Avi Perevolotsky

Agricultural Research Organization ARO | aro · Deprtment of Natural Resources

Human-driven landscape changes strongly influence landscape functionality and aesthetics. While landscape planners have access to biophysical data for decision-making, they often do not have the necessary information about social variables, such as aesthetic tastes, feelings, or functions of a place. Visualizing future landscapes under alternative...

The potential impacts of species colonization on the structure and functioning of ecosystems are poorly understood. We propose a novel approach for understanding the consequences of habitat colonization, highlighting the influence of colonists on the availability of limiting resources to resident species. We studied how colonization of dry oak wood...

Careful consideration of the cost-effectiveness of wildlife-friendly practices is key to promote fit-for-purpose agro-ecological policies, but quantitative evaluations of economic costs and ecological benefits compared to other land management alternatives are scarce. We compared the cost-effectiveness of uncultivated field-margins, a widespread wi...

Careful consideration of the cost-effectiveness of wildlife-friendly practices is key to promote fit-for-purpose agro-ecological policies, but quantitative evaluations of economic costs and ecological benefits compared to other land management alternatives are scarce. We compared the cost-effectiveness of uncultivated field-margins, a widespread wi...

Noy-Meir's simple but insightful model of grazing-system dynamics was used to draw broader inferences from empirical data generated by a 17-year field trial with beef cattle grazing a Mediterranean grassland in northern Israel. After calibration of its parameters against the field results, the model predictions were tested against an independent se...

Israel is a geographically small and relatively new state (founded in 1948) with high population density, industrial development and economic growth, all of which negatively affect the environment, particularly biodiversity. There is, however, a growing awareness in the country of the need for environmental and biodiversity protection. The Israel N...

Context Habitats characterized by improved soil moisture availability can function as microrefugia (hereafter referred to as “refugia”) for the persistence of rare plant species in dry environments. Such areas are dominated by Mediterranean woody vegetation (shrubland and woodland). An analysis of these refugia elucidates their spatial distribution...

This chapter presents a case study of the Israeli National Biodiversity Monitoring Program (IBM) that encompasses a diverse set of ecosystems. Israel is located at a crossroads of Africa, Asia, and Europe. It sits at the southeastern tip of the Mediterranean ecosystem, bordering the vast Saharo-Arabian desert belt to its south and connected via the...

The monitoring of natural ecosystems or species of conservation concern can be defined as the “collection and analysis of repeated observations or measurements to evaluate changes in condition and progress toward meeting a management objective.” A key aspect of monitoring is that the observations are repeatable and that they are done at regular int...

The ex situ collection of the Israel Plant Gene Bank (IGB) aims to encompass the rich local flora and its genetic diversity with an emphasis on crop wild relatives. However, to properly establish a core collection, collection efforts must be prioritized and strategized. We previously classified local plant genetic resources into four priority group...

What are the controls on biomass production and species diversity in Mediterranean grasslands? Do medium-term (i.e. inter-annual) precipitation legacy effects on biomass production and diversity occur in these grasslands? Karei Deshe Experimental Range Station, Upper Galilee, Northern Israel. We used a long-term (21-year) cattle-grazing experiment...

Landscape modulators are ecosystem engineers that create distinct patches that differ from their surroundings in abiotic conditions and species composition. Woody plants are principal landscape modulators in many terrestrial ecosystems. The effects of woody landscape modulators on herbaceous species richness have been studied at the site level in I...

This paper examines the effect of landscape heterogeneity on pine establishment and survival at both juvenile and mature stages. A field survey of seedlings (juvenile stage) was carried out in two sites (Shaharia and Nahal HaHamisha) close to planted forests of Pinus halepensis in the dry mediterranean region of Israel. Seedling establishment rate...

What might the future landscape look like? Which factors will shape it and what influence will managers and planners have on these processes? Will the landscape be "right" or desirable, and if so – for whom? These questions can be addressed by means of a 3D visual landscape model through which major landscape-shaping processes, such as wildfire, d...

Forest ecosystems function under increasing pressure due to global climate changes, while factors determining when and where mortality events will take place within the wider landscape are poorly understood. Observational studies are essential for documenting forest decline events, understanding their determinants, and developing sustainable manage...

A 17-yr grazing trial was conducted in the eastern Galilee of Israel to quantify trade-offs among the responses of pasture and livestock productivity, duration of grazing, amount of supplementary feed, and profitability to higher stocking density during the growing season of a Mediterranean grassland. Treatments included two stocking densities and...

Species affect the dynamics of litter decay through the intrinsic properties of their litter, but also by influencing the environmental conditions imposed by their canopy, roots, and litter layers. We examined how human-induced changes in the relative abundances of two dominant Mediterranean trees-Pinus halepensis and Quercus calliprinos-impact lea...

strongly reduce ANPP in arid and semi-arid sites. Moreo-ver, the effect of reduced precipitation on the CV of ANPP along the entire gradient may be modified by changes in inter-annual variability in MAP. Reduced precipitation combined with increased precipitation variability was the scenario most relevant to the wet end of the gradient, due to the...

We investigated forest responses to global warming by observing: (1) planted Pinus halepensis forests, (2) an aridity gradient—with annual precipitation (P) ranging from ~300 to ~700 mm, and (3) periods of wet and dry climate that included the driest period during at least the last 110 years. We examined: (1) how the length of climatic integration...

A synthesis of a long-term (19 years) study assessing the effects of cattle grazing on the structure and composition of a Mediterranean grassland in north-eastern Israel is presented, with new insights on the response of the vegetation to grazing management and rainfall. We hypothesized that the plant community studied would be resistant to high gr...

Human alterations of landscapes often lead to colonization of ecosystems by new species, which may alter ecosystem structure and function. Understanding canopy changes is important for management of gradually changing ecosystems. Here, we develop a model that both explains and predicts the rate at which colonizing native Pinus halepensis form an up...

Native wild boar (Sus scrofa lybicus) populations in Israel increased in the last decades, and their rooting activity presents an apparent severe disturbance that may affect herbaceous plant communities. We studied the extent of wild boar rooting and its effect on herbaceous vegetation in an east Mediterranean garrigue. We compared the effects of r...

Afforestation efforts have resulted in extensive plantations of either native or non-native conifers, which in many regions has led to the spread of those conifers into surrounding natural vegetation. This process of species colonization can trigger profound changes in both community dynamics and ecosystem processes. Our study disentangled the comp...

The function and structure of annual vegetation communities in rangeland ecosystems are the first to respond to extreme events such as drought. Changes in productive patch distribution patterns are a common indicator for ecosystem changes. Rarely, however, do realistic studies observe the effect of drought on patch distribution patterns in very hig...

Rangelands in temperate areas provide food to herds of domesticated animals and, there-fore, provide the infrastructure for two major industries: (a) the meat industry that feeds large populations around the globe; and (b) the wool industry that uses fibre from sheep. In the semiarid zone, rangelands have a socio-economic role as they support the e...

We examined if climate change in two dry ecosystems—Mediterranean (DME) and Semiarid (SAE)—would cause substantial reduction in the production of annual vegetation. Field measurements and computer simulations were used to examine the following six climate change scenarios: (1) rainfall amount reduction; (2) increases of 10 % in annual evaporation r...

Plant colonization studies usually address density-dependent processes in the narrow sense of recruitment constraints due to negative density-dependent seed and seedling mortality. However, complex density-dependent effects may be involved in additional stages of the recruitment process. We hypothesized that seed arrival and seedling establishment...

Introduction of goats into a Mediterranean nature park leads to changes in woody vegetation cover as well as changes in landscape properties. As part of the "adaptive management" approach, this management action should be accompanied by a monitoring program to assess the impact of grazing on various landscape parameters, and the extent to which man...

A single daily oral dose of polyethylene glycol (PEG) Ð a tannin-binding agent Ð has been shown to substantially improve feed intake and ef®ciency of utilization by sheep and goats consuming tannin-rich forage. The aim of this study was to quantify the effect of supplementing 10 g/day of PEG on the performance of does grazing on Mediterranean woodl...

The Mediterranean landscape is characterized by a heterogeneous structure: a mosaic of woody plants (trees or shrubs) with scattered patches of herbaceous vegetation. Although the herbaceous and woody patches are adjacent to each other, plant species composition in them is substantially different. This could be attributed to either differences in e...

Foraging behaviors of the Damascus, Mamber and Boer goat breeds were compared on shrublands of the South Carmel mountain ridge of Israel. Dietary choice was determined for a group of yearling animals of each breed (n=11 or 12), housed and grazed separately to prevent social facilitation, during a total of 4 (Mamber) or 5 (Damascus and Boer) session...

In Mediterranean regions, the combination of disturbances, life histories, plant regeneration traits, and microhabitat variability form highly heterogeneous vegetation mosaics which shift in space and time. Consequently, structure-based forest management is emerging as a superior alternative to management of vegetation formations in such areas. Del...

In May, 2002 fourteen Damascus goats were bought and held at the Ramat-Hanadiv Nature Park on Mt. Carmel, in central Israel. The main purpose of purchasing the goats was to collect scientific information regarding grazing behaviour of different goat breeds and seasons and apply it in the management of the nature park. The research aimed at bridging...

The main objective of this study was to determine to what extent grazing pressure and timing modulate the seasonal progression of herbage quality in hilly Mediterranean grassland systems. The study was conducted during six consecutive years between 2003 and 2008 at the Karei Deshe experimental farm, in eastern Galilee, Israel, dominated by rich hem...

Natural and semi-natural landscapes usually serve varied land uses, including grazing, forestry, recreation, and nature or biodiversity protection. In most cases areas with differing land uses are managed by different agencies, with differing perspectives, goals, and operating methodologies. In his teaching, Imanuel Noy-Meir emphasized the ecologic...

The impact of herbivores on herbaceous plant communities is usually attributed to direct consumption of plants. We hypothesized that goats affect herbaceous plants both directly (consumption by foraging) and indirectly, by changing environmental conditions through modification of woody plant structure. We assessed the effects of goats browsing on e...

Anemone coronaria, an attractive Mediterranean geophyte, seems to disappear from grazing-protected areas in Israel. We experimentally examined the ecological mechanism driving the decline of this geophyte. Ten plot-pairs were established, half we fenced as grazing exclosures and half were grazed by beef cattle. Grazing clearly reduced herbaceous bi...

Natural ecosystems are life-supporting systems providing diverse ecosystem services (ESs) and benefits to human societies: e.g., food and clean water, recreation opportunities or climate regulation. The contribution of natural and semi-natural ecosystems to the provision of such services depends to a large extent on vegetation structure and composi...

We investigated whether Mediterranean goats use salivary tannin-binding proteins to cope with tannin-rich forages by determining the affinity of salivary or parotid gland proteins for tannic acid or quebracho tannin. Mixed saliva, sampled from the oral cavity, or parotid gland contents were compared to the intermediate affinity protein bovine serum...

Primary production is an important indicator to climatic changes in drylands, while reduction in productivity has many consequences on ecosystem functioning. We suggest that the response of dry ecosystems to climate change should lead to a change in spatial patterns of grasses without a substantial change in ecosystem resilience. We used field data...

The concept of ecosystem engineer was proposed in order to understand abiotic environmental modulation by organisms and its effects on the distribution and abundance of biota. This concept was incorporated with patch theory in order to better understand the drivers of biodiversity dynamics. An organism that functions as an ecosystem engineer in the...

Geomorphic processes may have significant effects on vegetation productivity. This study reports on the effects of gully formation on rangeland productivity in the central arid Negev desert. The study region is hilly, with wide valleys transverse the landscape. The research was conducted at two sites: Boqer and Zipporim wadis, in which gullies are...

Ecosystems of the Mediterranean region are characterized by a heterogeneous and dynamic landscape mosaic of vegetation formations that provide diverse benefits: agro pastoral products, ecosystem services, and other utilities. Valuation of these benefits in different states of the ecosystem is an important step towards conservation, decision making,...

The aim of the present study was to determine the effect of polyethylene glycol (PEG) supplementation on grazing behaviour of beef cattle and on utilization of the woody components of a Mediterranean shrubland. Two experiments were conducted on two different sites in Northern Israel, Ramat Hanadiv (RH) and Hatal. On each site, the study area was di...

Forest management (silviculture) is a long-established applied science, but also a field whose sustainability and ecological implications have been questioned. In this paper, we present the basic features of commercial forestry together with a review of novel approaches for ecologically oriented forestry. The "new forestry" advocates for multiple-s...

Ecological research on organism-environment interactions has developed asymmetrically. Modulation of organisms by the environment has received much attention, while theoretical studies on the environmental impact of organisms have until recently been limited. We propose a theoretical framework for studying the environmental impacts of woody plants...

Background/Question/Methods: Ecosystems dominated by herbaceous vegetation can highlight plant-soil-water relationship and its effect on production processes. Therefore, one of the challenges in ecology is to quantify climate change effects on primary production of annuals. Results/Conclusions: We use field data and a recently published spatio-...

Background/Question/Methods Herbivores are considered to have significant impact on their environment. This impact is usually attributed to trophic relationships between the herbivores and plants. However, herbivores affect ecological systems not only by exploitation of plant biomass, but also by functioning as ecosystem engineers. We empirically...

Goat breeds differ in their consumption of tannin-rich browse, but the relative contributions of genetics and learning to these differences is unclear. The objective of this study was to differentiate between the effects of breed (nature) and rearing environment (nurture) on consumption of a tanniferous species by kid goats. We used Damascus and Ma...

Galls are abnormal plant growth induced by various parasitic organisms, mainly insects. They serve as “incubators” for the developing insects in which they gain nutrition and protection from both abiotic factors and natural enemies. Galls are typically armed with high levels of defensive secondary metabolites. Conspicuousness by color, size and sha...

The relationship between intensity and timing of cattle grazing on changes in the size and composition of the soil seed bank were investigated in a 3-yr study in a Mediterranean grassland in northeastern Israel. Treatments included manipulations of stocking rates and of grazing regimes, in a factorial design. The retrieved soil seed bank community...

Question: We studied the interactive effects of grazing and dwarf shrub cover on the structure of a highly diverse annual plant community. Location: Mediterranean, semi-arid shrubland in the Northern Negev desert, Israel. Methods: Variation in the biomass and plant density of annual species in the shrub and open patches was monitored during four ye...

Question: Large variation in the similarity between seed bank and standing vegetation generally occurs along environmental gradients. We asked: 1. How is seed bank-vegetation similarity in Mediterranean semi-arid annual plant communities related to variation in primary productivity; 2. How is this productivity-similarity relationship affected by ex...