Forest management and natural biocontrol of insect pests

Abstract

Current silvicultural practices are under revision as result of changing demands and pressing environmental issues. We compared the monoculture clear-cut regime commonly used during the recent decades in Europe, especially in Fennoscandia, and in North America, with three alternative forest management methods, short rotation forestry, mixed forest stands and continuous cover forestry. We evaluate how these alternative management methods are likely to affect the natural control of forest insect (regeneration pests, defoliators and bark beetles). Particular emphasis was placed on the effects of forest management on natural enemy pressure. We argue that changing forest management to any of the methods discussed will, in most cases, decrease the relative effects of bottom-up forces (resource quality and quantity) and increase the relative effects of top-down forces (natural enemy pressure) on forest pests. As population growth of the pest species presently causing most damage in European managed forests (i.e. pine weevil and spruce bark beetle) is mainly limited by bottom-up forces (quantity of suitable breeding material), changes in forest management could increase the relative importance of top-down forces by modifying stand characteristics to actively support the natural enemies. However, it remains to be investigated to what extent such alterations will result in decreased damage to trees even though some evidence points in that direction.

Continuous cover forestry is a cost-efficient tool to increase multifunctionality of boreal production forests in Fennoscandia

“…Disturbances do occur in forests regardless of management but their intensity and effects vary depending on management of the stand itself and its surrounding forests. Since CCF maintains natural tree species and more natural structure of forests it may be more resistant against the disturbances, such as wind damages (Couture et al, 2016;Pukkala et al, 2016), and insect pathogens (Klapwijk et al, 2016). We leave it as a challenge for future studies to accommodate disturbance effects on ecosystem services and biodiversity in forests under different management regimes.…”

CLONAL FORESTRY OF Piptocarpha angustifolia: SURVIVAL AND GROWTH VIGOR IN FIELD CONDITIONS

“…due to lack of commercial plantations of the species in Brazil, information regarding the incidence of pests and diseases do not exist in the literature, making it difficult to estimate the risk of establishment of plantations with the species. Damages caused by insects are commonly seen in forest plantations, generating significant changes in the morphological characteristics of the root and aerial parts of plants (KLAPWIJK et al, 2016).…”

ASOCIACIÓN DE COLEÓPTEROS XILÓFAGOS Y PREDADORES EN MADERA DE “BOLAINA BLANCA” (Guazuma crinita Martius) Y “CUCARDA” (Hibiscus rosa-sinensis Linnaeus)

“…En cambio, los estudios a nivel de comunidades sugieren que la abundancia de coleópteros predadores está directamente relacionada con el estado de conservación de los bosques (Weslien & Schroeder, 1999;Erbilgin & Raffa, 2002). En tal sentido, una reciente revisión de este tema sugiere que el control biológico de las plagas forestales puede ser promovido a través de prácticas de manejo forestal que mantengan la estructura y composición vegetal tan próximas como sea posible a su condición natural (Klapwijk et al, 2016).…”