Ioannis N. Vogiatzakis
Open University of Cyprus
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Featured researches published by Ioannis N. Vogiatzakis.
Plant Ecology | 2006
Ioannis N. Vogiatzakis; Geoffrey H. Griffiths
The aim of the study was to establish and verify a predictive vegetation model for plant community distribution in the alti-Mediterranean zone of the Lefka Ori massif, western Crete. Based on previous work three variables were identified as significant determinants of plant community distribution, namely altitude, slope angle and geomorphic landform. The response of four community types against these variables was tested using classification trees analysis in order to model community type occurrence. V-fold cross-validation plots were used to determine the length of the best fitting tree. The final 9node tree selected, classified correctly 92.5% of the samples. The results were used to provide decision rules for the construction of a spatial model for each community type. The model was implemented within a Geographical Information System (GIS) to predict the distribution of each community type in the study site. The evaluation of the model in the field using an error matrix gave an overall accuracy of 71%. The user’s accuracy was higher for the Crepis–Cirsium (100%) and Telephium–Herniaria community type (66.7%) and relatively lower for the Peucedanum–Alyssum and Dianthus–Lomelosia community types (63.2% and 62.5%, respectively). Misclassification and field validation points to the need for improved geomorphological mapping and suggests the presence of transitional communities between existing community types.
Hydrobiologia | 2009
Ioannis N. Vogiatzakis; George Kazakis; Dany Ghosn
The aims of this study were to explore the environmental factors that determine the distribution of plant communities in temporary rock pools and provide a quantitative analysis of vegetation–environment relationships for five study sites on the island of Gavdos, southwest of Crete, Greece. Data from 99 rock pools were collected and analysed using Two-Way Indicator Species Analysis (TWINSPAN), Detrended Correspondence Analysis (DCA) and Canonical Correspondence Analysis (CCA) to identify the principal communities and environmental gradients that are linked to community distribution. A total of 46 species belonging to 21 families were recorded within the study area. The dominant families were Labiatae, Gramineae and Compositae while therophytes and chamaephytes were the most frequent life forms. The samples were classified into six community types using TWINSPAN, which were also corroborated by CCA analysis. The principal gradients for vegetation distribution, identified by CCA, were associated with water storage and water retention ability, as expressed by pool perimeter and water depth. Generalised Additive Models (GAMs) were employed to identify responses of four dominant rock pool species to water depth. The resulting species response curves showed niche differentiation in the cases of Callitrichepulchra and Tillaeavaillantii and revealed competition between Zannichellia pedunculata and Charavulgaris. The use of classification in combination with ordination techniques resulted in a good discrimination between plant communities. Generalised Additive Models are a powerful tool in investigating species response curves to environmental gradients. The methodology adopted can be employed for improving baseline information on plant community ecology and distribution in Mediterranean ephemeral pools.
Ecological Informatics | 2015
Marianna Louca; Ioannis N. Vogiatzakis; Aristides Moustakas
Two endemic plant species in the Mediterranean island of Cyprus, Crocus cyprius and Ophrys kotschyi, were used as a case study. We have coupled climate change scenarios, and land use change models with species distribution models. Future land use scenarios were modelled by initially calculating the rate of current land use changes between two time snapshots (2000 and 2006) on the island, and based on these transition probabilities markov-chain cellular automata were used to generate future land use changes for 2050. Climate change scenarios A1B, A2, B1 and B2A were derived from the IPCC reports. Species climatic preferences were derived from their current distributions using classification trees while habitats preferences were derived from the Red Data Book of the Flora of Cyprus. A bioclimatic model for Crocus cyprius was built using mean temperature of wettest quarter, max temperature of warmest month and precipitation seasonality, while for Ophrys kotchyi the bioclimatic model was built using precipitation of wettest month, mean temperature of warmest quarter, isothermality, precipitation of coldest quarter, and annual precipitation. Sequentially, simulation scenarios were performed regarding future species distributions by accounting climate alone and both climate and land use changes. The distribution of the two species resulting from the bioclimatic models was then filtered by future land use changes, providing the species projected potential distribution. The species projected potential distribution varies depending on the type and scenario used, but many of both species current sites/locations are projected to be outside their future potential distribution. Our results demonstrate the importance of including both land use and climatic changes in predictive species modeling.
Environmental Conservation | 2015
Ioannis N. Vogiatzakis; Maria Teresa Stirpe; S. Rickebusch; Marc J. Metzger; Guangcai Xu; Mark Rounsevell; Riccardo Bommarco; Simon G. Potts
SUMMARY 11 Changes in landscape composition and structure may 12 impacttheconservationandmanagementofprotected 13 areas. Species that depend on specific habitats are at 14 risk of extinction when these habitats are degraded or 15 lost. Designing robust methods to evaluate landscape 16 composition will assist decision- and policy-making 17 in emerging landscapes. This paper describes a rapid 18 assessment methodology aimed at evaluating land19 cover quality for birds, plants, butterflies and bees 20 around seven UK Natura 2000 sites. An expert panel 21 assigned quality values to standard Coordination of 22
Biodiversity and Conservation | 2016
Ioannis N. Vogiatzakis; A. M. Mannion; D. Sarris
Abstract Mediterranean islands (MI) are hotspots of global biodiversity and lie in one of the most susceptible to climate change (CC) areas of the world; a big challenge for any conservation strategy. In fact, there is already increasing evidence for CC in the region and associated biological responses in MI ecosystems. These include phenological changes and upward elevation shifts of species and plant communities; although evidence is frequently contrasting for different taxa. Threats are also evident, mainly for endemic species from most taxonomic groups, while communities in mountain and coastal regions are likely to be affected most. For MI conservation under CC additional factors need to be considered: (i) their position at the crossroads of three continents; with which they share common environmental characteristics, (ii) their great variability in sizes and topography and (iii) their climatic differences; with a clear west-east basin divide. CC synergies with changing tourist aspiration and agricultural practices will, in the medium term, modify island landscapes and provide further challenges for biodiversity conservation. Such a combined impact from CC, land-use change, fragmentation of habitats and tourism is difficult to predict. Furthermore, the limited space on islands (especially habitat availability and climatic range limitations) imposes a barrier to species range expansion. Thus, conservation of MI biodiversity under CC requires: (i) future research to focus on improved climate predictions linked to improved understanding of ecological (climate-biotic) responses, incorporating lessons learnt from (island) biogeography, (ii) specific adaptation measures for spatial planning and improvement in regional institutional capacities.
Journal of Landscape Ecology | 2014
Maria Zomeni; Ioannis N. Vogiatzakis
Abstract The road network in Cyprus has seen an 88% increase in the last 20 years. This expansion has not been followed by any kind of assessment on the effects of the network on nature conservation. This is the first island-wide quantitative assessment of the size, character (surface types), pervasiveness and distribution of the road system with particular reference to Natura 2000 network on the island. We mapped roadless areas (i.e. areas at least one km away from nearest road) for the whole island and examined the spatial distribution with respect to Natura 2000. We tested the relationship between overall road density and road density of different road categories within terrestrial Natura 2000 sites to four zones which were defined on the basis of landform, principal land use and ownership. We employed three indices i.e. effective mesh size, splitting and division to measure fragmentation caused by the road network within Natura 2000 and investigated the relationship between road density and the above fragmentation metrics. Mean road density in Cyprus is 2.3 km/km2 which is comparable to road density values recorded in other Mediterranean countries such as France, Spain and Italy, which have much larger area and population. Roadless areas cover 4.5% of the island, and despite being scattered 80% is found within Natura 2000, which demonstrates the added value of the network for nature conservation. Road expansion has taken place throughout the island with the same intensity irrespectively of the zones examined. Fragmentation has been lower in sites on mountainous areas where sites are larger and under state ownership. Road density is negatively correlated (r = - 0.383, p = 0.05) with effective mesh size and positively correlated with both landscape division (r = 0.376, p = 0.05) and splitting index (r = 0.376, p = 0.05). Results corroborate that spatial configuration is an important property of the road network in addition to traffic load, length and density.With the shift from site based conservation to landscape level there is a challenge for integrating technical, human and ecological requirements into infrastructure planning.
First International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2013) | 2013
N. P. Symons; Ioannis N. Vogiatzakis; Geoffrey H. Griffiths; S. Warnock; V. Vassou; Maria Zomeni; V. Trigkas
The development of Landscape Typologies in Europe relies upon advances in geospatial tools and increasing availability of digital datasets. Landscape Character Assessment (LCA) is a technique used to classify, describe and understand the combined physical, ecological and cultural characteristics of a landscape. LCA uses a range of data sources to identify and describe areas of common character and can operate at a range of scales i.e.national and regional and local. The paper describes the steps taken to develop an island wide landscape typology for Cyprus, based on the use of GIS and remote sensing tools. The methodology involved integrating physiographical, ecological and cultural information about the Cypriot landscape. Datasets on the cultural attributes (e.g. settlement and field patterns) were not available, so they were created de novo based on information from topographical maps (for settlement dispersion and density) and medium resolution satellite imagery from Google Earth, from which a number of distinctive field patterns could be distinguished. The mapping work is carried out on two levels using a hierarchical approach. The first level at a 1:100, 000 scale has been completed resulting in a map with 17 distinct landscape types. The second level is under way with the view of producing a more detailed landscape typology at 1:50, 000 scale which will incorporate the cultural aspects of the island. This is the first time that such a typology has been produced for Cyprus and it is expected to provide an invaluable tool for landscape planning and management.
Archive | 2003
Ioannis N. Vogiatzakis; A. Malounis; Geoffrey H. Griffiths
The need to map vegetation communities over large areas for nature conservation and to predict the impact of environmental change on vegetation distributions, has stimulated the development of techniques for predictive vegetation mapping. Predictive vegetation studies start with the development of a model relating vegetation units and mapped physical data, followed by the application of that model to a geographic database and over a wide range of spatial scales. This field is particularly important for identifying sites for rare and endangered species and locations of high biodiversity such as many areas of the Mediterranean Basin. The potential of the approach is illustrated with a mapping exercise in the alti-meditterranean zone of Lefka Ori in Crete. The study established the nature of the relationship between vegetation communities and physical data including altitude, slope and geomorphology. In this way the knowledge of community distribution was improved enabling a GIS-based model capable of predicting community distribution to be constructed. The paper describes the development of the spatial model and the methodological problems of predictive mapping for monitoring Mediterranean ecosystems. The paper concludes with a discussion of the role of predictive vegetation mapping and other spatial techniques, such as fuzzy mapping and geostatistics, for improving our understanding of the dynamics of Mediterranean ecosystems and for practical management in a region that is under increasing pressure from human impact.
Frontiers in Ecology and Evolution | 2017
Alexander Bjarnason; Stelios Katsanevakis; Alexandros Galanidis; Ioannis N. Vogiatzakis; Aristides Moustakas
Invasive alien species cause major changes to ecosystem functioning and patterns of biodiversity, and the main factors involved in invasion success remain contested. Using the Mediterranean island of Crete as a case study, we present a framework for analyzing spatial data of alien species distributions, based on environmental predictors, aiming to gain an understanding of their spatial patterns and spread. Mediterranean islands are under strong ecological pressure from invading species due to their restricted size and increased human impact. Four hypotheses of invasibility, the ‘propagule pressure hypothesis’ (H1), ‘biotic resistance hypothesis vs. acceptance hypothesis’ (H2), ‘disturbance-mediated hypothesis’ (H3), and ‘environmental heterogeneity hypothesis’ (H4) were tested. Using data from alien, native, and endemic vascular plant species, the propagule pressure, biotic resistance versus acceptance, disturbance-mediated, and environmental heterogeneity hypotheses were tested with Generalized Additive Modelling (GAM) of 39 models. Based on model selection, the optimal model includes the positive covariates of native species richness, the negative covariates of endemic species richness, and land area. Variance partitioning between the four hypotheses indicated that the biotic resistance versus acceptance hypothesis explained the vast majority of the total variance. These results show that areas of high species richness have greater invasibility and support the acceptance hypothesis and “rich-get-richer” distribution of alien species. The negative correlation between alien and endemic species appears to be predominantly driven by altitude, with fewer alien and more endemic species at greater altitudes, and habitat richness. The negative relationship between alien and endemic species richness provides potential for understanding patterns of endemic and alien species on islands, contributing to more effective conservation strategies.
Landscape Ecology | 2008
Ioannis N. Vogiatzakis
Early on in the 1970s IUCN recognized that effective conservation could not be achieved by focusing on traditional eco-centric approaches alone and that it was necessary to involve humans and cultural landscapes. Subsequently to that many conventions brought landscapes to the worldwide political agenda with the fairly recent example of the European Landscape Convention. Each of these emphasizes the need for protection of the natural and cultural landscapes of an area as a whole and recognises that landscape scale approaches are fundamental to the understanding not just of past and present ecosystem patterns and processes but also cultural ones. This is an idea that was promoted by the author of this book very early in the foundation of landscape ecology where landscape was seen as the fabric that integrates nature and culture. This book encompasses Zev Naveh’s work of 40 years (1967–2007) in the fields of landscape and restoration ecology presented in a collection of papers published so far in scientific journal or books. The topics covered herein are of great breadth ranging from applied ecology and conservation such as fire, vegetation and habitat management to eloquent philosophical debates regarding the reconciliation of society and nature and the future of the discipline. As such, it illustrates well-adopted concepts such as holism and the multifunctionality of landscapes but also initiatives such as the Green Books for Threatened Landscapes that unfortunately was never widely adopted. The book starts with a review of the chapters by the author with the inclusion of some autobiographical comments and is further divided in three parts: