Insect herbivores and pollution: Studies by University of Turku in the Murmansk region

M. V. Kozlov & E. L. Zvereva Section of Ecology, University of Turku, Finland E-mail: [email protected] Research team (as on 1 January 2005) Janne Eränen Mikhail Kozlov Andrei Maisov Anna Liisa Ruotsalainen

Eija Toivonen Elena Zvereva Vitaly Zverev Visiting / cooperating researchers

Andrey Selikhovkin Pekka Niemelä Alexandr Alexeev Annamari Markkola Vladimir Zhirov Jari Valkama Alexandr Egorov Jukka Jalava Gennady Kataev Alex Gilyazov Alexandr Lvovsky Jaakko Kullberg Valery Barcan Olga Sumina Jarle Nielsen Current (1997-2007) projects

European Commission Effects of global changes on -plant interactions in subarctic forests (BASIS, 1998-1999) Effects of global changes on insect-plant interactions in subarctic forests (BALANCE, 2002-2005) Current (1997-2007) projects

Academy of Finland United we stand: Does the role of positive plant-plant interactions increase with abiotic stress? (2002-2007) Impact of industrial polluters on terrestrial ecosystems: a research synthesis (2004-2007) Current (1997-2007) projects Maj and Tor Nessling Foundation Promoting re-vegetation of heavily polluted habitats with planting of mountain (1998-2000) Geographical variation in ecosystem sensitivity to aerial pollution: Are the Northern forests most fragile? (2001-2002) Why leaf Chrysomela lapponica outbreaks in polluted areas? (2005-2007) Current (1997-2007) projects Nordic Academy for Advanced Study (NorFA) Vulnerability of northern ecosystems to pollution and climate change (2000-2003) Reforestation of northern barren lands: combating stress impacts (2002-2003) Interactive effects of pollution and fires on ground layer vegetation in northern boreal forests (2003-2006) Current (1997-2007) projects

Turku University Foundation Impact of delayed inducible resistance in host plant on herbivore mortality due to natural enemies (2000) Do northern ecosystems recover slower? (2001, 2004) How pollution affects reproduction of trees? (2002) Main study area: The Kola Peninsula

9Extremely high diversity of pristine and disturbed landscapes 9Relatively easy to access 9Background information available 9Well-developed network of cooperating researchers 9Low-cost technical assistance easily available Natural landscapes of the Kola Peninsula ‘The northernmost desert’

Kuzomen, 240 km E of Kandalaksha Major sources of environmental disturbance Severonikel smelter (Monchegorsk) Pechenganikel smelter (Nikel) Aluminum smelter (Kandalaksha) Recent impressions of Finnish researchers

Ruotsalainen A.L. & Markkola A.M. 2004. Kuolan niemimaalla kesällä 2003 - pieni matkakertomus. Luonnon Tutkija 4: 135-143. Pollution may cause severe habitat disturbance and create stressful environment for plants and herbivores

Industrial barren around nickel-copper Undisturbed forest 40 km from the smelter in Monchegorsk (NW Russia) the smelter The basic ideas

• Polluted habitats represent an evolutionary novel habitat for plants and • They are well-suited for testing ecological theories which are believed to be general • Industrial pollution can be viewed as long-lasting ‘unintentional experiment’ Brief history • 1981-1990 – short visits (<10 pers-days) • 1991-1994 – development of research, pilot studies (50-150 pers-days) • 1995-2000 – focus on and insect- plant relationships (100-500 pers-days) • 2001-2004 – focus on plant ecology and general environmental problems (300-800 pers-days) • 2005- …? – dedicated fieldwork, termination of some of monitoring programs (200-400 pers-days planned) ‘MMM’ strategy

• Monitoring (1981-2004 … ?) • Manipulations (1996-2005 … ?) • Modelling (2003-2005) Monitoring: herbivore assemblages • Birch-feeding herbivores: 4-30 study sites, 25 trees/site, twice during growth season since 1981 • Birch-feeding leaf-miners: 14 study sites, 4 plots 25 x 25 m, tagged birch trees (diam > 3 mm; ca. 8000 trees), annual censuses since 1992 • Willow-feeding herbivores: 10 sites, 10 bushes/site, 1997-2002 (discontinued) Birch-feeding leafrollers

Polluted (dotted line) vs. clean site (solid line) Monitoring: individual species

• semipurpurella • Eriocrania sangii • Epirrita autumnata • Chrysomela lapponica • caprea • Phratora vitellinae • Plagiodera versicolor •etc. Only extreme contamination decreases diversity of and butterflies Species richness of ants is independent of pollution load Population dynamics of Chrysomela lapponica

Undisturbed Disturbed habitats site 3 50 habitats site 4 180 site 1 site 5 150 40 site 2 120 30 90 60 20

Beetles count per 30

10 0

0 1991 1993 1995 1997 1999 2001 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 Among-year variation in host plant quality for C. lapponica

150 outbreak Fecundity Undisturbed sites * (eggs per 120 female) Disturbed sites 90 * 60

30

0 1993 1994 1995 1996 1997 1998 1999 Manipulations with host plants

• Passive greenhouse chambers • Defoliation • Shading • Fertilization, liming

Manipulations with animals

• Enemy exclusion experiments Predators of Chrysomela lapponica

Bugs (Pentatomidae)

Bugs (Miridae)

Larvae of Syrphid fly

Mites Wood ants Natural enemy pressure in polluted and unpolluted habitats

unpolluted habitats Predators 80 polluted habitats

60 Parasitoids 40 * * * Tachinidae Phoridae 20 Mortality (%) Mortality * Enemy exclusion 0 experiment Eggs Larvae Pupae Larvae Pupae Different responses of natural enemies to defensive secretion of larvae

• Repellence (ants, birds) • Overcoming/avoiding (predatory bugs, ants, sawflies, ladybirds) • Attraction (predatory larvae of Parasyrphus spp, parasitoids) Plans for the future •Financial constrains force us to discontinue many of monitoring programs since 2005 •During the nearest years, the focus will be made on the manipulative studies •Testing of general ecological theories will be the principal goal of further research •The data will be summarized in a form of monograph (to be completed in 2007)