@article{BergholzSittelRistowetal.2022, author = {Bergholz, Kolja and Sittel, Lara-Pauline and Ristow, Michael and Jeltsch, Florian and Weiss, Lina}, title = {Pollinator guilds respond contrastingly at different scales to landscape parameters of land-use intensity}, series = {Ecology and evolution}, volume = {12}, journal = {Ecology and evolution}, number = {3}, publisher = {Wiley}, address = {Hoboken}, issn = {2045-7758}, doi = {10.1002/ece3.8708}, pages = {11}, year = {2022}, abstract = {Land-use intensification is the main factor for the catastrophic decline of insect pollinators. However, land-use intensification includes multiple processes that act across various scales and should affect pollinator guilds differently depending on their ecology. We aimed to reveal how two main pollinator guilds, wild bees and hoverflies, respond to different land-use intensification measures, that is, arable field cover (AFC), landscape heterogeneity (LH), and functional flower composition of local plant communities as a measure of habitat quality. We sampled wild bees and hoverflies on 22 dry grassland sites within a highly intensified landscape (NE Germany) within three campaigns using pan traps. We estimated AFC and LH on consecutive radii (60-3000 m) around the dry grassland sites and estimated the local functional flower composition. Wild bee species richness and abundance was positively affected by LH and negatively by AFC at small scales (140-400 m). In contrast, hoverflies were positively affected by AFC and negatively by LH at larger scales (500-3000 m), where both landscape parameters were negatively correlated to each other. At small spatial scales, though, LH had a positive effect on hoverfly abundance. Functional flower diversity had no positive effect on pollinators, but conspicuous flowers seem to attract abundance of hoverflies. In conclusion, landscape parameters contrarily affect two pollinator guilds at different scales. The correlation of landscape parameters may influence the observed relationships between landscape parameters and pollinators. Hence, effects of land-use intensification seem to be highly landscape-specific.}, language = {en} } @article{BergholzSittelRistowetal.2022, author = {Bergholz, Kolja and Sittel, Lara-Pauline and Ristow, Michael and Jeltsch, Florian and Weiß, Lina}, title = {Pollinator guilds respond contrastingly at different scales to landscape parameters of land-use intensity}, series = {Ecology and Evolution}, volume = {12}, journal = {Ecology and Evolution}, number = {3}, publisher = {John Wiley \& Sons, Inc.}, address = {Hoboken (New Jersey)}, issn = {2045-7758}, doi = {10.1002/ece3.8708}, pages = {11}, year = {2022}, abstract = {Land-use intensification is the main factor for the catastrophic decline of insect pollinators. However, land-use intensification includes multiple processes that act across various scales and should affect pollinator guilds differently depending on their ecology. We aimed to reveal how two main pollinator guilds, wild bees and hoverflies, respond to different land-use intensification measures, that is, arable field cover (AFC), landscape heterogeneity (LH), and functional flower composition of local plant communities as a measure of habitat quality. We sampled wild bees and hoverflies on 22 dry grassland sites within a highly intensified landscape (NE Germany) within three campaigns using pan traps. We estimated AFC and LH on consecutive radii (60-3000 m) around the dry grassland sites and estimated the local functional flower composition. Wild bee species richness and abundance was positively affected by LH and negatively by AFC at small scales (140-400 m). In contrast, hoverflies were positively affected by AFC and negatively by LH at larger scales (500-3000 m), where both landscape parameters were negatively correlated to each other. At small spatial scales, though, LH had a positive effect on hoverfly abundance. Functional flower diversity had no positive effect on pollinators, but conspicuous flowers seem to attract abundance of hoverflies. In conclusion, landscape parameters contrarily affect two pollinator guilds at different scales. The correlation of landscape parameters may influence the observed relationships between landscape parameters and pollinators. Hence, effects of land-use intensification seem to be highly landscape-specific.}, language = {en} } @misc{BergholzSittelRistowetal.2022, author = {Bergholz, Kolja and Sittel, Lara-Pauline and Ristow, Michael and Jeltsch, Florian and Weiß, Lina}, title = {Pollinator guilds respond contrastingly at different scales to landscape parameters of land-use intensity}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1298}, issn = {1866-8372}, doi = {10.25932/publishup-57730}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-577307}, pages = {11}, year = {2022}, abstract = {Land-use intensification is the main factor for the catastrophic decline of insect pollinators. However, land-use intensification includes multiple processes that act across various scales and should affect pollinator guilds differently depending on their ecology. We aimed to reveal how two main pollinator guilds, wild bees and hoverflies, respond to different land-use intensification measures, that is, arable field cover (AFC), landscape heterogeneity (LH), and functional flower composition of local plant communities as a measure of habitat quality. We sampled wild bees and hoverflies on 22 dry grassland sites within a highly intensified landscape (NE Germany) within three campaigns using pan traps. We estimated AFC and LH on consecutive radii (60-3000 m) around the dry grassland sites and estimated the local functional flower composition. Wild bee species richness and abundance was positively affected by LH and negatively by AFC at small scales (140-400 m). In contrast, hoverflies were positively affected by AFC and negatively by LH at larger scales (500-3000 m), where both landscape parameters were negatively correlated to each other. At small spatial scales, though, LH had a positive effect on hoverfly abundance. Functional flower diversity had no positive effect on pollinators, but conspicuous flowers seem to attract abundance of hoverflies. In conclusion, landscape parameters contrarily affect two pollinator guilds at different scales. The correlation of landscape parameters may influence the observed relationships between landscape parameters and pollinators. Hence, effects of land-use intensification seem to be highly landscape-specific.}, language = {en} } @article{RistowPanitsaMeyeretal.2022, author = {Ristow, Michael and Panitsa, Maria and Meyer, Stefan and Bergmeier, Erwin}, title = {Factors of detection deficits in vascular plant inventories - an island case study}, series = {Diversity}, volume = {14}, journal = {Diversity}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {1424-2818}, doi = {10.3390/d14040303}, pages = {12}, year = {2022}, abstract = {The degree of completeness of large-scale floristic inventories is often difficult to judge. We compared prior vascular plant species inventories of the Mediterranean island of Limnos (North Aegean, Greece) with 231 recent records from 2016-2021. Together with the recent records, the known number of vascular plant species on the island is 960 native taxa, 63 established neophytes, and 27 species of as yet casual status for a total of 1050 taxa. We looked at a number of traits (plant family, size, flower color, perceptibility, habitat, reproduction period, rarity, and status) to investigate whether they were overrepresented in the dataset of the newly found taxa. Overrepresentation was found in some plant families (e.g., Poaceae and Chenopodiaceae) and for traits such as hydrophytic life form, unobtrusive flower color, coastal as well as agricultural and ruderal habitats, and late (summer/autumn) reproduction period. Apart from the well-known fact of esthetic bias, we found evidence for ecological and perceptibility biases. Plant species inventories based on prior piecemeal collated data should focus on regionally specific species groups and underrepresented and rare habitats.}, language = {en} } @article{VonRaabStraubeRausBazosetal.2019, author = {Von Raab-Straube, Eckhard and Raus, Thomas and Bazos, Ioannis and Cornec, J. P. and De Belair, Gerard. and Dimitrakopoulos, P. G. and El Mokni, Ridha and Fateryga, Alexander V. and Fateryga, Valentina V. and Fridlender, Alain and Gil, Jaime and Grigorenko, V. N. and Hand, Ralf and Kovalchuk, A. and Mastrogianni, A. and Otto, R. and R{\"a}tzel, Stefan and Raus, Th. and Ristow, Michael and Salas Pascual, M. and Strid, Arne and Svirin, S. A. and Tsiripidis, Ioannis. and Uhlich, Holger and Vela, Errol and Verloove, Filip and Vidakis, K. and Yena, Andriy Vasylyovych and Yevseyenkov, P. E. and Zeddam, A.}, title = {Euro plus Med-Checklist Notulae, 11}, series = {Willdenowia}, volume = {49}, journal = {Willdenowia}, number = {3}, publisher = {Botanischer Garten \& botanisches Museum Berlin-Dahlem}, address = {Berlin}, issn = {0511-9618}, doi = {10.3372/wi.49.49312}, pages = {421 -- 445}, year = {2019}, abstract = {This is the eleventh of a series of miscellaneous contributions, by various authors, where hitherto unpublished data relevant to both the Med-Checklist and the Euro+Med (or Sisyphus) projects are presented. This instalment deals with the families Anacardiaceae, Asparagaceae (incl. Hyacinthaceae), Bignoniaceae, Cactaceae, Compositae, Cruciferae, Cyperaceae, Ericaceae, Gramineae, Labiatae, Leguminosae, Orobanchaceae, Polygonaceae, Rosaceae, Solanaceae and Staphyleaceae. It includes new country and area records and taxonomic and distributional considerations for taxa in Bidens, Campsis, Centaurea, Cyperus, Drymocallis, Engem, Hoffmannseggia, Hypopitys, Lavandula, Lithraea, Melilotus, Nicotiana, Olimarabidopsis, Opuntia, Orobanche, Phelipanche, Phragmites, Rumex, Salvia, Schinus, Staphylea, and a new combination in Drimia.}, language = {en} } @article{BergholzMayRistowetal.2017, author = {Bergholz, Kolja and May, Felix and Ristow, Michael and Giladi, Itamar and Ziv, Yaron and Jeltsch, Florian}, title = {Two Mediterranean annuals feature high within-population trait variability and respond differently to a precipitation gradient}, series = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, volume = {25}, journal = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, publisher = {Elsevier}, address = {Jena}, issn = {1439-1791}, doi = {10.1016/j.baae.2017.11.001}, pages = {48 -- 58}, year = {2017}, abstract = {Intraspecific trait variability plays an important role in species adaptation to climate change. However, it still remains unclear how plants in semi-arid environments respond to increasing aridity. We investigated the intraspecific trait variability of two common Mediterranean annuals (Geropogon hybridus and Crupina crupinastrum) with similar habitat preferences. They were studied along a steep precipitation gradient in Israel similar to the maximum predicted precipitation changes in the eastern Mediterranean basin (i.e. -30\% until 2100). We expected a shift from competitive ability to stress tolerance with decreasing precipitation and tested this expectation by measuring key functional traits (canopy and seed release height, specific leaf area, N-and P-leaf content, seed mass). Further, we evaluated generative bet-hedging strategies by different seed traits. Both species showed different responses along the precipitation gradient. C. crupinastrum exhibited only decreased plant height toward saridity, while G. hybridus showed strong trends of generative adaptation to aridity. Different seed trait indices suggest increased bet-hedging of G. hybridus in arid environments. However, no clear trends along the precipitation gradient were observed in leaf traits (specific leaf area and leaf N-/P-content) in both species. Moreover, variance decomposition revealed that most of the observed trait variation (>> 50\%) is found within populations. The findings of our study suggest that responses to increased aridity are highly species-specific and local environmental factors may have a stronger effect on intraspecific trait variation than shifts in annual precipitation. We therefore argue that trait-based analyses should focus on precipitation gradients that are comparable to predicted precipitation changes and compare precipitation effects to effects of local environmental factors. (C) 2017 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved.}, language = {en} } @article{BergholzMayGiladietal.2017, author = {Bergholz, Kolja and May, Felix and Giladi, Itamar and Ristow, Michael and Ziv, Yaron and Jeltsch, Florian}, title = {Environmental heterogeneity drives fine-scale species assembly and functional diversity of annual plants in a semi-arid environment}, series = {Perspectives in plant ecology, evolution and systematics}, volume = {24}, journal = {Perspectives in plant ecology, evolution and systematics}, publisher = {Elsevier}, address = {Jena}, issn = {1433-8319}, doi = {10.1016/j.ppees.2017.01.001}, pages = {138 -- 146}, year = {2017}, abstract = {Spatial environmental heterogeneity is considered a fundamental factor for the maintenance of plant species richness. However, it still remains unclear whether heterogeneity may also facilitate coexistence at fine grain sizes or whether other processes, like mass effects and source sink dynamics due to dispersal, control species composition and diversity at these scales. In this study, we used two complimentary analyses to identify the role of heterogeneity within 15 m x 15 m plots for the coexistence of species-rich annual communities in a semi-arid environment along a steep precipitation gradient. Specifically, we: (a) analyzed the effect of environmental heterogeneity on species, functional and phylogenetic diversity within microsites (alpha diversity, 0.06 m(2) and 1 m(2)), across microsites (beta diversity), and diversity at the entire plot (gamma diversity); (b) further we used two null models to detect non-random trait and phylogenetic patterns in order to infer assembly processes, i.e. whether co-occurring species tend to share similar traits (trait convergence) or dissimilar traits (trait divergence). In general, our results showed that heterogeneity had a positive effect on community diversity. Specifically, for alpha diversity, the effect was significant for functional diversity, and not significant for either species or phylogenetic diversities. For beta diversity, all three measures of community diversity (species, functional, and phylogenetic) increased significantly, as they also did for gamma diversity, where functional measures were again stronger than for species or phylogenetic measures. In addition, the null model approach consistently detected trait convergence, indicating that species with similar traits tended to co-occur and had high abundances in a given microsite. While null model analysis across the phylogeny partly supported these trait findings, showing phylogenetic underdispersion at the 1m(2) grain size, surprisingly when species abundances in microsites were analyzed they were more evenly distributed across the phylogenetic tress than expected (phylogenetic overdispersion). In conclusion, our results provide compelling support that environmental heterogeneity at a relatively fine scale is an important factor for species co-existence as it positively affects diversity as well as influences species assembly. Our study underlines the need for trait-based approaches conducted at fine grain sizes in order to better understand species coexistence and community assembly. (C) 2017 Elsevier GmbH. All rights reserved.}, language = {en} } @misc{MuellerSchulzLauterbachetal.2016, author = {M{\"u}ller, Christina M. and Schulz, Benjamin and Lauterbach, Daniel and Ristow, Michael and Wissemann, Volker and Gemeinholzer, Birgit}, title = {Geropogon hybridus (L.) Sch.Bip. (Asteraceae) exhibits micro-geographic genetic divergence at ecological range limits along a steep precipitation gradient}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, number = {832}, issn = {1866-8372}, doi = {10.25932/publishup-42706}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427061}, pages = {16}, year = {2016}, abstract = {We analyzed the population genetic pattern of 12 fragmented Geropogon hybridus ecological range edge populations in Israel along a steep precipitation gradient. In the investigation area (45 x 20 km(2)), the annual mean precipitation changes rapidly from 450 mm in the north (Mediterranean-influenced climate zone) to 300 mm in the south (semiarid climate zone) without significant temperature changes. Our analysis (91 individuals, 12 populations, 123 polymorphic loci) revealed strongly structured populations (AMOVA I broken vertical bar(ST) = 0.35; P < 0.001); however, differentiation did not change gradually toward range edge. IBD was significant (Mantel test r = 0.81; P = 0.001) and derived from sharply divided groups between the northernmost populations and the others further south, due to dispersal or environmental limitations. This was corroborated by the PCA and STRUCTURE analyses. IBD and IBE were significant despite the micro-geographic scale of the study area, which indicates that reduced precipitation toward range edge leads to population genetic divergence. However, this pattern diminished when the hypothesized gene flow barrier was taken into account. Applying the spatial analysis method revealed 11 outlier loci that were correlated to annual precipitation and, moreover, were indicative for putative precipitation-related adaptation (BAYESCAN, MCHEZA). The results suggest that even on micro-geographic scales, environmental factors play prominent roles in population divergence, genetic drift, and directional selection. The pattern is typical for strong environmental gradients, e.g., at species range edges and ecological limits, and if gene flow barriers and mosaic-like structures of fragmented habitats hamper dispersal.}, language = {en} } @article{HornHempelRistowetal.2015, author = {Horn, Sebastian and Hempel, Stefan and Ristow, Michael and Rillig, Matthias C. and Kowarik, Ingo and Caruso, Tancredi}, title = {Plant community assembly at small scales: Spatial vs. environmental factors in a European grassland}, series = {Acta oecologica : international journal of ecology}, volume = {63}, journal = {Acta oecologica : international journal of ecology}, publisher = {Elsevier}, address = {Paris}, issn = {1146-609X}, doi = {10.1016/j.actao.2015.01.004}, pages = {56 -- 62}, year = {2015}, abstract = {Dispersal limitation and environmental conditions are crucial drivers of plant species distribution and establishment. As these factors operate at different spatial scales, we asked: Do the environmental factors known to determine community assembly at broad scales operate at fine scales (few meters)? How much do these factors account for community variation at fine scales? In which way do biotic and abiotic interactions drive changes in species composition? We surveyed the plant community within a dry grassland along a very steep gradient of soil characteristics like pH and nutrients. We used a spatially explicit sampling design, based on three replicated macroplots of 15 x 15, 12 x 12 and 12 x 12 m in extent. Soil samples were taken to quantify several soil properties (carbon, nitrogen, plant available phosphorus, pH, water content and dehydrogenase activity as a proxy for overall microbial activity). We performed variance partitioning to assess the effect of these variables on plant composition and statistically controlled for spatial autocorrelation via eigenvector mapping. We also applied null model analysis to test for non-random patterns in species co-occurrence using randomization schemes that account for patterns expected under species interactions. At a fine spatial scale, environmental factors explained 18\% of variation when controlling for spatial autocorrelation in the distribution of plant species, whereas purely spatial processes accounted for 14\% variation. Null model analysis showed that species spatially segregated in a non-random way and these spatial patterns could be due to a combination of environmental filtering and biotic interactions. Our grassland study suggests that environmental factors found to be directly relevant in broad scale studies are present also at small scales, but are supplemented by spatial processes and more direct interactions like competition. (C) 2015 Elsevier Masson SAS. All rights reserved.}, language = {en} } @article{BergholzJeltschWeissetal.2015, author = {Bergholz, Kolja and Jeltsch, Florian and Weiß, Lina and Pottek, Janine and Geißler, Katja and Ristow, Michael}, title = {Fertilization affects the establishment ability of species differing in seed mass via direct nutrient addition and indirect competition effects}, series = {Oikos}, volume = {124}, journal = {Oikos}, number = {11}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0030-1299}, doi = {10.1111/oik.02193}, pages = {1547 -- 1554}, year = {2015}, abstract = {Fertilization causes species loss and species dominance changes in plant communities worldwide. However, it still remains unclear how fertilization acts upon species functional traits, e.g. seed mass. Seed mass is a key trait of the regeneration strategy of plants, which influences a range of processes during the seedling establishment phase. Fertilization may select upon seed mass, either directly by increased nutrient availability or indirectly by increased competition. Since previous research has mainly analyzed the indirect effects of fertilization, we disentangled the direct and indirect effects to examine how nutrient availability and competition influence the seed mass relationships on four key components during seedling establishment: seedling emergence, time of seedling emergence, seedling survival and seedling growth. We conducted a common garden experiment with 22 dry grassland species with a two-way full factorial design that simulated additional nutrient supply and increased competition. While we found no evidence that fertilization either directly by additional nutrient supply or indirectly by increased competition alters the relationship between seed mass and (time of) seedling emergence, we revealed that large seed mass is beneficial under nutrient-poor conditions (seedlings have greater chances of survival, particularly in nutrient-poor soils) as well as under competition (large-seeded species produced larger seedlings, which suffered less from competition than small-seeded species). Based on these findings, we argue that both factors, i.e. nutrient availability and competition intensity, ought to be considered to understand how fertilization influences seedling establishment and species composition with respect to seed mass in natural communities. We propose a simple conceptual model, in which seed mass in natural communities is determined by competition intensity and nutrient availability. Here, we hypothesize that seed mass shows a U-shaped pattern along gradients of soil fertility, which may explain the contrasting soil fertility-seed mass relationships found in the recent literature.}, language = {en} }