Forest Management in an Era of Biotic Homogenization

1. Forest Management in an Era of Biotic Homogenization Zafar A. Reshi Department of Botany, University of Kashmir, Srinagar-190 006 Jammu & Kashmir, India E-mail: zreshi@yahoo.com

2. PROLOGUE • Biological invasions are a key component of global environmental change …………………………. • Ranked as second major threat to biodiversity • Alter structure and function of ecosystems • Cause Biotic ‘Globalization’ ( or Homogenization) • Cause heavy ecological and economic damage which is estimated as US$ 1.4 trillion per annum – close to 5% of GDP (GISP, 2009) and €12 billion per year for Europe (Kettunen et al. 2008)

3. What is ‘Biotic Homogenization’? • Biotic homogenization (or BH) refers to the process by which the genetic, taxonomic or functional similarities of regional biotas increase over time. It is a multifaceted process that encompasses species invasions, extinctions and environmental alterations, focusing on how the identities of species (or their genetic or functional attributes) change over space and time.

4. Genetic homogenization: • It is used to describe an increase in the genetic similarity of genepools over time resulting from intra- and inter-specific hybridization. • Genetic homogenization via the dilution of native gene pools byinvading exotic genes may be pervasive, and is likelyto be associated with a number of ecological and evolutionaryeffects.

5. Taxonomic homogenization: • It refers to an increase in the phylogenetic similarity of biota over time owing to the establishment of cosmopolitan species and extirpation of endemic species. • Taxonomic homogenization has been the primary focus of previous research and is used interchangeably with the term biotic homogenization throughout the literature.

6. Functional homogenization: • It is defined as an increase in the functional similarity ofbiotas over time associated with the establishment of species withsimilar ‘roles’ in the ecosystem (e.g. high redundancy of functionalforms or traits) and the loss of species possessing uniquefunctional ‘roles’.

7. The ecological and economic damage due to IAS is the rationale for the selection of ‘Trends in Invasive Alien Species’ as one of 22 Headline Indicators to measure progress towards the Convention on Biological Diversity’s target of reducing the rate of loss of biodiversity by 2010. The framework for assessing progress by 2010 has seven focal areas with goals and sub-targets for each area, as well as a number of Headline Indicators.

8. Headline indicator: Trends in invasive alien species • Trends in what? • Number of alien invasive species per country across different ecosystems • Number of IAS-management plans in place (per country) • Number of countries party to IAS-relevant international agreements • Targets under the indicator are: • Pathways for major potential alien invasive species controlled • Management plans in place for major alien species that threaten ecosystems, habitats or species

9. IAS and forest ecosystems • Invasion ecology has traditionally focused on alien plant species with early successional life-history traits, adapted to colonize areas following disturbance. • This focus neglects the types of plants most likely to invade established communities, particularly forests. contd.

10. Key questions • Are forests effectively immune to invasion even by alien species with late successional life-history traits, especially shade tolerance? • Are late-successional plants essentially non-invasive, suggesting a fundamental trade-off between invasive and competitive life-history traits?

11. Important Caveat The early succesional dominance of invasion ecology theory is overstated. Instead, many alien species with late successional life-history traits, especially shade tolerance have been reported to be invasive.

12. Source: Martin et al. 2009.

13. Database of shade-tolerant forest invasives: • http://landscapeecology.agsci.colostate.edu/research/invasives/forest_invaders/forestinvasives.html • You can add additional species to this database of shade-tolerant forest invasives.

14. We need to prepare a database of invasive alien species STRUCTURE OF THE DATABASE: • Origin: Native or Alien: • Historical records (scientific literature) • Biogeographical studies (Centre of diversity) • Evolutionary studies (Centre of origin)

15. Pathways and Vectors: • Intentional • Released (Deliberately released into the wild) • Escaped (Escaped into wild) • Forestry, Ornamental, Agricultural, etc. • Unintentional • Unaided • Transported – Seed containments • Minimum Residence Time: (Earliest record of the alien species in scientific literature with correctly identified specimen cited and deposited in recognized herbaria and museums). • Relevance for studies on lag phase and future prediction.

16. Stage of Invasion: Stages II-V, with explicit mention of spatial scale. • SPECIES INVASIVENESS: • Taxonomic affiliation • Invasive elsewhere • Mode of reproduction • Mode of dispersal • Propagule pressure • Herbivory • Allelopathy • Growth form • Mycorrhizal association

17. Stages of Invasion Stage 0 (Source pool) Stage I (Transport) Stage II (Introduced) Stage IVb Stage IVb (widespread but occasional) (localized but dominant) Stage III (Established) Stage V (widespread and dominant)

18. Elevational range: • Maxima and minima of altitude at which alien species is known to occur in India. • Latitudinal range: • Information valuable for whether alien taxa occurs in Tropical, Subtropical, Temperate or Alpine climates. • (Applications in spatial modeling and climate matching models)

19. Taxonomic composition of the alien flora of the Kashmir Himalaya

22. Number of alien plant species at different stages of invasion

23. 378 304 104 14 Distribution of alien plant species in different elevation zones

24. Invasion process and management options

25. Acknowledgements: Organizers and sponsors for financial support and invitation to attend this workshop.

26. Thank you