V4-1623 — Final report
1.
RITY - a phenology model of Ips typographus as a tool for optimization of its monitoring

We developed the RITY-2 phenology model for the spatial and temporal simulation of the seasonal development of Ips typographus based on the PHENIPS model and the data of Integrated Nowcasting through Comprehensive Analysis (INCA). Many parts of PHENIPS were improved with innovative approaches and a new model was developed. European spruce bark beetle phenology was monitored at eight study sites in 2017 and 2018, along with air and bark temperature measurements. RITY-2 predictions are based on air temperature from the INCA system, which is used to calculate the effective bark temperature for beetle development. An innovative procedure was introduced which finds most appropriate spring threshold from which calculation of the phenological model initiates. The onset of Norway spruce infestation in spring was estimated using a lower threshold of 14.5°C for flight activity and a mean thermal sum of 53.0 degree-days (dd) from 7th March onward. The rate of brood development was calculated from the cumulative effective thermal sum of 30-min temperature data using upper and lower temperature thresholds of 38.9 and 8.3°C, respectively, and a nonlinear function. For validation, we compared the timing of phenological events in the field with predicted events using both 30-minute recorded data from trap logs in the field and hourly data from INCA. The onset of spring swarming was estimated with a mean absolute error of 2.4 days. The onset of infestation was predicted with a mean absolute...

COBISS.SI-ID: 5450150
2.
Short-term forecasting of bark beetle outbreaks on two economically important conifer tree species

In recent years bark beetles have been shown to be an important risk factor in European forests. An early warning system is needed to mitigate bark beetle damage, and short-term forecasting models that assist efforts to identify attacked trees comprise an important part of such a system. The aim of this study was to develop short-term forecasting models of the probability of bark beetle outbreaks on two important conifer tree species: Norway spruce (Picea abies) and silver fir (Abies alba). For the development of the models, we used a time series of 20%years of sanitary felling because of bark beetles and relief data (altitude, slope and exposition), several soil variables, climate data (temperature and SPI), sanitary felling because of bark beetles, sanitary felling due to harmful abiotic factors, and amount of weakened trees due to bark beetles. The forecasting variable was sanitary felling because of bark beetles in the current year. The models were developed with a general linear model with binomial error distribution. For the probability of bark beetle outbreaks on silver fir, the amount of fir, soil base saturation percentage, sanitary felling of attacked fir, weakened fir, and sanitary felling because of abiotic factors increased the probability of sanitary felling because of fir bark beetles. Altitude, exposition, slope, phosphorus, soil depth, soil cation exchange capacity, SPI and temperature decreased the probability of sanitary felling because of fir bark...

COBISS.SI-ID: 5449382
3.
Calculation procedure for RITY-A phenology model of Ips typographus

The RITY-2 phenology model was developed for the spatiotemporal simulation of the seasonal development of European spruce bark beetle, Ips typographus . RITY-2 is based on the PHENIPS model and was developed through improving PHENIPS with innovative approaches and calibrating and validating it for Slovenia. RITY-2 predictions are based on air temperatures from Integrated Nowcasting through a Comprehensive Analysis (INCA) system, which is used to calculate the effective bark temperature for beetle development. In this paper we describe the calculation procedure for RITY-2.

COBISS.SI-ID: 5647270
4.
Phenology model for Ips typographus in Slovenia (RITY-1)

In this article first version of phenology model RITY-1 for the European spruce bark beetle (Ips typographus) is described. In this version of the model we implemented Austrian phenology model PHENIPS where input data for air temperature INCA system was used and German linear model for calculation of bark temperature was used.

COBISS.SI-ID: 4694182
5.
Spatial simulation of the European spruce bark beetle (Ips typographus) phenology in Slovenia

On the basis of point-based phenology model RITY-1 we developed spatial model, that enables display of Ips typographus phenology for the whole area of Slovenia. The model results include onset of swarming, onset of colonization, development of individual developmental stages for several filial and sister broods, number of filial and sister broods.

COBISS.SI-ID: 4714662