Biodiversity and ecosystemfunctioning – testing in different scales from fungal community to

bryophytes and boreal tree speciesRaisa Mäkipää1, Maija Salemaa1, Vladimir Shanin2, Lara Valentin3,

Mikko Peltoniemi1, Tiina Rajala1, Jussi Heinonsalo4, Taina Pennanen1 & Alexander Komarov2

1Finnish Forest Research Institute, 2Russian Academy of Science, 3Universitat Autonoma de Barcelona, University of Helsinki4

IAVS symposium 2013, June 25-30, Tartu, Estonia

Introduction

The loss of species diversity will alter ecosystems function, resiliency and their ability to provide goods and services to society. Primary productivity and ecosystem stability are negatively affected by a loss of diversity (e.g.

Loreau et al. 2001 Science, Hooper et al. 2012 Ecol

Monogr).Rate of decomposition and nutrient cycling may decrease with decreasing diversity (e.g. Gessner et

al. 2010 Trends Ecol Evol).

IntroductionMost of the studies on BD effects are fromtemperate grasslands, whereas boreal forestswith relatively small initial number of species areless studied.In boreal forests, even aged monocultures arefavored by management.Timber harvesting reduces dead-wood and hundreds of dead wood inhabiting species arenow threatened.However, effects of reduced diversity on ecosystem functioning are not widely studied

Our objectives

To test1. The effect of reduced fungal diversity on

rate of decomposition. 2. The biomass production of bryophytes

grown in mixtures in comparison to monocultures.

3. The effect of tree species mixtures on NPP of boreal forests over a rotation period.

Diversity of fungi and rate of decomposition

We analysed the decomposition of three decay stages of Norway spruce (early, middle and late decay), which had differences in the initial number of decomposing species.Fungal diversity was reduced by dilutions of the inoculaResponse variable was cumulative CO2 production over the experimental period of 3 months.

Effect of fungal diversity

In decomposing fungal communities positive biodiversity effect was observed with moderate species diversity, but not with most diverse communities due to the functional redundancy.Source: Valentin et al. Revised ms in Peerage of Science.

ND = non-diluted inoculum10-1 = dilution of 10-1 of inoculum10-2 = dilution of 10-2 of inoculumCtrl = control: sterile substrate

Biodiversity effect on productivity of bryophytes

We studied the growth rate of the three moss species grown in mixtures in comparison to monocultures.

16 weeks in growth chamber,Light intensity: 50 µmol s-1 m-2

Humidity 90%Sprayed with nutrient solutions

Biomass production of bryophytes

Pleu mono Dicr mono Expected tot. Observed tot.m

g

0

100

200

300

400

500

600

p < 0.01

Biomass production of boreal bryophytes (Pleurozium schreberi, Hylocomiun splendens and Dicranum polysetum) showed overyielding when species were grown in mixtures in comparison to monocultures.

Source: Salemaa et al 2008 Env Poll and Mäkipää & Salemaa ms in preparation.

NPP of forest stands

We simulated the growth of trees (NPP) in monocultures and in mixed stands with variedproportions of tree species.To assess overyielding of mixtures in comparison to monocultures, we calculated Dmaxfor each mixture.

where max(MNPP) is the maximal productivity among all species in the mixture (observed for their monocultures), and ONPP is the total observed productivity of the given mixture. Overyielding occurs when Dmax>0 (Loreau 1998; Loreauand Hector 2001).

Mixed stands are productive

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The mixed forest stands of two or three competing tree species (Piceaabies, Pinus sylvestris and Betula pendula) were more productive than monocultures; the highest overyielding was observed with mixture of two coniferous species.Source: Shanin et al, submitted manuscript

9B1P =90% Birch & 10% of Pine

Applied simulation model (EFIMOD) described by Shanin et al. 2013.

Effect of climate change on carbonstock of mixed birch-pine and birch-spruce stands.

Averages over the simulation periodand s.d. resulting from climaticcharacteristics of different climatescenarios.

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Conclusions

In these three cases on different scales we observed positive biodiversity effect on ecosystem functioning.Change in forest management from even aged monocultures to more productive mixed stands is supported by our results.Tools to integrate maintenance of biodiversity to forest management planning should be developed.

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Th

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