@article{SchiffersSchurrTielboergeretal.2008, author = {Schiffers, Katja and Schurr, Frank Martin and Tielb{\"o}rger, Katja and Urbach, Carsten and Moloney, Kirk A. and Jeltsch, Florian}, title = {Dealing with virtual aggregation : a new index for analysing heterogeneous point patterns}, issn = {0906-7590}, doi = {10.1111/j.0906-7590.2008.05374.x}, year = {2008}, language = {en} } @article{JeltschBlaumBroseetal.2013, author = {Jeltsch, Florian and Blaum, Niels and Brose, Ulrich and Chipperfield, Joseph D. and Clough, Yann and Farwig, Nina and Geissler, Katja and Graham, Catherine H. and Grimm, Volker and Hickler, Thomas and Huth, Andreas and May, Felix and Meyer, Katrin M. and Pagel, J{\"o}rn and Reineking, Bj{\"o}rn and Rillig, Matthias C. and Shea, Katriona and Schurr, Frank Martin and Schroeder, Boris and Tielb{\"o}rger, Katja and Weiss, Lina and Wiegand, Kerstin and Wiegand, Thorsten and Wirth, Christian and Zurell, Damaris}, title = {How can we bring together empiricists and modellers in functional biodiversity research?}, series = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, volume = {14}, journal = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, number = {2}, publisher = {Elsevier}, address = {Jena}, issn = {1439-1791}, doi = {10.1016/j.baae.2013.01.001}, pages = {93 -- 101}, year = {2013}, abstract = {Improving our understanding of biodiversity and ecosystem functioning and our capacity to inform ecosystem management requires an integrated framework for functional biodiversity research (FBR). However, adequate integration among empirical approaches (monitoring and experimental) and modelling has rarely been achieved in FBR. We offer an appraisal of the issues involved and chart a course towards enhanced integration. A major element of this path is the joint orientation towards the continuous refinement of a theoretical framework for FBR that links theory testing and generalization with applied research oriented towards the conservation of biodiversity and ecosystem functioning. We further emphasize existing decision-making frameworks as suitable instruments to practically merge these different aims of FBR and bring them into application. This integrated framework requires joint research planning, and should improve communication and stimulate collaboration between modellers and empiricists, thereby overcoming existing reservations and prejudices. The implementation of this integrative research agenda for FBR requires an adaptation in most national and international funding schemes in order to accommodate such joint teams and their more complex structures and data needs.}, language = {en} } @article{SporbertJakubkaBucheretal.2022, author = {Sporbert, Maria and Jakubka, Desiree and Bucher, Solveig Franziska and Hensen, Isabell and Freiberg, Martin and Heubach, Katja and K{\"o}nig, Andreas and Nordt, Birgit and Plos, Carolin and Blinova, Ilona and Bonn, Aletta and Knickmann, Barbara and Koubek, Tom{\´a}š and Linst{\"a}dter, Anja and Maškov{\´a}, Tereza and Primack, Richard B. and Rosche, Christoph and Shah, Manzoor A. and Stevens, Albert-Dieter and Tielb{\"o}rger, Katja and Tr{\"a}ger, Sabrina and Wirth, Christian and R{\"o}mermann, Christine}, title = {Functional traits influence patterns in vegetative and reproductive plant phenology - a multi-botanical garden study}, series = {New phytologist}, volume = {235}, journal = {New phytologist}, number = {6}, publisher = {Wiley}, address = {Hoboken}, issn = {0028-646X}, doi = {10.1111/nph.18345}, pages = {2199 -- 2210}, year = {2022}, abstract = {Phenology has emerged as key indicator of the biological impacts of climate change, yet the role of functional traits constraining variation in herbaceous species' phenology has received little attention. Botanical gardens are ideal places in which to investigate large numbers of species growing under common climate conditions. We ask whether interspecific variation in plant phenology is influenced by differences in functional traits. We recorded onset, end, duration and intensity of initial growth, leafing out, leaf senescence, flowering and fruiting for 212 species across five botanical gardens in Germany. We measured functional traits, including plant height, absolute and specific leaf area, leaf dry matter content, leaf carbon and nitrogen content and seed mass and accounted for species' relatedness. Closely related species showed greater similarities in timing of phenological events than expected by chance, but species' traits had a high degree of explanatory power, pointing to paramount importance of species' life-history strategies. Taller plants showed later timing of initial growth, and flowered, fruited and underwent leaf senescence later. Large-leaved species had shorter flowering and fruiting durations. Taller, large-leaved species differ in their phenology and are more competitive than smaller, small-leaved species. We assume climate warming will change plant communities' competitive hierarchies with consequences for biodiversity.}, language = {en} } @article{SchmidtWalzMartinLopezetal.2017, author = {Schmidt, Katja and Walz, Ariane and Martin-Lopez, Berta and Sachse, Rene}, title = {Testing socio-cultural valuation methods of ecosystem services to explain land use preferences}, series = {Ecosystem Services : Science, Policy and Practice}, volume = {26}, journal = {Ecosystem Services : Science, Policy and Practice}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2212-0416}, doi = {10.1016/j.ecoser.2017.07.001}, pages = {270 -- 288}, year = {2017}, abstract = {Socio-cultural valuation still emerges as a methodological field in ecosystem service (ES) research and until now lacks consistent formalisation and balanced application in ES assessments. In this study, we examine the explanatory value of ES values for land use preferences. We use 563 responses to a survey about the Pentland Hills regional park in Scotland. Specifically, we aim to (1) identify clusters of land use preferences by using a novel visualisation tool, (2) test if socio-cultural values of ESs or (3) user characteristics are linked with land use preferences, and (4) determine whether both socio-cultural values of ESs and user characteristics can predict land use preferences. Our results suggest that there are five groups of people with different land use preferences, ranging from forest and nature enthusiasts to traditionalists, multi-functionalists and recreation seekers. Rating and weighting of ESs and user characteristics were associated with different clusters. Neither socio-cultural values nor user characteristics were suitable predictors for land use preferences. While several studies have explored land use preferences by identifying socio-cultural values in the past, our findings imply that in this case study ES values inform about general perceptions but do not replace the assessment of land use preferences. (C) 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license.}, language = {en} } @article{PlathKromuszczynskiTiedemann2009, author = {Plath, Martin and Kromuszczynski, Katja and Tiedemann, Ralph}, title = {Audience effect alters male but not female mating preferences}, issn = {0340-5443}, doi = {10.1007/s00265-008-0672-7}, year = {2009}, abstract = {Males often face strong mating competition by neighboring males in their social environment. A recent study by Plath et al. (Anim Behav 75:21-29, 2008a) has demonstrated that the visual presence of a male competitor (i.e., an audience male) affects the expression of male mating preferences in a poeciliid fish (Poecilia mexicana) with a weaker expression of mating preferences when an audience male observed the focal male. This may be a tactic to reduce sperm competition, since surrounding males likely share intrinsic preferences for female traits or copy mate choice decisions. Here, we examined the hypothesis that a same-sex audience would affect female mate preferences less than male mating preferences. Our hypothesis was based on the assumptions that (1) competition for mates in a fashion that would be comparable in strength to sperm competition or overt male-male aggression is absent among Poecilia females, and (2) P. mexicana females typically form female-biased shoals, such that almost any female mate choice in nature occurs in front of a female audience. Poecilia females (P. mexicana, surface and cave form, and the closely related gynogenetic Poecilia formosa) were given a choice between a large and a small male, and the tests were repeated while a conspecific, a heterospecific, or no audience female (control) was presented. Females spent more time in the neutral zone and, thus, less time near the males during the second part of a trial when an audience was presented, but-consistent with predictions-females showed only slightly weaker expression of mate preferences during the second part of the tests. This decline was not specific to the treatment involving an audience and was significantly weaker than the effect seen in the male sex.}, language = {en} } @article{TiedemannSchneiderHavensteinetal.2014, author = {Tiedemann, Ralph and Schneider, Anja R. R. and Havenstein, Katja and Blanck, Torsten and Meier, Elmar and Raffel, Martina and Zwartepoorte, Henk and Plath, Martin}, title = {New microsatellite markers allow high-resolution taxon delimitation in critically endangered Asian box turtles, genus Cuora}, series = {Salamandra : German journal of herpetology}, volume = {50}, journal = {Salamandra : German journal of herpetology}, number = {3}, publisher = {Deutsche Gesellschaft f{\"u}r Herpetologie und Terrarienkunde}, address = {Darmstadt}, issn = {0036-3375}, pages = {139 -- 146}, year = {2014}, abstract = {We isolated and characterized 16 new di- and tetranudeotide microsatellite markers for the critically endangered Asian box turtle genus Cuora, focusing on the "Cuora trifasciata" species complex. The new markers were then used to analyse genetic variability and divergence amongst five described species within this complex, namely C. aurocapitata (n = 18), C. cyclornata (n = 31), C. pani (n = 6), C. trifasciata (n = 58), and C. zhoui (n = 7). Our results support the view that all five species represent valid taxa. Within two species (C. trifasciata and C. cyclornata), two distinct morphotypes were corroborated by microsatellite divergence. For three individuals, morphologically identified as being of hybrid origin, the hybrid status was confirmed by our genetic analysis. Our results confirm the controversial species (Cuora aurocapitata, C. cyclornata) and subspecies/morphotypes (C. cyclornata meieri, C. trifasciata cf. trifasciata) to be genetically distinct, which has critical implications for conservation strategies.}, language = {en} } @article{KoechyTielboerger2007, author = {K{\"o}chy, Martin and Tielb{\"o}rger, Katja}, title = {Hydrothermal time model of germination : parameters for 36 Mediterranean annual species based on a simplified approach}, issn = {1439-1791}, doi = {10.1016/j.baae.2006.04.002}, year = {2007}, abstract = {Germination rates and germination fractions of seeds can be predicted well by the hydrothermal time (HTT) model. Its four parameters hydrothermal time, minimum soil temperature, minimum soil moisture, and variation of minimum soil moisture, however, must be determined by lengthy germination experiments at combinations of several levels of soil temperature and moisture. For some applications of the HTT model it is more important to have approximate estimates for many species rather than exact values for only a few species. We suggest that minimum temperature and variation of minimum moisture can be estimated from literature data and expert knowledge. This allows to derive hydrothermal time and minimum moisture from existing data from germination experiments with one level of temperature and moisture. We applied our approach to a germination experiment comparing germination fractions of wild annual species along an aridity gradient in Israel. Using this simplified approach we estimated hydrothermal time and minimum moisture of 36 species. Comparison with exact data for three species shows that our method is a simple but effective method for obtaining parameters for the HTT model. Hydrothermal time and minimum moisture supposedly indicate climate related germination strategies. We tested whether these two parameters varied with the climate at the site where the seeds had been collected. We found no consistent variation with climate across species, suggesting that variation is more strongly controlled by site-specific factors.Abstract auch auf deutsch vorhanden:Keimungsgeschwindigkeit und Anteil gekeimter Samen lassen sich gut mit dem Hydrothermalzeit-Modell bestimmen. Dessen vier Parameter Hydrothermalzeit, Mindesttemperatur, Mindestbodenfeuchte und Streuung der Mindestbodenfeuchte m{\"u}ssen jedoch durch aufwendige Keimungsversuche bei Kombinationen von mehreren Temperatur- und Feuchtigkeitsstufen bestimmt werden. F{\"u}r manche Anwendungen des Hydrothermalzeit-Modells sind aber ungef{\"a}hre Werte f{\"u}r viele Arten wichtiger als genaue Werte f{\"u}r wenige Arten. Wenn die Mindesttemperatur und die Streuung der Mindestfeuchte aus Ver{\"o}ffentlichungen und Expertenwissen gesch{\"a}tzt w{\"u}rde, k{\"o}nnen die Hydrothermalzeit und Mindestbodenfeuchte aus vorhandenen Daten von Keimungsversuchen mit nur einer Temperatur- und Feuchtigkeitsstufe berechnet werden. Wir haben unseren Ansatz auf einen Keimungsversuch zum Vergleich der Keimungsquote wilder einj{\"a}hriger Arten entlang eines Trockenheitsgradienten in Israel angewendet. Mit diesem Ansatz bestimmten wir die Hydrothermalzeit und Mindestfeuchtigkeit von 36 Arten. Der Vergleich mit genauen Werten f{\"u}r drei Arten zeigt, dass mit unserem Ansatz Hydrothermalzeit-Parameter einfach und effektiv bestimmt werden k{\"o}nnen. Hydrothermalzeit und Mindestfeuchtigkeit sollten auch bestimmte klimabedingte Keimungsstrategien anzeigen. Deshalb testeten wir, ob diese zwei Parameter mit dem Klima am Ursprungsort der Samen zusammenh{\"a}ngen. Wir fanden jedoch keinen f{\"u}r alle Arten {\"u}bereinstimmenden Zusammenhang, so dass die Unterschiede vermutlich st{\"a}rker durch stand{\"o}rtliche als durch klimatische Ursachen hervorgerufen werden.}, language = {en} } @article{PlathSeggelBurmeisteretal.2006, author = {Plath, Martin and Seggel, Uta and Burmeister, Heike and Heubel, Katja U. and Schlupp, Ingo}, title = {Choosy males from the underground : male mating preferences in surface- and cave-dwelling Atlantic mollies (Poecilia mexicana)}, doi = {10.1007/s00114-005-0072-z}, year = {2006}, abstract = {Atlantic mollies (Poecilia mexicana) inhabit a variety of surface habitats, but they also occur in a sulfur cave in southern Mexico. We examined male mate choice relative to female body size in the cave population and in the most closely related surface-dwelling population from a nearby river. Males from both populations were either light- or dark-reared and could choose between two differently sized females either on the basis of visual cues in light or on the basis of solely nonvisual cues in darkness. Sexual preferences were estimated from the degree of association. Cave molly males always showed a preference for the larger female, both in light and in darkness. Among the surface males, only light-reared males showed a preference in the visual cues test, but not in darkness. In a control experiment, we demonstrated that male association preferences directly translate into actual mating preferences. Apparently, using visual cues for mate choice is the ancestral state in this system, and using nonvisual cues has evolved as a novel trait in the cave population. We discuss the evolution of nonvisual male mate choice in the context of changed environmental conditions, namely the absence of light, hypoxia, and toxic hydrogen sulfide in the cave}, language = {en} } @article{LauchtHohmEsseretal.2007, author = {Laucht, Manfred and Hohm, E. and Esser, G{\"u}nter and Schmidt, Martin H. and Becker, Katja}, title = {Association between ADHD and smoking in adolescence : shared genetic, environmental and psychopathological factors}, issn = {0300-9564}, doi = {10.1007/s00702-007-0703-y}, year = {2007}, abstract = {The present study aimed to examine the extent to which the co-occurrence of ADHD and smoking in adolescents could be attributed to common genetic, environmental and psychopathological factors. Data are from an ongoing prospective study of the outcome of early risk factors. At age 15 years, 305 adolescents completed self-report questionnaires measuring tobacco consumption and deviant peer affiliations. Lifetime psychiatric diagnoses were obtained using standardized interviews. DNA was genotyped for the dopamine D4 receptor (DRD4) gene exon III polymorphism. Adolescents with a lifetime diagnosis of ADHD displayed significantly higher smoking activity than non-ADHD controls. A major component of this association could be accounted for by deviant peer affiliations and the comorbidity with oppositional-defiant and conduct disorder, while a minor part was attributable to DRD4 in males but not in females. These findings suggest that the association of ADHD with smoking relies on risk factors shared by the two behaviors.}, language = {en} } @misc{KoechyTielboerger2006, author = {K{\"o}chy, Martin and Tielb{\"o}rger, Katja}, title = {Hydrothermal time model of germination : parameters for 36 Mediterranean annual species based on a simplified approach}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-12406}, year = {2006}, abstract = {Germination rates and germination fractions of seeds can be predicted well by the hydrothermal time (HTT) model. Its four parameters hydrothermal time, minimum soil temperature, minimum soil moisture, and variation of minimum soil moisture, however, must be determined by lengthy germination experiments at combinations of several levels of soil temperature and moisture. For some applications of the HTT model it is more important to have approximate estimates for many species rather than exact values for only a few species. We suggest that minimum temperature and variation of minimum moisture can be estimated from literature data and expert knowledge. This allows to derive hydrothermal time and minimum moisture from existing data from germination experiments with one level of temperature and moisture. We applied our approach to a germination experiment comparing germination fractions of wild annual species along an aridity gradient in Israel. Using this simplified approach we estimated hydrothermal time and minimum moisture of 36 species. Comparison with exact data for three species shows that our method is a simple but effective method for obtaining parameters for the HTT model. Hydrothermal time and minimum moisture supposedly indicate climate related germination strategies. We tested whether these two parameters varied with the climate at the site where the seeds had been collected. We found no consistent variation with climate across species, suggesting that variation is more strongly controlled by site-specific factors.}, language = {en} }