Forests and Water: A State of the Art Review for Colorado

• Year: 2003
• Title: Forests and Water: A State-of-the-Art Review for Colorado
• Author: Colorado State University
• Description: Colorado State University 2003
• Publications - Doc Type: Other

Table of Contents
ExecutiveSummary ....................................................................................................................... ............................... iii
Tableof Contents ............................................................................................................................. ............................... v
Aboutthe Authors ......................................................................................................................... ............................... vii
Acknowledgements...................................................................................................................... ............................... viii
1. Introduction and Objectives ......................................................................................................
...............................
l
1.1. Introduction and Background ............................................................................................
...............................
1.2. Objectives and Organization ...............................................................................................
..............................3
2. Effects of Forest Management on Runoff ..................................................................................
..............................5
2.1 Introduction ........................................................................................................................
..............................5
2.2. Effects of Changes in the Forest Canopy on Runoff ..........................................................
..............................6
2.2.1. Overall water balance .............................................................................................
..............................6
2.2.2. Timing of an increase in runoff ..............................................................................
..............................8
2.2.3. Causes and variability of water yield increases after forest harvest ........................ ..............................8
2.2.4. Rate of hydrologic recovery ...................................................................................
.............................11
2.2.5. Effects of vegetation change on the size of peak flows .........................................
.............................13
2.2.6. Effects of vegetation change on low flows . ...........................................................
.............................14
2.3. Effects of Roads on Runoff ..............................................................................................
.............................15
...................................................... ...............................
2.4. Effect of Fires on Runoff ............
........••••••.."......••••..17
2.5. Threshold of Response, Spatial Scaling, and the Detectability of a Change in Flows
...... .............................18
3. Effects of Forest Management Activities and Fire on Water Quality ....................................... .............................21
3.1. Introduction ....................................................................................................................... .............................21
3.2. Erosion and Sedimentation ................................................................................................ .............................21
3.2.1. Roads ..................................................................................................................... .............................23
3.3. Stream Temperature ........................................................................................................... .............................26
3.4. Nutrients ............................................................................................................................ .............................27
3.5. Fertilization ........................................................................................................................ .............................27
3.6. Prescribed Fire and Wildfire .............................................................................................. .............................27
4. Historic and Projected Changes in Runoff ............................................................................... .............................30
4.1. Natural and Anthropogenic Effects on Forests and Water Yields ...................................... .............................30
4.1.1. Effects of climatic fluctuations and climate changes on forests and runoff ........... .............................31
4.1.2. Historic changes in fire regimes ............................................................................. .............................32
4.1.3. Changes in forest structure over time ..................................................................... .............................35
4.1.4. Timber harvest rates on national forest lands ......................................................... .............................38
4.1.5. Fuel treatments and water yields from national forest lands ................................. .............................42
4.1.6. Grazing ................................................................................................................... .............................44
4.1.7. Insects, disease, and other abiotic disturbances ...................................................... .............................45
Effects of Past, Present and Future Forest Management on Water Quality .............................. .............................47
5.1. Introduction ....................................................................................................................... .............................47
5.2. Historic Trends in Water ualit 47
5.3. Timber Harvest, Roads, and Grazing ............................................................................ ...............................
5.4. Fire and Water Quality .................................................................................................................................... 48
5.5. Climate Change and Water Quality ................................................................................. ...............................
v