Rapid adaptation in temperature responses of seed germination in invasive populations of Amaranthus albus and Amaranthus blitoides- Towards a better understanding of species responses' to climate chang

Climate change is recognized as a major threat to species survival and integrity of ecosystems worldwide. Although extensive research has focused on climate impacts, relatively little work to date has been conducted on the practical application of strategies for adapting to climate change. This proposal focus on two relatively recent invasive species. The combination of newly introduced species and the sharp climatic gradient stretching throughout Israel, is a unique opportunity to study the interaction between species and different climatic conditions, and the ability of species to adjust to the intense selective pressures generated by the environmental differences between the native and invasive ranges either by rapid adaptation or by phenotypic plasticity. The conditions in the introduced range reach to extreme levels that mimic the expected conditions in the future in light of climatic changes. We expect that this research will broaden our understanding regarding the ability of species to cope with extreme conditions over a short time spans, identify the evolutionary mechanism and quantify the resulting ecological niche shift compared to the native range.   
​This project was funded by the US-Israel Binational Science Foundation (BSF) in collaboration with Prof. Mohsen Mesgaran (UC Davis).

​Publications:
Gafni R, Blank L and Eizenberg H (2024). Variability in germination fractions of Amaranthus albus in response to weed management and abiotic maternal conditions. European Journal of Agronomy: 127009 [pdf] Journal Link
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Amaranthus blitoides (green) and A. albus (red) occurrence data (GBIF data base) in native (USA) and invasive (Israel) ranges.

Germination experiment

Spatiotemporal dynamics of weed patches

Within agricultural fields, weed spread and establishment result from the interaction between the innate dynamics of the weed, spatial heterogeneities of the environmental and management-related process. This work aim to quantify the influence of cultural practices employed on rates of patch spread.
       
Publications:
Blank L, Birger N, and Eizenberg H (2019). Spatial and temporal distribution of Ecballium elaterium in almond orchards. Agronomy 9: 751 [pdf] Journal Link

Rozenberg G, Kent R and Blank L (2021). Consumer-grade UAV utilized for detecting and analyzing late-season weed spatial distribution patterns in commercial onion fields. Precision Agriculture 22: 1317-1332 [pdf] Journal Link

Rozenberg G, Catão-Dias JL, Anderson WM, Sellers BA, Boughton RK, Piccolo MB, and Blank L (2023). Using a low-cost Unmanned Aerial Vehicle for mapping Giant smutgrass in Bahiagrass Pastures. Precision Agriculture 24: 971-985 ​[pdf] Journal Link

Blank L, Rozenberg G, and Gafni R (Accepted). Spatial and temporal aspects of weeds distribution within agricultural fields- a review. Crop Protection [pdf] Journal Link

Upper image- Location of Squirting Cucumber plants in almond orchard. Lower image- Visualization of the spatial point patterns using heatmap.

Mapping giant smutgrass in bahiagrass pastures using UAV. FL, USA

Weed management on a regional scale

Nowdays, weed control recommendations are relativly uniform even between very distinct regions with different temperatures, soil typle, precipitation, radiation etc.  In addition, since weeds undergo relativlly rapid addaptation (short generation time coupled with large selection presure) it is possible that weed species are adapted to different conditions in different regions. We propose that management protocols should be modified in a way that they will capture the environmnetal, climatic and social variations characterizing specific regions. As a proof of this concept we are studing various species belonging to the Amaranths genus along a climatic gradient.
​This project was funded by the Israel's Ministry of Agriculture Chief Scientist in collaboration with Prof. Hanan Eizenberg (ARO). 

Publication:
Gafni R, Ziv GA, Eizenberg H and Blank L (2023). A regional-scale study of the contribution of local, management and climate factors to the infestation of processing tomato fields with Amaranthus species. European Journal of Agronomy 143: 126722 [pdf] Journal Link

Climatic conditions and plots locations in the study area

Cover-crops as a mean to reduce herbicide use in field crops and their effect on weed community structure

 Conventional agriculture in field crops relies heavily on herbicide application for weed control, which has negative effects to the environmental, health, and economic. The practice of cover-crops was reported to provide a variety of ecosystem services and was suggested as a sustainable weed management tool. In annual crops, cover-crops are sown in the period between the harvest of one season and the sowing of the following season. We hypothesize that the presence of cover-crops and stubble affect weed emergence in various ways, e.g., altering soil temperature and increasing competition with weeds, will reduce weed density and coverage as compared with conventional management. The objective of this study is to quantify the effect of cover-crops on weed species density, cover, biomass, and composition. For that, five 0.1 ha plots were planted with cover-crops and additional five were conventionally managed plots, ands sampled before and after sowing Corn (Zea mays L.). For each plot, weed coverage is estimated, and weed abundance is measured in 65 georeferenced quadrats. We also measure weed biomass in each plot. 
​This project was funded by the Nekudat-Hen Foundation for Sustainable Agriculture and the Israel's Ministry of Agriculture Chief Scientist in collaboration with Prof. Yohay Carmel (Technion)

Experimental plots in the Model Farm for Sustainable Agriculture, Newe Yaar Research Station

The effects of varying goat grazing intensities on the dynamics of cereals & broad leaves in semi-arid grasslands

Grasslands in arid regions provide essential ecosystem services, including land stabilization, hydrological functioning, and carbon sequestration. The composition of vegetation, particularly cereals and broad leaves, influences pasture quality and ecological functioning. This study aims to investigate the impact of goat grazing on the ratio and abundance of cereals and broad leaves using satellite imaging. By understanding these dynamics, we can improve pasture management and promote sustainable land practices in semi-arid grasslands.
This project is in collaboration with Dr. Eli Zaady (ARO) and Prof. Itamar Lensky (Bar-Ilan University)