Forest Protection

In the Upper Rhine region, climate change poses massive challenges for forestry. In addition to environmental changes due to climate change such as drought and heat, the local cockchafer populations represent another dimension. The potential changes in the tree species spectrum will be assessed in terms of risk from cockchafer and incorporated into a Species Distribution Modeling (SDM) as scenarios. This arises because of differences in food quality for females during their maturation feeding on leaves of deciduous trees, which affects egg production and thus reproductive potential. Here, the differences between native and new alternative tree species, which are considered to be climate stable, will be experimentally elaborated in two replicates. In addition to the established tree species red oak, sessile oak and littleleaf linden, downy oak, Norway maple and the neophytic black cherry will be tested in the feeding experiments.

As a sustainable renewable resource, softwoods will remain an indispensable basis for carbon-storing timber construction for a long time to come. Native silver fir will play a more important role in Germany in the future, as it is considered climate-stable and is therefore promoted.

However, bark beetle infestations on silver fir have risen significantly in recent years and will continue to increase due to climate change, particularly as a result of dry years.

In order to safeguard wood resources and all comprehensive forest functions, it is therefore urgently necessary to provide suitable monitoring and management options against bark beetles for resource-efficient forestry production and forest conservation in the future, also with regard to silver fir.

To this end, models for estimating beetle development and the risk of infestation are being developed for the first time based on field and laboratory studies and the evaluation of long-term infestation data; in addition, remote sensing detection methods are being compared with terrestrial detection of infestation on silver fir.

The knowledge gained enables far-reaching, knowledge-based recommendations for action and guidelines for forest protection in dealing with silver fir in climate-adapted forest management. This will significantly support the reliable and plannable provision of resources with fir logs.

The Verblps project aims to test the effectiveness of the use of SPLAT®Verb against Ips typographus aggregation and infestation. While the pheromone dispenser SPLAT®Verb is already used to manage and contain a variety of bark beetle outbreaks for species such as the Mountain pine beetle (Dendroctonus ponderosae) in the United States, its effectiveness has yet to be tested for the European spruce bark beetle Ips typographus.

SPLAT®Verb is a commercially produced and environmentally friendly pheromone dispenser that provides the controlled release of the anti-aggregation pheromone verbenone in the field. Verbenone is a naturally occurring anti-aggregation pheromone used by a variety of bark beetle species including I. typographus.

During this project, the effectiveness of the use of SPLAT®Verb against Ips typographus aggregation and infestation will be tested. The active inhibitory range, duration of effect and required quantities will be determined, its use for area protection will be investigated and application options presented.

This research is a joint project carried out by Chair of Forest Entomology and Forest Protection and the Chair of Ecosystem Physiology at the University of Freiburg together with the Forest Research Institute of Baden-Württemberg (FVA).

Passive acoustic techniques may offer a remote, non-invasive, automated alternative to traditional methods in the detection and monitoring of hard-to-access species. In recent applications, incidental sounds produced by wood borers—such as those generated in the process of feeding or moving through galleries—have been used for the early detection of some species in imported wooden packaging goods. Although a species of high economic interest, no literature exists on the incidental sounds of the European spruce bark beetle Ips typographus.
Through a series of laboratory oscilloscope measurements, we carried out an investigation into the performance of currently available acoustic equipment in detecting Ips typographus incidental sounds. Additionally, we described incidental sounds in larval, pupal and adult Ips typographus, by comparing recordings taken in infested and uninfested logs. A series of video recordings were further collected of artificial plexiglas sandwiches infested with larval, pupal and adult Ips typographus to allow for acoustic-visual correlations between the identified sounds and movement.
Our measurements revealed high disparities between the compared recordings in terms of sensitivity and signal-to-noise ratio, highlighting the importance of the two parameters when measuring a low amplitude acoustic signal such as incidental bark beetle sounds. Furthermore, we found incidental sounds of Ips typographus to be characterized by broad-band, short, irregular pulses ranging between 100Hz and 22kHz.
Our findings can be a useful point of departure for future investigations into the acoustics of Ips typographus, and may provide a stepping stone for eventual applications of acoustic technology in the early detection, monitoring and management of this species.

The effects of timber harvesting machinery on the soil structure of forest skid trails have been relatively well investigated. Soil compaction alters soil physical parameters, leading to a decreased soil macroporosity and to an impaired pore continuity. This process sets a chain of reactions in motion, altering the gas and water balance of skid trail soils and presumably their species composition. However, the state of knowledge about the effects of heavy machinery traffic on biodiversity does not yet allow for clear interpretation and assessments. A combined analysis of soil physical, soil ecological and entomological investigations is missing, as is the determination of the site characteristics which mediate the effects of traffic on soil organisms. The goal of our study is to develop an evaluation guide for forest soil compaction based on these interrelationships, with microbial, soil faunistic and entomological examinations at the core of this development work. Thus, the open question that we aim to address is how the degree of soil compaction affects the biodiversity of soil organisms, exploring the link between the abiotic indicators of the disturbance intensity and the susceptibility of the biotic community to this influence.