Analysis and design of multifunctional agricultural landscapes : a graph theoretic approach

This thesis deals with the development of quantitative methodologies for the evaluation of landscape functions and their interactions in multifunctional agricultural landscapes. It focuses on the spatial coherence of hedgerow networks for ecological functions and landscape character for perception of landscape identity, and on their integration in a multifunctional and multiscale trade-off analysis. Graph theory provided the basis for new methodologies that are applied in this research

The impact of FSC certification on timber tree regeneration and floristic composition in Honduran community forests

Forest certification has been put forward as a means to improve the sustainability of forest management in the tropical countries, where traditional environmental regulation has been inefficient in controlling forest degradation and deforestation. In these countries, the role of communities as managers of the forest resources is rapidly increasing. However, only a fraction of tropical community forests have been certified and little is known about the impacts of certification in these systems. Two areas in Honduras where community-managed forest operations had received FSC certifications were studied. Río Cangrejal represents an area with a longer history of use, whereas Copén is a more recent forest operation. Ecological sustainability was assessed through comparing timber tree regeneration and floristic composition between certified, conventionally managed and natural forests. Data on woody vegetation and environmental conditions was collected within logging gaps and natural treefall gaps. The regeneration success of shade-tolerant timber tree species was lower in certified than in conventionally managed forests in Río Cangrejal. Furthermore, the floristic composition was more natural-like in the conventionally managed than the certified forests. However, the environmental conditions indicated reduced logging disturbance in the certified forests. Data from Copén demonstrated that the regeneration success of light-demanding timber species was higher in the certified than the unlogged forests. In spite of this, the most valuable timber species Swietenia macrophylla was not regenerating successfully in the certified forests, due to rapid gap closure. The results indicate that pre-certification loggings and forest fragmentation may have a stronger impact on forest regeneration than current, certified management practices. The focus in community forests under low-intensive logging should be directed toward landscape connectivity and the restoration of degraded timber species, instead of reducing mechanical logging damage. Such actions are dependent on better recognition of resource rights, and improving the status of small Southern producers in the markets of certified wood products.Metsäsertifiointia on pidetty lupaavana keinona hillitä metsien tuhoutumista tropiikissa. Paikallisilla yhteisöillä on omistus- tai käyttöoikeus yhä suurempaan osaan tropiikin metsiä, mutta näistä yhteisömetsistä on toistaiseksi sertifioitu vain murto-osa. Tässä tutkimuksessa tarkasteltiin FSC-metsäsertifioinnin vaikutuksia hakkuiden ekologiseen kestävyyteen Hondurasin yhteisömetsissä. Ekologista kestävyyttä arvioitiin arvopuiden uusiutumismenestyksen ja lajiston luonnontilaisuuden kautta. Kasvillisuus- ja ympäristöoloja mitattiin sertifioitujen, perinteisellä tavalla hoidettujen ja luonnonmetsien puunkaatuma-aukoissa. Oletusten vastaisesti varjoa sietävien arvopuulajien uusiutumismenestys oli heikompaa sertifioiduissa kuin perinteisellä tavalla hoidetuissa metsissä. Perinteisesti hoidettujen metsien hakkuuaukkojen lajisto oli myös enemmän luonnontilaisen lajiston kaltaista, mikä viittaa siihen, että sertifioinnilla ei ole onnistuttu parantamaan hakkuiden kestävyyttä. Ympäristömuuttujien tarkastelu kuitenkin osoitti, että hakkuuhäiriötä oli vähemmän sertifioiduissa metsissä. Valoa vaativat arvopuulajit uusiutuivat oletusten mukaisesti paremmin sertifioiduissa kuin hakkaamattomissa metsissä. Pienissä hakkuuaukoissa ei kuitenkaan välttämättä ole tarpeeksi valoa arvokkaimman puulajin, mahongin (Swietenia macrophylla) uusiutumiselle. Tulosten perusteella metsien aiempi kestämätön käyttö ja pirstaloituneisuus saattavat vaikuttaa metsän uusiutumiseen enemmän kuin vähäintensiiviset sertifioidut hakkuut. Metsikkötason mekaanisen hakkuuhäiriön vähentämisen sijaan yhteisömetsien sertifioinneissa tulisi kiinnittää enemmän huomiota maisematason yhteyksiin metsien välillä ja loppuun hakattujen puulajien palauttamiseen. Tällaisten toimenpiteiden toteuttaminen on sidoksissa metsistä saatavaan toimeentuloon ja metsien omistusoikeuksiin. Kestävyyden parantaminen onnistuu vain, jos yhteisömetsätuottajien asemaa ja kilpailukykyä sertifioitujen tuotteiden markkinoilla pystytään parantamaan

Risk assessment on the possible introduction of three predatory snails (Ocinebrellus inornatus, Urosalpinx cinerea, Rapana venosa in the Dutch Wadden Sea

Recently three alien invasive predatory snails have been found in the Dutch marine waters, which are identified by the Ministry of Agriculture, Nature and Food Quality as potential high risk species due to their possible impact on bivalve species (TRCPD/2009/3587). These are: Japanese oyster drill Ocinebrellus inornatus (syn: Ceratostoma inornatum, Ocenebra japonica), American oyster drill Urosalpinx cinerea and Asian rapa whelk Rapana venosa. In this report we describe the potential ecological and economical risks of introduction of the three alien invasive predatory snails in the Nature 2000 Wadden Sea area

Annual Report of Undergraduate Research Fellows, August 2013 to May 2014

Annual Report of Undergraduate Research Fellows from August 2013 to May 2014

Metapopulation Genomics of American Goshawks in the Intermountain West

Understanding a species dispersal ecology and population dynamics is essential to effectively manage and conserve a species. As advancing technology improves our knowledge of species movements, it is becoming clear that many species form metapopulations to some extent. A metapopulation is a network of interconnected subpopulations that exchange reproductive individuals with subpopulations occupying nearby patches. Metapopulations have been observed in a variety of species, ranging from plants to vertebrates, and can vary greatly in their dynamics (level of connectivity and gene flow) based on the species behavior and life history strategy. Forming a metapopulation can add much resilience to the subpopulation. A steady inflow of new individuals can protect the subpopulation from inbreeding depression and adds more standing variation for natural selection to work on. However, as the metapopulation breaks down and patches become isolated, that resilience is quickly lost. Habitat fragmentation due to anthropogenic changes poses a significant danger to metapopulations. Understanding these metapopulation dynamics is of key importance to formulating effective and efficient conservation and management plans. Information such as where, when, and how these species are dispersing can tell us how to best preserve these paths and maintain the metapopulation structure. One species that forms a highly extensive metapopulation, is the American goshawk (Accipiter atricapillus). In this study we evaluated the metapopulation genomics of American goshawks in the Intermountain West by investigating the genetic diversity and differentiation, as well as gene flow and connectivity, of four subpopulations. The goshawk metapopulation is connected mainly through the natal dispersal of juveniles. Natal dispersal has been and continues to be very hard to track due the technological limitations. Here we show that genomics can offer an alternative when species cannot be easily tracked. While specific dispersal routes cannot be elucidated, we were able to discover the level and direction of gene flow between subpopulations, giving a rough idea of where and how far individuals were dispersing. We found little to no differentiation and very high gene flow between these subpopulations despite the hundreds of kilometers between them. There was no geographic structuring shown both by an isolation by distance test and a correlation test between geographic distances and the estimated number of migrants exchanged. This information is vital to understanding the species movements and ecology in order to create an effective management plan

Ice-movement history and kimberlite indicator mineral dispersal study, Pelly Bay, lower Boothia Peninsula, and Wager Plateau areas, Nunavut, Canada

This study reconstructs the ice flow history of the eastern portion of the Keewatin sector of the Laurentide Ice Sheet by integrating field work, remote imagery, and work by others. The study reveals at least seven ice flow phases during the Wisconsinan, including ice streams. A model was developed using inverse distance weighed (IDW) interpolation with GIS to identify and isolate potential kimberlite bedrock sources in kimberlite indicator mineral-rich areas in the Pelly Bay area, Nunavut. Kimberlite indicator mineral (KIM) data were normalized by “peer size” to better understand how KIM grains from three kimberlite sources are distributed within three size fractions of till. The IDW method successfully delineated previously unrecognized KIM dispersal trains that were hidden within the KIM-rich areas. The study also revealed that garnets reached their terminal grade at relatively short distances (2500-7500 m) down ice from their kimberlite sources. Mg-ilmenite is the dominant KIM in the area and Mg-ilmenite-rich samples tend to contain Cr-pyrope and orange garnets, with lesser Cr-diopside and chromite. Mg-olivine in these samples ranges from abundant to none. Mg-olivine-rich KIM in till is associated with the Umingmak kimberlites