Nachdem sich die Diskussion um die biologische Vielfalt bisher hauptsächlich um die floristische und faunistische Artenvielfalt drehte, rückt in den letzten Jahren die Landschaft verstärkt in das Blickfeld. So empfahl der Sachverständigenrat für Umweltfragen der Bundesrepublik in seinem Gutachten 1994 eine flächendeckende Ermittlung und Bewertung kritischer struktureller Veränderungen der Landschaft. Die Sachverständigen sehen das Ausmaß der Eingriffe in die Nutzungsstruktur der Kulturlandschaft sowie den Grad der Verdrängung naturnaher bzw. naturverträglicher Nutzungsformen und weitgehend vom Menschen unbeeinflußter Gebiete als wesentliches Kriterium für die Bewertung von Landschaften. Der Beitrag stellt die Methodik der Analyse und Beschreibung von Landschaften mit Indikatoren zur Landschaftsstruktur in den Vordergrund. Neben der Suche und Auswahl geeigneter Parameter bzw. Indizes, brauchbarer Datenquellen und den technischen Problemen der Software spielen zunehmend anwendungsorientierte Fragen eine große Rolle.

La géodiversité en tant qu’interprétation géographique de la diversité spatiale de la surface terrestre, peut être définie comme la diversité morphologique des milieux dits naturels, voire comme une diversité des paysages si l’on considère ces derniers comme un ensemble d’objets matériels. Afin de combler des lacunes théoriques et l’absence d’un regard multilinguistique et pluriculturel sur la géodiversité, ce travail s’insérant dans la recherche fondamentale géographique, met en lumière et différencie les notions de géodiversité et de diversité paysagère en langue française, allemande et anglaise, tout en explorant de façon empirique une question primordiale : comment mesurer la géodiversité, interprétée comme une diversité mésologique et paysagique tenant compte des structures verticales et horizontales de la diversité spatiale ? La géodiversité dite globale ne doit pas être confondue avec une géodiversité interprétée de façon géologique: elle prend en effet en compte les éléments biotiques autant que les éléments abiotiques et intègre l’anthropisation des milieux, sans séparer le minéral et le vivant, le naturel et l’artificiel. Dans une approche systémique, on peut considérer que les structures spatiales des milieux, leur morphologie, reflètent leur fonctionnement et leur dynamique et elles permettent de différencier ces milieux pour caractériser leur géodiversité. Saisie simultanément par une approche intégrée des milieux et par des relevés pédologiques et floristiques davantage disciplinaires, les composantes et enceintes des milieux relèvent de plusieurs niveaux organisationnels de la diversité. Le volet empirique de ce travail de recherche explore, par une démarche multiscalaire, la géodiversité du Massif du Madres –Coronat situé dans la partie orientale, franco-catalane, des Pyrénées. Sur le site d’intérêt communautaire« Massif de Madres-Coronat » la diversité des milieux se trouve accentuée par une variété des roches, des formes du relief, par un étagement bioclimatique et une utilisation des sols différenciée. Les relevés de terrain permettent d’étudier la diversité mésologique (ou diversité des milieux) et de mettre en évidence les relations entre géodiversité et phytodiversité. La cartographie des unités paysagiques élémentaires, les géons, mis en évidence par photo-interprétation, illustre la mosaïque des milieux et la diversité des structures spatiales latérales qu’on peut qualifier de diversité paysagique. Les indices de diversité et l’analyse exploratoire des données multivariées appliqués aux données mésologiques et paysagiques contribuent à la caractérisation de la géodiversité du massif. Ils mettent en évidence une diversité mésologique relativement importante dans les milieux forestiers et complexes et une diversité paysagique plus importante dans les secteurs élevés du massif, modelés par les glaciations quaternaires, ainsi qu’à proximité des talwegs. Les résultats de cette analyse descriptive et exploratoire constituent le fondement d’une discussion sur les propriétés et l’utilité potentielle de la géodiversité dans le cadre de la gestion des paysages et des espaces naturels. / Taking geodiversity to be a geographical interpretation of the spatial diversity of the Earth’s surface, it can be defined as the morphologic diversity of ‘natural environments’ (‘milieux naturels’), or alternatively as the diversity of landscapes, when considered as a physical landscape. In an effort to contribute to a more coherent body of theory and a multilingual and pluricultural approach to geodiversity, this work situates itself within the field of fundamental geographical research. It highlights and differentiates between the notions of geodiversity and landscape diversity, whilst using an empirical method to deal with a central question; ‘How can geodiversity be measured ?’, if it is interpreted as ‘mesologic diversity’ and ‘diversité paysagique’ (describing the diversity of physical structures within the landscape), taking into account the lateral and vertical structures of spatial diversity. A clear distinction should be made between general geodiversity, and geological diversity. Indeed, a general definition of geodiversity takes into account biotic as well as abiotic elements. It also encompasses the human effect on these environments, without making a distinction between minerals and living things, or between artificial and natural elements. A systemic approach might suggest that spatial structures; the morphology of the environment, reflect their processes and dynamics. In employing an integrated approach to these ‘natural environments’ whilst also consulting floristic and soil samples, it has been shown that diversity is organised on many levels.The empirical section of the work uses a multiscalar approach to exploring the geodiversity of the ‘Massif du Madres – Coronat’, which is situated in the Franco-Catalonian region of the Eastern Pyrenees. At the Site of Community Importance - the ‘Massif du Madres – Coronat’, the broad diversity of ‘natural environments’ is characterised by specific varieties of rock, topography, levels of vegetation and differentiated land use. Samples and observations taken from the study site have made it possible to bring mesologic diversity to the fore, and to study the relationship between geodiversity and phtyodiversity. A cartographic study of ‘géons’ (a spatial landscape unit) using remote sensing, illustrates the land mosaics - a range of lateral structures that represent the physical diversity of the landscapes (‘diversité paysagique’). When used in conjunction with the data, diversity metrics and multivariate statistics contribute to understanding the character of the site’s geodiversity. This has demonstrated a relatively high level of mesologic diversity in types of forests and shrubland, and an increased level of ‘diversité paysagique’ in elevated areaswhich have been shaped by Quaternary glaciation, and in areas close to talwegs. The results of this analysis form the basis of a discussion concerning the properties and useful potential of geodiversity within the framework of managing the landscape and protected areas. / Geodiversität als geographische Interpretation einer räumlichen Diversität der Erdoberfläche kann unter anderem als morphologische Diversität der Umwelt (im Sinne eines „natürlichen Milieus“: „milieux naturels“) oder auch als Landschaftsdiversität der physikalisch-materiellen Landschaft begriffen werden. Um dem Mangel an einer multilinguistischen und interkulturellen Betrachtung der Geodiversität abzuhelfen, enthält die vorliegende Dissertation einerseits eine Grundlagenforschung zur Differenzierung der Begriffe Geodiversität und Landschaftsdiversität im englischen, deutschen und französischen Sprachraum, und befasst sich andererseits empirisch mit der Frage, wie Geodiversität gemessen werden kann; insbesondere wenn sie als räumliche Diversität sowohl die vertikalen („diversité mésologique“) als auch horizontalen („diversité paysagique“) Strukturen der Umwelt und der Landschaften berücksichtigt. Eine so definierte „globale“ oder „allgemeine“ Geodiversität ist nicht mit einer sich nur auf das Geos beschränkten Geodiversität der unbelebten Natur zu verwechseln: Die global interpretierte Geodiversität bezieht sich ebenso auf biotische wie auf abiotische Geokomponenten und integriert die anthropogene Überprägung der „milieux naturels“; also ohne getrennte Betrachtung der mineralischen und lebendigen oder der natürlichen und künstlich geschaffenen Komponenten der Umwelt. Bei einem systematischen Ansatz kann davon ausgegangen werden, dass die räumliche Struktur (Morphologie) die Prozesse und Dynamik der Umwelt widerspiegelt, die Unterschiede der Raumstruktur die Geodiversität der als System begriffenen Umwelt also hinreichend charakterisieren. Simultane Aufnahmen der Umweltkomponenten durch einen integrativen Ansatz der Standortaufnahmen sowie die eher disziplinär orientierten Methoden der Vegetations- und Bodenaufnahmen veranschaulichen die verschiedenen Organisationsebenen der Diversität. Im empirischen Teil der Arbeit wird die Geodiversität des in den französisch-katalanischen Ostpyrenäen gelegenen Madres-Coronat-Massivs mittels eines multiskalaren Ansatzes untersucht. Im FFH-Gebiet „Massif de Madres-Coronat“ zeigt sich die Diversität der Landschaft durch eine auffallende Varietät der Gesteine und Reliefformen sowie durch die Vegetationshöhenstufen wie auch die differenzierte Landnutzung besonders deutlich. Die Geländeaufnahmen ermöglichen es, die Beziehung zwischen Geodiverstät und floristischer sowie pedologischer Diversität zu untersuchen und die Standortdiversität zu beschreiben, die als „diversité mésologique“ (nach „Milieu“ bzw. mesos) bezeichnet wird. Die durch Luftbildinterpretation kartierten elementaren Landschaftseinheiten, den sogenannten „géons“, veranschaulichen das Landschaftsmuster und erlauben es, die Diversität der horizontalen Raumstrukturen und somit die morphologische Landschaftsdiversität oder sogenannte „diversité paysagique“ (der Landschaft, „paysage“ zugeordnet) zu quantifizieren. Diversitätsindizes und multivariable Analysemethoden ermöglichen die Beschreibung der Standortaufnahmedaten und der Kartierdaten über die Geodiversität des Untersuchungsgebietes. So kann eine hohe Standortdiversität (diversité mésologique) in Waldstandorten und komplexen Standorten des Typs Heide- und Buschvegetation sowie eine hohe morphologische Landschaftsdiversität in der glazial überformten Gipfelregion und in Tallagen beobachtet werden. Die Ergebnisse bilden die Basis für eine Diskussion zu den Eigenschaften und dem potentiellen Nutzen der Geodiversität für das Management und den Schutz von Lebensräumen und Landschaften.

No description available.

Deer (<i> Odocoileus </i> spp.) are an important cultural and economic resource. They are the most popular game species in the United States and the number one driver of conservation funding. On the other hand, they also cause damage to resources including to the agricultural industry, private property and to humans via deer vehicle collisions. Many areas in eastern North America have experienced a decline in white-tailed deer (<i> Odocoileus virginianus </i>) populations over the past twenty years concurrent with changes in landscape, deer harvest strategies, and increasing and expanding black bear (<i> Ursus americanus </i>) and coyote (<i> Canis latrans </i>) populations. Most studies have addressed this problem at small spatial and temporal scales and in areas where predation was assumed to be limiting population growth. We evaluated white-tailed deer fawn recruitment both directly and indirectly at relatively broader spatial and temporal scales. We studied fawn survival on Marine Corps Base Quantico in Virginia, USA from 2008–2019. We used the Kaplan-Meier estimator, and Cox-proportional hazards models to assess annual survival and factors that influence hazard risk such as sex, weather, landscape composition and configuration and food availability. On Marine Corps Base Quantico, we found an increase in red oak mast abundance increases survival and probability of fawn survival was higher during the first interval of the study (2008–2010; 0.71 [0.52–0.96]; survival probability [CI95%]) than the last three intervals (2011–2013; 0.46 [0.30–0.70]; 2014–2016; 0.48 [0.35–0.66] and 2017–2019; 0.50 [0.39–0.63]). We also found that predation was the leading source of mortality. We assessed recruitment using lactation status from hunter harvest data collected by the Virginia Department of Game and Inland Fisheries during a 22-year period in 30 counties in the Appalachian Mountains of western Virginia. We predicted lactation status as a function of landscape composition and configuration, oak mast abundance, weather, age, and predator detection rates using generalized linear mixed models. We found land cover diversity index positively and black bear detection rate negatively influenced recruitment. Age also predicted lactation status with middle-aged females (3.5–4.5 years old) having a higher lactation probability than mature (≥5.5 years old) age and young (2.5 years old) age class deer. Based on these findings, recruitment is likely to be greater in areas that are heterogeneous. Therefore, if an increase in recruitment is desired silvicultural practices such as fire and timber harvest could be used to permanently change land cover types. These silvicultural practices could also be used to increase the number of oaks on the landscape, and augment production of mature oaks as red oak mast abundance influenced fawn survival. Also reducing predation by manipulating predator densities could improve recruitment. Another potential option which needs further research, would be to reduce predator efficiency by increasing hiding cover for fawns. / Master of Science / Deer (<i> Odocoileus </i> spp.) are an important cultural and economic resource. They are the most popular game species in the United States and the number one driver of conservation funding. Conversely, they also cause damage to resources including to the agricultural industry, private property and to humans via deer vehicle collisions. Some areas in eastern North America have experienced a decline in white-tailed deer (<i> Odocoileus virginianus </i>) populations over the past twenty years concurrent with the colonization of coyotes (<i> Canis latrans </i>) as well as changes in habitat. Therefore, we aimed to determine white-tailed deer fawn survival rates and factors affecting recruitment across a large spatial and temporal scale. Recruitment is when an individual becomes part of the reproductive population. However, for harvestable populations, recruitment is when individuals can be legally harvested for the first time. On Marine Corps Base Quantico from 2008–2019, in Virginia, USA we found that probability of fawn survival was higher during the first interval of the study (2008–2010; 0.71 [0.52–0.96]; survival probability [CI95%]) than the last three intervals (2011–2013; 0.46 [0.30–0.70]; 2014–2016; 0.48 [0.35–0.66] and 2017–2019; 0.50 [0.39–0.63]). We also discovered predation was the leading cause of death and probability of survival increased with increasing red oak mast abundance. Over a large spatial (30 counties) and temporal (22 years) scale we examined fawn recruitment by predicting lactation status of female harvested white-tailed deer in the Appalachians Mountains of western Virginia. We found land cover diversity index positively and black bear (<i> Ursus americanus </i>) detection rate negatively influenced recruitment. Age also predicted lactation status with middle-aged females (3.5–4.5 years old) having a higher lactation probability than mature (≥5.5 years old) age and young (2.5 years old) age class deer. Based on these findings, recruitment is likely to be greater in areas that have a mixture of land cover types. Therefore, if an increase in recruitment is desired silvicultural practices such as fire and timber harvest could be used to permanently change land cover types. These silvicultural practices could also be used to increase the number of oaks on the landscape, and augment production of mature oaks as red oak mast abundance influenced fawn survival. Also reducing predation by manipulating predator densities could improve recruitment. Overall, we found diversity of land cover types, food availability, predators, and age influences population dynamics of white-tailed deer.

Made available in DSpace on 2016-06-02T19:29:34Z (GMT). No. of bitstreams: 1 3657.pdf: 23563912 bytes, checksum: ceff0481d51dd5b9b20c1cb8cfdfe91f (MD5) Previous issue date: 2011-02-28 / Universidade Federal de Minas Gerais / The human activities are continually altering the ecosystems constituting an important environmental modifier agent, promoting changes in balance and dynamics of the landscape pattern and process. There are several examples of this interference, however the understanding of dimension and effects of human activities and the measures to aid in decision make are still incipient. In that sense, the watershed basin has been used as a physical-temporal component for natural resources planning, being supported by the use of landscape indicators, that has been proposed for better understanding the human activity influence in the ecosystems dynamics. This work analyzed the physical, socioeconomic and biotic factors interaction, in the integrity of the landscape, in the context of the watershed basin through indicators, between 1989 and 2009. The study area was the Medium-Superior Mogi-Guacu river watershed basin, inserted in the northeast area of the State of Sao Paulo, Brazil. This area was sub-divided in three geomorphological units (Cuestas Basalticas, Depressao Periferica and Planalto Ocidental) and in 12 geopolitical units, referring the municipal districts of its inclusion. It was proceeded the landscape environmental characterization and the use of the following indicators: topographical characteristics; landscape pattern; landscape structure (Landscape richness, Landscape diversity; Landscape naturalness (Urbanity and Hemeroby); landscape fragmentation, and the Index of Human Appropriation of the Liquid Primary Productivity (HANPP), considering the total area of the watershed basin (UGB), the geopolitical units (UGP) and thegeomorphological units (UGM). The data acquisition happened for field risings, bibliographical and of official documental sources. It was used LANDSAT TM-5 1989, 1999 and 2009 satellite images for land-use mapping, that subsidized the analysis of the landscape indicators, following specific literature. The correlation among the indicators was tested by models of linear regression and validated by Bootstrap method. It was observed a positive relation between HANPP and hemeroby; a weak positive relation between HANPP and urbanity and HANPP and steepness; a tiny positive relation between HANPP and slope orientation; a weak negative relation between HANPP and net road influence, and between HANPP and distance from highways; and tiny positive relation between HANPP and distance of urban settlements. The smallest values of HANPP were obtained in 1999 for all the landscape units. The landscape metric didn't show a significant correlation with HANPP, however, flotation of the values is verified among the years and between the units. For 1999 and for UGP-7 (municipal district of Luis Antonio) and UGP-11 (Santa Rita do Passa Quatro) registered the metric values that allow to infer better. / Padrão espacial e temporal das mudanças de uso da terra e sua relação com indicadores da paisagem. Estudo de Caso: Bacia Hidrográfica do Médio rio Mogi-Guaçu Superior (SP). O ser humano esta continuamente alterando os ecossistemas, constituindo de um relevante agente modificador do meio, promovendo mudancas no equilibrio e dinamica dos processos naturais. Diversos sao os exemplos desta interferencia, entretanto a compreensao da dimensao e dos efeitos das atividades humanas e as medidas para auxiliar na tomada de decisao ainda sao incipientes. Nesse sentido, a bacia hidrografica tem sido utilizada como um componente fisico-temporal para o planejamento e o gerenciamento dos recursos naturais, sendo auxiliada pelo uso de indicadores, que tem sido proposto para melhor compreensao da influencia antropica na dinamica dos ecossistemas. O presente trabalho analisou a interacao dos fatores fisico, socio-economicos e bioticos na integridade da paisagem, no contexto de bacia hidrografica por meio de indicadores, entre 1989 e 2009. A area de estudo compreende a Bacia Hidrografica do Medio Rio Mogi-Guacu Superior, inserida na regiao nordeste do Estado de Sao Paulo, Brasil e foi sub-dividida em tres unidades geomorfologicas (Cuestas Basalticas, Depressao Periferica e Planalto Ocidental) e em 12 unidades geopoliticas, referentes aos municipios de sua abrangencia. Procedeu-se a caracterizacao da paisagem e a geracao dos indicadores: de caracteristicas topograficas (Altimetria, Declividade, Orientacao de Vertentes), do padrao da paisagem (Numero de Fragmentos, Indice de Similaridade, Indice de Forma, Circulo Circunscrito Relacionado, Distancia Euclidiana do Vizinho mais Proximo, Indice de Area de Interior, Indice de Contraste de Borda), da estrutura da paisagem (Riqueza da Paisagem, Diversidade da Paisagem e Indice de Urbanidade), da fragmentacao (Influencia da Malha viaria, Proximidade de Rodovias, Proximidade de Estradas, Distancia de Areas Urbanas) e Indice de Apropriacao Humana da Produtividade Primaria Liquida (HANPP), considerando a area total da bacia hidrografica (UGB), as unidades geopoliticas (UGP) e as unidades geomorfologicas (UGM). A aquisicao de dados ocorreu por levantamentos de campo, bibliograficos e de fontes documentais oficiais. Utilizaram-se as imagens de satelite LANDSAT TM-5 de 1989, 1999 e 2009 para o mapeamento de uso e ocupacao da terra, que subsidiaram a analise dos indicadores, seguindo literatura especifica. A correlacao entre os indicadores foi testada por modelos de regressao linear e validados pelo metodo de reamostragem Bootstrap.Verificou-se que correlacao moderada positiva entre HANPP e hemerobia, fraca positiva entre HANPP e urbanidade e HANPP e declividade; infima positiva entre HANPP e orientacao de vertentes; fraca negativa entre HANPP e influencia da malha viaria e entre HANPP e distancia de estradas e de rodovias; e infima positiva entre HANPP e distancia de manchas urbanas. Os menores valores de HANPP foram obtidos em 1999 para todas as unidades de gerenciamento. As metricas da paisagem nao apresentaram correlacao significativa com HANPP, entretanto, verifica-se flutuacao dos valores entre os anos e entre as unidades, sendo que 1999 e as UGP- 7 (municipio de Luis Antonio) e UGP-11 (Santa Rita do Passa Quatro) registraram as metricas com valores que permitem inferir melhores condicoes para a conservacao da biodiversidade. Nessas unidades estao as duas unidades de conservacao de protecao integral da bacia hidrografica do Medio Rio Mogi-Guacu Superior. Como os indicadores utilizados neste trabalho mensuram principalmente a condicao das manchas e como estao espacializadas e a HANPP e eficaz na quantificacao da intervencao na paisagem como um todo, este estudo pode auxiliar na definicao dos fatores que podem interferir ou priorizar a ocupacao da terra, principalmente quando se destina a praticas agricolas.

Mettre en place des stratégies de lutte contre les ravageurs, indépendantes des produits chimiques est un objectif fondamental pour une protection durable des cultures contre les ravageurs et la conservation d’un environnement sain pour les populations humaines en zone rurale. L’objectif principal de ce travail était de contribuer à la mise en place d’une lutte biologique par gestion des habitats à l’échelle du paysage de la noctuelle polyphage Helicoverpa armigera, principal ravageur de cotonnier dans le nord Bénin. Cette thèse visait à analyser l’influence des pratiques agricoles et de l’organisation du paysage sur l’abondance et l’origine trophique de H. armigera. L’analyse biochimique d’individus élevés en laboratoire, nous a permis de confirmer le fait que le gossypol est un bon marqueur pour identifier les adultes qui ont passé leur vie larvaire sur le cotonnier. Au contraire de la tomatine qui ne peut être considérée comme un marqueur de la tomate car la tomatine a été détectée seulement chez les larves d’H. armigera et non chez les adultes. Notre étude sur le terrain au nord Bénin dans 40 parcelles, a montré que les pratiques agricoles avaient un fort effet sur l’infestation larvaire. La date de semis et la fréquence de sarclage étaient négativement corrélées à l’infestation larvaire. La proportion de cotonniers dans le paysage et celle de tomate ont influencé positivement l’infestation en larves d’H. armigera. Nous avons également montré qu’un précédent cultural tomate présentait une abondance larvaire en moyenne trois fois supérieur à un précédent cultural maïs. Ensuite, dans des rayons de 100 m, 250 m et 500 m, nous avons étudié les effets de la composition et de l’hétérogénéité du paysage d’une part sur l’abondance des adultes d’H. armigera et d’autre part sur leur origine trophique. L’hétérogénéité du paysage en plantes hôtes est le facteur paysager principal qui a influencé positivement l’abondance des adultes. Les isotopes stables de Carbone nous ont permis d’identifier les individus dont la larve s’était nourrie sur des plantes de type photosynthétique C3 (cotonniers, tomates, ...) ou C4 (maïs, sorgho, …). L’origine trophique, plantes hôtes C3 ou C4, est reliée positivement à la proportion de plantes hôtes respectivement C3 ou C4 dans un rayon de 500m. Seulement 10% des individus ayant consommés des plantes en C3 ont été détecté positif au gossypol. La proportion de cotonniers dans le paysage ne semble pas expliquer la proportion d’individus détectés positif au gossypol. Nous formulons des propositions de gestion de l’assolement et des rotations culturales pour contribuer à la régulation d’H. armigera. Ainsi, il faudrait éviter que le cotonnier soit semé sur un précédent cultural tomate. Il serait important de décaler les dates de semis entre les parcelles de cotonniers voisines et de respecter la fréquence de sarclage minimale qui est de trois. Par ailleurs, il serait judicieux de préférer un environnement paysager homogène autour d’une parcelle de cotonnier, en privilégiant par exemple, le maïs. / The development of strategies independent of pesticides is a fundamental objective for sustainable crop protection against pests as well as for maintaining of a healthy environment for human populations. The rationale of the research presented here was to improve our ability to control the cotton bollworm, Helicoverpa armigera by non-pesticide methods via habitat conservation. We analyzed the influence of agricultural practices and landscape composition and diversity on the abundance and trophic origin of H. armigera and assessed gossypol and tomatine in individual H. armigera as cotton and tomato biomarkers respectively. Gossypol was shown to be a stable cotton biomarker, even in adult H. armigera 12 days after emergence. In contrast, tomatine was only detected in larvae of H. armigera and not adults; thereby tomatine can not be considered as a marker of tomato plants. Subsequently, in north Benin, the abundance of H. armigera larvae and adults was monitored in cotton fields. We found a strong effect of agricultural practices on H. armigera larvae abundance. Delay sowing date and increase frequency of weeding reduced the abundance of H. armigera in cotton fields; whereas the proportion of cotton and tomato in the landscape increased. This study also highlights the role of the previous landcover in the infestation of a cotton field: A previous tomato landcover increased infestation three times more than a previous maize landcover. At nested scales ranging from 100 m, 250 m to 500 m, we studied the effects of landscape composition and diversity firstly on the abundance of adult H. armigera and secondly on their trophic origin. We found that, landscape diversity was the main factor that influenced both the abundance adult and their trophic origin at 500 m scale. Analyses of stables isotopes of Carbone showed that proportion of hosts plants with C3 photosynthetic pathway in the landscape was positively related to H. armigera moths with C3 trophic origin signal at 500 m scale. Only 10% of moths were positive to gossypol signal. The proportion of cotton in the landscape seems not important to explain the trophic origin of individual which were positive to gossypol signal. Therefore, for integrated management of H. armigera our results suggest it is necessary to consider the following agricultural practices and crop diversity regimes (in regard to the resource use strategies of this polyphagous pest). A tomato previous landcover should be avoid; shift sowing date between cotton fields, and have at less three manual weedings. In additional, we suggest employing maize around cotton fields rather than other crops.

Nachdem sich die Diskussion um die biologische Vielfalt bisher hauptsächlich um die floristische und faunistische Artenvielfalt drehte, rückt in den letzten Jahren die Landschaft verstärkt in das Blickfeld. So empfahl der Sachverständigenrat für Umweltfragen der Bundesrepublik in seinem Gutachten 1994 eine flächendeckende Ermittlung und Bewertung kritischer struktureller Veränderungen der Landschaft. Die Sachverständigen sehen das Ausmaß der Eingriffe in die Nutzungsstruktur der Kulturlandschaft sowie den Grad der Verdrängung naturnaher bzw. naturverträglicher Nutzungsformen und weitgehend vom Menschen unbeeinflußter Gebiete als wesentliches Kriterium für die Bewertung von Landschaften. Der Beitrag stellt die Methodik der Analyse und Beschreibung von Landschaften mit Indikatoren zur Landschaftsstruktur in den Vordergrund. Neben der Suche und Auswahl geeigneter Parameter bzw. Indizes, brauchbarer Datenquellen und den technischen Problemen der Software spielen zunehmend anwendungsorientierte Fragen eine große Rolle.

During last century rising populations and changed market preferences have led to large structuralchanges in agriculture in the developed world. Most conventional cultivation methods involve theproduction of few monoculture crops within a homogenous landscape, where pesticides and inorganicfertilizers are used to increase yields. The cereal aphid Rhopalosiphum padi (L.) is a pest in cerealsresulting in large economic losses for farmers throughout Europe, and are currently removed withchemical pest control. However, the pesticides also affect existing ecosystem services like potentiallypest-controlling insects as well as the surrounding environment negatively. According to previousstudies higher landscape diversity leads to a higher diversity of natural enemies to pest insects, but nostudy has investigated if the pest control is enhanced around non-crop remnants such as midfield islets(MI). This thesis investigates (i) if MI will reduce the number of aphids in crop field, (ii) if larger MIwill be more effective than smaller MI by having higher aphid predation rate, and (iii) if larger MI willprovide a more effective reduction of pest insects over a longer distance from edge. To assess thepotential for pest control, aphids were glued on papers and placed at ground level in crop fields andaround MI in nine fields. The collected data was processed statistically, and the result demonstratesthat MI play an important role by providing habitats for natural enemies to pests. The increased size ofMI have a positive effect of number of aphids consumed around MI, however the distance from edgewas not significance. This study highlights the value of MI in crop fields as an existing ecosystemservice in biological pest control. The naturally occurring predators are able to reduce R.padi andthereby minimize the need for insecticide applications. / Ökat befolkningstryck och större efterfrågan av jordbruksprodukter på marknaden har det senasteseklet lett till stora förändringar i västvärldens jordbrukslandskap. Odlingslandskapet är idaghomogent och monokulturellt där besprutningsmedel används för att ge större avkastning iproduktionen. Skadeinsekten havrebladlus (Rhopalosiphum padi) angriper vårgrödor vilket leder tillstora ekonomiska förluster för bönder runtom i Europa. Pesticider används för att reducera angreppenmen påverkar även miljön negativt samt existerande ekosystemtjänster, såsom naturliga fiender sombiologiskt kan begränsa skadeinsekters angrepp. Tidigare studier visar att heterogena landskap har enhög biologisk mångfald, men ingen studie har undersökt åkerholmars (ÅH) eventuella potential förbiologisk bekämpning av skadeinsekter i säd. Denna studie undersöker därför (i) om ÅH leder tillökad reducering av havrebladlöss i säd, (ii) om större ÅH är mer effektiva än mindre i frågan ompestreducering, samt (iii) om större ÅH begränsar lusangrepp längre ut i fält från ÅH:s kant än mindreholmar. Studiens hypoteser testades genom experiment utförda i nio fält med vårgrödor där lössklistrades på etiketter som placerades ut i omgivande fält. Dessa samlades in efter tjugo fyra timmarför att studera antal löss konsumerade i relation till ÅH. Det insamlade materialet är bearbetatstatistiskt och resultatet visar att ÅH spelar en betydande ekologisk roll för naturliga fiender tillskadeinsekten havrebladlus. Fler löss konsumerades runt större ÅH än de med mindre yta eller i de fältutan ÅH. Däremot har avståndet från ÅH en mindre betydelse, vilket indikerar att pestreduceringen ärmest effektiv nära stora ÅH. Denna studie synliggör värdet av existerande ÅH som inhysernyttoinsekter i jordbrukslandskapet, samt att heterogena landskap har högre potential för en mernaturlig skadedjursbekämpning. Naturliga fiender är därmed en existerande ekosystemtjänst som kanbegränsa bladlusangreppen (R.padi), som i sin tur ger möjligheten att reducera användandet avbekämpningsmedel, vilket för oss närmare miljömålet ”en giftfri miljö”.