0000000000362630
AUTHOR
Kristiina Nyholm
Assessing the conservation priority of freshwater lake sites based on taxonomic, functional and environmental uniqueness
Aim We propose a novel approach that considers taxonomic uniqueness, functional uniqueness and environmental uniqueness and show how it can be used in guiding conservation planning. We illustrate the approach using data for lake biota and environment. Location Lake Puruvesi, Finland. Methods We sampled macrophytes and macroinvertebrates from the same 18 littoral sites. By adapting the original “ecological uniqueness” approach, we used distance-based methods to calculate measures of taxonomic (LCBD–t), functional (LCBD–f) and environmental (LCEH) uniqueness for each site. We also considered the numbers and locations of the sites needed to protect up to 70% of total variation in taxonomic, fu…
Vendace (Coregonus albula) Disperse Their Eggs Widely during Spawning
Depending on their reproductive strategy, different fish species either aggregate or disperse eggs and larvae in their reproductive habitat. Because yolk-sac larvae of vendace (Coregonus albula) disperse widely across the littoral and pelagic zones of boreal lakes, it is unclear where the exact spawning and egg incubation locations are. Vendace egg and larvae densities were studied in Lake Southern Konnevesi to clarify its spawning strategy. In autumn 2019, 1–2 weeks prior to spawning, 500 egg samplers were installed in five depth zones in 20 sampling plots. Fertilized eggs were found in 18 plots. The mean density of eggs was 74 eggs m–2 and the mean fertilization rate 85%. During spawning,…
Dispersion of vendace eggs and larvae around potential nursery areas reveals their reproductive strategy
Depending on their reproductive strategy, different fish species aim to aggregate or disperse eggs and larvae in their reproductive habitat. Many pelagic species disperse their eggs widely around the potential nursery areas. Larval dispersion or aggregation affects population sub‐structuring, which has important implications in fisheries management and conservation of the natural spatial diversity in populations. The dispersion of larval vendace (Coregonus albula) was quantified in two oligotrophic Finnish lakes, and effects of density and environmental variables on the inter‐annual variation in the larval distribution were examined by analysing spatial abundance data from the lakes from 19…
Do the ecological drivers of lake littoral communities match and lead to congruence between organism groups?
AbstractLake littoral environments are heterogeneous, and different organisms typically show specific responses to this environmental variation. We examined local environmental and spatial factors affecting lake littoral biodiversity and the structuring of assemblages of phytoplankton, zooplankton and macroinvertebrates within and among three basins of a large lake system. We explored congruence of species composition and species richness among the studied organism groups to evaluate their general indicator potential to represent spatial variation in other groups. We expected that effects of water chemistry on plankton assemblages were stronger than effects of habitat characteristics. In co…
Challenges of ecological restoration: Lessons from forests in northern Europe
The alarming rate of ecosystem degradation has raised the need for ecological restoration throughout different biomes and continents. North European forests may appear as one of the least vulnerable ecosystems from a global perspective, since forest cover is not rapidly decreasing and many ecosystem services remain at high level. However, extensive areas of northern forests are heavily exploited and have lost a major part of their biodiversity value. There is a strong requirement to restore these areas towards a more natural condition in order to meet the targets of the Convention on Biological Diversity. Several northern countries are now taking up this challenge by restoring forest biodiv…
Using GIS tools to identify conservation hot spots in large boreal lakes
Balancing the growing demands of human population and sustainable use of natural resources is a great challenge for humankind and the target of several international environmental conventions. Water Framework Directive (WFD) of the European Union aims at perceiving ecosystem services provided by aquatic ecosystems, while EU Habitats Directive (HD) along with the Natura 2000 network is to ensure the long-term survival of valuable habitats in aquatic as well as terrestrial environments. Both WFD and HD treat boreal lakes as large entities. In large lake systems, the assessment of lake bodies’ ecological and conservation status is determined over tens or even hundreds of square kilometres and …