Features in and around residential gardens affecting the presence and abundance of questing Ixodes ricinus ticks.

People may be exposed to questing Ixodes ricinus ticks in urban settings, e.g. residential gardens. Little is known about the garden characteristics that support a tick population. To determine which features in and around residential gardens support or limit the occurrence and abundance of questing I. ricinus ticks, we sampled them in residential gardens in the Braunschweig region that differed in various intrinsic and extrinsic parameters. We recorded the number of questing nymphal and adult ticks on transects, and by using mixed-effects generalized linear regression models, we related their occurrence and abundance to garden characteristics, meteorological covariates, and landscape features in the vicinity. We detected questing I. ricinus ticks in about 90% of the 103 surveyed gardens. Our occurrence model (marginal R2 = 0.31) predicted the highest probability of questing ticks on transects with hedges or groundcover in gardens, which are located in neighborhoods with large proportions of forest. The abundance of questing ticks was similarly influenced. We conclude that I. ricinus ticks are frequent in residential gardens in Northern Germany and likely associated with intrinsic garden characteristics on a small scale, such as hedges, as well as extrinsic factors on a local scale, such as the proportion of nearby woodland.

Drawing transformation pathways for making use of joint effects of food and energy production with biodiversity agriphotovoltaics and electrified agricultural machinery.

The achievement of the Sustainable Development Goals is being pursued worldwide. While energy production and consumption are to be oriented towards renewable energies, ecologically and socially sustainable agriculture is also a target for science and society. Due to the expansion of renewable energies, agricultural land in particular is the focus of various interest groups, from food production to energy production. In this interdisciplinary study, we show the opportunities and limits of joint synergies from the nexus of food production, energy production, energy consumption, biodiversity protection and social acceptance of renewable energies in a scenario. Biodiversity agriphotovoltaics, i.e. agriphotovoltaics in combination with biodiversity protection measures, such as flower strips, can make a valuable contribution to promoting biotope connectivity in addition to significant energy production. We show this in a GIS-based regional assessment for Lower Saxony in northern Germany. This rough spatial assessment is followed by a modelling of energy production and consumption during the cultivation of a characteristic agricultural field in the loess region of Lower Saxony. Our focus here is on the possibilities of using cable electricity or battery storage for carrying out the cultivation. In an accompanying survey of farmers regarding the use of agriphotovoltaics, we collected and evaluated their prior knowledge, experiences, and attitudes towards this technology. Finally, we show which advantages agriphotovoltaics and electrified agricultural machinery can also have for the sustainable transformation of agriculture and which challenges exist for a truly sustainable use of these technologies.

From population-level effects to individual response: modelling temperature dependence in Gammarus pulex.

Population-level effects of global warming result from concurrent direct and indirect processes. They are typically described by physiologically structured population models (PSPMs). Therefore, inverse modelling offers a tool to identify parameters of individual physiological processes through population-level data analysis, e.g. the temperature dependence of growth from size-frequency data of a field population. Here, we make use of experiments under laboratory conditions, in mesocosms and field monitoring to determine the temperature dependence of growth and mortality of Gammarus pulex. We found an optimum temperature for growth of approximately 17°C and a related temperature coefficient, Q(10), of 1.5°C(-1), irrespective of whether we classically fitted individual growth curves or applied inverse modelling based on PSPMs to laboratory data. From a comparison of underlying data sets we conclude that applying inverse modelling techniques to population-level data results in meaningful response parameters for physiological processes if additional temperature-driven effects, including within-population interaction, can be excluded or determined independently. If this is not the case, parameter estimates describe a cumulative response, e.g. comprising temperature-dependent resource dynamics. Finally, fluctuating temperatures in natural habitats increased the uncertainty in parameter values. Here, PSPM should be applied for virtual monitoring in order to determine a sampling scheme that comprises important dates to reduce parameter uncertainty.