Centre for Ecology and Hydrology (CEH)

River temperature is an important control on the health of fish populations. Under climate change it is expected that river temperature will rise with negative consequences for fish populations. Management of riparian woodland is proven to protect cold water habitats. However, the creation of new riparian woodland can be costly and logistically challenging. It is therefore important that woodland creation is prioritised to areas where (1) river temperatures are hottest (2) most sensitive to climate change (see SRTMN Predictions: http://marine.gov.scot/information/scotland-river-temperature-monitoring...) and (3) where riparian woodland can be most effective in reducing maximum summer river temperatures. Together these tools can be used to prioritise riparian tree planting in Scotland to protect freshwater fish and fisheries from the effects of climate change.

These layers identify where river temperatures can be reduced through riparian shading in Scotland (3 above). Details of modelling work that produced these layers can be found in the associated peer reviewed manuscript: Jackson et al (2021) A deterministic river temperature model to prioritise management of riparian woodlands to reduce summer maximum river temperatures (see link under ‘Additional Information’ Tab).

The outputs of this work are illustrated as three layers on Marine Scotland Maps NMPi: 
1.    Prioritisation where both banks can be planted
2.    Prioritisation where only north banks can be planted 
3.    Prioritisation where only south banks can be planted 

The rankings and colour scales run from 0- 10, with 0 being low priority (no temperature reduction) and 10 high priority (large temperature reduction). First order (Strahler) rivers have been removed from this dataset. NAs are where we were unable to make predictions of planting potential e.g. lochs, or in circumstances where we cannot generate the required covariates.
 

Increasing river temperatures are a threat to many of Scotland's freshwater species which are often adapted to live in cool environments. This includes ecologically and economically important freshwater fish species such as Atlantic salmon and brown trout. Management of riparian woodland is proven to protect cold water habitats. However, Scotland has ca. 108,000 km of rivers, of which only ca. 35% are protected by any substantial tree cover. Furthermore, the creation of new riparian woodland can be costly and logistically challenging compared to other forms of large scale woodland creation. It is therefore important that riparian tree planting is prioritised to areas where it can have greatest benefits for river temperature, specifically, where  rivers are (1) hottest (2) most sensitive to climate change and (3) can be effectively cooled by riparian woodland. These three individual criteria can be combined with an equal weight to provide a single riparian woodland prioritisation score that looks to maximise the benefits of riparian tree planting for protecting Scotland’s rivers from the adverse effects of climate change.  

Details of the modelling work that produced the river temperature and climate sensitivity predictions can be found in the peer reviewed manuscript: Jackson et al (2018) ‘A spatio-temporal statistical model of maximum daily river temperatures to inform the management of Scotland's Atlantic salmon rivers under climate change.’

Details of the modelling work that identifies where riparian trees can have the greatest effect in reducing summer maximum river temperatures can be found in: Jackson, F.L., Hannah, D.M., Ouellet, V. and Malcolm, I.A. (2021) A deterministic river temperature model to prioritise management of riparian woodlands to reduce summer maximum river temperatures.

Given the variety of potential tree planting options (southerly banks, northerly banks, both banks) and the need to scale results both nationally and locally, the outputs are illustrated as six layers on Marine Scotland Maps NMPi:

1. Nationally scaled tree planting prioritisation score where trees are planted on both banks
2. Nationally scaled tree planting prioritisation score where trees are planted on only the most southerly bank
3. Nationally scaled tree planting prioritisation score where trees are planted on only the most northerly bank
4. Locally scaled tree planting prioritisation score where trees are planted on both banks
5. Locally scaled tree planting prioritisation score where trees are planted on only the southerly bank
6. Locally scaled tree planting prioritisation score where trees are planted on only the northerly bank

Riparian woodland prioritisation scores are on a scale of 1- 20, where 1 is low priority (low temperature, weak sensitivity to climate change and only a small reduction in temperature gained from planting trees) and 20 is high priority (high temperature, strong sensitivity to climate and a large expected reduction in temperature where trees are planted).

To visualise the three bank scenarios it is necessary to produce a total of 3 spatial layers (i.e. planting both banks, planting on southerly bank, planting on northerly bank). However, the scores are consistent between these layers. To support decision making at different spatial scales layers were produced to identify priorities at a national scale and then re-scaled at a hydrometric area (regional) scale to highlight local priority areas

Very small rivers (First (Strahler) order rivers on the CEH digital river network) were removed from this dataset. NAs exist where we are unable to make predictions of maximum temperature, climate sensitivity or planting potential. This includes locations in lochs or in circumstances where we cannot generate the required predictor variables.

Increasing river temperatures are a threat to many of Scotland's freshwater species which are often adapted to live in cool environments. This includes ecologically and economically important freshwater fish species such as Atlantic salmon and brown trout. Management of riparian woodland is proven to protect cold water habitats. However, Scotland has ca. 108,000 km of rivers, of which only ca. 35% are protected by any substantial tree cover. Furthermore, the creation of new riparian woodland can be costly and logistically challenging compared to other forms of large scale woodland creation. It is therefore important that riparian tree planting is prioritised to areas where it can have greatest benefits for river temperature, specifically, where  rivers are (1) hottest (2) most sensitive to climate change and (3) can be effectively cooled by riparian woodland. These three individual criteria can be combined with an equal weight to provide a single riparian woodland prioritisation score that looks to maximise the benefits of riparian tree planting for protecting Scotland’s rivers from the adverse effects of climate change.  

Details of the modelling work that produced the river temperature and climate sensitivity predictions can be found in the peer reviewed manuscript: Jackson et al (2018) ‘A spatio-temporal statistical model of maximum daily river temperatures to inform the management of Scotland's Atlantic salmon rivers under climate change.’

Details of the modelling work that identifies where riparian trees can have the greatest effect in reducing summer maximum river temperatures can be found in: Jackson, F.L., Hannah, D.M., Ouellet, V. and Malcolm, I.A. (2021) A deterministic river temperature model to prioritise management of riparian woodlands to reduce summer maximum river temperatures.

Given the variety of potential tree planting options (southerly banks, northerly banks, both banks) and the need to scale results both nationally and locally, the outputs are illustrated as six layers on Marine Scotland Maps NMPi:

1. Nationally scaled tree planting prioritisation score where trees are planted on both banks
2. Nationally scaled tree planting prioritisation score where trees are planted on only the most southerly bank
3. Nationally scaled tree planting prioritisation score where trees are planted on only the most northerly bank
4. Locally scaled tree planting prioritisation score where trees are planted on both banks
5. Locally scaled tree planting prioritisation score where trees are planted on only the southerly bank
6. Locally scaled tree planting prioritisation score where trees are planted on only the northerly bank

Riparian woodland prioritisation scores are on a scale of 1- 20, where 1 is low priority (low temperature, weak sensitivity to climate change and only a small reduction in temperature gained from planting trees) and 20 is high priority (high temperature, strong sensitivity to climate and a large expected reduction in temperature where trees are planted).

To visualise the three bank scenarios it is necessary to produce a total of 3 spatial layers (i.e. planting both banks, planting on southerly bank, planting on northerly bank). However, the scores are consistent between these layers. To support decision making at different spatial scales layers were produced to identify priorities at a national scale and then re-scaled at a hydrometric area (regional) scale to highlight local priority areas

Very small rivers (First (Strahler) order rivers on the CEH digital river network) were removed from this dataset. NAs exist where we are unable to make predictions of maximum temperature, climate sensitivity or planting potential. This includes locations in lochs or in circumstances where we cannot generate the required predictor variables.

Increasing river temperatures are a threat to many of Scotland's freshwater species which are often adapted to live in cool environments. This includes ecologically and economically important freshwater fish species such as Atlantic salmon and brown trout. Management of riparian woodland is proven to protect cold water habitats. However, Scotland has ca. 108,000 km of rivers, of which only ca. 35% are protected by any substantial tree cover. Furthermore, the creation of new riparian woodland can be costly and logistically challenging compared to other forms of large scale woodland creation. It is therefore important that riparian tree planting is prioritised to areas where it can have greatest benefits for river temperature, specifically, where  rivers are (1) hottest (2) most sensitive to climate change and (3) can be effectively cooled by riparian woodland. These three individual criteria can be combined with an equal weight to provide a single riparian woodland prioritisation score that looks to maximise the benefits of riparian tree planting for protecting Scotland’s rivers from the adverse effects of climate change.  

Details of the modelling work that produced the river temperature and climate sensitivity predictions can be found in the peer reviewed manuscript: Jackson et al (2018) ‘A spatio-temporal statistical model of maximum daily river temperatures to inform the management of Scotland's Atlantic salmon rivers under climate change.’

Details of the modelling work that identifies where riparian trees can have the greatest effect in reducing summer maximum river temperatures can be found in: Jackson, F.L., Hannah, D.M., Ouellet, V. and Malcolm, I.A. (2021) A deterministic river temperature model to prioritise management of riparian woodlands to reduce summer maximum river temperatures.

Given the variety of potential tree planting options (southerly banks, northerly banks, both banks) and the need to scale results both nationally and locally, the outputs are illustrated as six layers on Marine Scotland Maps NMPi:

1. Nationally scaled tree planting prioritisation score where trees are planted on both banks
2. Nationally scaled tree planting prioritisation score where trees are planted on only the most southerly bank
3. Nationally scaled tree planting prioritisation score where trees are planted on only the most northerly bank
4. Locally scaled tree planting prioritisation score where trees are planted on both banks
5. Locally scaled tree planting prioritisation score where trees are planted on only the southerly bank
6. Locally scaled tree planting prioritisation score where trees are planted on only the northerly bank

Riparian woodland prioritisation scores are on a scale of 1- 20, where 1 is low priority (low temperature, weak sensitivity to climate change and only a small reduction in temperature gained from planting trees) and 20 is high priority (high temperature, strong sensitivity to climate and a large expected reduction in temperature where trees are planted).

To visualise the three bank scenarios it is necessary to produce a total of 3 spatial layers (i.e. planting both banks, planting on southerly bank, planting on northerly bank). However, the scores are consistent between these layers. To support decision making at different spatial scales layers were produced to identify priorities at a national scale and then re-scaled at a hydrometric area (regional) scale to highlight local priority areas

Very small rivers (First (Strahler) order rivers on the CEH digital river network) were removed from this dataset. NAs exist where we are unable to make predictions of maximum temperature, climate sensitivity or planting potential. This includes locations in lochs or in circumstances where we cannot generate the required predictor variables.