Description

Riparian buffer strips are linear bands of permanent natural or semi-natural vegetation adjacent to streams and rivers. A general, multi-purpose, riparian buffer design consists of a strip of grass, shrubs, and trees between the normal bank-full water level and more intensively used land, such as cropland, roads, built-up areas. Riparian buffer strips are an adaptation option able to: 

  • prevent flooding: riparian buffers give room for natural dynamics of a river, such as rising and falling water levels, and allow for the slowing down of streamflow and creation of meandering flow paths. This reduces the channel erosion potential of rivers and thus the potential of downstream flooding. 
  • mitigate drought: through improving groundwater recharge by increasing soil permeability and increased contact time of water with soils, or through shading effects provided by trees and shrubs that improve micro-climatic conditions. 
  • ensure cooling: the shading effect of riparian buffers helps to create a microclimate that serves to cool over-shadowed water bodies, increasing air humidity and stabilizing temperatures. 

Beyond adaptation, a multitude of benefits is expected from riparian buffer strips, since they act as: 

  • Natural filter for pollutants and preventers of eutrophication: they act as a shield against overland flow from agricultural fields by reducing the run-off of sediments and pollutants reaching the watercourse. Buffer zones averagely reduce NO3–N by 33% in surface runoff and by 70% in groundwater (Valkama et al., 2019). 
  • Natural corridor connecting habitats and species that facilitates natural species dispersal. They allow connectivity across both longitudinal (upstream-downstream) and lateral (between stream and land) gradients. Longitudinal connectivity is particularly important for dispersal of species across temperature gradients, while lateral connectivity allows for heterogeneous microclimates that help species cope with fluctuating weather.  

Given the range of benefits, riparian buffers are important features to maintain and restore in the landscape. Buffer strips are thus being widely supported as agro-environmental measures in European rural development programs. The width of a functional buffer strip depends on the landscape context, stream width and dynamics of the stream. In intensive agricultural lowlands, wide buffer strips of 10- 100 m are especially important. The width of the riparian buffer and the management of its natural or semi-natural vegetation should be context-specific and take special account of the hydraulics of the river and the entire catchment. For this reason, it requires coordination between different levels of governance and integration in regional and river basin plans 

Adaptation Details

IPCC categories
Structural and physical: Ecosystem-based adaptation options
Stakeholder participation

The implementation of riparian buffer strips requires the involvement of various actors (river managers, farmers, etc.) who should be involved to make the adoption of the adaptation option feasible. The option is usually well accepted by the public due to its positive effects on the landscape and the multiple co-benefits it provides. Local authorities involved in agro-environmental schemes and high nature value farmland can assist with on ground implementation. 

Success and limiting factors

The success of vegetated buffer strips is strongly dependent on characteristics such as buffer zone width, slope of the adjacent fields, soil type and variety, and density of vegetation. Minor temporary negative side-effects during the plantation of vegetation and related works along the water body are highly compensated but medium to long term positive effects, if the option is carefully designed and planned.  

Flood and drought mitigation effects could be variable, depending on local conditions and on the quality of the design and implementation. Forested buffers create woody debris which influences stream morphology most. Tree and shrub size, age and density are factors to be considered in the effectiveness of flood control, water retention and filtration capacities. Vegetative strips which are planted with native species can also contribute to the local biodiversity in the long term. Where non-native species are planted,  they may have negative effects on the long term sustainability of the buffers, or potentially harm natively established ecosystems in the area.  Indeed, the selection of appropriate vegetation needs to be carefully evaluated to ensure high capacity to retain soil and water and to contribute to the local biodiversity. The need for regular maintenance of vegetation should also be considered to minimise efforts needed for its preservation in the long term. 

There are also a variety of social and economic factors that can curb the adoption of riparian buffers, including: a lack of incentive programmes, poorly defined goals, lack of maintenance, and opposition from landowners. 

Costs and benefits

The total cost of riparian buffer strips includes the costs of planning, the costs of planting (trees, shrubs, local vegetation), the costs of land and/or revenue lost from replacing farm/grazing areas, and the cost of maintenance works. These costs are hugely dependent on the location and size of the buffer strip, yet they are shown to be greatly balanced with the long term benefits. 

Riparian buffers provide multiple benefits for adaptation to climate change like microclimate creation, flood and drought mitigation. Moreover, by acting as biodiversity corridor and by improving local water quality through their filtration capacity for nutrients and pollutants, riparian buffers are important features to maintain and restore in the landscape. Buffer strips may also reduce the costs of fertilization due to the reduction of nutrient runoff and may reduce the frequency of riverbank restoration due to reduced flooding and erosion.  

Additionally, perennial vegetation such as trees are particularly beneficial for long-term atmospheric carbon sequestration, also making riparian buffers a potential tool to further progress towards climate change mitigation. 

Implementation time

10-15 years could be needed to develop a fully mature riparian buffer which includes trees and shading benefits as well as creating a biodiversity corridor. However, within 1 year, shrubs and local vegetation could be planted which already begin to display their first positive effects in terms of reduced erosion, and pollutant filtration. Monitoring and upkeep of the area should be carefully managed especially during the first 5 years, scaling down management efforts between 5-10 years after the buffer establishment, once it becomes more mature and less vulnerable to local environmental pressures.  

Lifetime

The expected life time is more than 25 years if the measures are well established in the first years of implementation, with the majority of the maintenance in the first 5-10 years. 

Reference information

Websites:
References:

Stutter, M., Kronvang, B., Ó hUallacháin, D. and Rozemeijer, J. (2019), Current Insights into the Effectiveness of Riparian Management, Attainment of Multiple Benefits, and Potential Technical Enhancements. J. Environ. Qual., 48: 236-247. https://doi.org/10.2134/jeq2019.01.0020 

 Haddaway, N.R., Brown, C., Eales, J. et al. The multifunctional roles of vegetated strips around and within agricultural fields. Environ Evid 7,14 (2018). https://doi.org/10.1186/s13750-018-0126-2 

 Lorna J. Cole, Jenni Stockan, Rachel Helliwell, Managing riparian buffer strips to optimise ecosystem services: A review, Agriculture, Ecosystems & Environment, Volume 296, 2020, 106891, ISSN 0167-8809, https://doi.org/10.1016/j.agee.2020.106891 

 Valkama, E., Usva, K., Saarinen, M. and Uusi-Kämppä, J. (2019), A Meta-Analysis on Nitrogen Retention by Buffer Zones. J. Environ. Qual., 48: 270-279. https://doi.org/10.2134/jeq2018.03.0120  

 Englund, O., Börjesson, P., Mola-Yudego, B. et al. Strategic deployment of riparian buffers and windbreaks in Europe can co-deliver biomass and environmental benefits. Commun Earth Environ 2, 176 (2021). https://doi.org/10.1038/s43247-021-00247-y 

 

Published in Climate-ADAPT Sep 3, 2016   -   Last Modified in Climate-ADAPT May 17, 2024

Language preference detected

Do you want to see the page translated into ?

Exclusion of liability
This translation is generated by eTranslation, a machine translation tool provided by the European Commission.