No description available.

In present thesis, I treat the topic of impacts of plant-animal interactions, namely herbivory and pollination, on plant life cycle and lifetime fitness. First, I identify the components of the impact of plant-animal interactions: i) interaction frequency; ii) per-interaction effect; iii) sensitivity of the plant's life cycle to the changes in vital rate impacted by the animals. Furthermore, I also classify other causes changing the outcome of a plant-animal interaction into two categories: i) plant's traits; ii) plant's environment. A review of extant literature on the topic revealed that especially the role of plant's environment in changing the outcome of plant-animal interactions is largely understudied and I attempt to reduce this gap in knowledge in the five detailed studies encompassed in this thesis. The detailed studies focus on a model system of Central European wet grasslands and especially on three species typical to it: Succisa pratensis, Achillea millefolium and A. ptarmica. The first two studies examine the effects of environment on frequency of plant- animal interactions. The next two studies are more integrative, one focusing on the impacts of different herbivore groups on the complete life cycle and the other on interaction of herbivory and pollination on plant lifetime fitness....

<p>U&nbsp; radu&nbsp; je&nbsp; prikazana&nbsp; distribucija,&nbsp; dinamika&nbsp; i&nbsp; diverzitet&nbsp; insekata opra&scaron;ivača iz reda Hymenoptera&nbsp; -&nbsp; Apiformes (Anthophila) i Diptera Syrphidae)&nbsp; na&nbsp; stepskim&nbsp; fragmentima&nbsp; i&nbsp; na&nbsp; suncokretu&nbsp; u agroekosistema&nbsp; Vojvodine.&nbsp; U&nbsp; cilju&nbsp; uvida&nbsp; u&nbsp; strukturu&nbsp; predela&nbsp; injenog&nbsp; uticaja&nbsp; na&nbsp; sastav&nbsp; i&nbsp; brojnost&nbsp; polinatora,&nbsp; kartirani&nbsp; su&nbsp; tipovistani&scaron;ta&nbsp; oko&nbsp; svakog&nbsp; stepskog&nbsp; fragmenta.&nbsp; Na&nbsp; osnovu&nbsp; podataka dobijenih kartiranjem, odabrano je sedam stepskih fragmenata kojiu&nbsp; svom&nbsp; okruženju&nbsp; imaju&nbsp; visok&nbsp; udeo&nbsp; suncokreta&nbsp; kao&nbsp; masovnocvetajuće&nbsp; kulture&nbsp; i&nbsp; sedam&nbsp; stepskih&nbsp; fragmenata&nbsp; koji&nbsp; su&nbsp; bez&nbsp; ili&nbsp; saniskim&nbsp; udelom&nbsp; suncokreta.&nbsp; Iz&nbsp; reda&nbsp; Hymenoptera&nbsp; &ndash;&nbsp; Apoideazabeleženo&nbsp; je&nbsp; &scaron;est&nbsp; familija:&nbsp; Andrenidae,&nbsp; Apidae,&nbsp; Colletidae,Halictidae,&nbsp; Melittidae&nbsp; i&nbsp; Megachilidae,&nbsp; 114&nbsp; vrsta,&nbsp; a&nbsp; iz&nbsp; reda&nbsp; Diptera(Syrphidae),&nbsp; registrovano&nbsp; je&nbsp; ukupno&nbsp; 11&nbsp; vrsta.&nbsp; Predstavnici&nbsp; familija Andrenidae, Apidae i Halictidae su distribuirani na svim lokalitetima,predstavnici&nbsp; familije&nbsp; Megachilidae&nbsp; su&nbsp; distribuirani&nbsp; na&nbsp; 15&nbsp; od&nbsp; 16lokaliteta,&nbsp; a&nbsp; najmanje&nbsp; su&nbsp; zastupljene&nbsp; jedinke&nbsp; familija&nbsp; Colletidae&nbsp; i<br />Melittidae,&nbsp; distribuirane&nbsp; na&nbsp; pet&nbsp; lokaliteta.&nbsp; Polinatori&nbsp; reda&nbsp; Diptera familije&nbsp; Syrphidae&nbsp; su&nbsp; distribuirani&nbsp; na&nbsp; svim&nbsp; lokalitetima.&nbsp; Rezultati Kruskal-Volisovog H testa ukuzuju da je tokom sve tri sezone (2011.,2012.,&nbsp; 2013.)&nbsp; na&nbsp; stepskim&nbsp; fragmentima&nbsp; najvi&scaron;e&nbsp; bilo&nbsp; zastupljeno vrsta&nbsp; solitarnih&nbsp; pčela,&nbsp; zatim&nbsp; vrsta&nbsp; osolikih&nbsp; muva,&nbsp; a&nbsp; najmanje&nbsp; vrsta bumbara.&nbsp; Istim&nbsp; testom&nbsp; je&nbsp; dobijano&nbsp; da&nbsp; je&nbsp; tokom&nbsp; sve&nbsp; tri&nbsp; sezone&nbsp; na stepskim&nbsp; fragmentima,&nbsp; registrovano&nbsp; najvi&scaron;e&nbsp; jedinki&nbsp; osolikih&nbsp; muva,<br />zatim&nbsp; medonosne&nbsp; pčele,&nbsp; solitarne&nbsp; pčele,&nbsp; a&nbsp; najmanje&nbsp; jedinki bumbara.&nbsp; Fridmanovim&nbsp; testom&nbsp; su&nbsp; utvrđene&nbsp; razlike&nbsp; u&nbsp; brojnosti (dinamici)&nbsp; polinatora&nbsp; kroz&nbsp; sezone,&nbsp; uočen&nbsp; je&nbsp; porast&nbsp; broja&nbsp; jedinki medonosne pčele i opadanje broja jedinki solitarnih pčela.Rezultati&nbsp; dobijeni&nbsp; Man-Vitnijevim&nbsp; U-testom&nbsp; pokazuju&nbsp; da&nbsp; je&nbsp; na<br />stepskim&nbsp; fragmentima&nbsp; koji&nbsp; imaju&nbsp; niži&nbsp; udeo&nbsp; suncokreta&nbsp; u&nbsp; predelu zastupljeno&nbsp; vi&scaron;e&nbsp; jedinki&nbsp; i&nbsp; vrsta&nbsp; bumbara.&nbsp; Istim&nbsp; testom&nbsp; je&nbsp; dobijen rezultat&nbsp; da&nbsp; je&nbsp; na&nbsp; stepskim&nbsp; fragmentima&nbsp; sa&nbsp; visokim&nbsp; udelom suncokreta&nbsp; ima&nbsp; vi&scaron;e&nbsp; jedinki&nbsp; medonosne&nbsp; pčele.&nbsp; Vilkoksonovim testom&nbsp; sume&nbsp; rangova&nbsp; je&nbsp; pokazano&nbsp; da&nbsp; su&nbsp; jedinke&nbsp; i&nbsp; vrste&nbsp; bumbara zastupljenije na stepskim fragmentima nakon cvetanja suncokreta, za&nbsp; vreme&nbsp; cvetanja&nbsp; suncokreta&nbsp; na&nbsp; stepskim&nbsp; fragmentima&nbsp; je registrovano&nbsp; vi&scaron;e&nbsp; jedinki&nbsp; <em>Apis&nbsp; mellifera</em>,&nbsp; osolikih&nbsp; muva&nbsp; i&nbsp; solitarnih pčela.&nbsp; Modeli&nbsp; regresionih&nbsp; analiza&nbsp; linearnih&nbsp; me&scaron;ovitih&nbsp; modela&nbsp; su pokazali&nbsp; da&nbsp; se&nbsp; sa&nbsp; porastom&nbsp; udela&nbsp; suncokreta&nbsp; u&nbsp; predelu&nbsp; smanjuje broj jedinki divljih pčela i jedinki i vrsta bumbara. Sa porastom udela polu-prirodnih&nbsp; stani&scaron;ta&nbsp; u&nbsp; predelu&nbsp; i&nbsp; većom&nbsp; cvetnom&nbsp; pokrovnosti, povećava se udeo jedinki i vrsta osolikih muva.</p> / <p>This&nbsp; paper&nbsp; shows&nbsp; distribution,&nbsp; dynamic&nbsp; and&nbsp; pollinator&nbsp; diversity Hymenoptera&nbsp; -&nbsp; Apiformes&nbsp; (Anthophila)&nbsp; and Diptera (Syrphidae)&nbsp; in semi-natural&nbsp; habitats&nbsp; and&nbsp; in&nbsp; sunflower&nbsp; crops&nbsp; in&nbsp; Vojvodina&nbsp; agroecosystems.&nbsp; Around&nbsp; each&nbsp; of&nbsp; 16&nbsp; selected&nbsp; steppe&nbsp; fragments,&nbsp; habitat types&nbsp; were&nbsp; mapped&nbsp; to&nbsp; test&nbsp; how&nbsp; do&nbsp; landscape&nbsp; structure&nbsp; affects pollinator&nbsp; diversity&nbsp; and&nbsp; abundance&nbsp; in&nbsp; semi&nbsp; natural&nbsp; habitats&nbsp; and&nbsp; in sunflower&nbsp; crops.&nbsp; Based&nbsp; on&nbsp; the&nbsp; results&nbsp; obtained&nbsp; by&nbsp; mapping,&nbsp; seven study sites with high % of sunflower like mass flowering crops, and eight&nbsp; study&nbsp; sites&nbsp; with&nbsp; no&nbsp; or&nbsp; low&nbsp; %&nbsp; of&nbsp; mass&nbsp; flowering&nbsp; crops&nbsp; are selected. In total, there were 114 species from 6 families&nbsp; from order Hymenoptera-Apiformes:&nbsp; Andrenidae,&nbsp; Apidae,&nbsp; Colletidae, Halictidae, Melittidae and Megachilidae, and 11 species from order Diptera&nbsp; (Syrphidae).&nbsp; Insects&nbsp; from&nbsp; families:&nbsp; Andrenidae,&nbsp; Apidae, Colletidae&nbsp; and&nbsp; Halictidae&nbsp; were&nbsp; distributed&nbsp; on&nbsp; all&nbsp; study&nbsp; sites,&nbsp; while insects&nbsp; from&nbsp; family&nbsp; Megachilidae&nbsp; were&nbsp; distributed&nbsp; almost&nbsp; on&nbsp; all study&nbsp; sites&nbsp; (15&nbsp; sites).&nbsp; At&nbsp; least&nbsp; only&nbsp; on&nbsp; five&nbsp; study&nbsp; sites&nbsp; were distributed insects from family: Colletidae and Melittidae. Hoverflies were distributed on all study sites.&nbsp; Kruskal-Wallis H test shows that an&nbsp; all&nbsp; three&nbsp; seasons&nbsp; (2011.,&nbsp; 2012.,&nbsp; 2013.)&nbsp; in&nbsp; semi&nbsp; natural&nbsp; habitats wild bees species were most abundant, followed by hoverfly species, and bumblebee species at the end. Same test&nbsp; shows that&nbsp; in all three seasons in semi natural habitats individuals of hoverflies were more abundant than individuals of honey bees, wild bees&nbsp; and individuals of&nbsp; bumblebees,&nbsp; which&nbsp; were&nbsp; least&nbsp; abundant.&nbsp; Friedman&nbsp; test&nbsp; shows differences in densities of pollinator through the seasons, and these results&nbsp; shows&nbsp; increasing&nbsp; in&nbsp; Apis&nbsp; mellifera&nbsp; densities&nbsp; and&nbsp; decline&nbsp; of wild bees densities through seasons. Man-Whitney&nbsp; U-test&nbsp; shows&nbsp; that&nbsp; there&nbsp; were&nbsp; more&nbsp; species&nbsp; and individuals of bumble bees in semi-natural habitats which landscapes are without&nbsp; or low % of sunflower. Same test shows that there were more&nbsp; individuals&nbsp; of&nbsp; honey&nbsp; bees&nbsp; in&nbsp; semi-natural&nbsp; habitats&nbsp; which landscapes&nbsp; have&nbsp; high&nbsp; %&nbsp; of&nbsp; sunflower.&nbsp; Wilcoxon&nbsp; signed-rank&nbsp; test shows&nbsp; that&nbsp; in&nbsp; semi-natural&nbsp; habitats&nbsp; species&nbsp; and&nbsp; individuals&nbsp; of bumblebees&nbsp; were&nbsp; more&nbsp; abundant&nbsp; after&nbsp; blooming&nbsp; sunflower,&nbsp; while species&nbsp; and&nbsp; individuals&nbsp; of&nbsp; wild&nbsp; bees&nbsp; as&nbsp; well&nbsp; as&nbsp; individuals&nbsp; of hoverflies and&nbsp; <em>Apis mellifera</em>&nbsp; were&nbsp; more abundant during blooming sunflower.&nbsp; Linear mixed-effect model shows that with increase of % of&nbsp; sunflower&nbsp; in&nbsp; landscape&nbsp; number&nbsp; of&nbsp; individuals&nbsp; of&nbsp; wild&nbsp; bees&nbsp; and species and individuals of bumblebees decreasing, and individuals of hoverflies increasing. With an increase of % of semi natural habitats and&nbsp; increase&nbsp; of&nbsp; flower&nbsp; cover,&nbsp; abundance&nbsp; and&nbsp; species&nbsp; of&nbsp; hoverflies<br />increases.</p>

Montane meadows comprise less than 5% of the landscape of the western Cascades of Oregon, but they provide habitat for diverse species of plants and pollinators. Little is known about plant-pollinator network structure at these sites. This study quantified plant-pollinator interactions over the summer of 2011, based on six observations of 10 permanent subplots in 15 meadows, stratified by size and isolation. The study examined (1) relationships between richness and abundance of flowers, pollinators, and interactions; (2) distribution of abundance and richness of flowers, pollinators, and interactions with regards to surrounding meadow habitat; (3) change in flower and pollinator abundance over the season; (4) factors associated with the presence of various guilds of pollinators; and (5) the structure of plant-pollinator networks. The study showed that (1) richness of pollinators increased 2x faster than richness of flowers with increased abundance; (2) density of flowers and interactions was positively correlated with meadow size and diversity of pollinators and interactions were both correlated with surrounding habitat at two spatial scales; (3) peak flower abundance coincided with or preceded peaks in pollinator populations; (4) abundance of three guilds of bees exhibited different patterns of association to surrounding habitat and meadow soil moisture corresponding to various dispersal potential and phenology of guild species; and (5) the number of network pairings for plants and pollinators increased with increasing species richness of potential interaction partners and all networks were found to be significantly nested. Results of this study indicate that plant-pollinator networks are complex assemblages of species, in which spatial and temporal patterns of habitat affect species composition and network structure. In particular, flower and pollinator abundance and richness are depressed in small and isolated meadows. Significant nestedness emerged as a pattern of network level organization across the study meadows. / Graduation date: 2013

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The world-wide intensification of agriculture has led to a decline in species richness due to land use change, isolation, and fragmentation of natural and semi-natural habitats in agricultural and forestry landscapes. As a consequence, there is a current landscape management focus on the importance of green infrastructure to mitigate biodiversity decline and preserve ecosystem functions e.g. pollination services and pest control. Even though intensification in agriculture has been ongoing for several hundreds of years, remnant habitats from earlier management practices may still be remaining with a surprisingly high plant richness. Preserving these habitats could help conserving plant species richness in agricultural landscapes, as well as other organisms that are dependent on plants for food and shelter. In this thesis I focus on two small remnant habitats; midfield islets and borders between managed forest and crop field in southeastern Sweden. In the past, both habitats were included in the grazing system and therefore often still have remnant population of grassland specialist species left today. I have used these two remnant habitats as model habitats to investigate the effect of landscape factors and local factors on species richness of plants, flower morphologies and plants with fleshy fruits. Additively, I analysed the effect of surrounding landscape and local openness on the functions; pollination success, biological pest control of aphids and seed predation on midfield islets. One of my studies showed that spatial distribution and size of the habitat affected plant species richness. Larger habitat size and higher connectivity between habitats increased species richness of plants in the habitats. Openness of the habitats was shown to be an important factor to increase species richness and richness of flower morphologies, both on midfield islets and in forest borders. Even though midfield islets had the highest species and morphology richness, both habitat types are needed for habitat complementary as forest borders have more plants with fleshy fruits and a higher richness of plant species that flowers in spring/early summer. It was also shown that a more complex forest border, not just with gaps in the canopy, but also with high variation in tree stem sizes increases plant species richness in the field layer. The conclusion is that by managing small remnant habitats to remain or become more semi-open and complex in their structure, would increase species richness of plants, grassland specialist species, and flower morphologies. It would also increase some ecosystem functions as seed predation and biologic pest control of aphids are more effective close to trees. If both midfield islets and forest borders would be managed to be semi-open, the area and connectivity of semi-open habitat would increase in the agricultural landscape, which may also improve pollination success as the connectivity between populations has a possibility to increase. Grassland specialist species are clearly abundant in the small remnant habitats. As the decline of semi-natural grasslands is causing a decline in grassland specialists’ species, not only plants, I recommend that small remnant habitats are included in conservation and management plans and strategies to improve habitat availability and connectivity for grassland species in agricultural landscapes. / <p>Research funder Ekoklim. Project:4339602.</p><p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Manuscript.</p>