores visitadas por besouros em todas quatro fitofisionomias de Cerrado estudadas (12-40%), indicando que os dados disponíveis até o momento subestimam a ocorrência de cantarofilia para áreas de Cerrado. Este consiste no primeiro estudo focando toda uma comunidade de besouros associados a flores. Não houve variação temporal entre anos tanto para as redes de visitantes-flores ou para redes de polinizadores-plantas. Redes de polinizadores-plantas tiveram espécies de besouros altamente especialistas. Attalea geraensis¸ C. pubescens, D. furfuracea>, D. hispida, K. coriacea, S. petrea, T. formosa e X. aromatica consistem em espécies de planta envolvidas em muitas interações e foram consideradas espécies centrais. Tanto as redes de visitantes-flores, como a rede de polinizadores-plantas evidenciaram uma estrutura composta combinando estrutura de rede aninhada com compartimentada, mas com predomínio do padrão compartimentado. Estes compartimentos são resultantes tanto das muitas interações espécie-específica entre espécies de besouros e plantas, como daquelas espécies de planta que interagem com várias espécies especialistas de besouros. De modo geral, focando atenção nos besouros, ambas as redes, visitantes-flores e polinizadores-plantas foram definidas como altamente especializadas já que visitaram flores poucas espécies de planta tanto para comparações entre anos, como entre fitofisionomias. O presente estudo mostrou que o Cerrado apresenta sistemas de interação entre besouros e flores de espécies de planta com alta especificidade. Dentre as várias espécies de planta compreendidas nestas redes de interação de alta especificidade, merece desta D. furfuracea que apresenta uma fauna composta por várias espécies de besouros polinizadores altamente especialistas. Duguetia furfuracea é uma espécie auto-incompatível, cuja população estudada apresentou limitação polínica e de recursos no solo. Há duas guildas especializadas de besouros interagindo com esta espécie de planta. A primeira é composta por uma única espécie de curculionídeo (Plasilia sp.) que visitou suas flores em baixa abundância (média de 0,55 besouros por flor), mas com alta freqüência de ocorrência (44,9% das flores) e suas larvas consomem as sementes dos frutos que se desenvolvem. A segunda guilda é composta por várias espécies de besouros nitidulídeos, principalmente Colopterus sp.3 que visitaram as flores em grande abundância (média de 99 besouros por flor) e também com alta ocorrência de visitação (92% das flores) e que efetivamente promoveram a polinização. O sistema de polinização de D. furfuracea consiste no primeiro caso de polinização mutualística obrigatória envolvendo diferentes guildas de visitantes florais. Este também é o primeiro sistema de polinização combinando polinizadores previsíveis e confiáveis, consumo de sementes, limitação polínica e limitação por recursos, o que resulta em um complexo e eficiente mecanismo para regulação da população do visitante floral consumidor de sementes e para otimizar o sucesso reprodutivo da planta. / Plant-animal interactions, such as pollination, are a key element in many terrestrial communities. The study of who interacts with whom is an important approach for understanding ecological and evolutionary processes. In some tropical communities, up to one quarter of all plant species may be pollinated by beetles. They are an ancient and much diversified insect group and they interact with angiosperms since the time of their origin and early diversification. Additionally, the interaction between beetle and floral resource provide unique opportunity to evaluate the complexity of interactions and the possibility of generalization as the tendency for plants to use a large proportion of the available beetle-visiting fauna as pollinators, or specialization with plants using a relatively small proportion of the available beetle visiting fauna as pollinators. The spatial distributions of plant species have been considered an important component in the determination of plant-animal interactions, and it is expected that many patterns observed in these systems resulting from variations in the resource distribution of plants. The availability of floral resources presents spatio-temporal variations that may affect the pollinator efficiency in its quantitative traits through frequency of occurrence of the interaction, or qualitative by its contribution to the fitness plant. Thus, the main objectives of this present thesis were: 1) describe the natural history and interactions of beetle with flowers in Cerrado species focusing the spatio-temporal heterogeneity of the resource distribution among phytophysiognomies located in the Itirapina Ecological Station and in the Cerradão area belongs to the Arruda Botelho Institute (22º12- 22º10S and 47º55- 47º57W, respectively) during two consecutive years.; 2) verify the local pattern of flowers and beetle distribution in the four cerrado phytophysiognomies studied; 3) characterize in the community level the interaction patterns observed in the community composed by beetles associated to flowers; 4) finally, comprehend deeply one of the several beetle-flower systems recorded to this studied area. We chose the D. furfuracea-beetle interaction system with aim to describe its flowering and fruit phenology and its reproductive biology verifying if there are pollen and resource limitation. Also was evaluated the role and effect of floral visitors in the fitness plant. A high number of flowering species was visited by beetles (12-40%) indicating that the data available up to now underestimate the representation of this interaction in Cerrado areas. This work represents the first study focusing in the entire beetle community associated to flowers. Was found no temporal variation in the interaction between beetles and flowers. Pollinator-plant webs had beetle species highly specialist. A. geraensis¸ C. pubescens, D. furfuracea, D. hispida, K. coriacea, S. petrea, T. formosa and X. aromatica , involved in many interactions were considered as core species. Both the visitor-flower and the pollinator-plant webs showed a compound structures mixing nested and compartmented networks structure, but predominating the compartmented pattern. These compartments are resultant from both of the many species-specific interactions between beetle and plant species and of the plant species that interact with several specialist beetle species. Both visitor-flower and pollinator-plant webs may be denominated as highly specialist from the beetle perspective whereas that these beetle fauna visited flowers of very few plant taxa over time and space. The present study showed that the Cerrado presents interaction systems between beetles and plants species with high specificity. Among the several plant species comprised in these interaction webs with high specificity, D. furfuracea presents a very interesting pollinator system, presenting a fauna composed by several pollinator beetle species highly specialized. D. furfuracea is a self-incompatible species, which studied population presented pollen and resource limitation. There are two specialized beetle guilds interacting with this plant species. The first guild is composed just by one curculionid species (Plasilia sp.) that visited flowers with low abundance (median of 0.55 beetles per flower), but presenting high frequency of occurrence (44.9% of the flowers) and their larvae consumed seed of that fruits that developed. The second guild is composed by several nitidulid beetles, principally Colopterus sp.3 that visited flowers in large abundance (median of 99 beetles per flower) and also presented high visitation occurrence (92% of flowers) and that effectively promoted the pollination. The pollination system of D. furfuracea consists is the first case of obligate pollination mutualism case involving different guilds of floral visitors. This also constitutes the first pollination system combining predictable and reliable pollinators, seed consumption, pollen and resource limitation resulting in a complex and efficient mechanism to regulate the seed consuming by floral visitor`s population and to optimize the plant fitness
163

Metabolismo de lipídeos em inseto coleóptero: digestão e transporte de ácidos graxos / Lipid metabolism in coleóptera insect: digestion and transport of fatty acids

Freire, Camilla Camerino Santana Davino 17 August 2018 (has links)
Coleoptera is an order of insects well known as beetles. Most coleopteran species are phytophagous insects and for this reason are essential to crop and storage pests such as the Tribolium castaneum. Lipid metabolism is vital for the biological functions of insects, playing a role in the generation of metabolic energy and other cellular processes. Fatty acid transport proteins (FATPs) play a crucial role in the transport of extracellular fatty acids to cells, have a conserved sequence between species and are involved in the synthesis of hormones and pheromones. Recent studies show that silencing the gene for FATPs through interfering RNAi techniques (RNAi) in insects affects fatty acid uptake and pheromone synthesis. This work aims to characterize proteins homologous to FATPs present in the genome of Tribolium castaneum, to evaluate the gene expression in tissues, developmental stages and insects treated with Orlistat and to evaluate the effect of FATP silencing on energy metabolism. Bioinformatics analyzes were performed with the amino acid sequences, and real-time PCR evaluated the gene expression. The effects of the drug Orlistat were evaluated through qPCR and analysis of nutritional index. The search for sequences in the T. castaneum genome revealed two sequences of proteins homologous to FATPs and bioinformatic analysis was performed. The study of the gene expression of FATPs by qPCR demonstrated more significant expression of the two genes in the fat body of larvae and many expressions in all stages of development of the insect, with higher expression in the pupa stage. The effects of Orlistat on the expression of FATPs evidenced the influence of diet composition on the regulation of the gene expression of these proteins. Gene silencing of TcasFATP was achieved, but no direct effects on the energetic dynamics of the larvae were observed since triacylglycerol levels, and β-oxidation rates were not affected. Thus, more detailed studies with the use of gene silencing will be necessary to characterize FATPs better and elucidate their role in insect energy metabolism. / FAPEAL - Fundação de Amparo à Pesquisa do Estado de Alagoas / Os coleópteros constituem uma ordem de insetos bastante conhecidos como besouros. A maioria das espécies de coleóptero são insetos fitófagos e por esta razão constituem importantes pragas de culturas e de armazenamento, como o Tribolium castaneum. O metabolismo de lipídeos é importante para as funções biológicas de insetos, exercendo papel na geração de energia metabólica e em outros processos celulares. As proteínas transportadoras de ácidos graxos (FATPs) exercem papel crucial no transporte de ácidos graxos extracelulares para as células, possuem sequência conservada entre as espécies e estão envolvidas na síntese de hormônios e feromônios. Estudos recentes mostram que o silenciamento do gene para FATPs através de técnicas de RNA de interferência (RNAi) em insetos afetam a absorção de ácidos graxos e a síntese de feromônio. Este trabalho tem como objetivo caracterizar proteínas homólogas à FATPs presentes no genoma de Tribolium castaneum, avaliar a expressão gênica nos tecidos, fases de desenvolvimento e em insetos tratados com Orlistate e avaliar o efeito do silenciamento de FATPs no metabolismo energético. Foram realizadas análises bioinformáticas com as sequências de aminoácidos e a avaliação da expressão gênica foi realizada por PCR em tempo real. Os efeitos do fármaco Orlistate foram avaliados através de qPCR e análise dos índices nutricionais. A busca de sequências no genoma do T. castaneum revelou duas sequências de proteínas homólogas à FATPs e a análise bioinformática foi realizada. O estudo da expressão gênica de FATPs por qPCR demonstrou maior expressão dos dois genes no corpo gorduroso de larvas e expressão considerável em todos os estágios de desenvolvimento do inseto, com maior expressão no estágio de pupa. Os efeitos do Orlistate na expressão das FATPs evidenciaram a influência da composição da dieta na regulação da expressão gênica dessas proteínas. O silenciamento gênico de TcasFATP foi alcançado, mas não foram observados efeitos diretos na dinâmica energética das larvas, pois os níveis de triacilglicerol e as taxas de β-oxidação não foram afetadas. Dessa forma, estudos mais detalhados com uso do silenciamento gênico serão necessários para melhor caracterização funcional das FATPs e elucidação do seu papel no metabolismo energético do inseto.
164

Modelling the impact of an alien invasion : Harmonia axyridis in Britain

Comont, Richard Francis January 2014 (has links)
Harmonia axyridis is a ladybird native to Asia, but introduced widely as a biocontrol agent. It is invasive and detrimental to native species in North America, which meant its arrival in Britain was met with concern. Establishment was seen as an opportunity to track the spread of an invasive alien species (IAS) whilst also monitoring impacts on native species. The aims of this thesis were to examine the responses of native British ladybirds to the arrival of H. axyridis, to establish the effect of the IAS on native ladybirds when compared to other drivers, and to investigate the possible facilitation of the H. axyridis invasion by natural enemy release. Modelling ladybird distributions with life-history and resource-use traits found that species predatory on a wide range of prey families had larger range sizes than those which ate fewer prey types. This suggests that the wide diet breadth of the IAS is likely to have played a critical role in the species’ rapid spread. Dietary niche overlap between H. axyridis and native ladybirds showed positive correlation with declines of native ladybirds. This indicates that the IAS is playing an important role, but the significance of urbanisation suggests habitat destruction is also significant. Abundance of H. axyridis was influenced by habitat type and aphid abundance, but not by the native ladybird community, suggesting the spread of the IAS will not be slowed by biotic resistance. Harmonia axyridis is attacked by native parasitoids, but at a much lower rate than is the native Coccinella septempunctata, in line with natural-enemy release theory. There was no evidence of attack rate increasing with time since arrival in an area. Overall, H. axyridis is an extremely successful IAS, with detrimental effects on native ladybirds which are likely to continue.
165

Complex photonic structures in nature : from order to disorder

Onelli, Olimpia Domitilla January 2018 (has links)
Structural colours arise from the interaction of visible light with nano-structured materials. The occurrence of such structures in nature has been known for over a century, but it is only in the last few decades that the study of natural photonic structures has fully matured due to the advances in imagining techniques and computational modelling. Even though a plethora of different colour-producing architectures in a variety of species has been investigated, a few significant questions are still open: how do these structures develop in living organisms? Does disorder play a functional role in biological photonics? If so, is it possible to say that the optical response of natural disordered photonics has been optimised under evolutionary pressure? And, finally, can we exploit the well-adapted photonic design principles that we observe in Nature to fabricate functional materials with optimised scattering response? In my thesis I try to answer the questions above: I microscopically investigate $\textit{in vivo}$ the growth of a cuticular multilayer, one of the most common colour-producing strategies in nature, in the green beetles $\textit{Gastrophysa viridula}$ showing how the interplay between different materials varies during the various life stages of the beetles; I further investigate two types of disordered photonic structures and their biological role, the random array of spherical air inclusions in the eggshells of the honeyguide $\textit{Prodotiscus regulus}$, a species under unique evolutionary pressure to produce blue eggs, and the anisotropic chitinous network of fibres in the white beetle $\textit{Cyphochilus}$, the whitest low-refractive index material; finally, inspired by these natural designs, I fabricate and study light transport in biocompatible highly-scattering materials.
166

Restoration of Black Oak (<i>Quercus velutina</i>) Sand Barrens via three different habitat management approaches

Kriska, David J. 03 October 2017 (has links)
No description available.
167

Ermittlung von Struktur-Indikatoren zur Abschätzung des Einflusses forstlicher Bewirtschaftung auf die Biozönosen von Tiefland-Buchenwäldern / Identification of structure indicators for assessing the impact of forest management on the biocoenosis of lowland beech forests

Winter, Susanne 24 September 2005 (has links) (PDF)
Buchenwälder sind die großflächigste potenziell natürliche Vegetationsform Deutschlands und ein nach EU-FFH-Richtlinie besonders zu schützender Biotoptyp. Eine hohe Naturnähe ist auch in Wirtschaftswäldern (WiWald) notwendig, um die typischen Lebensgemeinschaften naturnaher Wälder langfristig zu erhalten, doch mangelt es an praktikablen/verifizierten Indikatoren, wie die nutzungsbedingte Abweichung vom Naturzustand ermittelt werden kann. In &amp;gt;100 Jahre alten und ~40 ha großen Tiefland-Buchenwäldern (Mecklenburg-Vorpommern/Brandenburg) wurde anhand von 13 WiWäldern, vier seit &amp;lt;20 Jahren (k20) und drei seit &amp;gt;50 Jahren (r50) unbewirtschafteten Beständen den folgenden Fragen nachgegangen: Wie groß sind die strukturellen, vegetationskundlichen und carabidologischen Unterschiede zwischen bewirtschafteten, kurz- und langfristig unbewirtschafteten Buchenwäldern? Gibt es strukturelle Indikatoren und quantitative Größen zur Abschätzung des Einflusses forstlicher Bewirtschaftung auf die Biozönosen von Tiefland-Buchenwäldern? In Probekreisen (Pk) von 500 m² an Rasterpunkten (100 m x 100 m) wurden strukturelle und in Pk von 314 m² vegetationskundliche Daten erhoben. In fünf Pk/Bestand wurde jeweils eine Barberfalle über die Vegetationsperiode installiert. Ganzflächig wurden die Verteilung der Waldentwicklungsphasen (WEP)und zusätzlich zu den Pk-Aufnahmen hektarweise Sonderstrukturen aufgenommen. U. a. wurden folgende Sonderstrukturen aufgenommen: Zunderschwamm, Kronen- und Zwieselbrüche, Ersatzkronen, Blitzrinnen, Risse/Spalten, Höhlen, Mulmkörper/-taschen. Diese naturschutzfachlich wichtigen Sonderstrukturen wurden aus den Habitatansprüchen der typischen Buchenwaldfauna abgeleitet.Es konnten große Unterschiede zwischen WiWald und r50-Flächen (v. a. &amp;gt;100 Jahre unbewirtschafteten Flächen) aufgezeigt werden. Die k20-Flächen unterscheiden sich nicht wesentlich vom WiWald. Die Anzahl verschiedener WEP/ha und WEP-Patches/ha liegt in den r50-Flächen signifikant höher als im WiWald. Der Holzvorrat der r50-Flächen liegt mit ~600 m³/ha (Terminal- ~800 m³/ha, Zerfallsphase 450 m³/ha) deutlich höher als im WiWald. Charakteristisch für die r50-Flächen ist das Vorkommen von in ihrer Vitalität eingeschränkten Bäume ab 80 cm BHD und ein inhomogeneres Lichtmosaik im Bestand. Die Stammqualitäten (u. a. Astigkeit) in r50-Flächen unterscheiden sich kaum von denen in WiWald. In den r50-Flächen kommt bedeutend mehr Totholz (&amp;gt;142 m³/ha) als im WiWald (max. 34 m³/ha) vor. Im WiWald können Stubben dominieren. Verschiedene Totholzqualitäten sind im WiWald nur unvollständig vorhanden. Etwa 40 % des Totholzes besitzt keine Totholznachbarn (r50-Flächen: &amp;lt;2 %) und die Lichtverhältnisse am Totholz sind nicht so vielfältig (wenig sonnenexponiert und wenig gering besonnt). In den &amp;gt;100 Jahre unbewirtschafteten Flächen kommen ~12 Sonderstrukturtypen mit &amp;gt;200 Sonderstrukturen/ha vor. 19 von 20 Sonderstrukturen sind im WiWald signifikant seltener und 11 Sonderstrukturen sind als Naturnähe-Indikatoren geeignet.Vegetation: In der Krautschicht sind höhere Deckungsgrade, mehr (lichtanzeigende) Arten, weniger Waldarten und eine höhere Diversität zu verzeichnen. Im WiWald wird u. a. das Vorkommen von Calamagrostis epigeios, Impatiens parviflora und Rubus idaeus gefördert. Stark gefährdete Moosarten sind im WiWald seltener als in den Referenzwäldern, da sie vor allem auf liegendem Totholz und auf den Stammanläufen vorkommen. Carabiden: Im WiWald gibt es weniger Individuen und Biomasse von mesophilen Waldarten und eine geringere Anzahl von flugunfähigen Individuen. Als Indikatoren für naturnahe Tiefland-Buchenwälder können die drei Arten Carabus glabratus, C. hortensis und Cychrus caraboides bezeichnet werden. Indikatoren: Es wurden Zielgrößen für 29 Struktur-Indikatoren für naturnahe Wälder vorgeschlagen. Für WiWälder wurden gesonderte Zielgrößen festgelegt, die die nutzungsbedingte, nicht zu vermeidende Abweichung vom Naturzustand berücksichtigen. / Beech forests are the most important natural vegetation type of Germany,and they are included in annex II of the EU-FFH-Directive,which requests nature conservation for the listed habitat types.High naturalness is necessary in managed forests (w-sites) to maintain the typical biocoenosis of forests near nature. But there is a lack of practicable/verified indicators to determine the degree of alteration managed forests have compared to natural forests. In &amp;gt;100 year old and ~40 ha big lowland beech forests in Mecklenburg-Vorpommern and Brandenburg, 13 w-sites, 4 study sites which are unmanaged since &amp;lt;20 years (k-sites) and 3 sites which are unmanaged since &amp;gt;50 years (r50-sites) were investigated to answer these questions: What the differences are between w-, k- and r-sites according to forest structure, vegetation and carabids? Are there valid structural indicators with thresholds to assess the impact of forestry use on the biocoenosis of lowland beech forests? At grid points(distance 100 mx 100 m),on circular sample plots (SP) of 500 m² the structural data and on SP of 314 m² the vegetation was investigated. At five SP/study site a pitfall trap was installed during the entire vegetation period. On the whole study site the distribution of forest development phases (FDP) was mapped, and on full one ha plots the special structures were investigated. The following special structures were mapped e.g. Fomes fomentarius trees, crown and crotch breakage, substitute crowns, lightning shakes,gutters/rifts, cavities, mould and bark bag. These special structures have been derived from the habitat needs of the typical beech forest fauna.The results revealed tremendous differences between w- and r50-sites. The k-sites show no clear differences to the managed sites.In the r50-sites, the number of different FDP/ha and FDP units/ ha is significant higher than in w-sites. The timber stock of the r50-sites is ~600 m³/ha (terminal phase ~800 m³/ha, decay phase ~450³/ha). A characteristic feature of the r50-sites is the occurrence of trees with 80 cm bhd or more with reduced vitality. The timber trunk) qualities of r-sites differ only slightly from managed stands. In the r50-sites the dead wood volume (&amp;gt;142 m³/ha) is much higher than in the w-sites (max. 34 m³/ha). Many different features of dead wood occur only fragmentary within w-sites. About 40 % of the dead wood objects have no &amp;quot;dead wood neighbour&amp;quot; (r50-sites: &amp;lt;2 %), and the light distribution is much less diverse. In &amp;gt;100 years unmanaged r-sites ~12 different types of special structures and 200 single special structures occur per ha. 19 out of 20 special structures are significantly less frequent in w-sites; 11 special structures are specifically valuable to be used as naturalness indicators.Vegetation: In the herb layer occur higher coverage values, more (light-indicating) species, but only few species indicating ancient forests and a higher diversity index value. In w-sites, the occurrence of e. g. Calamagrostis epigeios, Impatiens parviflora and Rubus idaeus is supported. reduced. Threatened moss species are rare in w-sites compared to r-sites, since they mainly grow on laying dead wood, which is rare in forests in use, and on inclined/rough-barked stem bases. Ground beetles: The forestry use of lowland beech forests leads to less individuals and lower biomass of so-called mesophilous forest species. Furthermore, the number of flightless individuals is lower. As proper indicators for near-natural lowland beech forests, the three species Carabus glabratus, C. hortensis und Cychrus caraboides could be identified. Indicators: 29 structural indicators were identified and thresholds were given. But even in lowland beech forests managed in a conservation-friendly way, these target values for near-natural and natural forests are unlikely to be reached. Therefore, for w-sites special threshold values have been defined, which consider the inevitable difference between managed and natural forests.
168

Ermittlung von Struktur-Indikatoren zur Abschätzung des Einflusses forstlicher Bewirtschaftung auf die Biozönosen von Tiefland-Buchenwäldern

Winter, Susanne 01 September 2005 (has links)
Buchenwälder sind die großflächigste potenziell natürliche Vegetationsform Deutschlands und ein nach EU-FFH-Richtlinie besonders zu schützender Biotoptyp. Eine hohe Naturnähe ist auch in Wirtschaftswäldern (WiWald) notwendig, um die typischen Lebensgemeinschaften naturnaher Wälder langfristig zu erhalten, doch mangelt es an praktikablen/verifizierten Indikatoren, wie die nutzungsbedingte Abweichung vom Naturzustand ermittelt werden kann. In &amp;gt;100 Jahre alten und ~40 ha großen Tiefland-Buchenwäldern (Mecklenburg-Vorpommern/Brandenburg) wurde anhand von 13 WiWäldern, vier seit &amp;lt;20 Jahren (k20) und drei seit &amp;gt;50 Jahren (r50) unbewirtschafteten Beständen den folgenden Fragen nachgegangen: Wie groß sind die strukturellen, vegetationskundlichen und carabidologischen Unterschiede zwischen bewirtschafteten, kurz- und langfristig unbewirtschafteten Buchenwäldern? Gibt es strukturelle Indikatoren und quantitative Größen zur Abschätzung des Einflusses forstlicher Bewirtschaftung auf die Biozönosen von Tiefland-Buchenwäldern? In Probekreisen (Pk) von 500 m² an Rasterpunkten (100 m x 100 m) wurden strukturelle und in Pk von 314 m² vegetationskundliche Daten erhoben. In fünf Pk/Bestand wurde jeweils eine Barberfalle über die Vegetationsperiode installiert. Ganzflächig wurden die Verteilung der Waldentwicklungsphasen (WEP)und zusätzlich zu den Pk-Aufnahmen hektarweise Sonderstrukturen aufgenommen. U. a. wurden folgende Sonderstrukturen aufgenommen: Zunderschwamm, Kronen- und Zwieselbrüche, Ersatzkronen, Blitzrinnen, Risse/Spalten, Höhlen, Mulmkörper/-taschen. Diese naturschutzfachlich wichtigen Sonderstrukturen wurden aus den Habitatansprüchen der typischen Buchenwaldfauna abgeleitet.Es konnten große Unterschiede zwischen WiWald und r50-Flächen (v. a. &amp;gt;100 Jahre unbewirtschafteten Flächen) aufgezeigt werden. Die k20-Flächen unterscheiden sich nicht wesentlich vom WiWald. Die Anzahl verschiedener WEP/ha und WEP-Patches/ha liegt in den r50-Flächen signifikant höher als im WiWald. Der Holzvorrat der r50-Flächen liegt mit ~600 m³/ha (Terminal- ~800 m³/ha, Zerfallsphase 450 m³/ha) deutlich höher als im WiWald. Charakteristisch für die r50-Flächen ist das Vorkommen von in ihrer Vitalität eingeschränkten Bäume ab 80 cm BHD und ein inhomogeneres Lichtmosaik im Bestand. Die Stammqualitäten (u. a. Astigkeit) in r50-Flächen unterscheiden sich kaum von denen in WiWald. In den r50-Flächen kommt bedeutend mehr Totholz (&amp;gt;142 m³/ha) als im WiWald (max. 34 m³/ha) vor. Im WiWald können Stubben dominieren. Verschiedene Totholzqualitäten sind im WiWald nur unvollständig vorhanden. Etwa 40 % des Totholzes besitzt keine Totholznachbarn (r50-Flächen: &amp;lt;2 %) und die Lichtverhältnisse am Totholz sind nicht so vielfältig (wenig sonnenexponiert und wenig gering besonnt). In den &amp;gt;100 Jahre unbewirtschafteten Flächen kommen ~12 Sonderstrukturtypen mit &amp;gt;200 Sonderstrukturen/ha vor. 19 von 20 Sonderstrukturen sind im WiWald signifikant seltener und 11 Sonderstrukturen sind als Naturnähe-Indikatoren geeignet.Vegetation: In der Krautschicht sind höhere Deckungsgrade, mehr (lichtanzeigende) Arten, weniger Waldarten und eine höhere Diversität zu verzeichnen. Im WiWald wird u. a. das Vorkommen von Calamagrostis epigeios, Impatiens parviflora und Rubus idaeus gefördert. Stark gefährdete Moosarten sind im WiWald seltener als in den Referenzwäldern, da sie vor allem auf liegendem Totholz und auf den Stammanläufen vorkommen. Carabiden: Im WiWald gibt es weniger Individuen und Biomasse von mesophilen Waldarten und eine geringere Anzahl von flugunfähigen Individuen. Als Indikatoren für naturnahe Tiefland-Buchenwälder können die drei Arten Carabus glabratus, C. hortensis und Cychrus caraboides bezeichnet werden. Indikatoren: Es wurden Zielgrößen für 29 Struktur-Indikatoren für naturnahe Wälder vorgeschlagen. Für WiWälder wurden gesonderte Zielgrößen festgelegt, die die nutzungsbedingte, nicht zu vermeidende Abweichung vom Naturzustand berücksichtigen. / Beech forests are the most important natural vegetation type of Germany,and they are included in annex II of the EU-FFH-Directive,which requests nature conservation for the listed habitat types.High naturalness is necessary in managed forests (w-sites) to maintain the typical biocoenosis of forests near nature. But there is a lack of practicable/verified indicators to determine the degree of alteration managed forests have compared to natural forests. In &amp;gt;100 year old and ~40 ha big lowland beech forests in Mecklenburg-Vorpommern and Brandenburg, 13 w-sites, 4 study sites which are unmanaged since &amp;lt;20 years (k-sites) and 3 sites which are unmanaged since &amp;gt;50 years (r50-sites) were investigated to answer these questions: What the differences are between w-, k- and r-sites according to forest structure, vegetation and carabids? Are there valid structural indicators with thresholds to assess the impact of forestry use on the biocoenosis of lowland beech forests? At grid points(distance 100 mx 100 m),on circular sample plots (SP) of 500 m² the structural data and on SP of 314 m² the vegetation was investigated. At five SP/study site a pitfall trap was installed during the entire vegetation period. On the whole study site the distribution of forest development phases (FDP) was mapped, and on full one ha plots the special structures were investigated. The following special structures were mapped e.g. Fomes fomentarius trees, crown and crotch breakage, substitute crowns, lightning shakes,gutters/rifts, cavities, mould and bark bag. These special structures have been derived from the habitat needs of the typical beech forest fauna.The results revealed tremendous differences between w- and r50-sites. The k-sites show no clear differences to the managed sites.In the r50-sites, the number of different FDP/ha and FDP units/ ha is significant higher than in w-sites. The timber stock of the r50-sites is ~600 m³/ha (terminal phase ~800 m³/ha, decay phase ~450³/ha). A characteristic feature of the r50-sites is the occurrence of trees with 80 cm bhd or more with reduced vitality. The timber trunk) qualities of r-sites differ only slightly from managed stands. In the r50-sites the dead wood volume (&amp;gt;142 m³/ha) is much higher than in the w-sites (max. 34 m³/ha). Many different features of dead wood occur only fragmentary within w-sites. About 40 % of the dead wood objects have no &amp;quot;dead wood neighbour&amp;quot; (r50-sites: &amp;lt;2 %), and the light distribution is much less diverse. In &amp;gt;100 years unmanaged r-sites ~12 different types of special structures and 200 single special structures occur per ha. 19 out of 20 special structures are significantly less frequent in w-sites; 11 special structures are specifically valuable to be used as naturalness indicators.Vegetation: In the herb layer occur higher coverage values, more (light-indicating) species, but only few species indicating ancient forests and a higher diversity index value. In w-sites, the occurrence of e. g. Calamagrostis epigeios, Impatiens parviflora and Rubus idaeus is supported. reduced. Threatened moss species are rare in w-sites compared to r-sites, since they mainly grow on laying dead wood, which is rare in forests in use, and on inclined/rough-barked stem bases. Ground beetles: The forestry use of lowland beech forests leads to less individuals and lower biomass of so-called mesophilous forest species. Furthermore, the number of flightless individuals is lower. As proper indicators for near-natural lowland beech forests, the three species Carabus glabratus, C. hortensis und Cychrus caraboides could be identified. Indicators: 29 structural indicators were identified and thresholds were given. But even in lowland beech forests managed in a conservation-friendly way, these target values for near-natural and natural forests are unlikely to be reached. Therefore, for w-sites special threshold values have been defined, which consider the inevitable difference between managed and natural forests.
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Birds, bats and arthropods in tropical agroforestry landscapes: Functional diversity, multitrophic interactions and crop yield

Maas, Bea 20 November 2013 (has links)
No description available.

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