Physiological Plant Ecology (Kahmen)Head of Research Unit Prof. Dr.Ansgar KahmenOverviewMembersPublicationsProjects & CollaborationsProjects & Collaborations OverviewMembersPublicationsProjects & Collaborations Projects & Collaborations 31 foundShow per page10 10 20 50 Shifted snowmelt timing and recurrent summer drought in alpine grassland: deciphering the role of soil biota and symbiotic partners for the distinct plant species responses Research Project | 1 Project MembersImported from Grants Tool 4703035 From Bauhin to Lachenal: Enabling digital access to the historic 16th-18th century herbaria in Basel Research Project | 2 Project MembersThe scope of the project is enabling digital access to almost 10'000 singular historic (16th-18th century) herbarium specimens at the Herbaria Basel , by updating and expanding the digital information associated with five partially digitized, important historic herbaria following standards laid out in Frick & Greeff (2021). Meta-data for digital specimens will include all fields required for specimen filing and finding (physically, in the database, and online), such as collecting information (names, dates, administrative areas) and taxonomic information (determination, consistent name resolution, type status). This project is important because it promotes digital accessibility to important specimens : Accessibility and conservation of research-relevant data are a core task of herbaria and are within the scope of SwissCollNet. Our project mobilizes the information of close to 10'000 singular historic specimens and presents them online, besides via our institutional internet-portal (herbarium.unibas.ch, in development), also via Global Biodiversity Information Facility ( www.gbif.org ) and within the timeframe of the project also via Global Plants on JSTOR (plants.jstor.org). All data will also be integrated in the Swiss Virtual Natural History Collection portal (in development) by meeting established Swiss-wide standards. In the footsteps of Sarasin and Christ: digitization of fern collections at the herbaria in Basel and Zürich Research Project | 2 Project MembersThe world's herbaria document the diversity of plant life across the globe and through time. Many of the first descriptions of plants were based on material stemming from rather adventurous collection expeditions and remarkable personalities. Therefore, many historic collections are simultaneously of exceptional cultural, historic, and scientific value, often interwoven with colonial history. This is particularly true for tropical regions. The Sarasin cousins (Karl Friedrich (Fritz), 1859-1942; and Paul Benedict, 1856-1929) from Basel are such remarkable personalities with profound impacts both on cultural and natural history. Being born wealthy in the upper societal echelons of Basel, their gay love was taboo, prompting them to spend their fortunes to make a career as scientific explorers in Asia, primarily in Ceylon (now Sri Lanka), Celebes (now Sulawesi, Indonesia) and New Caledonia (incl. the loyalty Islands, where Fritz was the first-ever plant collector; Schär 2015). By traveling and collecting in the largely uncontacted interiors of these places collaborating with colonial rulers, their expeditions had a political note, but also resulted in profound impacts on natural history. The collecting expeditions of the Sarasin cousins resulted in rich collections; estimated at ca. 300'000 specimens of gastropods, arthropods, birds, mammals, and spiders, as well as 680 ethnographic objects and 600 photographs from Celebes alone (Schär 2015). These specimens form important parts of the collections of the Natural History Museum and Museum of Cultures in Basel. Strikingly less known, but equally important, are the estimated 3000 botanical collections of the Sarasin cousins. These specimens were sent back to Switzerland, where they were examined and identified by specialists, resulting in a flurry of new species. Hermann Christ (1833-1933) of Basel, the world's primary fern specialist at the time, despite being professionally a lawyer, described at least 36 fern species from Celebes alone ("Filices Sarisinianae", Christ, 1894-97). These plants were then donated to the Herbarium of the University of Basel, but remained unincorporated. In Zurich, Hans Schinz (1858-1941) and colleagues treated the angiosperms from New Caledonia, a significant part of which were then donated to Basel for reasons unknown. The importance of the Sarasin collections is underlined by regular re-discovery of Type material (e.g. Chen et al. 2021), always in association with Christ's previous work on these specimens. Overall, Christ's influence on fern taxonomy is paramount, already from his ca. 310 papers and ca. 1800 basionyms that he published. Asessing the drought response strategies of ten temperate tree species and their drought acclimation potential in a throughfall exclusion experiment in a mature forest Research Project | 5 Project MembersGlobal climate change and in particular changes in the hydroclimate towards dryer and warmer summers will impact the structure and composition of central European and other forests on the planet. The extremely hot and dry summers that Europe has experienced in 2003 and in 2018 have already demonstrated the severe impacts that a changing climate will have on tree and forest function and composition for these ecosystems. Critical mechanisms that determine how drought will impact the functioning of trees and forests are, however, poorly understood. This makes it difficult to anticipate the consequences of a future and dryer climate for key ecosystem functions and prevents the development of silvicultural management plants for more resistant and resilient forest ecosystems. Here we propose to close this gap and to address the effects of drought on mature trees from ten different temperate European species in a large-scale ecosystem manipulation experiment. From our work, we expect the following outcome: we will provide thefirst comprehensive empirical characterization of the drought response strategies of key temperate European tree species, we will identify the trait syndromes that govern the different drought response strategies in these species and will identify important tradeoffs between traits and function, we will provide one of the first large scale across-species assessments of the acclimation potential of mature temperate European tree species to reduced water availability and we will identify the key traits that are responsible for these acclimations. A novel through fall exclusion experiment to assess the physiological and biogeochemical consequences of precipitation changes for temperate forests (NF R'Equip) Research Project | 2 Project MembersRising global temperatures, fewer number of precipitation days and an increased intensity of drought events are projected to shape the future climate of central Europe. Changes in water availability and more intense drought events will have significant impacts on the central European vegetation and on temperate European forests in particular. Importantly, critical mechanisms that determine how changes in water availability and drought will impact the functioning of temperate European forests are poorly understood and not well represented in earth system models. Anticipating the consequences of a future climate for the functioning of temperate European forests is therefore difficult and hinders the design of mitigation options and future forest management plans. Most experiments that attempt to improve the mechanistic understanding of drought responses of terrestrial ecosystem have to date focused either on the experimental manipulation of grasslands or on investigations with tree seedlings or saplings. Although forests play an essential role for the delivery of ecosystem goods and services, very few experiments exist in established temperate European forests that mechanistically investigate the responses of mature trees and forest to changes in water availability or drought. To close this critical research gap, it is the goal of this proposal to establish an experimental research platform in a species rich and mature temperate forest in Switzerland. This experimental platform will provide the opportunity over the next two decades to host research projects addressing some of the most important unresolved questions with respect to tree and forests responses to changes in the precipitation regime and drought. Specifically, these projects will address the long-term acclimation potential of individual species or entire forests to precipitation changes, physiological and biogeochemical thresholds and tipping points during drought, and recovery processes during and after extended drought events. The experimental research platform that we seek to establish will combine a unique infrastructure that we request with this proposal. This infrastructure will include (i) a canopy crane that will allow scientific investigations in the canopy of more than 250 mature trees, (ii) six mobile roofs that will be installed 2.5 m above the ground and will cover a total area of 3398 m2 for the manipulation of precipitation inputs into the forest, and (iii) state of the art scientific instrumentation. Vergleich der Trockenheitstoleranz Schweizer Waldbaumarten Research Project | 2 Project MembersDie Gefährdung heimischer Baumarten durch die zunehmende Häufigkeit von heissen und trockenen Sommern wird in der forstlichen Praxis intensiv diskutiert. Die Auswahl von «Zukunftsbaumarten», die sowohl eine hohe Toleranz gegenüber diesen Extremen zeigen, als auch die zahlreichen wirtschaftlichen und landeskulturellen Waldleistungen garantieren, ist der Schlüssel für eine klimagerechte Waldwirtschaft. Die nach der extremen Trockenheit im Jahr 2018 beobachteten Schäden im Schweizer Wald haben die Diskussion über Zukunftsbaumarten neu entfacht. Das vorliegende Projekt der Universität Basel soll einen wichtigen Beitrag leisten, um anhand von vergleichenden wachstumskundlichen und ökophysiologischen Untersuchungen Zukunftsbaumarten für den Schweizer Wald zu identifizieren. A novel through fall exclusion experiment to assess the physiological and biogechemical consequences of precipitation changes for temperate forests Research Project | 2 Project MembersNo Description available Revealing the genomic signature of tomato domestication in Europe using Caspar Bauhin's (1560-1624) herbarium specimens. Research Project | 1 Project MembersThe herbarium of Caspar Bauhin (1560-1624) at the Department of Environmental Sciences of the University of Basel is among the oldest surviving worldwide. Because techniques for ancient DNA analysis have progressed substantially in recent years, we have been able to extract DNA from three of Bauhin's tomato specimens (Solanum lycopersicum L.) of a quality that allows for sequencing their whole genomes. We request funding to sequence these genomes, as well as those from another three specimens stored at the Herbaria Basel and collected between 1730 and 1836 (Fig. 1). Combined with data from an ongoing, funded project that emphasizes herbarium and modern specimens collected between 1900 and the present, this project will allow us to trace more than 400 years of tomato domestication in Europe using genomic data. Domestication is an important model of plant evolution. Therefore, our results will not only inform our understanding of the genetic basis of "useful" traits in one of the most important crops worldwide; it will also shed light on the genetic basis of adaptation more generally. The requested laboratory expenses are hard to fund elsewhere and the project is intimately tied to the history of botany in Basel since the 16th century. Therefore, the project matches the goals of the Basler Stiftung für biologische Forschung well. Using millet-legume model intercropping systems to establish mycorrhiza-facilitated bioirrigation in dryland agriculture Research Project | 3 Project MembersIn the years to come, sustainable land use is one of the big challenges for plant science. One promising low-input strategy is to make use of the potential of intercropping. In dryland agriculture, deep-rooting plants, intercropped within shallow-rooting ones, may act as "bioirrigators" that can transfer water from deep soil layers to the topsoil for the benefit of the system. Our recent experiments have shown that bioirrigation is facilitated by the presence of arbuscular mycorrhizal fungi (AMF), which connect the intercropped plants by a common mycorrhizal network (CMN). The ambition of the research that we propose in this project is to identify the morphological, physiological and competitive traits that make plants ideal bioirrigators in CMN facilitated intercropping systems. With this research we seek to establish the basic knowledge that will allow establish effective CMN facilitated bioirrigation in intercropping systems as a measure to stabilize and increase the yield of small holder or subsistence farmers in dryland agriculture. Cold root effects on water-uptake and C-relations in temperate tree species Research Project | 2 Project MembersPrevious studies indicated that low root zone temperatures can induce drought-like water shortage in trees, with severe consequences also for their C-household. The restricted water conductivity of roots cannot be explained by the increased viscosity of water at cold temperatures alone. The very high sensitivity against non-freezing, colder root temperatures rather suggests that the water uptake of roots is likely stronger dependent on active processes (e.g. via aquaporins) than is generally assumed. Cold root temperature induced drought-like stress might thus contribute to the observed growth restriction of trees at their cold limits. In this 4-year PhD project, we will built upon recent experiments at the University of Basel to deepen our understanding of cold root zone effects on temperature trees. We will investigate seedlings of different temperate tree species at warm air temperatures and different root temperatures by means of a temperature-controlled water bath system. Water- and nitrogen-uptake, as well as carbon assimilation at different root temperatures will be quantified by pulse labelling with stable isotopes ( 2 H-H 2 O and 15 N-NO 3 enriched water, 13 C-CO 2 enriched air). Especially, we will address the following questions: Is the water uptake capacity of tree species with low elevational distribution limits more sensitive to low root zone temperatures than in species with high elevation distribution limits? Is the strong restriction of the phloem C-transport at cold root temperatures leading to accumulated non-structural carbohydrate (NSC) reserves in the aboveground tissue of tree seedlings? Are trees, which are raised at colder temperatures better adapted to low root zone temperatures in terms of water-uptake and -transport, than trees raised at warmer temperatures (test for long-term acclimatization)? Is the magnitude of nitrogen (N) uptake and -transport at cold root zone temperatures restricted to the same magnitude as the uptake of water? Besides detailed physiological insights in cold soil effects on the water, carbon and nutrient household of temperate tree species, this project will provide important information for climate-growth models of trees in general, and it will contribute quantitative data for mechanistic tree species distribution models. 1234 1...4 OverviewMembersPublicationsProjects & Collaborations
Projects & Collaborations 31 foundShow per page10 10 20 50 Shifted snowmelt timing and recurrent summer drought in alpine grassland: deciphering the role of soil biota and symbiotic partners for the distinct plant species responses Research Project | 1 Project MembersImported from Grants Tool 4703035 From Bauhin to Lachenal: Enabling digital access to the historic 16th-18th century herbaria in Basel Research Project | 2 Project MembersThe scope of the project is enabling digital access to almost 10'000 singular historic (16th-18th century) herbarium specimens at the Herbaria Basel , by updating and expanding the digital information associated with five partially digitized, important historic herbaria following standards laid out in Frick & Greeff (2021). Meta-data for digital specimens will include all fields required for specimen filing and finding (physically, in the database, and online), such as collecting information (names, dates, administrative areas) and taxonomic information (determination, consistent name resolution, type status). This project is important because it promotes digital accessibility to important specimens : Accessibility and conservation of research-relevant data are a core task of herbaria and are within the scope of SwissCollNet. Our project mobilizes the information of close to 10'000 singular historic specimens and presents them online, besides via our institutional internet-portal (herbarium.unibas.ch, in development), also via Global Biodiversity Information Facility ( www.gbif.org ) and within the timeframe of the project also via Global Plants on JSTOR (plants.jstor.org). All data will also be integrated in the Swiss Virtual Natural History Collection portal (in development) by meeting established Swiss-wide standards. In the footsteps of Sarasin and Christ: digitization of fern collections at the herbaria in Basel and Zürich Research Project | 2 Project MembersThe world's herbaria document the diversity of plant life across the globe and through time. Many of the first descriptions of plants were based on material stemming from rather adventurous collection expeditions and remarkable personalities. Therefore, many historic collections are simultaneously of exceptional cultural, historic, and scientific value, often interwoven with colonial history. This is particularly true for tropical regions. The Sarasin cousins (Karl Friedrich (Fritz), 1859-1942; and Paul Benedict, 1856-1929) from Basel are such remarkable personalities with profound impacts both on cultural and natural history. Being born wealthy in the upper societal echelons of Basel, their gay love was taboo, prompting them to spend their fortunes to make a career as scientific explorers in Asia, primarily in Ceylon (now Sri Lanka), Celebes (now Sulawesi, Indonesia) and New Caledonia (incl. the loyalty Islands, where Fritz was the first-ever plant collector; Schär 2015). By traveling and collecting in the largely uncontacted interiors of these places collaborating with colonial rulers, their expeditions had a political note, but also resulted in profound impacts on natural history. The collecting expeditions of the Sarasin cousins resulted in rich collections; estimated at ca. 300'000 specimens of gastropods, arthropods, birds, mammals, and spiders, as well as 680 ethnographic objects and 600 photographs from Celebes alone (Schär 2015). These specimens form important parts of the collections of the Natural History Museum and Museum of Cultures in Basel. Strikingly less known, but equally important, are the estimated 3000 botanical collections of the Sarasin cousins. These specimens were sent back to Switzerland, where they were examined and identified by specialists, resulting in a flurry of new species. Hermann Christ (1833-1933) of Basel, the world's primary fern specialist at the time, despite being professionally a lawyer, described at least 36 fern species from Celebes alone ("Filices Sarisinianae", Christ, 1894-97). These plants were then donated to the Herbarium of the University of Basel, but remained unincorporated. In Zurich, Hans Schinz (1858-1941) and colleagues treated the angiosperms from New Caledonia, a significant part of which were then donated to Basel for reasons unknown. The importance of the Sarasin collections is underlined by regular re-discovery of Type material (e.g. Chen et al. 2021), always in association with Christ's previous work on these specimens. Overall, Christ's influence on fern taxonomy is paramount, already from his ca. 310 papers and ca. 1800 basionyms that he published. Asessing the drought response strategies of ten temperate tree species and their drought acclimation potential in a throughfall exclusion experiment in a mature forest Research Project | 5 Project MembersGlobal climate change and in particular changes in the hydroclimate towards dryer and warmer summers will impact the structure and composition of central European and other forests on the planet. The extremely hot and dry summers that Europe has experienced in 2003 and in 2018 have already demonstrated the severe impacts that a changing climate will have on tree and forest function and composition for these ecosystems. Critical mechanisms that determine how drought will impact the functioning of trees and forests are, however, poorly understood. This makes it difficult to anticipate the consequences of a future and dryer climate for key ecosystem functions and prevents the development of silvicultural management plants for more resistant and resilient forest ecosystems. Here we propose to close this gap and to address the effects of drought on mature trees from ten different temperate European species in a large-scale ecosystem manipulation experiment. From our work, we expect the following outcome: we will provide thefirst comprehensive empirical characterization of the drought response strategies of key temperate European tree species, we will identify the trait syndromes that govern the different drought response strategies in these species and will identify important tradeoffs between traits and function, we will provide one of the first large scale across-species assessments of the acclimation potential of mature temperate European tree species to reduced water availability and we will identify the key traits that are responsible for these acclimations. A novel through fall exclusion experiment to assess the physiological and biogeochemical consequences of precipitation changes for temperate forests (NF R'Equip) Research Project | 2 Project MembersRising global temperatures, fewer number of precipitation days and an increased intensity of drought events are projected to shape the future climate of central Europe. Changes in water availability and more intense drought events will have significant impacts on the central European vegetation and on temperate European forests in particular. Importantly, critical mechanisms that determine how changes in water availability and drought will impact the functioning of temperate European forests are poorly understood and not well represented in earth system models. Anticipating the consequences of a future climate for the functioning of temperate European forests is therefore difficult and hinders the design of mitigation options and future forest management plans. Most experiments that attempt to improve the mechanistic understanding of drought responses of terrestrial ecosystem have to date focused either on the experimental manipulation of grasslands or on investigations with tree seedlings or saplings. Although forests play an essential role for the delivery of ecosystem goods and services, very few experiments exist in established temperate European forests that mechanistically investigate the responses of mature trees and forest to changes in water availability or drought. To close this critical research gap, it is the goal of this proposal to establish an experimental research platform in a species rich and mature temperate forest in Switzerland. This experimental platform will provide the opportunity over the next two decades to host research projects addressing some of the most important unresolved questions with respect to tree and forests responses to changes in the precipitation regime and drought. Specifically, these projects will address the long-term acclimation potential of individual species or entire forests to precipitation changes, physiological and biogeochemical thresholds and tipping points during drought, and recovery processes during and after extended drought events. The experimental research platform that we seek to establish will combine a unique infrastructure that we request with this proposal. This infrastructure will include (i) a canopy crane that will allow scientific investigations in the canopy of more than 250 mature trees, (ii) six mobile roofs that will be installed 2.5 m above the ground and will cover a total area of 3398 m2 for the manipulation of precipitation inputs into the forest, and (iii) state of the art scientific instrumentation. Vergleich der Trockenheitstoleranz Schweizer Waldbaumarten Research Project | 2 Project MembersDie Gefährdung heimischer Baumarten durch die zunehmende Häufigkeit von heissen und trockenen Sommern wird in der forstlichen Praxis intensiv diskutiert. Die Auswahl von «Zukunftsbaumarten», die sowohl eine hohe Toleranz gegenüber diesen Extremen zeigen, als auch die zahlreichen wirtschaftlichen und landeskulturellen Waldleistungen garantieren, ist der Schlüssel für eine klimagerechte Waldwirtschaft. Die nach der extremen Trockenheit im Jahr 2018 beobachteten Schäden im Schweizer Wald haben die Diskussion über Zukunftsbaumarten neu entfacht. Das vorliegende Projekt der Universität Basel soll einen wichtigen Beitrag leisten, um anhand von vergleichenden wachstumskundlichen und ökophysiologischen Untersuchungen Zukunftsbaumarten für den Schweizer Wald zu identifizieren. A novel through fall exclusion experiment to assess the physiological and biogechemical consequences of precipitation changes for temperate forests Research Project | 2 Project MembersNo Description available Revealing the genomic signature of tomato domestication in Europe using Caspar Bauhin's (1560-1624) herbarium specimens. Research Project | 1 Project MembersThe herbarium of Caspar Bauhin (1560-1624) at the Department of Environmental Sciences of the University of Basel is among the oldest surviving worldwide. Because techniques for ancient DNA analysis have progressed substantially in recent years, we have been able to extract DNA from three of Bauhin's tomato specimens (Solanum lycopersicum L.) of a quality that allows for sequencing their whole genomes. We request funding to sequence these genomes, as well as those from another three specimens stored at the Herbaria Basel and collected between 1730 and 1836 (Fig. 1). Combined with data from an ongoing, funded project that emphasizes herbarium and modern specimens collected between 1900 and the present, this project will allow us to trace more than 400 years of tomato domestication in Europe using genomic data. Domestication is an important model of plant evolution. Therefore, our results will not only inform our understanding of the genetic basis of "useful" traits in one of the most important crops worldwide; it will also shed light on the genetic basis of adaptation more generally. The requested laboratory expenses are hard to fund elsewhere and the project is intimately tied to the history of botany in Basel since the 16th century. Therefore, the project matches the goals of the Basler Stiftung für biologische Forschung well. Using millet-legume model intercropping systems to establish mycorrhiza-facilitated bioirrigation in dryland agriculture Research Project | 3 Project MembersIn the years to come, sustainable land use is one of the big challenges for plant science. One promising low-input strategy is to make use of the potential of intercropping. In dryland agriculture, deep-rooting plants, intercropped within shallow-rooting ones, may act as "bioirrigators" that can transfer water from deep soil layers to the topsoil for the benefit of the system. Our recent experiments have shown that bioirrigation is facilitated by the presence of arbuscular mycorrhizal fungi (AMF), which connect the intercropped plants by a common mycorrhizal network (CMN). The ambition of the research that we propose in this project is to identify the morphological, physiological and competitive traits that make plants ideal bioirrigators in CMN facilitated intercropping systems. With this research we seek to establish the basic knowledge that will allow establish effective CMN facilitated bioirrigation in intercropping systems as a measure to stabilize and increase the yield of small holder or subsistence farmers in dryland agriculture. Cold root effects on water-uptake and C-relations in temperate tree species Research Project | 2 Project MembersPrevious studies indicated that low root zone temperatures can induce drought-like water shortage in trees, with severe consequences also for their C-household. The restricted water conductivity of roots cannot be explained by the increased viscosity of water at cold temperatures alone. The very high sensitivity against non-freezing, colder root temperatures rather suggests that the water uptake of roots is likely stronger dependent on active processes (e.g. via aquaporins) than is generally assumed. Cold root temperature induced drought-like stress might thus contribute to the observed growth restriction of trees at their cold limits. In this 4-year PhD project, we will built upon recent experiments at the University of Basel to deepen our understanding of cold root zone effects on temperature trees. We will investigate seedlings of different temperate tree species at warm air temperatures and different root temperatures by means of a temperature-controlled water bath system. Water- and nitrogen-uptake, as well as carbon assimilation at different root temperatures will be quantified by pulse labelling with stable isotopes ( 2 H-H 2 O and 15 N-NO 3 enriched water, 13 C-CO 2 enriched air). Especially, we will address the following questions: Is the water uptake capacity of tree species with low elevational distribution limits more sensitive to low root zone temperatures than in species with high elevation distribution limits? Is the strong restriction of the phloem C-transport at cold root temperatures leading to accumulated non-structural carbohydrate (NSC) reserves in the aboveground tissue of tree seedlings? Are trees, which are raised at colder temperatures better adapted to low root zone temperatures in terms of water-uptake and -transport, than trees raised at warmer temperatures (test for long-term acclimatization)? Is the magnitude of nitrogen (N) uptake and -transport at cold root zone temperatures restricted to the same magnitude as the uptake of water? Besides detailed physiological insights in cold soil effects on the water, carbon and nutrient household of temperate tree species, this project will provide important information for climate-growth models of trees in general, and it will contribute quantitative data for mechanistic tree species distribution models. 1234 1...4
Shifted snowmelt timing and recurrent summer drought in alpine grassland: deciphering the role of soil biota and symbiotic partners for the distinct plant species responses Research Project | 1 Project MembersImported from Grants Tool 4703035
From Bauhin to Lachenal: Enabling digital access to the historic 16th-18th century herbaria in Basel Research Project | 2 Project MembersThe scope of the project is enabling digital access to almost 10'000 singular historic (16th-18th century) herbarium specimens at the Herbaria Basel , by updating and expanding the digital information associated with five partially digitized, important historic herbaria following standards laid out in Frick & Greeff (2021). Meta-data for digital specimens will include all fields required for specimen filing and finding (physically, in the database, and online), such as collecting information (names, dates, administrative areas) and taxonomic information (determination, consistent name resolution, type status). This project is important because it promotes digital accessibility to important specimens : Accessibility and conservation of research-relevant data are a core task of herbaria and are within the scope of SwissCollNet. Our project mobilizes the information of close to 10'000 singular historic specimens and presents them online, besides via our institutional internet-portal (herbarium.unibas.ch, in development), also via Global Biodiversity Information Facility ( www.gbif.org ) and within the timeframe of the project also via Global Plants on JSTOR (plants.jstor.org). All data will also be integrated in the Swiss Virtual Natural History Collection portal (in development) by meeting established Swiss-wide standards.
In the footsteps of Sarasin and Christ: digitization of fern collections at the herbaria in Basel and Zürich Research Project | 2 Project MembersThe world's herbaria document the diversity of plant life across the globe and through time. Many of the first descriptions of plants were based on material stemming from rather adventurous collection expeditions and remarkable personalities. Therefore, many historic collections are simultaneously of exceptional cultural, historic, and scientific value, often interwoven with colonial history. This is particularly true for tropical regions. The Sarasin cousins (Karl Friedrich (Fritz), 1859-1942; and Paul Benedict, 1856-1929) from Basel are such remarkable personalities with profound impacts both on cultural and natural history. Being born wealthy in the upper societal echelons of Basel, their gay love was taboo, prompting them to spend their fortunes to make a career as scientific explorers in Asia, primarily in Ceylon (now Sri Lanka), Celebes (now Sulawesi, Indonesia) and New Caledonia (incl. the loyalty Islands, where Fritz was the first-ever plant collector; Schär 2015). By traveling and collecting in the largely uncontacted interiors of these places collaborating with colonial rulers, their expeditions had a political note, but also resulted in profound impacts on natural history. The collecting expeditions of the Sarasin cousins resulted in rich collections; estimated at ca. 300'000 specimens of gastropods, arthropods, birds, mammals, and spiders, as well as 680 ethnographic objects and 600 photographs from Celebes alone (Schär 2015). These specimens form important parts of the collections of the Natural History Museum and Museum of Cultures in Basel. Strikingly less known, but equally important, are the estimated 3000 botanical collections of the Sarasin cousins. These specimens were sent back to Switzerland, where they were examined and identified by specialists, resulting in a flurry of new species. Hermann Christ (1833-1933) of Basel, the world's primary fern specialist at the time, despite being professionally a lawyer, described at least 36 fern species from Celebes alone ("Filices Sarisinianae", Christ, 1894-97). These plants were then donated to the Herbarium of the University of Basel, but remained unincorporated. In Zurich, Hans Schinz (1858-1941) and colleagues treated the angiosperms from New Caledonia, a significant part of which were then donated to Basel for reasons unknown. The importance of the Sarasin collections is underlined by regular re-discovery of Type material (e.g. Chen et al. 2021), always in association with Christ's previous work on these specimens. Overall, Christ's influence on fern taxonomy is paramount, already from his ca. 310 papers and ca. 1800 basionyms that he published.
Asessing the drought response strategies of ten temperate tree species and their drought acclimation potential in a throughfall exclusion experiment in a mature forest Research Project | 5 Project MembersGlobal climate change and in particular changes in the hydroclimate towards dryer and warmer summers will impact the structure and composition of central European and other forests on the planet. The extremely hot and dry summers that Europe has experienced in 2003 and in 2018 have already demonstrated the severe impacts that a changing climate will have on tree and forest function and composition for these ecosystems. Critical mechanisms that determine how drought will impact the functioning of trees and forests are, however, poorly understood. This makes it difficult to anticipate the consequences of a future and dryer climate for key ecosystem functions and prevents the development of silvicultural management plants for more resistant and resilient forest ecosystems. Here we propose to close this gap and to address the effects of drought on mature trees from ten different temperate European species in a large-scale ecosystem manipulation experiment. From our work, we expect the following outcome: we will provide thefirst comprehensive empirical characterization of the drought response strategies of key temperate European tree species, we will identify the trait syndromes that govern the different drought response strategies in these species and will identify important tradeoffs between traits and function, we will provide one of the first large scale across-species assessments of the acclimation potential of mature temperate European tree species to reduced water availability and we will identify the key traits that are responsible for these acclimations.
A novel through fall exclusion experiment to assess the physiological and biogeochemical consequences of precipitation changes for temperate forests (NF R'Equip) Research Project | 2 Project MembersRising global temperatures, fewer number of precipitation days and an increased intensity of drought events are projected to shape the future climate of central Europe. Changes in water availability and more intense drought events will have significant impacts on the central European vegetation and on temperate European forests in particular. Importantly, critical mechanisms that determine how changes in water availability and drought will impact the functioning of temperate European forests are poorly understood and not well represented in earth system models. Anticipating the consequences of a future climate for the functioning of temperate European forests is therefore difficult and hinders the design of mitigation options and future forest management plans. Most experiments that attempt to improve the mechanistic understanding of drought responses of terrestrial ecosystem have to date focused either on the experimental manipulation of grasslands or on investigations with tree seedlings or saplings. Although forests play an essential role for the delivery of ecosystem goods and services, very few experiments exist in established temperate European forests that mechanistically investigate the responses of mature trees and forest to changes in water availability or drought. To close this critical research gap, it is the goal of this proposal to establish an experimental research platform in a species rich and mature temperate forest in Switzerland. This experimental platform will provide the opportunity over the next two decades to host research projects addressing some of the most important unresolved questions with respect to tree and forests responses to changes in the precipitation regime and drought. Specifically, these projects will address the long-term acclimation potential of individual species or entire forests to precipitation changes, physiological and biogeochemical thresholds and tipping points during drought, and recovery processes during and after extended drought events. The experimental research platform that we seek to establish will combine a unique infrastructure that we request with this proposal. This infrastructure will include (i) a canopy crane that will allow scientific investigations in the canopy of more than 250 mature trees, (ii) six mobile roofs that will be installed 2.5 m above the ground and will cover a total area of 3398 m2 for the manipulation of precipitation inputs into the forest, and (iii) state of the art scientific instrumentation.
Vergleich der Trockenheitstoleranz Schweizer Waldbaumarten Research Project | 2 Project MembersDie Gefährdung heimischer Baumarten durch die zunehmende Häufigkeit von heissen und trockenen Sommern wird in der forstlichen Praxis intensiv diskutiert. Die Auswahl von «Zukunftsbaumarten», die sowohl eine hohe Toleranz gegenüber diesen Extremen zeigen, als auch die zahlreichen wirtschaftlichen und landeskulturellen Waldleistungen garantieren, ist der Schlüssel für eine klimagerechte Waldwirtschaft. Die nach der extremen Trockenheit im Jahr 2018 beobachteten Schäden im Schweizer Wald haben die Diskussion über Zukunftsbaumarten neu entfacht. Das vorliegende Projekt der Universität Basel soll einen wichtigen Beitrag leisten, um anhand von vergleichenden wachstumskundlichen und ökophysiologischen Untersuchungen Zukunftsbaumarten für den Schweizer Wald zu identifizieren.
A novel through fall exclusion experiment to assess the physiological and biogechemical consequences of precipitation changes for temperate forests Research Project | 2 Project MembersNo Description available
Revealing the genomic signature of tomato domestication in Europe using Caspar Bauhin's (1560-1624) herbarium specimens. Research Project | 1 Project MembersThe herbarium of Caspar Bauhin (1560-1624) at the Department of Environmental Sciences of the University of Basel is among the oldest surviving worldwide. Because techniques for ancient DNA analysis have progressed substantially in recent years, we have been able to extract DNA from three of Bauhin's tomato specimens (Solanum lycopersicum L.) of a quality that allows for sequencing their whole genomes. We request funding to sequence these genomes, as well as those from another three specimens stored at the Herbaria Basel and collected between 1730 and 1836 (Fig. 1). Combined with data from an ongoing, funded project that emphasizes herbarium and modern specimens collected between 1900 and the present, this project will allow us to trace more than 400 years of tomato domestication in Europe using genomic data. Domestication is an important model of plant evolution. Therefore, our results will not only inform our understanding of the genetic basis of "useful" traits in one of the most important crops worldwide; it will also shed light on the genetic basis of adaptation more generally. The requested laboratory expenses are hard to fund elsewhere and the project is intimately tied to the history of botany in Basel since the 16th century. Therefore, the project matches the goals of the Basler Stiftung für biologische Forschung well.
Using millet-legume model intercropping systems to establish mycorrhiza-facilitated bioirrigation in dryland agriculture Research Project | 3 Project MembersIn the years to come, sustainable land use is one of the big challenges for plant science. One promising low-input strategy is to make use of the potential of intercropping. In dryland agriculture, deep-rooting plants, intercropped within shallow-rooting ones, may act as "bioirrigators" that can transfer water from deep soil layers to the topsoil for the benefit of the system. Our recent experiments have shown that bioirrigation is facilitated by the presence of arbuscular mycorrhizal fungi (AMF), which connect the intercropped plants by a common mycorrhizal network (CMN). The ambition of the research that we propose in this project is to identify the morphological, physiological and competitive traits that make plants ideal bioirrigators in CMN facilitated intercropping systems. With this research we seek to establish the basic knowledge that will allow establish effective CMN facilitated bioirrigation in intercropping systems as a measure to stabilize and increase the yield of small holder or subsistence farmers in dryland agriculture.
Cold root effects on water-uptake and C-relations in temperate tree species Research Project | 2 Project MembersPrevious studies indicated that low root zone temperatures can induce drought-like water shortage in trees, with severe consequences also for their C-household. The restricted water conductivity of roots cannot be explained by the increased viscosity of water at cold temperatures alone. The very high sensitivity against non-freezing, colder root temperatures rather suggests that the water uptake of roots is likely stronger dependent on active processes (e.g. via aquaporins) than is generally assumed. Cold root temperature induced drought-like stress might thus contribute to the observed growth restriction of trees at their cold limits. In this 4-year PhD project, we will built upon recent experiments at the University of Basel to deepen our understanding of cold root zone effects on temperature trees. We will investigate seedlings of different temperate tree species at warm air temperatures and different root temperatures by means of a temperature-controlled water bath system. Water- and nitrogen-uptake, as well as carbon assimilation at different root temperatures will be quantified by pulse labelling with stable isotopes ( 2 H-H 2 O and 15 N-NO 3 enriched water, 13 C-CO 2 enriched air). Especially, we will address the following questions: Is the water uptake capacity of tree species with low elevational distribution limits more sensitive to low root zone temperatures than in species with high elevation distribution limits? Is the strong restriction of the phloem C-transport at cold root temperatures leading to accumulated non-structural carbohydrate (NSC) reserves in the aboveground tissue of tree seedlings? Are trees, which are raised at colder temperatures better adapted to low root zone temperatures in terms of water-uptake and -transport, than trees raised at warmer temperatures (test for long-term acclimatization)? Is the magnitude of nitrogen (N) uptake and -transport at cold root zone temperatures restricted to the same magnitude as the uptake of water? Besides detailed physiological insights in cold soil effects on the water, carbon and nutrient household of temperate tree species, this project will provide important information for climate-growth models of trees in general, and it will contribute quantitative data for mechanistic tree species distribution models.
