Cairngorms Upland Advisory group - February 2020 - River Dee Trust Riparian Woodlands update

Hab­it­at Res­tor­a­tion — Background

Spring (1 Feb — 31 May) Sum­mer & Autumn (1 Jun — 30 Sep) 1 — 15 October

• Star­ted hab­it­at res­tor­a­tion late 90’s due to decline in Sal­mon stocks.
• Early work con­cen­trated on middle and lower catchment.
• Star­ted tree plant­ing in the uplands around 2015.

The River Dee

Hab­it­at Res­tor­a­tion — Large Scale Enclosures

• Due to high grazer num­bers all ripari­an wood­land has to be protected.
• Pre­ferred meth­od is large scale tree enclosures.
• Fun­ded through vari­ous means, forestry/​agri schemes, Wood­land Trust, SNH.
• Over 175,000 nat­ive trees planted with­in large enclosures.
• Work with land managers.
• Main­ten­ance.

The River Dee

Hab­it­at Res­tor­a­tion — Small Enclosures

• Where we can’t get agree­ment for large enclos­ure we use small enclosures.
• Stock fenced, typ­ic­ally 4.5 x 4.5m, 20 – 30 trees per enclos­ure, tube & stake.
• 1,315 small enclos­ures to date, 33,000 trees.
• Fun­ded through com­pan­ies, indi­vidu­als and hab­it­at schemes.
• Issues — not func­tion­ing wood­land, expens­ive and main­ten­ance requirements.
• But they start the pro­cess of get­ting trees estab­lished, seed source.
• Also tri­al fun­ded by CNPA using mob plant­ing technique.

The River Dee

Hab­it­at Res­tor­a­tion – Large Woody Structures

• Rare hab­it­at that would have once been very com­mon fea­ture of our rivers.
• Fallen trees and large wood in a stream are the build­ing blocks of instream hab­it­at complexity.
• LWS cre­ate cov­er from pred­at­ors, deep cool pools, help cre­ate spawn­ing sites and trap nutrient.
• Designed and anchored properly.
• 64 LWS cre­ated in last 2 years.
• Gen­er­ally sup­por­ted by land managers.
• Mon­itored by PHD stu­dents, RDT and cbec.

The River Dee

Hab­it­at Res­tor­a­tion – Why?

• Rivers in the Cairngorms have been sub­stan­tially altered from their nat­ur­al state.
• Sum­mer peak tem­per­at­ures poten­tial stress on sal­mon, 27.5°C recor­ded on Gairn.
• 50% shad­ing can reduce sum­mer tem­per­at­ures by 2 — 3°C
• UP to 50% of the energy in a stream can be provided by good bank­side vegetation.
• Rivers without trees are typ­ic­ally 30% wider than tree lined rivers.
• To re-instate a healthy river with nat­ur­al pro­cess, more resi­li­ent to cli­mate change.
• NFM, improved water qual­ity, increased biod­iversity, link­ing hab­it­ats and store carbon.

The River Dee

Hab­it­at Res­tor­a­tion – Long Term Strategy

• 1 mil­lion ripari­an trees by 2035.
• Cre­ated more large wood structures.
• Rein­state wet­land, bog and flood plain con­nectiv­ity and function.
• Restore func­tion­ing nat­ur­al river process.
• Restore abund­ant sal­mon pop­u­la­tion, not just a mar­ine sur­viv­al issue.

The River Dee

Hab­it­at Res­tor­a­tion – Long Term Strategy

• Key­stone spe­cies at crisis point.
• Eco­nom­ic & Cul­tur­al importance.
• Work with­in exist­ing land use to estab­lish plant­ing sites.
• To achieve a func­tion­ing ripari­an zone in Upper Deeside would require less than 1% of the land.
• Sav­ing the sal­mon and rein­stat­ing abund­ance will be transformative.

The River Dee