NEC05883 Ecological implications of increased storm disturbance: will substrate exposure and flooding generate vacant niche space under global change

In December 2015, Storm Desmond (5-6th), Storm Eva (23rd) and Storm Frank (28th) caused extensive flooding and land slippage across Cumbria, Lancashire and Yorkshire. Urban and rural environments and transport routes were impacted exposing typically freely draining flood-plain grasslands to severe inundation and exposing sub-soils and parent material along valley sides and river banks. We take the 28th as the date when the science opportunity became fully available. We propose work to sample exposed and flooded substrates in Cumbria resulting from these three storm events. The work is urgent because as flood waters recede and agricultural management cycles restart, soil conditions will be less reflective of the immediate storm impact. Also land slips and major erosion may be subject to remediation and maybe capped or otherwise landscaped thus removing the sampling opportunity.

Across the UK extremes of wind and rainfall are becoming more frequent under a warming climate. Storm-induced vegetation disturbance resulting from flooding and land-slip will therefore become a more common feature of urban and rural environments. Because we rely on soil and vegetation complexes for a range of natural 'services' such as crop production, soil stabilisation, flood defence and pollination, knowledge is required about whether and how storm-induced gaps will naturally re-vegetate in the short and longer term, and whether re-colonising species will be in shorter supply because newly exposed substrates and a changing climate, provide unsuitable conditions for native and naturalised plants present in the local, regional or wider species pools. Identifying which plant species are favoured by new configurations of soil and climate is important because new colonists may provide a different suite of 'botanical services' to the pre-existing vegetation. In Cumbria flooding and land-slip have impacted high and lower quality agricultural grassland, river bank, municipal parkland and other urban vegetation. If left to re-colonise naturally would present and future vegetation gaps provide different levels and types of 'botanical service' or is re-colonisation failure likely to occur because new conditions represent new niche space with respect to the local and regional flora?

With increasing frequency of high wind and intense rainfall expected as the climate further warms we expect that our results will find ready audiences among a range of stakeholders and land owners in Cumbria and also in those communities beyond the study area thathave also been affected by extreme weather in the last decade. The data and results generated will have wider utility, beyond the scientific questions being asked, in assessing and predicting impacts of climate change and its effects on both semi-natural and agricultural habitats. The project will therefore be of benefit to different land owners and managers (Farmers, Conservation bodies) and the relevant departmental bodies concerned with management of water and land (Environment Agency and Natural England). The results of this project will increase understanding of the tempo and trajectory of ecosystem recovery following extreme weather events, including an assessment of whether recovery of vegetation and botanical services provided by plants prior to impact from the storm events could be hampered by a lack of suitable colonists. This knowledge can be integrated into land management plans and used to help mitigate against effects of extreme weather (for example, advice on plant species tolerant of flooding, and hence selected seed mix, depending on regularity or likelihood of flooding events in grassland). The project will also provide a test of the ability to forecast the impact of future events on Natural capital (NC) in these habitats (plant species, soil characteristics) and the Ecosystem Services (ES) they provide, including soil stabilisation, flood control, carbon storage, pollination support from nectar plants, crop and grass forage production. Both of these aspects can provide fundamental details contributing to cost-benefit analysis of remediation versus natural recovery, supporting planning and decision-making by local authorities.