23 March: Inger Kappel Schmidt

Plant responses to climate change in contrasting heathland ecosystems

Inger Kappel Schmidt

Dept. of Forest and Landscape Ecology, Forest and Landscape, Copenhagen University

Climate change affects the performance of species in different ways and potentially it changes community composition. In large scale climate manipulation experiments across Northern Europe, we studied the sensitivity of heathland species to climate during 12 years. A naturally occurring outbreak of heather beetles (Lochmaea suturalis Thompson) defoliated the heather at one site. This enabled studies of the climate sensitivity of adult plants as well as during the regenerative phase. We found the strongest effects of climatic change related to extreme events and biotic interactions resulting in a replacement of C. vulgaris with species connected to acid grassland. The transition was altered with extended drought periods and warming due to altered impact by the heather beetles and due to lower recruitment. The future climate with higher minimum temperatures and extended drought periods and with increased impact of herbivores and diminished window for regeneration may have major impact on the distribution of C. vulgaris heathlands and the area of heathlands in Europe may decrease further due to invasion by grasses and trees.

9 March: Sanna Huttunen

Phylogeny of moss order Hypnales - current state of knowledge and future challenges

Sanna Huttunen

Department of Biology, University of Turku, Finland

The Hypnales are the largest moss order comprising circa 4200 species, i.e. 1/3 of all mosses. Phylogenetic reconstruction of the group has proven to be difficult due to rapid radiation at an early stage of their evolution, but the most studies applying molecular systematic methods favor its position as a crown clade in the phylogeny of mosses. Within the order, however, relationships among groups have remained poorly resolved. The most recent phylogenetic inference is based on four sequence regions, namely, nuclear ITS1-5.8S-ITS2, plastid trnL-F and rps4, and mitochondrial nad5, for 122 Hypnalean species and 34 species from closely related groups. Tree topologies resolve the order as monophyletic, although monophyly, as well as the backbone nodes within the Hypnales, gained significant support only under Bayesian inferences. The phylogenetic tree differs only in few details from recent classifications, but familial relationships especially among the apical crown clade within the Hypnales were mainly unsupported. Ancestral distribution based on Bayesian dispersal-vicariance analysis support a Gondwanan origin of the Hypnales and subsequent geographical radiation in the area of the former Laurasian supercontinent. Reconstruction of historical biogeography is congruent with mainly tropical and Gondwanan distributions in the sister groups Hypnodendrales, Ptychomniales, and Hookeriales, and with the dating for the oldest pleurocarp and Hypnalean fossils. Scattered fossil data, unique character combinations in some of the fossil pleurocarps and lack of a well-supported phylogeny, however, still hamper testing diversification events using molecular dating. In the presentation I will summarize current knowledge on the evolutionary history and relationships among the Hypnales and present an overview of the recent fossil data on pleurocarpous mosses. In light of these two sources of the information I aim at discussing evolution of the Hypnales and point out potential directions for future research.

24 February: Tamara van Mölken

Three-way interactions between pathogens, plants and herbivores: consequences for herbivore feeding, disease development and plant fitness. 

Tamara van Mölken 

Department of Agriculture and Ecology, University of Copenhagen, Denmark. 

Under natural conditions plants are often simultaneously exposed to pathogen attack and damage by insect herbivores. As a consequence of sharing the same host plant, interactions between pathogens and herbivores are bound to occur. The plant plays a central role in mediating such interactions, whereby pathogen induced changes in the host plant can affect herbivory and vice versa. Mechanisms underlying these effects include pathogen induced changes in: secondary metabolite levels; nutritional value; plant volatile emissions; and crosstalk between defence pathways. In turn, these biochemical changes may affect herbivore feeding and behaviour. Given that both pathogens and herbivores can impair plant performance, reciprocal effects between pathogens and herbivores are expected to result in altered plant growth and reproduction. To gain more insight into the ecological implications of pathogen infection for plant-herbivore interactions, we need a better understanding of the tripartite interactions between plants originating from wild populations and their naturally associated pathogens and herbivores. Barbarea vulgaris is well studied for its chemical defences against a range of herbivores. This herbaceous plant is susceptible to Phyllotreta nemorum flea beetles and the oomycete pathogen Albugo candida which both occur in wild B. vulgaris populations. In a series of experiments we have addressed the following questions: (i) does infection with the oomycete have an effect on flea beetle induced changes in plant nitrogen, glucosinolate and saponin levels; (ii) what are the effects of the pathogen on herbivore preference, consumption and fitness; and (iii) how do biochemical changes and variation in pathogen and herbivore damage affect plant growth, development and fitness?

10 February: Bjarne Larsen

Botanisk indsamlingstur 2011: Crocus oreocreticus på Kreta

Bjarne Larsen

dept. Agriculture and Ecology, Copenhagen University

8 February: Marco Thines

Diversity, evolution, and ecology of white blister rusts 

Marco Thines 

Biodiversity and Climate Research Centre Frankfurt, Germany

White blister rusts are a cosmopolitan group of obligate biotrophic oomycetes and are not related to true fungi, but to diatoms and other members of the Straminipila. While the host spectrum of the white blister rusts encompasses a wide range of flowering plants, recent investigations have revealed that some white blister rusts are highly host specific. Until five years ago it was believed that the Brassicaceae are parasitised by a single species, Albugo candida, which has a broad host range, encompassing several hundred species in this family. Recent molecular and morphological studies have revealed that in addition to Albugo candida, which has indeed a very broad host range, extending even to related families like Cleomaceae and Capparaceae, several specialized species exist. These include a specialized species on Arabidopsis thaliana, at least four distinct species in the genus Cardamine, and a specialized species on Barbarea. Based on the current knowledge, it seems likely that in Brassicaceae alone a few dozen species await their discovery. This could also extend to predominantly endophytic species, as we could recently demonstrate that Albugo candida can infest host plants asymptomatically and can potentially be transmitted vertically to the next generation of host plants. Potential factors influencing pathogenic development of asymptomatic endophytes will be shortly discussed on the example of two oomycete pathogens (Protobremia sphaerosperma and Pustula obtusata) infecting goatsbeard (Tragopogon pratensis agg.).

27 January: Roland von Bothmer

The Svalbard Global Seed Vault – is it important for plant genetic resources? 

Roland von Bothmer

Swedish University of Agricultural Sciences, Svalbard Global Seed Vault, NordGen, Sweden

The domestication of crops some 10 000 years ago lead to a process to a considerable increase in genetic variation. The process included major genetic changes in several adaptive traits. To be transferred from a state of adaptation for competition in natural habitats to an environment dominated by human interaction meant considerable genetic shifts. The domestication influenced major genetic systems such as reproduction and dispersal mechanisms, life forms, growth habits etc. The initial phase of domestication was followed by rapid migration and adaptation to completely new areas and environments. Unconscious and conscious selection lead to the establishment of a great number of locally and regionally adapted landraces. The great diversity was a starting point for modern plant breeding in the end of the 19th century. What has happened during later decades is that the great genetic variation established over centuries and millennia has diminished, due to “genetic erosion”.

The international genebank movement started comparatively late. The great Russian pioneer N. I. Vavilov developed the basic concepts with worldwide collections and conservation of plant genetic resources (PGR). In later decades a great number of genebanks have been established. Collecting expeditions in remote areas have been carried out and the current number of genebank holdings exceeds 7 million, mainly of the world’s major crops. However, this figure includes an unknown number of duplications. Since there are a number of unforeseen, serious problems facing the genebanks today there is an increasing demand for a worldwide back up system for storing safety duplications. The Global Seed Vault at Svalbard was established four years ago with the objective to store all unique accessions of the world, which has been estimated to between 3 and 4 millions. The remote and exotic location of Svalbard at 78o N puts a particular focus on the necessity for conservation and utilization of plant genetic resources to fight the big challenges of the world: overpopulation, hunger, climate change and a sustainable long term production of food. A number of international agreements and treaties regulate the access to and utilization of PGR.

13 January: Henrik Ærenlund Pedersen

The relevancy and perspectives of scientific flora projects: two examples from the Flora of Thailand project

Henrik Ærenlund Pedersen

Associate Professor, Ph.D., Botanical Garden & Museum, Natural History Museum of Denmark, University of Copenhagen


Is it really worthwhile revising the same flora repeatedly? A case study in Thai Orchidaceae. – In many contexts, scientific floras (dealing with one, several or all plant families on a national or regional scale) are the most intensively used surveys and identification tools for species of vascular plants. Flora of Thailand will be the first real standard flora to cover all families of flowering plants in Thailand. Nevertheless, the Thai representatives of a number of plant groups have undergone one or more revisions previously. Is it worthwhile revising such groups again for Flora of Thailand – and would it even make sense to start thinking of a second edition of the flora? To throw some light on this, I compared three successive revisions of the orchid subfamily Orchidoideae in Thailand (published in 1958–1964, 1977–1978 and 2011, respectively). Together, the three revisions exhibited a progressive increase in the net number of accepted taxa. The relative increase was highest from the first to the second revision, but still substantial from the second to the third. The net results covered an even higher number of changes (additions end exclusions of taxa) that partly neutralized each other – and other changes were in themselves neutral in relation to the net number of taxa accepted. Classification at species level, but not at genus level, tended to stabilize over time. Altogether, the results demonstrate that both the second and the third revision were worthwhile indeed, as each of them provided comprehensive changes (arguably improvements) compared to the latest previous revision.

Flora projects as drivers of biodiversity research, exemplified by the treatment of the Orchidaceae for Flora of Thailand. – Any scientific flora project relies primarily on a taxonomic revision of the flora accommodated in the region covered by that project. Furthermore, it is commonly recognized that once the flora handbook has been published, it represents a major source of knowledge and data that can be utilized in other research fields such as biogeography, vegetation ecology and macro-ecology. On the other hand, surprisingly little attention has been given to the fact that flora projects can to a wide extent initiate and facilitate complementary research activities during their own lifetime. Using the ongoing treatment of the Orchidaceae for Flora of Thailand as an example, it is demonstrated how the organization of field trips and the establishment of research groups within the framework of the flora project – together with the recurrent need for achieving taxonomic clarity beyond the borders of Thailand – have given rise to complementary research on multiple aspects of orchid-related biodiversity. Examples include: the preparation of global monographs; traditional or morphometrically based revisions of intricate species complexes throughout mainland Asia; minor biogeographic studies and autecological studies of epiphytic as well as terrestrial species. Additionally, it is demonstrated how the efforts of making existing data available for the flora project (e.g. through the Seidenfaden Database of Orchids and the Native Thai Orchid Network) may highly benefit non-floristic research as well.

6 January: Else Østergaard Andersen

Thy National Park – the first National Park in Denmark

Else Østergaard Andersen, M.Sc. & MPA, Manager, Thy National Park

Denmark inaugurated its first National Park in 2008 – 99 years after the first European National Parks were established in Sweden. Thy National Park lies in the north-westernmost part of Denmark. It is often said to be the largest – and last – wilderness in Denmark. The main habitats of the park are Atlantic dunes and dune heaths.

Thy National Park is also a landscape with a special cultural history. A natural catastrophe starting in the 15th century and lasting almost 400 years ruined arable land by sand drift. The sand drift lead farmers to move their farms further inland, or to settle by the sea and survive by fishing. During the fight against the sand, plantations have been created – with tree species from central Europe and even North America.

Officially, the Danish national parks do not correlate with the IUCN Protected Area Management Categories. However, Thy National Park contains most of the IUCN categories, ranging from strict nature reserve with no access from man (category Ia), through Wilderness Areas (Ib), National Park (II), etc., and to Protected Area with sustainable use of natural resources (VI).

The seminar will focus on the process since the 1999 OECD Environmental Performance Review, the Danish National Park Act from 2007, and till 2012, 3½ years after the inauguration of Thy National Park. What are the legal aims? How does the national park operate? What are the plans? How will nature benefit from the National Park? Can rural development go hand in hand with nature protection?

9 December: Susanna Saari

Grass endophyte in food chain – friend or foe?

Susanna Saari

University of North Carolina at Greensboro, NC, USA


Plants harbour many different microbes, fungi and bacteria that take advantage of their hosts. However, the host can also benefit from these organisms, which are known as endophytes. I have studied obligate endosymbiosis and the nature of the relationship between the symbiont and the host, using fungal Neotyphodium endophyte-grass symbiosis as a model system. According to my PhD thesis research, endophyte infections were found to be common in the meadow fescue cultivars in Finland, although the frequency varied considerably both between and within cultivars. European tall fescue cultivars were practically endophyte-free. Microfungi were common in natural meadow fescue populations found in the Åland Islands, Estonia, the coastal area of Södermanland in Sweden, and Gotland. The high level of infection indicates that endophytes are beneficial to their natural grass hosts at least in these areas. The reason behind the varying infection levels found in cultivars may be that where an endophyte affects one of the agriculturally important characteristics of its host grass, plant breeders may have inadvertently promoted or restricted the prevalence of the endophyte by favouring or rejecting individual plant characteristics. The toxins produced by endophytes affect the pest-resistance of grass in many ways. The study concluded that endophytes increased the resistance of meadow fescue to bird cherry-oat aphids, overriding the effects of seed lot and cultivar. Endophytes did not affect the body mass or population size of voles that consume endophyte-infected grass, but they did reduce the voles' mobility. In predation tests, immobility and calmness appeared to protect voles from weasels, as they were no longer able to detect voles among the grass. Fungal endophytes can also affect grass reproduction and growth. The fungi appeared to increase seed production in meadow fescue but to stunt growth after mowing in some circumstances. Endophytes appear to affect the competition between certain growth functions inside the plant. Endophytes have been found to benefit their hosts especially in fertile agricultural environments. In natural infertile environments, however, the fungus can be an enemy. The plant has to share the little resources that it collects from the soil with the fungus, which in turn may produce fewer toxins. This prevents the fungus from protecting its host effectively against pests. Endophytes have caused serious toxic symptoms in cattle fed on infected grass in the US and in New Zealand. Seed production companies in these countries now routinely examine animal feed for endophytes in order to prevent these problems from recurring. Endophytes affect many agriculturally important characteristics of the host grass, which is why they should be acknowledged in agricultural management in Europe as well.

25 November: Søren Rosendahl

Stochastic processes and human activity are important drivers in mycorrhizal evolution.

Søren Rosendahl

Department of Biology, University of Copenhagen, Denmark

The plant root symbiotic arbuscular mycorrhizal fungi are common in most ecosystems. Several cosmopolitan species are found on all continents except the Antartica. Three hypotheses may explain this worldwide distribution. Either speciation occurred before the continents separated 120 mill yr ago, or the distribution is a result of human mediated dispersal related to agriculture. Finally, morphologically defined species may encompass several local endemic species. To test these hypotheses three genes were sequenced from 82 isolates of Glomus mosseae originating from six continents. Sequences were analyzed for geographic subdivision and estimation of migration between continents. Coalescent analyses estimated divergence and age of mutations. Baysian coalescent modeling was used to reveal important past population changes in the global population. The sequence data showed no geographical structure, with identical genotypes found on different continents. Coalescence analyses indicated a recent diversification in the species, and the data could be explained by a recent population expansion in G.mosseae. The results suggest that speciation and the range expansion happened much later than continental spread and that human activity may have had a major impact on the dispersal and the population structure of the fungus. At the local scale analyses of haplotype networks suggested a subdivision of G. mosseae haplotypes between fields with different land use history. The results show that agricultural practices differently affect both the abundance and the population genetic structure of arbuscular mycorrhizal fungi.

11 November: Laura Rose

Land-use intensification in grassland ecosystems: effects from leaf to ecosystem

Laura Rose

Department of Ecology and Ecosystem Research, University of Goettingen, Germany

In the last 50 years, land-use changes in temperate grassland ecosystems occurred either by land-use intensification, i.e. increased fertilization, cutting frequency and stocking rate, or by abandonment of non-profitable sites mostly on low productive soils. Such land-use changes can have profound effects on the species composition, the amount of standing and produced biomass, and on biogeochemical cycles. I am going to present results from the GrassMan experiment, an interdisciplinary meadow experiment at the University of Göttingen, which is designed to investigate the effects of plant biodiversity, fertilizer application and different cutting frequencies on several aspects of grassland functioning.

Fertilizer application and alterations of the cutting frequency severely affect functional leaf traits: NPK-fertilization leads to generally higher leaf-level water use efficiency (WUE), accompanied by an increase in the specific leaf area and leaf nitrogen concentration. Cutting effects are more species specific. Besides these effects on leaf trait values, fertilization additionally alters the interspecific relationships between leaf traits.

Although the increase in leaf-level water use efficiency with fertilization is mirrored by an increase in WUE on the stand level, fertilization leads to higher evapotranspiration rates and thereby decreases ground-water recharge. This is mostly attributed to the higher amount of biomass produced in fertilized compared to unfertilized meadows. Irrespective of its positive effect on aboveground biomass production, fertilization increases nitrogen leaching.

28 October: Justin Thomas Wynns

Status of an ongoing systematic study of Plagiothecium.

Justin Thomas Wynns

dept. Agriculture and Ecology, Copenhagen University


Plagiothecium is a conspicuous and widely distributed genus of pleurocarpous mosses, typically growing on soil or humus in forests, heaths and swamps. The genus is well characterized morphologically by plants that are mostly medium-sized to large, flattened, and highly glossy, with decurrent leaves. Many species produce characteristic small uniseriate gemmae in abundance.

Plagiothecium appears to be a mostly natural genus that includes several species-complexes and some anomalous species. A large number of taxa have been described, and some are very poorly known. Although several excellent regional treatments of the genus exist, Plagiothecium has not been monographed on a worldwide scale. The goal of my study is to obtain a molecular phylogeny of Plagiothecium that will serve as the systematic basis for a projected worldwide monograph.

Pleurocarpous mosses have undergone rapid morphological diversification in recent evolutionary history, and DNA sequence data can be very uniform in this group. To identify the most useful genetic loci for evolutionary reconstruction in Plagiothecium, I have sequenced a number of different loci (mostly chloroplast, some nuclear) for a small number of taxa. In this Ph.D. Status Seminar, I discuss the results of this ongoing initial phase of my study, including the taxonomic conclusions that are emerging.

14 October: Toby Kiers

Reciprocal Rewards in the Rhizosphere: Underground markets and the evolution of cooperation in plant-fungal mutualisms.

Toby Kiers

Free University Amsterdam, Department of Animal Ecology, Faculty of Earth and Life Sciences, Netherlands

Associating with microbes in the rhizosphere can have both costs and benefits for host plants. Because associations generally involve multiple microbial genotypes varying in mutualistic benefit, a potential tragedy of the commons can arise. How do plants maintain cooperation with the most beneficial rhizosphere microbes over the course of evolution? Specific mechanisms may be employed that reduce the fitness benefits to microbes from “cheating”. In the mycorrhizal mutualism, the fungal symbiont cannot be “enslaved.” Rather, the mutualism is evolutionarily stable because control is bidirectional, and partners offering the best rate of exchange are rewarded. The existence of underground biological markets will be discussed.

10 June: Katharine Ann Marske

Historical Biogeography

Katharine Ann Marske

Ecology and Evolution, Department of Biology, Copenhagen University


Phylogeographic structure and its underlying causes are not necessarily shared among community members, with important implications for using individual organisms as indicators for ecosystem evolution, such as the identification of forest refugia. Over 1000 mitochondrial DNA (COI) sequences and newly developed coalescent phylogeography models were used to construct geo-spatial histories for four co-distributed New Zealand forest beetles. These methods identify historical dispersal patterns via ancestral state reconstruction. Ecological niche models were used to reconstruct the potential geographic distribution of each species during the Last Glacial Maximum (LGM). Combined results yielded a complex picture of temperate forest community evolution. Each species shared some features of its LGM distribution or range expansion pathways with every other, but no general patterns were detected among all four. These results indicate that forest species retreated into and expanded out from the same refugia by a variety of routes, rather than travelling together as an intact forest community, which has important implications for using individual taxa to detect historical ecosystem dynamics.

27 May: Koen Verhoeven

Epigenetic inheritance in asexual dandelions

Koen Verhoeven

Netherlands Institute of Ecology, dept. Terrestrial Ecology, the Netherlands


Epigenetic mechanisms such as DNA methylation can cause stable but reversible changes in gene activity without changes in the underlying DNA sequence. Recent studies in plants have shown that DNA methylation patterns can be modified by environmental and genomic stresses, that they can be transmitted between generations and that they can cause heritable trait variation in absence of genetic (sequence) variation. This implies that heritable variation may not be fully understood from genetic variation alone. To date, however, the evolutionary relevance of epigenetic inheritance is unknown and much of the underlying mechanisms remains poorly understood. To gain better insight in the factors that generate heritable methylation variation I used methylation-sensitive AFLP markers to evaluate the epigenetic consequences of ecological stress exposure and polyploidization events in apomictic dandelions. Especially stress exposure triggered methylation changes and most of these changes were faithfully transmitted to unexposed offspring. This suggests that heritable methylation variation is readily generated that is independent of genetic variation between individuals, which can have consequences for the adaptive potential of asexual species such as dandelions. I will briefly sketch some perspectives for linking epigenetics and ecological research, which can improve our understanding of the evolutionary relevance of epigenetic inheritance.