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Studying weed spatial distribution patterns and implementing precise herbicide applications requires accurate weed mapping. In this study, a simple unmanned aerial vehicle (UAV) was utilized to survey 11 dry onion (Allium cepa L.) commercial fields to examine late-season weed classification and investigate weeds spatial pattern. In addition, orthomosaics were resampled to a coarser spatial resolution to simulate and examine the accuracy of weed mapping at different altitudes. Overall, 176 weed maps were generated and evaluated. Pixel and object-based image analyses were assessed, employing two supervised classification algorithms: Maximum Likelihood (ML) and Support Vector Machine (SVM). Classification processes resulted in highly accurate weed maps across all spatial resolutions tested. Weed maps contributed to three insights regarding the late-season weed spatial pattern in onion fields: 1) weed coverage varied significantly between fields, ranging from 1 to 79%; 2) weed coverage was similar within and between crop rows; and 3) weed pattern was patchy in all fields. The last finding, combined with the ability to map weeds using a low cost, off-the-shelf UAV, constitutes an important step in developing precise weed control management in onion fields.

Potato powdery scab caused by Spongospora subterranea subsp . subterranea (Sss) causes extensive damage to the quality and marketability of tubers. Disease outbreaks in potatoes grown in virgin soils in south Israel, lead us to the hypothesis that wind-driven inoculum may also be a source of new infections. Wind and ground traps (13 of each type) were positioned near contaminated commercial potato fields with a history of powdery scab in two plots during 2013–14 (‘Nave 5’ and ‘Nave 89’). Quantification of pathogen density in soil/dust was carried out by DNA extraction and qPCR analysis. In ‘Nave 5’ plot, 58 and 45% (December and January, respectively) and 75 and 50% of the ground and wind traps, respectively, were Sss-positive, with no significant differences in Sss concentrations. In ‘Nave 89’ plot, the percentage of Sss-positive traps increased from 31% and 18% in the ground and wind traps, respectively, in February, to 100% in both trap types, in April, with no significant differences. Evaluation of the dispersal distance of Sss inoculum from contaminated fields was examined in soil samples taken from the top layer of the ground in the uncultivated area adjacent to the contaminated commercial potato fields with a history of powdery scab, in two sites (‘Nave 5’ and ‘Shalom 7’) during 2016. All soil samples, taken from uncultivated areas near the infested fields in various distances of up to 750 m, were Sss positive. This study demonstrated that Sss can be dispersed by wind, particularly in an intensive potato production region where contaminated fields exist.

Effective amphibian conservation requires knowledge of both the aquatic and terrestrial phases of life. As extinction probabilities are a function of population size, it is crucial not only to understand the habitat requirement of the species but also to estimate its population size. In this work, we studied the endangered fire salamander, Salamandra infraimmaculata, and analyzed the population size at a total of 14 sites—eight temporary and six permanent. For identifying the local and landscape scales factors predicting S. infraimmaculata’s breeding sites we monitored 54 aquatic sites. We found that permanent sites support larger populations of adult salamanders. The breeding site characteristics analyses revealed that at the local scale water depth and shade were the most important factors and two regional variables were found to be important: proximity to another breeding site and elevation. This work provides two clear conservation implications permanent breeding sites will support much larger populations compared to temporary sites, particularly if close to other potential breeding sites, and both terrestrial and aquatic features are important for a site to be suitable for breeding.

Genetic studies on core versus peripheral populations have yielded many patterns. This diversity in genetic patterns may reflect diversity in the meaning of peripheral populations as defined by geography, gene flow patterns, historical effects, and ecological conditions. Populations at the lower latitude periphery of a species' range are of particular concern because they may be at increased risk for extinction due to global climate change. In this work we aim to understand the impact of landscape and ecological factors on different geographical types of peripheral populations with respect to levels of genetic diversity and patterns of local population differentiation. We examined three geographical types of peripheral populations of the endangered salamander, Salamandra infraimmaculata, in Northern Israel, in the southernmost periphery of the genus Salamandra, by analyzing the variability in 15 microsatellite loci from 32 sites. Our results showed that: (1) genetic diversity decreases towards the geographical periphery of the species' range; (2) genetic diversity in geographically disjunct peripheral areas is low compared to the core or peripheral populations that are contiguous to the core and most likely affected by a founder effect; (3) ecologically marginal conditions enhance population subdivision. The patterns we found lead to the conclusion that genetic diversity is influenced by a combination of geographical, historical, and ecological factors. These complex patterns should be addressed when prioritizing areas for conservation.

The Mediterranean fruit fly, Ceratitis capitata (Wied.) (Diptera: Tephritidae) (medfly), is a major pest among all varieties of citrus. Despite advances in recent years, knowledge about the effects of various variables on the spatiotemporal spread of the medfly is still limited. The goal of this study was to characterize the effects of various local and landscape variables on the population density of medfly in citrus orchards in Israel, utilizing the ecoinformatics approach. Data were collected during three citrus growing seasons (years). The medfly population data consisted of a weekly inspection of ~ 2300 traps. Thirteen potentially explanatory variables believed to influence the medfly populations were quantified. The contributions of the explanatory variables were analyzed using multimodel inference. Results show that the medfly population is affected by both local and landscape variables. Further analysis was focused on the data from November (representing the fall peak) and April (representing the beginning of the spring peak). The major findings were: Medfly population was higher in plots that were closer to human communicates, presumably due to their proximity to private gardens; the medfly population was negatively affected by the proportion of the surrounding crop; larger plots with lower perimeter-to-area ratio and plots inside large citrus clusters had smaller populations of medflies; variety had inconsistent effect; and elevation showed inverse response (positive in November and negative in April). Additionally, during the fall peak, the medfly population was positively affected by the proportion of the surrounding deciduous orchards and negatively affected by pest aerial spraying rounds up to a certain number. The results of this study demonstrate that the medfly populations in citrus are affected by the composition of the external landscape. Thus, similar to other studies, this study encourages the adoption of area-wide integrated pest management protocols.

From an ecological perspective, urban green roofs can be viewed as green islands embedded in an urban matrix. Island biogeography theory suggests that species richness on an island is the outcome of dynamic equilibrium between immigration and extinction. Immigration is affected by the size of an island and distance of an island from a colonizing source. In the context of green roofs, building height and horizontal distance from green areas can potentially be a limiting factor for many species. Here, we considered two distance components of green roofs - vertical (building height) and horizontal (distance of building from open green areas). Based on island biogeography theory, we would expect species richness or community similarity to be negatively related to horizontal or vertical distances from colonizing sources. The green roof literature addressing such questions is currently sparse. In our review comprised of 10 studies, we were unable to identify consistent statistically significant richness-distance or community similarity-distance (vertical or horizontal) relationships. The absence of statistically significant relationships could be due in large part to low statistical power as a consequence of both the paucity of roofs and limited range of vertical distances in many of the existing studies. In addition, these roofs differ in numerous aspects (e.g. roof size, age, substrate type, plant composition and building height). The low number of replicates, combined with the lack of homogeneity among replicates combines to reduce statistical power and our ability to detect differences.

Understanding species’ distributions often requires taking into consideration the characterization of the environment at different spatial scales. The habitat characteristics of the endangered fire salamander, S. infraimmaculata, have received little attention. In this study, at this species’ most peripheral and xeric limit (Mt. Carmel, Israel), we examined predictors of the larval distribution of S. infraimmaculata at aquatic-breeding sites at both local and landscape scales. We investigated the predictive power of environmental variables using two methods: generalized linear models and conditional inference trees (CTREE). Both multi-model approaches yielded similar results. At the local site scale, hydroperiod predicted breeding site use. At the landscape scale, Salamandra presence was best predicted by proximity to other breeding sites. In addition, our study indicates that sites selected for breeding are far from roads and agricultural fields. Overall, this study demonstrates that ultimately, both local and landscape scale predictors are necessary to understand properly a species’ habitat requirements and thus can help in planning future management around the breeding sites.

Ecology seeks to study the factors affecting the distribution of species. In terms of their effects on species richness and composition, woody plants can be considered as dominant factors which extensively affect their environment, changing the distribution of resources in space and time. In structurally rich and diverse plant communities, such as Mediterranean ecosystems, the specific species that form the woody patch can be important. The specific woody species patch type may impose a set of abiotic conditions, which in turn would result in specific traits of the given herbaceous community under that patch. Evidence revealed in this study suggests that the general notion of a two-patch type (woody and non-woody) system for describing ecosystems is simplistic, and may be misleading. We found that patterns of herbaceous species richness and composition are related to specific woody species patch type. We found that herbaceous species richness under each patch type coincided with respective differences in solar radiation reaching the sub-canopy. Accounting for specific patch characteristics may largely enhance our understanding of plant community structure.

Amphibians are among the most threatened taxonomic groups worldwide. A fundamental step in species conservation is identifying the habitat requirements of the target species. However, this determination can often be problematic in endangered species because, by definition, they often only occupy a very limited number of sites. Moreover, when found, they are often in low abundance, and thus their detectability is low, yielding false “absence” data. Maximum entropy niche modeling provides a tool using only the presence data to predict potential habitat distributions of endangered species whose distributions have become highly limited. We provide two examples in the current study for the fire salamander, Salamandra infraimmaculata, and the green toad, Bufo viridis. S. infraimmaculata is considered endangered in Israel and near endangered worldwide. B. viridis is classified as locally endangered in Israel. Soil type was the most important predictor of the distribution of S. infraimmaculata and, to a lesser extent, also predicted the distribution of B. viridis. In addition, S. infraimmaculata larvae were also associated with high elevation areas. B. viridis was negatively associated with distance to urban areas and low solar radiation level. The potential distribution maps determined for S. infraimmaculata and B. viridis can help in planning future wetland use management around its existing populations, discovering new populations, identifying top-priority survey sites, or set priorities to restore its natural habitat for more effective conservation.