Bereczki et al. 2014. Caterpillar control service provided by birds. Forest Ecology and Management 327: 96-105.

Bereczki, K., Ódor, P., Csóka, Gy., Mag, Zs., Báldi, A.
2014
Effects of forest heterogeneity on the efficiency of caterpillar control service provided by birds in temperate oak forests.
Forest Ecology and Management 327: 96-105.
Csatolt dokumentum: 
Összefoglaló: 

Controlling herbivore insects by insectivorous birds is a major ecosystem service, nevertheless little is
known about how local habitat features and forest management influence the efficiency of this service
and about how the pest control service birds provide can be maintained and improved. We conducted
an experiment in temperate oak forests in the Mátra Mountains, northern Hungary to measure bird predation
rate of artificial caterpillars resembling winter moth (Operophtera brumata L.) larvae, to evaluate
the relationships among insectivorous bird communities, caterpillar populations and leaf damage caused
by caterpillars and to assess the effect of forest heterogeneity on these processes. We found, that
structurally heterogeneous forests maintained a significantly higher abundance of insectivorous birds.
Especially the tree size heterogeneity increased bird abundance. The rate of bird predation was positively
related to the abundance of insectivorous birds as well as to caterpillar abundance, which indicates that
birds were able to respond to caterpillar density. We were not able to demonstrate a direct negative effect
of bird predation on caterpillar abundance and a positive effect of caterpillar abundance on leaf damage.
Structurally heterogeneous forests, however, suffered from less leaf damage than did homogeneous forests,
which result may indicates that the higher activity of insectivorous birds in heterogeneous stands
resulted in lower activity of insect herbivores. Thus, we concluded that forest management can contribute
to the mitigation of insect damages by maintaining the suitability of forest stands to the insectivorous
bird communities through the maintenance of high stand heterogeneity and the presence of some key
elements (e.g. retention tree groups, tree diversity, shrub layer).

Angol nyelvű összefoglaló: 

Controlling herbivore insects by insectivorous birds is a major ecosystem service, nevertheless little is
known about how local habitat features and forest management influence the efficiency of this service
and about how the pest control service birds provide can be maintained and improved. We conducted
an experiment in temperate oak forests in the Mátra Mountains, northern Hungary to measure bird predation
rate of artificial caterpillars resembling winter moth (Operophtera brumata L.) larvae, to evaluate
the relationships among insectivorous bird communities, caterpillar populations and leaf damage caused
by caterpillars and to assess the effect of forest heterogeneity on these processes. We found, that
structurally heterogeneous forests maintained a significantly higher abundance of insectivorous birds.
Especially the tree size heterogeneity increased bird abundance. The rate of bird predation was positively
related to the abundance of insectivorous birds as well as to caterpillar abundance, which indicates that
birds were able to respond to caterpillar density. We were not able to demonstrate a direct negative effect
of bird predation on caterpillar abundance and a positive effect of caterpillar abundance on leaf damage.
Structurally heterogeneous forests, however, suffered from less leaf damage than did homogeneous forests,
which result may indicates that the higher activity of insectivorous birds in heterogeneous stands
resulted in lower activity of insect herbivores. Thus, we concluded that forest management can contribute
to the mitigation of insect damages by maintaining the suitability of forest stands to the insectivorous
bird communities through the maintenance of high stand heterogeneity and the presence of some key
elements (e.g. retention tree groups, tree diversity, shrub layer).