Is there a solution to the spatial scale mismatch between ecological processes and agricultural management? Céline Pelosi, Jacques Baudry, Michel Goulard, Gerard Balent To cite this version: Céline Pelosi, Jacques Baudry, Michel Goulard, Gerard Balent. Is there a solution to the spatial scale mismatch between ecological processes and agricultural management?. Is What Humans Do Natural? 2010 US-IALE Twenty-fifth Anniversary Symposium, Apr 2010, Athens, United States. hal-01458564 HAL Id: hal-01458564 https://hal.archives-ouvertes.fr/hal-01458564 Submitted on 3 Jun 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. 25th Annual Landscape Ecology Symposium Is What Humans Do Natural? Athens, GA | April 5-9, 2010 AABBSSTTRRAACCTTSS 1. Vertex centrality predicts patch occupancy and dynamics in a directed spatial network Authors: ACEVEDO, Miguel, University of Florida; Robert Fletcher, University of Florida Offered Presentations: Network Theory - Thursday, April 8: 1:40-2:00 - Q Abstract: Landscape connectivity has been identified as one of the most important factors affecting the movement of genes and individuals at different spatial and temporal scales. Graph theory has been recently proposed as an effective way to measure landscape connectivity. We used a graph-theoretic approach to test whether vertex centrality (i.e. connectivity of each patch relative to others in the graph) is able to predict patch occupancy and dynamics in directed spatial network. We described the Lepanthes rupestris orchid metapopulation as a directed graph in which patches (boulders and trees) are represented as vertices while the connection between patches are represented by edges. The dataset includes >900 occupied and unoccupied patches that have been surveyed more than 17 times. Lepanthes rupestris is an endemic orchid to the island of Puerto Rico that lives along rivers in the mountains. It is wind dispersed with an average dispersal distance of 5m. We used wind direction and the average dispersal distance to construct the directed network. We found that two vertex centrality measures, degree and graph strength, significantly predicted patch occupancy and dynamics, and that directed graph descriptions of landscape connectivity provided better explanatory power than undirected ones. While metapopulation theory has long emphasized how patch characteristics influence patch occupancy and dynamics, our application of directed graphs further refines our ability to understand (and predict) the role of patches in a spatially explicit context. Keywords: graph theory, Lepanthes, metapopulations, patch dynamics, spatial networks 3. Impacts of land use change in tropical rainforest ecosystem, Ondo State, Nigeria on forest landscape, rural livelihood and soil properties Authors: ADEKUNLE, Victor, Federal University of Technology, Akure, Nigeria Offered Presentations: Resource Management I - Tuesday, April 6: 2:00-2:20 - K-L Abstract: This study examined the effects of land use change in a tropical rainforest ecosystem on forest landscape, rural livelihood and soil physical, chemical and biological properties. The study was carried out in a Strict Nature Reserve (SNR) and Gmelina arborea and Tectona grandis plantations located in Akure forest reserve. While tree species identification were carried out in randomly located four one-hectare plots in the SRN, composite soil samples were collected from the three different forest types at two depths. The soil samples were taken to the departmental laboratory for analyses. Data were also collected with well-structured questionnaire administered on 50 randomly selected household head in six rural communities around the forest. There are 393 trees/ha, belonging to 72 tropical hardwood species, in 28 families in the SNR, The most abundant species was Pterygota macrocarpa, Sterculiaceae family had the highest number of species. Shannon-Wiener diversity index and evenness are 3.34 and 0.82 respectively. All essential nutrients were present in the soil samples in different proportion with significantly higher values (p<0.05) for SNR. Twenty-three species of bacterial and twelve of fungi were isolated in the SNR. The most occurred bacterial species was Pseudomanas syringage (2.28 x 106) and Clostridium sporogenes had the lowest number of occurrence (0.37 x 106). For fungi, Mamaria echinobotryides had the highest population (0.41 x 102) while Varicoloporium elodeae had the lowest population of 0.02 x 102. Majority of the respondents were male, household heads and breadwinners. Their major occupation is farming and the major source of farmland for crop production is through taungya agroforestry system. There is economical, social, ecological and environmental contributions of the forests to rural dwellers. They are involved in the conservation and maintenance of the SNR and the plantations by cleaning the boundaries and footpaths and guarding the forests. Keywords: forest Reserves, Fungi, nutrient status, Rural livelihood, Strict Nature Reserve 4. Future challenges for US-IALE, Jack Ahern, Chair 1998-2000 Authors: AHERN, Jack, UNIVERSITY OF MASSACHUSETTS Invited Symposium: US-IALE Presidents’ Symposium I - Tuesday, April 6: 11:40-12:00 - Masters Hall Abstract: I became involved with US-IALE explicitly because of its interdisciplinary nature and applications focus. I believe that I was elected as US-IALE Chair to direct planning and programs to strengthen these defining characteristics. During my tenure as chair I worked to expand communications, to engage more academics and professionals from the applications discipliners and professional fields, and to strengthen international collaborations with IALE. Some 10 years later, I see new challenges and opportunities ahead. US-IALE is poised for leadership in the scholarship and practice of sustainability - deriving, in large part from its fundamental focus on landscape pattern:process dynamics. Our empirical and modeling research will continue to build a robust foundation for practitioners to base informed actions and decisions. In a context of increasing uncertainty and dynamics, landscape ecology can help to build the capacity to think – and act – adaptively, promoting learning-by-doing, and safe-to-fail design experiments. The challenge to bring “landscape” theory, methods and knowledge to urban environments, is critical in this century of urbanization. Resilience is increasingly understood as the fourth dimension of sustainability. Under a non-equilibrium view of the world, particularly an urban world, the capacity to recover from disturbance is fundamental to sustainability. Advancing and applying resilience theory to build resilience capacity is, arguably, the fundamental challenge for the global quest for sustainable conditions. Landscape ecology has reached a level of intellectual maturity at which it is prepared for these challenges. Keywords: adaptation, resilience, uncertainty, urbanization 5. Measuring boundary convexity at multiple spatial scales using a linear “moving window” analysis: an application to coastal river otter habitat selection Authors: ALBEKE, Shannon, University of Georgia; Nathan Nibbelink, University of Georgia; Lan Mu, University of Georgia; Daniel Ellsworth, University of Texas Offered Presentations: Technological Innovation - Thursday, April 8: 4:40-5:00 - Q Abstract: Landscape metrics have been used to quantify ecological patterns and to evaluate relationships between animal presence/abundance and habitat at multiple spatial scales. However, many ecological flows occur in linear systems such as streams, or across patch/landscape boundaries (ecotones). Some organisms and flows may depend on the boundary shape, but metrics for defining linear boundary characteristics are scarce. While sinuosity and fractal dimension address some elements of shape, they fail to specify the dominate shape direction (convexity / concavity). We propose a method for measuring boundary convexity (BC) and assess its utility, along with sinuosity and fractal dimension, for predicting site selection by coastal river otters. First, we evaluate the characteristics of BC using a hypothetical boundary. Second, to compare convexity with other linear metrics BC, sinuosity and fractal dimension were calculated for the coastline of a set of islands in Prince William Sound, AK. Finally, we use logistic regression in an information-theoretic framework to assess site selection of river otters as a function of these linear metrics. Boundary convexity, fractal dimension and sinuosity are relatively uncorrelated at all scales. Otter latrine sites occurred at significantly more convex locations on the coastline than random sites. Using logistic regression and convexity values at the 100 meter window-size, 69.5% of the latrine sites were correctly classified. Coastal terrestrial convexity appears to be a promising landscape-scale metric for predicting otter latrine sites. We suggest that boundary convexity may be an important landscape metric for describing species use or ecological flows at ecotones.