Hans Martin Hanslin
Research Scientist
(+47) 404 75 239
hans.martin.hanslin@nibio.no
Place
Særheim
Visiting address
Postvegen 213, NO-4353 Klepp stasjon
Attachments
CVBiography
My research interests in plant ecology and ecophysiology centre around trait based approaches, phenotypic plasticity, local adaptation, seedling ecology and functional ecology of roots. To pursue the impact of environmental drivers and especially multiple co-varying stressors on plant-soil systems, I use designed experiments to manipulate biotic and abiotic factors under controlled or semi-controlled and field conditions. I have a strong focus on applied aspects and recent projects include multifunctionality in urban constructed systems, restoration of ecological processes and functions, urban climate adaptation, and impact studies of invasive plant species. In turn, these contributions improve planning and management of urban green infrastructure and ecological restoration.
Abstract
No abstract has been registered
Abstract
Green roofs provide vital functions within the urban ecosystem, from supporting biodiversity, to sustainable climate-positive ESS provisioning. However, how plant communities should best be designed to reach these objectives, and how specific green roof systems vary in their capacity to support these functions is not well understood. Here we compiled data on plant traits and plant–insect interaction networks of a regional calcareous grassland species pool to explore how designed plant communities could be optimised to contribute to ecological functionality for predefined green roof solutions. Five distinct systems with practical functionality and physical constraints were designed, plant communities modelled using object-based optimization algorithms and evaluated using five ecological functionality metrics (incl. phylogenetic and structural diversity). Our system plant communities supported a range of plant–insect interactions on green roofs, but not all species were equally beneficial, resulting in wide-ranging essentiality and redundancy in ecological processes. Floral traits were not predictive of pollinator preferences, but phylogeny was observed to govern the preferences. Large differences in ecological functionality can be expected between green roofs depending on system design and the extent of the plant community composition. Multifunctionality covariance diverged between systems, suggesting that ecological functionality is not inherently universal but dependent on structural limitations and species pool interactions. We conclude that informed system design has a potential to simultaneously support ecosystem services and urban biodiversity conservation by optimising green roof plant communities to provide landscape resources for pollinating insects and herbivores.
Abstract
Background Vegetated infiltration systems such as raingardens and bioswales are challenging for plant growth and survival due to fluctuating hydrological conditions and further subsequent stresses. Aim Here, we investigated the effect of fluctuation hydrology on growth and flowering and subsequent winter frost hardiness or spring salt tolerance for two common raingarden plant species, Filipendula ulmaria, and Calamagrostis ×acutiflora ‘Karl Foerster’, under controlled conditions. Methods During summer, plants were exposed to four hydrological regimes, each with a different combination of repeating dry and wet cycles. Then, after natural winter acclimation and storage, plants went through standardized freezing tests to determine LT50 and regrowth potential or were exposed to four levels of salt treatments (Control, 28 mM, 56 mM, and 84 mM NaCl) in the following spring. Results We found that fluctuating hydrology reduced the growth of Filipendula ulmaria, experiencing cycles of 72 hours of flooding and 264 hours of drained conditions, followed by a reduction of growth and flowering after salt exposure. Calamagrostis xacutiflora was less responsive to both fluctuating hydrology and salinity. Cycles with the longest dry conditions (Wet-dry cycles) showed the strongest negative effect on the performance of tested species. The hydrological regimes did not influence freezing tolerance in either species. Conclusion Moderate hydrological fluctuations did not cause damage to vegetation in vegetated infiltration systems, at least under shaded conditions. At the same time, drought tolerance is an important trait for species and cultivars in raingardens during hydrological fluctuations. Our prediction that hydrological conditions that negatively affected plant growth would reduce subsequent frost and salinity tolerance was only partially supported.
