Open Access

Over the last two decades, European forest ecosystems have been exposed to increasing stress associated with an increasing number, duration and severity of extreme events triggered by climate change (Dyderski et al., 2018). For forest plants, the concomitant stresses are not limited to direct detrimental effects of rising temperatures, drought and heavy rainfall, but also include enhanced virulence of native plant pathogens and herbivores and the introduction of new pests (Stenlid and Oliva, 2016). The detection of forest diseases at an early stage, when visible symptoms cannot yet be observed, is a crucial prerequisite to counteract regional spreading of pathogens. However, the effective monitoring of forest damage and diseases requires reliable and easy-to-use portable test systems.

To support the adaption of soybean [Glycine max (L) Merrill] cultivation across Central Europe, the availability of compatible soybean nodulating Bradyrhizobia (SNB) is essential. Little is known about the symbiotic potential of indigenous SNB in Central Europe and the interaction with an SNB inoculum from commercial products. The objective of this study was to quantify the capacity of indigenous and inoculated SNB strains on the symbiotic performance of soybean in a pot experiment, using soils with and without soybean history. Under controlled conditions in a growth chamber, the study focused on two main factors: a soybean cropping interval (time since the last soybean cultivation; SCI) and inoculation with commercial Bradyrhizobia strains. Comparing the two types of soil, without soybean history and with 1–4 years SCI, we found out that plants grown in soil with soybean history and without inoculation had significantly more root nodules and higher nitrogen content in the plant tissue. These parameters, along with the leghemoglobin content, were found to be a variable among soils with 1–4 years SCI and did not show a trend over the years. Inoculation in soil without soybean history showed a significant increase in a nodulation rate, leghemoglobin content, and soybean tissue nitrogen concentration. The study found that response to inoculation varied significantly as per locations in soil with previous soybean cultivation history. An inoculated soybean grown on loamy sandy soils from the location Müncheberg had significantly more nodules as well as higher green tissue nitrogen concentration compared with non-inoculated plants. No significant improvement in a nodulation rate and tissue nitrogen concentration was observed for an inoculated soybean grown on loamy sandy soils from the location Fehrow. These results suggest that introduced SNB strains remained viable in the soil and were still symbiotically competent for up to 4 years after soybean cultivation. However, the symbiotic performance of the SNB remaining in the soils was not sufficient in all cases and makes inoculation with commercial products necessary. The SNB strains found in the soil of Central Europe could also be promising candidates for the development of inoculants and already represent a contribution to the successful cultivation of soybeans in Central Europe.

Habitat use by cervids can have large effects on vegetation. Therefore, factors influencing habitat use are pertinent to ecology, nature conservation as well as management of forests and hunting. The aim of this study was to identify factors influencing habitat use by red and roe deer, Cervus elaphus and Capreolus capreolus, in the Lüneburger Heide, Germany. We used faecal pellet counts as an indicator of habitat use and applied generalized linear models to conclude that habitat use by both cervids was largely explained by the availability of food plants. In particular, the occurrence of bilberry Vaccinium myrtillus and deciduous trees such as beeches Fagus sylvatica were of major importance. Nonetheless, red and roe deer showed preferences for different plant species, but for both deer, the presence of large trees and conifers, with exception of young Norway spruce Picea abies providing shelter for roe deer, was less attractive. Furthermore, the proximity of mineral licks was important for both cervids. Relative to roe deer, red deer showed a stronger avoidance of well-used paths. Surprisingly, landscape features such as distance to settlements and elevated hunting standshad no significant effect. Our study demonstrates similarities and differences in habitat use of two important herbivores of the Northern temperate forests. We propose that managers establish ‘decoy’ sites for deer: areas with a high proportion of ground vegetation and young trees of lower forestry value. This will serve to divert deer from valuable trees and thereby enhance biodiversity. These open stands could be interspersed with dense islands of young coniferous trees to offer shelter and should be distant to frequently used pathways. Mineral licks may help enhance use of these sites. Providing an attractive resource for both species of cervids is the best way to manage large herbivores in economically valuable forests.