Asset Details
Do you wish to reserve the book?
An assessment of carbon and nutrient limitations in the formation of the southern Andes tree line
Hey, we have placed the reservation for you!
By the way, why not check out events that you can attend while you pick your title.
Oops! Something went wrong.
Looks like we were not able to place the reservation. Kindly try again later.
Are you sure you want to remove the book from the shelf?
An assessment of carbon and nutrient limitations in the formation of the southern Andes tree line
Do you wish to request the book?
An assessment of carbon and nutrient limitations in the formation of the southern Andes tree line
Please be aware that the book you have requested cannot be checked out. If you would like to checkout this book, you can reserve another copy
We have requested the book for you!
Your request is successful and it will be processed during the Library working hours. Please check the status of your request in My Requests.
Oops! Something went wrong.
Looks like we were not able to place your request. Kindly try again later.
Journal Article
An assessment of carbon and nutrient limitations in the formation of the southern Andes tree line
2017
Overview
1. Although the principal mechanism determining tree line formation appears to be carbon (C)-sink limitations due to low temperatures, few studies have assessed the complementary role of reduced soil nutrient availability with elevation. We tested the hypothesis that nutrient (especially nitrogen, N) limitations at tree line may directly (via C-source) or indirectly (via C-sink) reduce the growth of a winter deciduous tree line species. 2. If a shortage of soil N with elevation is involved in tree line formation, it should occur in two alternative ways: (i) through sink limitations because N is required for tissue formation, which would indirectly limit C investments (N decreases and C reserves increase with elevation), and (ii) through C limitations because this would lead directly to a reduction of photoassimilates (N and C reserves decrease with elevation). 3. In testing our hypothesis, we analysed tree growth rates (basal area increment), twig non-structural carbohydrate (NSC) and N concentrations, leaf N, phosphorus (P), N:P ratio concentrations, and soil nutrient levels (NO₃⁻, NH₄⁺, Olsen–P) in four disparate climate and soil Nothofagus pumilio tree lines spanning 18 degrees of latitude in the southern Andes of Chile. 4. We found a significant decrease in tree growth with elevation. Twig NSC concentrations pooled across locations also decreased significantly with elevation (starch constituted most of the NSC and was highly responsible for the negative trend), although this trend was mostly driven by the northernmost locations. Contrary to soil N availability, leaf N and P concentrations increased significantly with elevation. Twig N concentrations, soil P and leaf N:P ratios did not change with elevation. 5. Synthesis. The elevational decrease in NSC concentrations supports C-source limitation in N. pumilio trees at tree line elevation. In the light of this, we assert that the current global explanation for tree line formation (C-sink-limitation driven by low temperatures) must be revisited. Given that leaf N and P concentrations increased and twig N concentrations did not change with elevation, nutrient limitation is not likely to be involved in the C-limitations and could not therefore be an explanation for tree line formation.
