Abstract
Evaporation of precipitation from plant surfaces, or interception, is a major component of the global water budget. Interception has been measured and/or modelled across a wide variety of forest types; however, most studies have focused on mature, second-growth forests, and few studies have examined interception processes across forest age classes. We present data on two components of interception, total canopy interception (Ei) and litter interception—that is, Oi + Oe horizon layers—(Eff), across a forest age chronosequence, from 2 years since harvest to old growth. We used precipitation, throughfall, and stemflow collectors to measure total rainfall (P) and estimate Ei; and collected litter biomass and modelled litter wetting and drying to estimate evaporative loss from litter. Canopy Ei, P minus throughfall, increased rapidly with forest age and then levelled off to a maximum of 21% of P in an old-growth site. Stemflow also varied across stands, with the highest stemflow (~8% of P) observed in a 12-year-old stand with high stem density. Modelled Eff was 4–6% of P and did not vary across sites. Total stand-level interception losses (Ei + Eff) were best predicted by stand age (R2 = 0.77) rather than structural parameters such as basal area (R2 = 0.49) or leaf area (R2 < 0.01). Forest age appears to be an important driver of interception losses from forested mountain watersheds even when stand-level structural variables are similar. These results will contribute to our understanding of water budgets across the broader matrix of forest ages that characterize the modern forest landscape.
| Original language | English (US) |
|---|---|
| Article number | e2081 |
| Journal | Ecohydrology |
| Volume | 12 |
| Issue number | 4 |
| DOIs | |
| State | Published - Jun 2019 |
Bibliographical note
Funding Information:This study was supported by Agriculture and Food Research Initiative Competitive Grant 2012-67019-19484 from the USDA National Institute of Food and Agriculture to the USDA Forest Service Southern Research Station and US Forest Service/University of Minnesota cooperative agreement 12-CS-11330140-128. National Science Foundation Grant DEB0823293 to the Coweeta LTER programme at the University of Georgia provided logistical support. We acknowledge the support of the staff at Coweeta Hydrologic Laboratory, especially C. Sobek. N. Muldoon, and B. McCollum for field data collection. We thank M. Gavazzi, J. Van Stan, M. Coenders-Gerrits, and two anonymous reviewers for providing comments on previous versions of this manuscript.
Funding Information:
National Science Foundation, Grant/Award Number: DEB0823293; Coweeta Hydrologic Laboratory; Coweeta LTER programme at the University of Georgia; US Forest Service/University of Minnesota cooperative agreement, Grant/Award Number: 12‐CS‐ 11330140‐128; USDA Forest Service Southern Research Station; United States Department of Agriculture National Institute of Food and Agriculture; Agriculture and Food Research Initiative Competitive, Grant/Award Number: 2012‐67019‐19484
Funding Information:
This study was supported by Agriculture and Food Research Initiative Competitive Grant 2012‐67019‐19484 from the USDA National Institute of Food and Agriculture to the USDA Forest Service Southern Research Station and US Forest Service/University of Minnesota cooperative agreement 12‐CS‐11330140‐128. National Science Foundation Grant DEB0823293 to the Coweeta LTER programme at the University of Georgia provided logistical support. We acknowledge the support of the staff at Coweeta Hydrologic Laboratory, especially C. Sobek. N. Muldoon, and B. McCollum for field data collection. We thank M. Gavazzi, J. Van Stan, M. Coenders‐Gerrits, and two anonymous reviewers for providing comments on previous versions of this manuscript.
Publisher Copyright:
© 2019 John Wiley & Sons, Ltd.
Keywords
- forest succession
- funnelling ratios
- interception
- stemflow
- throughfall