Elli Groner | Arava Dead Sea Science Center (original) (raw)

Papers by Elli Groner

Despite the burgeoning popularity of the term ‘ecosystem services’, relatively little work has ye... more Despite the burgeoning popularity of the term ‘ecosystem services’, relatively little work has yet been done to identify, characterize and quantify ecosystem services and their spatial distribution across the landscape. In this study, we test a methodology for taking inventory of ecosystem services in Israel’s semi-arid Northern Negev region. We survey site managers of five long-term ecological research (LTER) sites regarding the presence/absence of 86 ecosystem services, and their level of confidence regarding their answers. There was a high percentage of services in three categories (provisioning, regulating and cultural) across all sites, and no significant differences based on environmental factors between sites. The only factor that correlated with differences in the package of services offered at each site was management agency (Ministry of Agriculture or Jewish National Fund-Keren Kayemeth LeIsrael). Through principle component analysis, we find that management agencies, through their land use policies, can alter the package of services, for example by emphasizing agricultural- or forestry-oriented services or particular cultural services, like those associated with education or tourism. We conclude our analysis with a discussion on both the distribution of services and our reflections on the learning process from our ecosystem service assessment.

Monitoring, Simulation, Prevention and Remediation of Dense Debris Flows II, 2008

A new type of debris flow mitigation measure, flexible ring-net barrier systems, are cost-effecti... more A new type of debris flow mitigation measure, flexible ring-net barrier systems, are cost-effective and efficient compared to massive concrete barriers. However, the performance of these systems has not yet been investigated systematically. For this reason a wire ring-net barrier system has been installed in the Illgraben torrent, to investigate its performance, measure the forces and to provide information on the expected maintenance. Additionally, this net-testing facility allows for optimization of the structure and provides a basis for design guidelines. This paper describes the measurement facilities at the barrier and the debris flow events of 2006. First results of the filling event and their interpretation with the computational model are discussed.

Journal of Insect Science, 2021

Biological control theory has long been based on the model of arthropod community structure first... more Biological control theory has long been based on the model of arthropod community structure first proposed by Hairston, Smith and Slobodkin, in which communities are built from three functionally discrete trophic levels (plants, herbivores, predators). Under this model, predator diversity is expected to have a uniformly positive influence on biological control success (i.e., the suppression of herbivore populations). I will describe a case study of a cotton arthropod community whose interactions are fundamentally incompatible with the three trophic level model. Generalist predators in this system eat not only herbivores but also each other. The result is a mixture of 3-and 4-trophic level behavior, and the failure of biological control. I conclude that a deeper understanding of predator ecology is needed to predict predator function, and highlight some recent attempts to understand why some predators function primarily as consumers of herbivores, while others function primarily as c...

Journal of Plant Ecology, 2020

Aims In plant eco-physiology, less negative (enriched) carbon 13 (13C) in the leaves indicates co... more Aims In plant eco-physiology, less negative (enriched) carbon 13 (13C) in the leaves indicates conditions of reducing leaf gas exchange through stomata, e.g. under drought. In addition, 13C is expected to be less negative in non-photosynthetic tissues as compared with leaves. However, these relationships in δ 13C from leaves (photosynthetic organs) to branches, stems and roots (non-photosynthetic organs) are rarely tested across multiple closely related tree species, multiple compartments, or in trees growing under extreme heat and drought. Methods We measured leaf-to-root 13C in three closely related desert acacia species (Acacia tortilis, A. raddiana and A. pachyceras). We measured δ 13C in leaf tissues from mature trees in southern Israel. In parallel, a 7-year irrigation experiment with 0.5, 1.0 or 4.0 L day−1 was conducted in an experimental orchard. At the end of the experiment, growth parameters and δ 13C were measured in leaves, branches, stems and roots. Important Findings ...

The Science of the total environment, 2018

Through litter decomposition enormous amounts of carbon is emitted to the atmosphere. Numerous la... more Through litter decomposition enormous amounts of carbon is emitted to the atmosphere. Numerous large-scale decomposition experiments have been conducted focusing on this fundamental soil process in order to understand the controls on the terrestrial carbon transfer to the atmosphere. However, previous studies were mostly based on site-specific litter and methodologies, adding major uncertainty to syntheses, comparisons and meta-analyses across different experiments and sites. In the TeaComposition initiative, the potential litter decomposition is investigated by using standardized substrates (Rooibos and Green tea) for comparison of litter mass loss at 336 sites (ranging from -9 to +26 °C MAT and from 60 to 3113 mm MAP) across different ecosystems. In this study we tested the effect of climate (temperature and moisture), litter type and land-use on early stage decomposition (3 months) across nine biomes. We show that litter quality was the predominant controlling factor in early sta...

Journal of Environment Quality, 2017

Land Degradation & Development, 2017

Coastal dunes are fragile dynamic environments characterised by low productivity and high levels ... more Coastal dunes are fragile dynamic environments characterised by low productivity and high levels of bare and shifting sands. They are highly threatened by urbanisation and human development. The dunes in Nizzanim Dunes Nature Reserve, Israel, have additionally incurred shrub encroachment following exclusion of grazing and wood extraction from the area. The temporal changes over the last few decades have been monitored in the Nizzanim Long-Term Ecological Research project and are reflected by spatial heterogeneity. Some dunes are fixed with high plant cover and associated characteristics, while other dunes are still in semi-fixed and mobile states. Measures of beetle abundance, richness and diversity showed significant differences, among dune states. Cluster analysis and ordination of species composition revealed distinct assemblages for three different states, with more psammophilous species found in mobile dunes than in other dune states. Variation within a dune state was not significant for any dune state, while among states species composition was significantly different, demonstrating high β-diversity between dune states. Landscape heterogeneity contributes to high β-diversity and γ-diversity in the coastal dunes and continued shrub encroachment, and the associated fixation of mobile dunes will lead to habitat homogenisation and a decline in γ-diversity. This finding highlights the importance of disturbance in dynamic Mediterranean coastal dunes. We recommend a restorative intervention that promotes disturbance and heterogeneity at the landscape level by conserving all three dune states. Copyright © 2017 John Wiley & Sons, Ltd.

Ecology and evolution, 2017

The study of ecosystem processes over multiple scales of space and time is often best achieved us... more The study of ecosystem processes over multiple scales of space and time is often best achieved using comparable data from multiple sites. Yet, long-term ecological observatories have often developed their own data collection protocols. Here, we address this problem by proposing a set of ecological protocols suitable for widespread adoption by the ecological community. Scientists from the European ecological research community prioritized terrestrial ecosystem parameters that could benefit from a more consistent approach to data collection within the resources available at most long-term ecological observatories. Parameters for which standard methods are in widespread use, or for which methods are evolving rapidly, were not selected. Protocols were developed by domain experts, building on existing methods where possible, and refined through a process of field testing and training. They address above-ground plant biomass; decomposition; land use and management; leaf area index; soil m...

Journal of Arid Environments, 2016

Abstract The classical paradigm describe desert communities as being controlled by abiotic condit... more Abstract The classical paradigm describe desert communities as being controlled by abiotic conditions and therefore it was assumed that predation had a limited role in the determination of desert community structure and that only one effective trophic level was expected. In the Negev desert, the desert isopod ( Hemilepistus raeumuri ) is common in the less productive habitats but almost absent from the more productive wadis. In the present study we tested whether predation by ectothermic predators has a role in controlling isopod populations in wadis. We hypothesized that plant cover provides a refuge for these predators from secondary endothermic predators. We addressed this hypothesis by comparing isopod survivorship with and without predation exclusion, and with and without plant cover removal. Isopods protected from predation had a sustainable population whereas unprotected isopods had an unsustainable sink population. Removal of plant cover did not affect the survivorship of predator-protected isopods, however it did increase the survivorship and reduced predation pressure when not protected from predators, for at least four years. Hence, we conclude that predation controls isopod population and causes an unsustainable sink population in wadis. We have shown that plant cover mediates predation and that some habitats in the desert have an effective third trophic level, suggesting that energy is not the major limiting factor in determining the length of food chains.

... Dent Elli Groner Scott Morrison Danny Rosenfeld Uzi Avner Noah Brosch Avi Golan Goldhirsh Pin... more ... Dent Elli Groner Scott Morrison Danny Rosenfeld Uzi Avner Noah Brosch Avi Golan Goldhirsh Pinchas Alpert Boris Portnov Rex Cates Robin White Anastasios Tsonis Moshe Schwartz Yoram Ayal Berry Pinshow Dan Cohen Thomas Dem Haim Sha Andrew Warren Emanuel ...

Journal of Arid Land, 2021

Water availability, which enables plant growth and animal activity, regulates dryland ecosystem f... more Water availability, which enables plant growth and animal activity, regulates dryland ecosystem function. In hyper-arid ecosystems, rain cannot support vascular plant growth. Therefore, hyper-arid vegetation is restricted to the lower topography, where runoff accumulates. Typically, food resources originating from areas of dense vegetation are dispersed across the desert floor, enabling animal life in areas lacking vascular plant growth. However, certain regions, such as the hyper-arid upper topography, may be devoid of plant-derived food resources. The present study examined arthropod activity in the upper topography of a hyper-arid desert, in comparison with arthropod activity in the lower topography. Pitfall traps were utilized to compare arthropod activity along unvegetated ridges with activity in parallel, vegetated riverbeds. Surprisingly, the study revealed dense arthropod communities in the barren upper topography. Arthropods collected in the upper topography represented 26% of total arthropod abundance. In addition, the overlap between arthropod identity in the ridges and wadis (i.e., riverbeds) was low, and certain arthropods were strongly affiliated with the ridges. The upper topographic communities included high numbers of silverfish (Zygentoma: Lepismatidae), malachite beetles (Psiloderes), and predatory mites (Acari: Anystidae), and these arthropods were present at various life stages. It remains unclear how arthropod communities can persist in the unvegetated upper topography of the hyper-arid study area. These results raise the possibility that other food sources, independent from vascular plants, may play a significant role in the life history of hyper-arid arthropods.

Journal of Arid Environments, 2013

This research explores local resident perspectives on ecosystem services (ES) in the hyper-arid A... more This research explores local resident perspectives on ecosystem services (ES) in the hyper-arid Arava Valley/Wadi Araba, which spans across both Israel and Jordan. Identifying and characterizing ES, an increasingly popular precursor for crafting sustainable natural resource management and land use policy, is an inherently multidisciplinary endeavor. Our goal is to apply social research tools, in particular indepth interviews with local residents, to understand their perspectives concerning ES. Since the research is conducted on two sides of an international border, it also illuminates the potential role of culture, nationality and economics in formulating perceptions on ES in deserts. The results show that, although deserts are often considered to be lacking in ES, local residents feel that their environment is abundant in services, particularly cultural services. Furthermore, although they live in a nearly identical ecosystem, local residents from two sides of the border showed distinct differences, as well as some shared patterns, in how they use and value ES. The study highlights the importance of applying social methods for ES identification and characterization in tandem with other disciplinary approaches, in order to avoid common problems including disregard of the importance of social and cultural perspectives, leading to undervaluing of intangible cultural services.

Entomological Society of America, 2021

The construction of vehicular roads likely affects the distribution of natural resources. Althoug... more The construction of vehicular roads likely affects the distribution of natural resources. Although the effects of roads on different ecosystem aspects have been extensively studied, studies in arid and, particularly, in hyper-arid ecosystems are scarce. In drylands, where water is the main limiting factor, the effect of roads on the redistribution of water may have strong subsequent effects on the ecosystem, especially when roads cross natural water flow paths. To fill this knowledge gap, we studied the effects of a road that runs across a slope on the distribution of plants and animals in a hyper-arid environment. Changes in shrub cover, below and above the road, were quantified by remote sensing and image classification, while plant-associated arthropods were vacuum-sampled from shrub canopies and from open (inter-shrub) areas. We found that the spatial distribution of shrubs, a vital resource facilitating many other organisms, was affected by the road, with an increase in the shrub cover immediately above the road and a decrease below it. Arthropod abundance generally followed shrub cover, but the exact pattern depended on the specific group sampled. While some arthropod groups (e.g., aphids, parasitic wasps and barklice) thrived under the disturbed conditions above the road, other arthropod groups (e.g., mites and true bugs) were less abundant in the disturbed patches. Our results highlight the strong effects of human-made structures on the distribution of flora and fauna in arid ecosystems.

Communities often lack a framework to guide research and action by which to mitigate complex soci... more Communities often lack a framework to guide research and action by which to mitigate complex socio-ecological challenges in the face of conflicting interests and poorly understood ecological and socio-political mechanisms. In an effort to provide such a framework, this article offers an approach for the systematic analysis of societal interactions with the landscape as well as for the structure and function of the ecosystem. Using an approach informed both by transdisciplinary research (TdR) and participatory action research (PAR), modeling is employed to identify trajectories of human influence on the ecosystem, which is illustrated using a case from the Negev Highlands of Israel. The approach identifies several cascades of effects, allowing diverse stakeholders to better understand the mechanisms by which human activities change the capacity of the ecosystem to support human well-being over time, as well as building capacity for stakeholder cooperation for sustainable management.

The identification of parameters to monitor the ecosystem services delivered at a site is fundame... more The identification of parameters to monitor the ecosystem services delivered at a site is fundamental to the concept's adoption as a useful policy instrument at local, national and international scales. In this paper we (i) describe the process of developing a rapid comprehensive ecosystem service assessment methodology and (ii) test the applicability of the protocol at 35 long-term research (LTER) sites across 14 countries in the LTER-Europe network (www.lter-europe.net) including marine, urban, agricultural, forest, desert and conservation sites. An assessment of probability of occurrence with estimated confidence score using 83 ecosystem service parameters was tested. The parameters were either specific services like food production or proxies such as human activities which were considered surrogates for cultural diversity and economic activity. This initial test of the ecosystem service parameter list revealed that the parameters tested were relatively easy to score by site managers with a high level of certainty (92% scored as either occurring or not occu