SUBJECT

Plant Strategies

lecture

Master

Faculty of Science

Biology MSc

2

Semesters 1-4

Autumn/Spring semester

1. Modular organization Modularity in the Plant and Animal kingdoms. Morphogenetic vs. functional units. Metamers, branches, sectors, and other building blocks. Hierarchical selection.

2. The dynamics of growth Birth and death of the modules: demographic rules. Spatial positions of the modules: geometric rules. Transport and other links between modules: physiological rules. Regulatory mechanisms. Internal signals and environmental effects. Some examples for correlative phenomena. Cooperation and competition between different parts of the same organism.

3. Basic types of growth forms Practical motivations for classifying growth forms. Some classification systems. Relation to life strategies. Rigid vs. plastic growth forms. The importance of chance.

4. Phenotypic plasticity: ecological and evolutionary implications Some examples for environmental signals and plastic responses. Experimental designs - results and some doubts. Limits and costs of plasticity. Allocation trade-offs. The information content of environmental signals. “Points of decision” and commitment in individual development.

5. Computer modelling of growth Biological rules and computer algorithms. Lindenmayer systems. Dynamic morphology according to Bell. Multiple species: from individual morphogenesis to community organisation. Matching between growth patterns. Gap dynamics.

6.  Physiological links between modules Transport of resources (water, nutrients, and carbohydrates). Sectoriality in the plant body. Physiological integration: some experiments in laboratories and in the field. Ways of disintegration (splitting). Some ecological consequences of disintegration. Adaptation by “falling apart”.  Regulation of competition between parts of the same organism. Seasonal patterns and environment-dependence.  

7. Clones in nature Evolutionary transitions from modularity to clonality. Clonal plants and animals. Notes on the distribution of clonal organisms on the phylogentic tree of plants. An example for the origin of clonality by convergent evolution within a genus. Necessary conditions for the evolution of clonal development.

8. Clonal plant species: abundance and importance Clones everywhere: the importance of clonal species in the flora and vegetation of the Earth. Dominant clonal species. Invasive clonal species. Implications for the protection of natural communities.

9. Clonal spreading in space: observations, experiments, and models Clonal dispersal. Computer models on spatial spreading: some methods and examples. Predictions and empirical references. Strategies of spreading (phalanx vs. guerilla, consolidator vs. competitor, etc.).

10. Foraging for resources Exploration and exploitation of patchy resources. A behavioural ecological model of foraning. Application for a clonal plant: Cuscuta subinclusa. Experiments and computer simulations on foraging growth. Effects of heterogeneity in space and time.

11. Strategies of growth and integration The degree of integration: patterns in space and over time. The relationship between foraging and integration. Variation within and between species.  Two basic startegies: Integrator and Splitter. Sharing of risk vs. spreading of risk. Competition between different strategies.   

12. Life history strategies A short review on sexual vs. asexual reproduction, and their evolutionary significance. Energy allocation between the two modes of reproduction. Models on optimal life history in various environments. 13. Giant plants: ages and sizes of clones Notes on the definition of an individual. Genets and ramets. Some problems related to the estimation of age and size. Aging in clonal plants. Some “champions” of age: genetic individuals several thousand years old! Pseudo-annuals: annual ramets, perennial genets.  

14. An outlook to ecosystems  Ecosystem-level implications of long life and large size. Coexistence of strategies: some observations in plant communities. Models of competition, facilitation, and coexistence. The importance of clonal species in forming and stabilizing the spatial structure of communities.

15.  Closing remarks: the relation between ecology and developmental biology Challenges from the environments, and limitation in the response. Ways of adaptation to the spatial and temporal heterogeneity of the environment. Mechanisms of coexistence. Stability of communities. From infra-individual to supra-individual phenomena: building a bridge between different levels of organisation. 

• De Kroon H., and Van Groenendael J. (eds.) (1997) The ecology and evolution of clonal plants. Blackhuys Publishing, Leiden, Hollandia.

• Sachs, T. (2002) Developmental processes and the evolution of plant clonality. Evolutionary Ecology 15: 485-500.

• Novoplansky, A. (ed.) (2002) Developmental plasticity in plants. Special Issue of Evolutionary Ecology, Vol. 16.