Project structure WP

WP1. When is the optimal time for mowing of the invasive species, i.e. when will vitality of the plant be affected most negatively by biomass removal?

We hypothesise that this point in time occurs after a phase of rapid plant growth and development in spring when the amount of essential resources in aboveground biomass is highest, while belowground reserves are most depleted. We suggest a large field study (WP1) to identify this optimal mowing time. Combined with the phenological state of the species this enables the development of easy-to-recognize phenological indicators for optimal mowing.

WP2. Which is the most efficient combination of mowing time and mowing frequency that could be used as a short-term control and eradication regime for Garden Lupine?

While the time of mowing determines the relative amount of aboveground resources removed, mowing frequency may serve to remove regrowth and further deplete the species’ resources. We hypothesise that the most efficient control regime through mowing will probably consist of an early cut at the optimal point in time (see above) plus one or two later cuts. In a large field experiment (WP 2) along a latitudinal gradient, we plan to identify the control mowing regime that most efficiently reduces the cover of Garden Lupine (or even eradicates it locally) while having as little negative impact on the native vegetation as possible. Even in this study, we aim to link mowing time with indicators of the species’ phenological state to go beyond fixed-date management but develop a control regime that can easily be adapted to other regions.

WP3. Which other management measures do have significantly negative effects on the cover and vitality of Garden Lupine along road verges?

In another field experiment (WP 3), we will directly compare the effects of mowing with other ways of control such as uprooting, cutting of inflorescences, and liming on Garden Lupine. We hypothesise that while mowing may be the most economic and feasible management at a larger scale and in large populations of the invasive plant, other control measures may be more efficient and cost effective in certain situations. In this study, we directly compare the costs (in terms of time and money) and effects on Garden Lupine and the native vegetation of different control measures.

WP4. How can utilization of geospatial technology aid in developing a cost efficient monitoring strategy, in designing management plans at the landscape scale and in controlling the effects and success of management efforts of invasive Garden Lupine along roads?

Commonly, species-rich road verges are treated as single isolated objects without a landscape context. With this local focus, even the most efficient management regime for invasive species will be a waste of money and energy, if potential immigration and recolonization from nearby populations is ignored. Conservation as a multi-scale and multi-objective scheme demands a multidisciplinary approach and we call for a landscape perspective on conservation of species-rich road verges that considers the multifunctionality of landscapes. Therefore, in WP 4, we intend to develop a tool for management planning and success control of Garden Lupine management based on geospatial technology and remotely sensed data. The spatial composition and configuration of the landscape with respect to Garden Lupines will be quantified by the well-known concept of landscape metrics.