Noam Levin

Remotely Sensed Spectral Heterogeneity As a Proxy of Species Diversity: Recent Advances and Open Challenges

Abstract Environmental heterogeneity is considered to be one of the main factors associated with biodiversity given that areas with highly heterogeneous environments can host more species due to their higher number of available niches. In this view, spatial variability extracted from remotely sensed images has been used as a proxy of species diversity, as these data provide an inexpensive means of deriving environmental information for large areas in a consistent and regular manner. The aim of this review is to provide an overview of the state of the art in the use of spectral heterogeneity for estimating species diversity. We will examine a number of issues related to this theme, dealing with: i) the main sensors used for biodiversity monitoring, ii) scale matching problems between remotely sensed and field diversity data, iii) spectral heterogeneity measurement techniques, iv) types of species taxonomic diversity measures and how they influence the relationship between spectral and species diversity, v) spectral versus genetic diversity, and vi) modeling procedures for relating spectral and species diversity. Our review suggests that remotely sensed spectral heterogeneity information provides a crucial baseline for rapid estimation or prediction of biodiversity attributes and hotspots in space and time.

Between-country collaboration and consideration of costs increase conservation planning efficiency in the Mediterranean Basin

The importance of global and regional coordination in conservation is growing, although currently, the majority of conservation programs are applied at national and subnational scales. Nevertheless, multinational programs incur transaction costs and resources beyond what is required in national programs. Given the need to maximize returns on investment within limited conservation budgets, it is crucial to quantify how much more biodiversity can be protected by coordinating multinational conservation efforts when resources are fungible. Previous studies that compared different scales of conservation decision-making mostly ignored spatial variability in biodiversity threats and the cost of actions. Here, we developed a simple integrating metric, taking into account both the cost of conservation and threats to biodiversity. We examined the Mediterranean Basin biodiversity hotspot, which encompasses over 20 countries. We discovered that for vertebrates to achieve similar conservation benefits, one would need substantially more money and area if each country were to act independently as compared to fully coordinated action across the Basin. A fully coordinated conservation plan is expected to save approximately US

A spectral based recognition of the urban environment using the visible and near-infrared spectral region (0.4-1.1 μm). A case study over Tel-Aviv, Israel

67 billion, 45% of total cost, compared with the uncoordinated plan; and if implemented over a 10-year period, the plan would cost ≈0.1% of the gross national income of all European Union (EU) countries annually. The initiative declared in the recent Paris Summit for the Mediterranean provides a political basis for such complex coordination. Surprisingly, because many conservation priority areas selected are located in EU countries, a partly coordinated solution incorporating only EU-Mediterranean countries is almost as efficient as the fully coordinated scenario.

Setting Priorities for Regional Conservation Planning in the Mediterranean Sea

This work examines the feasibility of using detailed spectral information in the visible (VIS) and near-infrared (NIR) spectral region (0.4-1.1 μm) for recognizing the urban environment. This was done by carefully studying pure and mixed spectral based materials from laboratory and airborne imaging spectroscopy (IS) data. The motivation for this study is the fact that although the IS technique has introduced a promising quantitative capability in many applications, it has not yet received attention in urban-related studies. For this study the Compact Airborne Spectral Imager (CASI) IS sensor (which operates in the VISNIR region) and the city of Tel-Aviv (Israels largest city) were selected. A pure spectral library of Tel-Avivs urban objects within the CASI channel configuration was generated from an existing spectral library. It was shown that even though the VIS-NIR spectral region is rather featureless, objects in the urban environment are characterized by spectral fingerprints. Examining this observation under a real, complex urban IS domain showed that minor spectral variations among targets could be easily used to spatially distinguish similar objects. Water bodies, asphalt pavement, shade, vegetation species and soil in the urban area can be spectrally and spatially recognized and mapped. For the purpose of spectral recognition the IS data must be of high quality (spectrally and spatially), the sensor status should be evaluated and the atmospheric attenuation should optimally be removed. These factors were carefully considered in the performance of this study, and the results, validated on the ground, showed remarkable agreement with reality. It was concluded that the IS technique is promising for use in the urban environment, and it is hoped that this paper will serve as a precursor for future urban-related IS studies.

Accurate prediction of bird species richness patterns in an urban environment using Landsat-derived NDVI and spectral unmixing

Spatial prioritization in conservation is required to direct limited resources to where actions are most urgently needed and most likely to produce effective conservation outcomes. In an effort to advance the protection of a highly threatened hotspot of marine biodiversity, the Mediterranean Sea, multiple spatial conservation plans have been developed in recent years. Here, we review and integrate these different plans with the goal of identifying priority conservation areas that represent the current consensus among the different initiatives. A review of six existing and twelve proposed conservation initiatives highlights gaps in conservation and management planning, particularly within the southern and eastern regions of the Mediterranean and for offshore and deep sea habitats. The eighteen initiatives vary substantially in their extent (covering 0.1–58.5% of the Mediterranean Sea) and in the location of additional proposed conservation and management areas. Differences in the criteria, approaches and data used explain such variation. Despite the diversity among proposals, our analyses identified ten areas, encompassing 10% of the Mediterranean Sea, that are consistently identified among the existing proposals, with an additional 10% selected by at least five proposals. These areas represent top priorities for immediate conservation action. Despite the plethora of initiatives, major challenges face Mediterranean biodiversity and conservation. These include the need for spatial prioritization within a comprehensive framework for regional conservation planning, the acquisition of additional information from data-poor areas, species or habitats, and addressing the challenges of establishing transboundary governance and collaboration in socially, culturally and politically complex conditions. Collective prioritised action, not new conservation plans, is needed for the north, western, and high seas of the Mediterranean, while developing initial information-based plans for the south and eastern Mediterranean is an urgent requirement for true regional conservation planning.

A digital camera as a tool to measure colour indices and related properties of sandy soils in semi-arid environments

Urban landscapes are expanding rapidly and are reshaping the distribution of many animal and plant species. With these changes, the need to understand and to include urban biodiversity patterns in research and management programmes is becoming vital. Recent studies have shown that remote sensing tools can be useful in studies examining biodiversity patterns in natural landscapes. The present study aimed to explore whether remote sensing tools can be applied in biodiversity research in an urban landscape. More specifically, the study examined whether the Landsat‐derived Normalized Difference Vegetation Index (NDVI) and linear spectral unmixing of urban land cover can predict bird richness in the city of Jerusalem. Bird richness was sampled in 40 1‐ha sites over a range of urban environments in 329 surveys. NDVI and the per cent cover of built‐up area were strongly and negatively correlated with each other, and were both very successful in explaining the number of bird species in the study sites. Mean NDVI in each site was positively correlated with the site bird species richness. A hump‐shaped relationship between NDVI and species richness was observed (when calculated over increasing spatial scales), with a maximum value (Pearsons R = 0.87, p<0.001, n = 40) at a scale of 15 ha. We suggest that remote sensing approaches may provide planners and conservation biologists with an efficient and cost‐effective method to study and estimate biodiversity across urban environments that range between densely built‐up areas, residential neighbourhoods, urban parks and the peri‐urban environment. †The two first authors contributed equally to this paper and are listed alphabetically.

Remote sensing as a tool for monitoring plasticulture in agricultural landscapes

Soil colour carries important information regarding the soils chemical and physical properties. However, common practices for measuring soil colour, either by Munsell charts or by field/laboratory spectrometers, are insufficient, due to the subjective and nonquantitative character of the Munsell charts, and to the high cost and inconvenience of field spectrometers. We present herein, a method to characterize the colour of soil samples, and related chemical and physical properties of the soil, using a digital camera, and an array of coloured plastic chips, that are used for calibration purposes. Using 370 samples of sandy soils, we have demonstrated that both RGB values from digital images and their derived soil indices, correlate highly with similar measurements performed by a field spectrometer. When checked against free iron oxide content and against the percentage of fine particles in a sub‐sample set of 42 soils, the redness index as measured by the digital camera gave similar or better correlations than those obtained from a field spectrometer, against both free iron oxides and fine particle contents (R 2 of 89% for the iron oxides, and of 81% for the fine particles). We propose the use of a digital camera as a field analytical tool to determine precisely: soil colour, iron oxide and fine particle content. Further study in this direction, with other soil population and more soil properties, is strongly advised in order to launch this as a vastly applicable and generic method.

Back-extrapolating a land use regression model for estimating past exposures to traffic-related air pollution

Agricultural landscapes are changing their appearance with the increasing use of man‐made plastic materials in covered agriculture (plasticulture) all around the world. As these affect the landscape visually, increase pollution and decrease local biodiversity, better monitoring and planning of their uses and areas are needed. Using a field spectrometer we studied the spectral properties of a sample of polyethylene sheets and various nets used in Israel. We detected three major absorption features around 1218 nm, 1732 nm and 2313 nm. These were not affected by settling dust, whitewashing or by the underlying surface, but were not apparent in black coloured polyethylene sheets or nets. A hyperspectral AISA‐ES image with a spatial resolution of 1 m achieved a detection accuracy of above 90% for bright sheets and nets but of only 70% for the black nets. The best spectral feature for plastic mapping was found to be that around 1732 nm as it does not coincide with spectral features of other minerals, soils, vegetation or atmospheric attenuation. As most of the greenhouses patches in Israel are smaller than 3200 m2, the optimal spatial resolution of a sensor for mapping them should be equal or better than 8–16 m. As a result of their low spectral and spatial resolution, Landsat images proved inadequate for mapping greenhouses, and strengthen the need of hyperspectral technology for that end.

From the Levant to Gibraltar: A Regional Perspective for Marine Conservation in the Mediterranean Sea

Land use regression (LUR) models rely on air pollutant measurements for their development, and are therefore limited to recent periods where such measurements are available. Here we propose an approach to overcome this gap and calculate LUR models several decades before measurements were available. We first developed a LUR model for NOx using annual averages of NOx at all available air quality monitoring sites in Israel between 1991 and 2011 with time as one of the independent variables. We then reconstructed historical spatial data (e.g., road network) from historical topographic maps to apply the models prediction to each year from 1961 to 2011. The models predictions were then validated against independent estimates about the national annual NOx emissions from on-road vehicles in a top-down approach. The models cross validated R2 was 0.74, and the correlation between the models annual averages and the national annual NOx emissions between 1965 and 2011 was 0.75. Information about the road network and population are persistent predictors in many LUR models. The use of available historical data about these predictors to resolve the spatial variability of air pollutants together with complementary national estimates on the change in pollution levels over time enable historical reconstruction of exposures.

Incorporating Socioeconomic and Political Drivers of International Collaboration into Marine Conservation Planning

Marine protected areas (MPAs) are critical to the well-being of threatened ecosystems and thus can be highly beneficial to humans, especially to those residing nearby. We explore the qualities of 117 MPAs in the Mediterranean basin and develop a taxonomy of their characteristics. We relate the spatial distribution of the MPAs to the various characteristics of the taxonomy (size, distance from shore, protection levels, management regimes, etc.) and to areas of high human impact and influence levels. To do this we use information on biogeographic regions and information from two different human influence models; one model developed for the marine environment and one covering the littoral terrestrial environment. Our analysis provides insights to planners and managers working in a regional capacity and trying to build MPA networks. Generally, current MPAs have not been established in high impact areas despite their being close to shores containing intense human activity. Decision-makers wishing to design and establish new MPAs may seek out areas of high cumulative human impacts (near the marine–terrestrial interface) or avoid them depending on marine conservation objectives, including the desire to vary types of MPAs within a network. Limitations of our analysis and methodology indicate areas for further research.