Plant Ecology Projects

Joint Funct Animal Ecol	Chem Ecol & Ecotox Limnology	Microbial Ecol Plant Ecol	Plant Syst & Evol Theoretical Ecol

	PLANT ECOLOGY Section head: Prof. Ursula Falkengren-Grerup Secretary: Inger Jönssson Phone: 046-2229295, Fax: 046-2224423 RESEARCH GROUPS Forest Ecology Research projects Soil Plant Research Research projects Functional ecology and ecophysiology Research projects Nutrient dynamics and stress responses Nutrient sustainability and plant vitality Research projects Climate Impacts Group Other research activities Ecology of subarctic and arctic cryptogams Mire ecology Urban ecology Soil chemistry and plant research EXAMINATIONS Honour’s thesis Ph.D. dissertations PUBLICATIONS Scientific articles Proceedings and congress abstracts Reports, reviews and popular communications Overall section note Plant Ecology has several active research groups. A substantial part of the research relates to forest ecosystems but there is considerable research on most ecosystems in Sweden, from the nemoral southern part to the sub arctic northern part, and many research projects have a European or world wide application. The large variation in the research focus is shown below. Laboratory for water, plant and soil chemical analyses Maj-Lis Gernersson, T Maj-Britt Larsson, T Tommy Olsson, T (manager) This is a chemical testing laboratory specializing in chemical inorganic analysis of plant, soil, water and animal materials using ICP-OES, ICP-MS, AAS (flame), FIA (nitrate, ammonium, phosphate), Autoanalyser (nitrogen och phosphorus in low concentrations), TOC in water and solid materials, IC, and trace-gas analyses (GC). The laboratory also executes commissions for external clients both within and outside Lund University.

	Forest Ecology Torleif Bramryd, PhD Bo Fransman, D Anna Hagen-Thorn, D Anna Maria Jönsson, PhD Ulrika Jönsson, D Christer Kalén, D Bengt Nihlgård, Prof. Ragnhild Ohlin, T Kurt Olsson, T Kerstin Sonesson, PhD Ingrid Stjernquist, PhD Gunnar Thelin, PhD The research of the Forest ecology research group is focused on the biogeochemistry and health of south Swedish forests as influenced by soil and forest types, nutrient status, acid rain and soil acidification, nitrogen deposition, and management. Studied key parameters are: The health, growth, and regeneration of conifer and deciduous species. Nutrient status and dynamics of trees, soils, ecosystems and watersheds. Nutrients, carbon and energy of different solid waste fractions. The research is based on studies and experiments in field, greenhouse, and climate chambers including: Monitoring of forest damage and tree nutrient status. Treatments with organic or inorganic fertilisers, e.g. wood ash, minerals, sewage sludge, compost and leachates. Manipulation of growth factors like water, nutrients, and light. Effects of different forest management practices, e. g. mixed-species stands, natural regeneration. During 2002 many group members were still involved in the MISTRA-programme: Sustainable Forestry in southern Sweden (SUFOR), performed in co-operation esp. with SLU in Alnarp (the Forest research Group) and LTH (Chemical Engineering). Some of the below projects belong to this programme. Research projects Nutrient balance in deciduous tree species (IS, GT, AHT) Long-term monitoring of Scanian conifer forest plots (BN, GT) Recycling of hardened wood ash to forest ecosystems (BN, KS) Slash burning and nutrient leaching from forest soils (BN, AMJ) Mineral macro and micro nutrient addition of spruce, pine and beech stands (BN, AMJ, GT) Wood ash and lime in forest ecosystems (BN, BF, TB) Sustainable forestry in south Sweden, SUFOR, research program (BN,GT, IS) Usage of sewage sludge, compost, leachates and other urban rest products in forest and energy forest plantations (TB) Anaerobic decomposition of solid wastes in bioreactor cells with regard to nutrient balance, heavy metals, yield of biogas and recovered nutrients, and effects on the global carbon dioxide balance (TB) The effects of wood ash, lime, sewage sludge, compost and leachates on soil and nutrient balances in trees, on soil water and runoff water are studied in long-term experiments as measures against soil acidification and forest damiges (TB) Optimization of anaerobic degradation processes as performed in bioreactor cells for different solid wastes. Comparisons of processes between landfills and natural peatlands (TB) Seedling of deciduous trees - resistance to multiple stress and nutrient uptake elasticity (AHT, IS) Competition strategies for mixed forests - the reaction to stress owing to life strategy (IS) Modelling the impact of climate extremes ( IS, Lars Bärring) Bark lesions and sensitivity to frost in beech and Norway spruce (AMJ) Forest condition of beech, oak and mixed forests in southern Sweden (KS) Strategies for forestry measures (KS, GT) Recording of the oak pathogen Phytophthora quercina in Sweden (KS, UJ) Importance of Phytophthora spp. and nutrient availability for root vitality of pedunculate oak (Quercus robur) (UJ)
	Soil-Plant Research Germund Tyler, Prof. Bo Bergkvist, lecturer Ann-Mari Fransson, postdoc. Maj-Britt Larsson, T Aparna Misra, D Åke Rühling, Researcher Angelika Zohlen, PhD The research is focussed on mechanisms accounting for the distribution of plants among soils of different chemical properties and the differing ability of plant species to modify their soil environment. An additional interest is element budgets and nutrient cycling in ecosystems. Research projects Soil acidity and trace element solubility (GT) Soil chemical limits of existence in vascular plants (GT) Long-term changes in vegetation structure and floristic diversity (GT) Mechanisms of plant adaptation to acid and calcareous soils (GT) Budgets of carbon, macro- and micronutrients in forests (BB) Solubility and transport of nitrogen and phosphorus species in forest soils as influenced by nitrogen supply (BB) Influence of liming on the availability of nutrients and solubility of heavy metals in forest soil treated with 'vitality fertilizers' or wood-ash (BB) Short and long-term solubility of applied phosphorus in acid forest soils (AMF) Differences among plant species in which phosphorus fractions they are able to utilise (AMF) Effects of soil moisture regimes on mineral nutrient uptake by plants on calcareous soils (AM) Monitoring atmospheric heavy-metal deposition; coordination of a European program (ÅR) Importance of iron as limiting factor for plant colonization of contrasting (calcareous and acid) soils, related to different translocation and immobilization mechanisms of iron in plant tissues (AZ)
	Functional Ecology and Ecophysiology
	Ursula Falkengren-Grerup, Prof Tina D'Hertefeldt, Research Associate Georgios Gaitanis, D Pernilla Göransson, D Katarina Månsson, D Yngve Persson, D Magnus Thorén, PhD Eva Waldemarson, PhD Karin Valtinat, D Sofie Wikberg, PhD Fig. 1. Deciduous forest in spring in southern Sweden. Our research focuses on effects of nutrient limitation, potential toxicity and availability of inorganic and organic nitrogen on wild species in deciduous forests. The full interests of our group can be described as biodiversity, ecophysiology, plant-soil interactions and population biology. Research projects: Effects of nitrogen deposition on ground vegetation of deciduous forests in Sweden (UFG). The vegetation of ca. 650 sites in south Sweden is analysed in relation to soil ammonification and nitrification rates and to the deposition gradient (5-20 kg N ha^-1 yr^-1). Effects of anthropogenic deposition of acid and eutrophying substances on temperate deciduous forests in Sweden and Greece. (GG, UFG) Study of structural and functional characteristics of temperate deciduous forests in Sweden and Greece. How is the knowledge best conveyed to pupils and teachers in two different cultures to get involvement and responsibility for the environment ? Impact of land use history on soil properties and vegetation in relation to habitat fragmentation (KV, UFG). A study of deciduous forests with history known for 300 years. Soil acidity and nutrient availability are studied in relation to history and plant species establishment. Efficiency in nutrient uptake and turnover in species with seemingly low-exploiting root systems (UFG). Nutrients in acid soils are scarce and plants are usually dependent on mycorrhiza for phosphorus and nitrogen uptake. Are plants with few and coarse roots especially dependent on their AM-symbiosis? Importance of amount and form of nitrogen on growth and competitiveness of vascular plants (KM, MO, UFG). Nitrification is hampered in acid soils; the question is if acid-tolerant plants prefer ammonium more than plants living in less acid soils. And do they short-circuit the turnover of nitrogen and absorb organic nitrogen? Growth is studied in solution experiments and in the field by use of the natural abundance of ¹⁵N and measurement of nitrification. Ability of field-layer species to reduce nitrate leaching in deciduous forests (MO, UFG). Nitrate leaching is a problem in some forest ecosystems with high deposition of nitrogen and acidity. To what degree can this be prevented by the field-layer? The seasonal nitrogen uptake, as related to the trees, is followed during all seasons by measurement of nitrate reductase activity. Why do soils of similar C:N ratios, pH and dominating tree species, show differences in nitrogen mineralisation and nitrification? (KM, UFG). Can the differences be explained by altered C:N ratios of the active fraction of the organic material, as an effect of nitrogen deposition or by differing efficiency of microbial? Is the soil C:N ratio affecting the competition for N between plants and soil micro-organisms in deciduous forest soils. (KM, UFG) The competition is evaluated in short-term (24 h) experiments using ¹⁵N labelled ammonium and nitrate. Soils with C:N ratios 20, 31, and 35 were used. In the soil with C:N ratio 35 litter fragments < 1mm was added to evaluate the effect of C-availability on competition. Does drying and rewetting of a soil affect the competition for ammonium, glutamate and glycine between plants and soil microorganisms? (KM, MO, UFG) The response of bacteria to osmotic stress may increase glutamate concentrations in soil after mild drying and rewetting. Glycine is also an abundant amino acid in soil, but it is not part of the osmotic regulation in microorganisms. The competition is evaluated in short-term (24 h) experiments using ¹⁵N labelled ammonium and doubled labelled (¹³C and ¹⁵N) amino acids. The importance of soil C:N ratios to the microbial activity, nitrogen immobilisation and mineralisation that follows after rewetting of dry soils (KM). Nitrogen mineralisation and immobilisation will be measured by use of ¹⁵N short-term pool dilution technique. The aim of the study is to test whether microbial communities from soils with different C:N ratios differ in their ability to use the nutrient flush after rewetting of the soils. Species specific changes of rhizosphere chemistry studied in environments with varying stress (MS, UFG). Plants may influence the soil chemistry and microorganisms in their root zone - the rhizosphere - by selective ion uptake or release or by exploiting soil heterogeneity. The research project considers the strategies used by wild plant species in southern Swedish ecosystems. Detoxification of Al by exudation of organic-acid anions (MS). Organic acids chelate Al, rendering it non-toxic to plants. It is studied to what extent wild plants use this mechanisms and the impact of microorganisms and biodegradation. Effects of acidification on the genetic diversity of plants. (PG, UFG) How does a relatively fast increase in soil acidity, due to anthropogenic activities, affect the tolerance and the genetic variation within a plant species? This is studied in a solution experiment, in which we expose genotypes from different populations to low pH and aluminium. Feral populations of oilseed rape in Sweden. (TDH) Feral (weedy) Brassicas are increasing as weeds in the UK. This project will assess the potential for establishment and persistence of feral Brassicas in Sweden. Variation in seed dormancy: a key life history trait. (TDH). Variation in secondary seed dormancy in wild Brassica rapa ssp. sylvestris and feral Brassica rapa ssp. oleifera is studied in relation to the establishment of feral Brassica-populations. Effects of insect herbivory on population persistence and plant performance. (TDH) In a 4-year field experiment, the effects of insect herbivory on plant performance and population persistence of Brassica rapa ssp. sylvestris (åkerkål) will be studied. Morphological plasticity of two sedges in a spatially heterogeneous environment (TD). Plants that are adapted to nutrient-poor environments have been hypothesized to have low morphological plasticity in response to nutrient manipulation. Growth patterns of sedges from differing nutrient habitats are compared using high, low or heterogeneous nutrient availability Is the degree of physiological integration in plants plastic ? (TD, UFG) Rhizomatous plants of resource-poor environments often translocate resources over large distances within the plant, i.e., they are highly integrated. We study if the degree of translocation is plastic when plants grow in high or low availability of water or mineral nutrients
	Nutrient Dynamics and Stress Responses Ingrid Stjernquist, assistant professor Anna Hagen-Thorn, D Anna Maria Jönsson, postdoc. Carna Sigvardsson Lööv, D
	The sustainability of the forest ecosystem is threatened by anthropogenic and biotic stress factors, such as climate change, nitrogen deposition, soil acidification and weather extremes. The knowledge about how different tree species cope with these stress factors is fundamental to obtain sustainable forests in the future through an environmental sound design of the forest stand. Our research focuses on nutrient and carbon allocation within different levels of the forest ecosystem, from single tree to forest stand. The resistance capacity of the individual as well as the ecosystem against stress factors is dependent on changes in nutrient and carbon allocation. As a consequence of changes in soil conditions and forest management the surface water quality and the biodiversity in the streams are affected. We use models to study the long term effect of multiple stress on forest vitality.
	Nutrient Sustainability and Plant Vitality Ulrika Rosengren, Docent Ann-Mari Fransson, postdoc. Hans Göransson, D Ulrika Jönsson, D Eva Waldemarsson, PhD Gunnar Thelin, PhD
	The sustainability of the forest ecosystem is threatened by anthropogenic and biotic stress factors, such as climate change, nitrogen deposition, soil acidification and weather extremes. The knowledge about how different tree species cope with these stress factors is fundamental to obtain sustainable forests in the future through an environmental sound design of the forest stand. Our research focuses on nutrient and carbon allocation within different levels of the forest ecosystem, from single tree to forest stand. The resistance capacity of the individual as well as the ecosystem against stress factors is dependent on changes in nutrient and carbon allocation. As a consequence of changes in soil conditions and forest management the surface water quality and the biodiversity in the streams are affected. We use models to study the long term effect of multiple stress on forest vitality. Research focus The nutrient sustainability of different management systems in forestry and agriculture Nutrient uptake strategies of plants Plant vitality in response to acidification, eutrophication, and biotic stress. Research projects: Nutrient recycling to forests using pulp industry waste products (GT) Site-customized vitality fertilization to the canopy (GT) Single-tree fertilization with different P-compounds (GT) The branch development method - a new way to estimate tree vitality (GT) Modelling nutrient addition effects in forest ecosystems (GT) Importance of Phytophthora spp. and nutrient availability for root vitality of pedunculate oak(Quercus robur) (UJ) Geographic distribution of Phytophthora spp. in oak forests in southern Sweden (UJ) Pathogenicity of Phytophthora species to Quercus robur in acid forest soils (UJ) Are roots of importance in oak decline? - Root biomass and vitality of healthy and declining pedunculate oak (Quercus robur) in Scania, southern Sweden (UJ) Effects of nutrient availability on Phytophthora-induced root damage to Q. robur (UJ) Effects of vitality fertilizers on root vitality of Q. robur (UJ) Statististical and spatial analyses of effects of airpollutants on forest vitality (UR together with P. Schlyter) Root distribution and nutrient uptake of different tree species (HG, UR) Distribution of mycorrhizal mycelium down in the soil profile of different forset types (HG, UR, together with H. Wallander Nutrient sustainability of different forest types types (GT, UR, HG) Differences in phosphorus uptake mechanisms among plant species in order to minimize the risk of P leaching from soils (AMF) The influence of wood-decaying fungi on phosphorus availability in acid forests (AMF together with Håkan Wallander Episodic events and P leaching through podsols (AMF together with Bo Bergkvist) Low molecular organic acids in acid soils, decomposition and importance in P nutrition (AMF)
	Climate Impacts Group Martin Sykes, Prof. Torben R. Christensen, Assoc. Prof. Ben Smith, Research Assoc. Lena Ström, Research Assoc. Anna-Maria Fosaa, D Thomas Hickler, D Maria Olsrud, D Mikhail Mastepanov, T Predicting effects of climate change and changes in atmospheric composition on terrestrial ecosystems at global and regional scales, as well as the associated feedbacks through effects of vegetation structure and function on the global biogeochemical cycles. Our research objectives are: to develop a predictive understanding of the impacts of changes in climate and atmospheric composition on regional terrestrial ecosystems; to model past vegetation responses to changing climate with the help of palaeoecological data; to project future climate-change impacts on natural ecosystems; to investigate dynamics of trace gas exchange in northern wetland and tundra environments including measuring and modelling spatial and temporal variability in ecosystem/atmosphere fluxes and the environmental factors controlling this variability; to develop and apply theories on plant species co-existence, maintenance of diversity and plant species mobility.
	Other Research Activities Ecology of subarctic and arctic cryptogams (lichens and mosses) Mats Sonesson, Prof. em. Bengt Carlsson PhD The programme started in mid-80s at the Abisko Research Station for the study of plants which are particularly prominent in subarctic-arctic areas but ecologically less known as to general biology and role in the ecosystems. Research deals with both theoretical problems and problems of a more applied interest. Field experiments are emphasized and problems related to climate change have been particularly addressed during the past ten years. Response variables for long-term studies are primarily growth (length increment, areal extension), demographic variables and/or biomass changes. Short-term response is usually studied on physiological variables (e.g. CO₂-exchange, chlorophyll fluorescence, pigment/mineral contents, stable isotopes of C and N). The following projects are current examples: Research projects: *Physiological and anatomical changes in elevational populations of the boreal lichen species Nephroma arcticum. Responses due to long-term reciprocal transplantation.* *CO₂-environment and ecophysiology of epiphytic lichens indicating snow depth (i.a. Parmelia olivacea* and Parmeliopsis ambigua) Response of peat forming mosses to simulated climate change (enhanced UV-B, temperature and precipitation). Effects of open-top chamber treatments of enhanced carbon dioxide concentration and elevated air temperature on growth and growth related physiology of the moss Pleurozium schreberi. The effects of UV-B radiation on photosynthesis and flavonoid content of fructicose lichen species. Mire ecology Nils Malmer, Prof em Biogeochemistry and vegetation changes in Sphagnum-dominated peatlands. Since many years I have used inoculations with ¹⁴C and the C/N-quotient in the peat to estimate both past and present productivities, decay losses and carbon accumulation rates in peatlands and its variation in relation to climatic and edaphic conditions. This line of research is supported with special studies on the interaction between vascular plants and Sphagnum mosses in the competition for light and mineral nutrients. Studies on changes in the mire vegetation are performed on selected mires from which old inventories and other vegetation records including aerial photographs are available. This line of research also include comparisons of analyses of nitrogen and phosphorous in plant material from different periods and different regions. As Editor-in-Chief for Oikos and member of the executive board for Ambio I am also deeply involved in scientific publishing in the fields of ecology and environmental science. Research projects: Vegetation, productivity and carbon sequestering in Sphagnum mires, its regional variation, dependence on mire type, and effects on the peat accumulation (together with Göran Svensson and Bo Wallén.) The variation in the carbon accumulation rates in bogs during Late Holocene (together with Göran Svensson and Bo Wallén.) Mathematical modelling of the peat accumulation in a South Swedish bog (together with Lisa Belyea, Edinburgh) Interactions between vascular plants and Sphagnum mosses - effects on plant community structure and peat accumulation (together with Crister Albinsson and Bo Wallén.) Changes in the vegetation on Sphagnum mires during the last century (together with Torben Christensen, Torbjörn Johansson, Urban Gunnarsson, and Håkan Rydin) The variation in growth and concentrations of nitrogen and phosphorus in three mire plants during 50 years in southwestern Sweden. (together with Bo Wallén.) The regional variation in the concentrations of nitrogen and phosphorous in the Sphagnum mosses on bogs in North America and Scandinavia. Urban ecology Torleif Bramryd, Assoc. Prof. Research projects in the Urban Ecology group focus on ecological processes linked to the human society, with special emphasis on biogeochemical balances, nutrient cycling and effects of environmental pollution on soil and vegetation. The research also concentrate on possible, ecologically based, measures to counteract disturbances caused by Man. Examples of such compensating processes are e.g. the use of vegetation as filter for air pollution, re-circulation of nutrients to improve the vitality of trees affected by air pollution, or the accumulation of organic carbon in the urban system (e.g. in soil layers, vegetation, buildings or landfills). Soil chemistry and plant research** Anna-Maj Balsberg-Påhlsson, Assoc. Prof.

	Adress: Ecology building, S-223 62 Lund Phone: +46 46-222 00 00, Fax: +46 46-222 38 00 webmaster Last updated: 2003-06-23