Dina lineata (O.F. Müller, 1774) – an interesting species of leech in astatic reservoirs of the city of Olsztyn and its surroundings

The aim of the presently study was to provide information about the occurrence of Dina lineata in selected reservoirs of the city of Olsztyn and its surroundings. The material was collected applying the qualitative method. The leeches were found in the overflows of Olsztyn lakes (Skanda Lake and Redykajny Lake) and small astatic midfield reservoir near Samławki

Ground Beetles (Carabidae) in the Short-Rotation Coppice Willow and Poplar Plants—Synergistic Benefits System

In a short period, we have observed the rapid expansion of bioenergy, resulting in growth in the area of energy crops. In Europe, willow and poplar growing in short-rotation coppices (SRC) are popular bioenergy crops. Their potential impact on biodiversity has not yet been fully investigated. Therefore, there are many uncertainties regarding whether commercial production can cause environmental degradation and biodiversity impoverishment. One of the aspects examined is the impact of these crops on entomofauna and ecosystem services. The best-studied insect group is ground beetles from the Carabidae family. This work gathers data on biodiversity and the functions of carabids in willow and poplar energy plants. The results of these investigations show that energy SRC plants and Carabidae communities can create a synergistic system of mutual benefits. Willow and poplar plants can be a valuable habitat due to the increased biodiversity of entomofauna. Additionally, SRC creates a transitional environment that allows insect migration between isolated populations. On the other hand, ground beetles are suppliers of ecosystem services and make a significant contribution to the building of sustainable agriculture by pest control, thereby ameliorating damage to field crops

Environmental heterogeneity at different scales: key factors affecting caddisfly larvae assemblages in standing waters within a lowland river catchment

We examined the importance of environmental parameters at different spatial scales influencing the occurrence of caddisfly larvae at different levels of their organization (species, faunistic metrics and functional groups) in lentic floodplain waters, in order to gain information on the ecological status and management of a small lowland river catchment. At the lowest spatial level – pH, sediment grain size, insolation and the presence of aquatic macrophytes proved significant for caddisfly larvae, at higher and the highest level (including buffer zones and the catchment) – the surface areas of watercourses and the river, distance from standing waters and distance from broadleaf forests, respectively. Rheophilous hydropsychids accounted for 17% of the whole fauna of the examined water bodies. They spread from the river via water during flood in the spring. We also detected some significant correlations between functional groups of caddisfly larvae and parameters describing buffer zones and the river catchment against the sub-catchment type use. Information provided by the Caddisfly Habitat Index showed an overall  good ecological status of the river-floodplain. Caddisfly larvae may be good indicators of numerous factors and processes, but they should be studied comprehensively, at different levels of organization. Our results can be useful for preservation of biodiversity and management of river valleys. We suggest: 1) maintaining the varied structure of aquatic macrophytes in water bodies, 2) securing the long-term presence of broadleaf trees in buffer zones in order to provide detritus input, varied insolation and shelter for caddisflies, 3) limiting drainage activities in the river valley in order to save varied habitats, especially temporary ones, 4) providing heterogeneous landscape in the river catchment (homogenous land use is inappropriate). </p

Early recolonization of a dredged lowland river by dragonflies (Insecta: Odonata)

The influence of dredging on the dragonfly assemblages of the small regulated lowland River Krąpiel (north-western Poland) was analyzed a short time after the dredging. Dragonfly assemblages were destroyed, but they began to recover rapidly. Many biocoenotic indices reached high values at just six months after the dredging. The recolonization first occurred as a result of larval drift, and then, via dispersion of adult dragonflies. This process took place in conditions different from the prevailing conditions in the period before dredging, in terms of microhabitat availability and physico-chemical conditions. Compared to the previous assemblage, the emerging assemblage was more typical of assemblages found in small, natural running waters. Therefore, dredging (carried out for economic reasons) could be regarded as a process that unintentionally had a positive influence on odonate assemblages. Currently, when most small watercourses are regulated, dredging that is properly planned and controlled has proven to protect the natural fauna. It is worthwhile to apply lessons learned from examples of active fauna protection to what is currently known as “the rotational model” for dredging

Early recolonization of a dredged lowland river by dragonflies (Insecta: Odonata)

The influence of dredging on the dragonfly assemblages of the small regulated lowland River Krąpiel (north-western Poland) was analyzed a short time after the dredging. Dragonfly assemblages were destroyed, but they began to recover rapidly. Many biocoenotic indices reached high values at just six months after the dredging. The recolonization first occurred as a result of larval drift, and then, via dispersion of adult dragonflies. This process took place in conditions different from the prevailing conditions in the period before dredging, in terms of microhabitat availability and physico-chemical conditions. Compared to the previous assemblage, the emerging assemblage was more typical of assemblages found in small, natural running waters. Therefore, dredging (carried out for economic reasons) could be regarded as a process that unintentionally had a positive influence on odonate assemblages. Currently, when most small watercourses are regulated, dredging that is properly planned and controlled has proven to protect the natural fauna. It is worthwhile to apply lessons learned from examples of active fauna protection to what is currently known as “the rotational model” for dredging