Dynamics and drivers of aboveground biomass accumulation during recovery from selective harvesting in an uneven-aged forest

European Journal of Forest Research - Selective harvesting is a common silvicultural practice to ensure sustainable use of uneven-aged forests, but our understanding of how multiple forest...     

German farmers’ intention to use autonomous field robots: a PLS-analysis

Autonomous field robots are a promising technology for solving several problems in agriculture, as they are electrical driven, can control weeds single-plant based mechanically or with microdoses of pesticides and exert less ground pressure on the field. Whether such robots will be applied on a large scale in German agriculture depends on various parameters. Therefore, the factors influencing the behavioural intention of farmers with respect to their future adoption of autonomous field robots were investigated. The analysis applies a structural equation model based on an extended version of the Unified Theory of Acceptance and Use of Technology. The dataset, collected in 2019, consists of 500 German farmers. The results reveal significantly positive effects of farmers’ expected performance, social influence and trust as well as significantly negative effects of farmers’ effort expectancy and anxiety on the behavioural intention to use autonomous field robots. Additionally, moderating effects of age on the relationship of individual constructs to the behavioural intent to use robots could be confirmed. The results provide important information for various stakeholders. Robot suppliers should better inform farmers about the performance of their products, for instance by involving farmers in the development process of the robots. The ecological benefits attributed to field robots could meet public expectations and should be better communicated to address farmers’ social influence on the behavioural intention to use the robots. Policymakers could try to create better framework conditions, for example by establishing a stable legal situation for autonomous systems or promote its use.

     

An investigation of the effects of ketoprofen following rumen fistulation surgery in lactating dairy cows

Post-operative pain management following rumen surgery is not common practice. We examined the effect of providing the pain medication ketoprofen to dairy cattle following the first stage of a rumen cannulation surgery, which involves an incision in the body wall and exteriorizing and clamping the rumen. The results of this study provide clear evidence that the first stage of the surgery was painful and ketoprofen at the time of and 24 h following surgery, alleviated some, but not all, of the post-surgical pain. Pain mitigation should be included when performing flank surgery in cattle.     

Comparison of two real-time RT-PCR assays for differentiation of C-strain vaccinated from classical swine fever infected pigs and wild boars

Classical swine fever is one of the most important infectious diseases for the pig industry worldwide due to its economic impact. Vaccination is an effective means to control disease, however within the EU its regular use is banned owing to the inability to differentiate infected and vaccinated animals, the so called DIVA principle. This inability complicates monitoring of disease and stops international trade thereby limiting use of the vaccine in many regions. The C-strain vaccine is safe to use and gives good protection. It is licensed for emergency vaccination in the EU in event of an outbreak. Two genetic assays that can distinguish between wild type virus and C-strain vaccines have recently been developed. Here the results from a comparison of these two real-time RT-PCR assays in an interlaboratory exercise are presented. Both assays showed similar performance.     

Panagrellus redivivus mass produced on solid media as live food for Litopenaeus vannamei larvae

The free‐living soil nematode Panagrellus redivivus is well known to be an excellent food source for first feeding fish larvae. It represents an alternative to the highly expensive Artemia, which is commonly used. The lack of a proper method for mass production of P. redivivus has prevented its wider use in commercial hatcheries. A new cultivation method allows the production of a sufficient quantity of nematodes to deliver a standardized and permanently available live food of high quality, throughout the larval rearing period. In two experiments – carried out at the Centro de Investigación en Alimentación y Desarrollo, Mexico – several feeding regimes were established to prove the quality of the mass produced P. redivivus for larvae of Litopenaeus vannamei, the Pacific white shrimp. Two different nematode treatments were compared with a no‐feed group and a control group that was fed with Artemia. All treatments had an additional algal co‐feed and were run in five replicates. Panagrellus redivivus was cultured on two different media (wheat/corn flour and oat flour) to compare these for their suitability as high‐quality live food for the larvae. Shrimp fed nematodes grown on wheat/corn medium reached the postlarval stage earlier than those from other treatments. The nematode treatments showed promising results; however, further research is needed on the development of improved culture media or enrichment methods to further increase the nutritional value of P. redivivus.     

Experimental evidence for direct in situ binding of IgM and IgT to early trophonts of Ichthyophthirius multifiliis (Fouquet) in the gills of rainbow trout, Oncorhynchus mykiss (Walbaum)

Freshwater fish are able to mount a protective immune response against the parasite Ichthyophthirius multifiliis (Ich) following a non‐lethal exposure. Factors involved in immunity comprise cellular and humoral factors, but antibodies have been suggested to play a prominent role in protection. However, host antibodies have not yet been demonstrated to bind to the parasite in situ. By the use of immunohistochemical techniques, this study demonstrated that IgT and IgM bind to surface structures, including cilia, on the early feeding stage of the parasite in the gills of immune rainbow trout, Oncorhynchus mykiss, shortly (2 h) after invasion. No binding of IgT and no or only a weak binding of IgM was observed on the parasites in the gills of similarly exposed but naïve rainbow trout. This study indicates that antibodies play an important part in the protection of immune fish against Ich although additional humoral and cellular factors may contribute to this reaction.     

Age determination of large live trees with inner cavities: radiocarbon dating of Platland tree,a giant African baobab

• Introduction   

For large trees without a continuous sequence of growth rings in their trunk, such as the African baobab (Adansonia digitata L.), the only accurate method for age determination is radiocarbon dating. As of today, this method was limited to dating samples collected from the remains of dead specimens.     

Estimating balanced structure areas in multi-species forests on the Sierra Madre Occidental,Mexico

• Introduction   

This study presents a method for estimating the minimum area which exhibits a balanced diameter distribution, and the corresponding number of trees, for different tree species and forest types in the Santiago Papasquiaro region in the State of Durango, Mexico. The balanced structure area is defined as the minimum contiguous area that is required for sustainable management of a multi-sized selection forest. A multi-sized forest represents a balanced structure unit if the relationship between harvest and growth can be maintained, using a defined target diameter distribution and disregarding major natural disturbances. The study is based on 17,577 sample plots in uneven-aged forests, which are selectively harvested by local communities.