My research topics deal with the interaction of plants with their environment and with other organisms in the ecosystem. For the past decade, I have been interested in the connection between plants and ectomycorrhizal fungi in the soil and how this relationship affects seedlings of forest trees.
1. The role of ectomycorrhizal fungi in the resistance of pine seedlings to conditions of competition and drought. In collaboration with Dr. Stav Livne-Luzon and Dr. Tamir Klein of the Weizmann Institute of Science.
2. The role of ectomycorrhizal fungi from Australian sources in the process of establishment of eucalyptus seedlings in open spaces in Israel. In collaboration with Dr. Oded Cohen of the Shamir Research Institute.
3. Characterization of the spatial structure of the mushroom community along the precipitation gradient in Israel. In collaboration with Dr. Stav Livne-Luzon and Dr. Tamir Klein of the Weizmann Institute of Science.
4. Monitoring and management of populations of the Iris lortetii species, a rare species in danger of extinction. Examination of the importance of genetic variation and environmental conditions on creation of seeds and establishment of seedlings. In collaboration with the Israel Nature and Parks Authority.
5. Examination of the ability of plant roots to sense volatile substances underground and to use this information to position roots in space. In collaboration with Dr. Asaf Sadeh from the Volcani Institute.
6. Long-term survival of fungal spores, in collaboration with the research group led by Professor Tom Bruns from University of California, Berkeley.
Dr. Hagai Shemesh – Head of the Laboratory
Email: [email protected]
Understanding the factors that determine the spatial distribution of species is crucial for conservation planning. In this short communication, we review previous distribution models of the fire salamander (Salamandra infraimmaculata) in northern Israel, produced by the group of the late Prof. Leon Blaustein, while suggesting a biologically-informed reinterpretation of their main predictions. We argue for the prime importance of bedrock, specifically hard limestone, because it is tightly associated with the availability of karstic formations that are key to adult survival throughout the summer.
Furthermore, we suggest that the spatial distribution of limestone bedrock also determines large-scale inter-population connectivity, and may explain the observed genetic differentiation among populations, as well as the southernmost limit of
the species’ global distribution.
1. In response to contemporary changes in climate, many tree species are shifting upslope to find favorable habitat. In the case of obligate ectomycorrhizal species, seedling growth above upper treeline depends on fungal spore availability. In the
mountain ranges of the Great Basin, a recent shift in tree species stratification has been recorded, with limber pine (LP, Pinus flexilis) leapfrogging above the ancient bristlecone pine (BCP, Pinus longaeva) forest and establishing above current treeline.
2. We compared the ability of LP and BCP to interact with soil spore banks collected at different microhabitats (next to dead trees, young live trees or in a treeless control) above current treeline in the White Mountains of California.
3. We found an ectomycorrhizal fungal spore bank community composed of 15 species that was dominated by an undescribed and a hitherto unsequenced species of Geopora and Rhizopogon, respectively. This represents a much richer community than was found previously in this system. While both LP and BCP were able to establish ectomycorrhiza, LP was twice as likely to do so, and when comparing only seedlings that were colonized, its root system was colonized to a three‐fold greater extent. BCP seedlings grown on soils collected under young live trees were much more likely to be colonized compared to soils from the other two microhabitats.
4. Synthesis. These differences in ectomycorrhizal receptivity might help to explain why LP is currently establishing at higher rates above the BCP treeline. Furthermore, it is possible that LP saplings above treeline can provide ectomycorrhizal facilitation for BCP seedlings, enabling the subsequent shift of BCP above treeline.
The effects of spatial heterogeneity in negative biological interactions on individual performance and species diversity have been studied extensively. However, little is known about the respective effects involving positive biological interactions, including the symbiosis between plants and ectomycorrhizal (EM) fungi. Using a greenhouse bioassay, we explored how spatial heterogeneity of natural soil inoculum influences the performance of pine seedlings and composition of their root associated EM fungi. When the inoculum was homogenously distributed, a single EM fungal taxon dominated the roots of most pine seedlings, reducing the diversity of EM fungi at the treatment level, while substantially improving pine seedling performance. In contrast, clumped inoculum allowed the proliferation of several different EM fungi, increasing the overall EM fungal diversity. The most dominant EM fungal taxon detected in the homogeneous treatment was also a highly beneficial mutualist, implying that the trade-off between competitive ability and mutualistic capacity does not always exist.
Livne-Luzon S, Shemesh H, Osem Y, Carmel Y, Migael H, Avidan Y, Tsafrir A, Glassman S.I, Bruns T.D, & O Ovadia (2021). High resilience of the mycorrhizal community to prescribed seasonal burnings in eastern Mediterranean woodlands. Mycorrhiza 31 (2), 203-216.
Dener E, Shemesh H & I Gilaadi (2021) The effect of pollen source on seed traits and dispersability in the heterocarpic annual Crepis sancta. Journal of Plant Ecology 14 (3), 425-437
Dener E, Ovadia O, Shemesh H, Altman A, Chen S and I Giladi (2021) Direct and indirect effects of fragmentation on seed dispersal traits in a fragmented agricultural landscape. Agriculture, Ecosystems & Environment 309, 107273.
Manela N, Ovadia O & H Shemesh (2021) The ability of short-term responses to predict the long-term consequences of conservation management actions: the case of the endangered Paeonia mascula (L.) Mill. Journal for Nature Conservation 60, 125956
Livne-Luzon S, Perlson O, Avidan Y, Sivan G, Bruns T.D & H Shemesh (2021) A none-linear effect of the spatial structure of the soil ectomycorrhizal spore bank on the performance of pine seedlings. Mycorrhiza 31 (3), 325-333.
Manela N, Shemesh H, Osem Y, Carmel Y, Soref C, Tsafrir A & O Ovadia (2021). Seasonal fires shape the germinable soil seed bank community in eastern Mediterranean woodlands. Journal of Plant Ecology 15 (1), 13-25
Gavron T & H Shemesh (2022). "I am actually growing my art": Building an Expressive Terrarium as an Intervention Tool in Arts Therapy. Accepted for publication in Journal of Creativity in Mental Health.
Shemesh H, Dener E and A Sadeh (2022). Bedrock may dictate the distribution of the Fire Salamander in the southern border of its global range. Accepted for publication in Israel Journal of Ecology and Evolution.
Shemesh H, Bruns T.D, Peay K.G, Kennedy P.G, Nguyen N.H (2022). Changing balance between dormancy and mortality determines trajectory of ectomycorrhizal fungal spore longevity over a 15 year burial experiment. Accepted for publication in New Phytologist.