Skip to Main Content
Due to a lapse in federal funding, this USDA website will not be actively updated. Once funding has been reestablished, online operations will continue.
Tradeoffs in overstory and understory aboveground net primary productivity in southwestern ponderosa pine standsAuthor(s): Kyla E. Sabo; Stephen C. Hart; Carolyn Hull Sieg; John Duff Bailey
Source: Forest Science. 54(4): 408-416.
Publication Series: Scientific Journal (JRNL)
Station: Rocky Mountain Research Station
PDF: View PDF (346.15 KB)
DescriptionPrevious studies in ponderosa pine forests have quantified the relationship between overstory stand characteristics and understory production using tree measurements such as basal area. We built on these past studies by evaluating the tradeoff between overstory and understory aboveground net primary productivity (ANPP) in southwestern ponderosa pine forests at the landscape level and over a gradient of stand structural types and burn histories. We measured overstory and understory attributes in 2004 and 2005 in four stand structural types (unmanaged, thinned, thinned and burned, and low basal area thinned and burned) relative to a stand-replacing wildfire site. Thinning alone and with prescribed burning reduced stand-level wood and total tree production relative to unmanaged stands. Understory (herbaceous) ANPP was highest in wildfire stands and low basal area thinned and burned plots but did not differ among the other stand structural types, apparently because of high residual basal area and relatively uniform tree spacing. Contemporary ponderosa pine forests are low productivity ecosystems that exhibit a threshold response between reductions in tree density and increases in understory production at ~5.9 m2 ha. We calculated the slope of the relationship between tree and herbaceous ANPP to be -0.14, which was lower than the values we estimated from other, more productive savanna ecosystems. Our results suggest that to maintain more fire-resistant and hence sustainable southwestern ponderosa pine ecosystems, tree densities need to be substantially reduced from contemporary levels. Large, landscape-level reductions in tree density will decrease total ecosystem production of this forest type, but this reduction will probably be small relative to ecosystem production losses after widespread, stand-replacing wildfires.
- You may send email to firstname.lastname@example.org to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationSabo, Kyla E.; Hart, Stephen C.; Sieg, Carolyn Hull; Bailey, John Duff. 2008. Tradeoffs in overstory and understory aboveground net primary productivity in southwestern ponderosa pine stands. Forest Science. 54(4): 408-416.
Keywordsaboveground tree production, aboveground understory production, basal area, thinning and prescribed burning, northern Arizona
- Stripcut-thinning of ponderosa pine stands: An Arizona case study
- Susceptibility of ponderosa pine, Pinus ponderosa (Dougl. Ex Laws.), to mountain pine beetle, Dendroctonus ponderosae Hopkins, attack in uneven-aged stands in the Black Hills of South Dakota and Wyoming USA
- Role of fire in restoration of a ponderosa pine forest, Washington
XML: View XML