Browsed Betula pubescens trees are not carbon‐limited

Abstract

Summary 1.Slower growth after repetitive browsing of young trees has been attributed to a carbon (C) limitation, but data from long-term studies are lacking. To determine if repeated summer browsing causes a C (source) limitation in trees in the long-term, we analysed the non-structural carbohydrate (NSC) and nitrogen (N) concentrations and pools of Betula pubescens saplings subjected to different clipping treatments (unclipped, 33% and 66% shoot removal) for 7 years. 2. The short-term effect of browsing on C allocation was assessed by clipping trees with different browsing histories and analyzing their C and N responses within the same growing season. 3. Long-term repetitive summer browsing significantly decreased sapling growth and soluble sugar (SS) concentrations in fine roots. However, trees subjected to different browsing histories did not change their C partitioning into starch. Although trees with a different browsing history showed differences in the NSC concentrations and pools of leaves, these differences were not maintained through time. 4. Simulated browsing had no significant short-term effect on root C and N pools of birch trees, but it decreased all C pools in leaves, 1-year and current-year stems and the starch and total NSC pools in main stems. 5. We conclude that although browsing may cause a temporary decrease in C pools, B. pubescens trees are able to compensate for such losses and hence are not C-limited in the long-term.

A large herbivore triggers alternative successional trajectories in the boreal forest

“…The seedlings may thereafter grow vigorously once deer herbivory stops. Indeed, it was shown that Betula species may tolerate severe clipping over prolonged periods (Kinnaird 1974, Palacio et al 2008. Although regeneration in the delayed exclosures was a mix between browse-sensitive and resistant species, we expect the climax to be dominated by the only abundant late-successional species: Picea spp.…”

Effects of nitrogen and phosphorus supply on growth and physiological traits of two Larix species

“…Non-structural carbohydrates (NSC) are major forms of C reserves and they are used for evaluating the C balance (Chapin et al, 1990;Palacio et al, 2008;Sala et al, 2010). Whenever photosynthetic production is insufficient to meet the metabolic demands (i.e., C gain does not meet C demand), the amount of NSC must decrease as trees mobilize carbohydrates from storage sites (Chapin et al,1990).…”

Phenological and Temperature Controls on the Temporal Non-Structural Carbohydrate Dynamics of Populus grandidentata and Quercus rubra

“…Warmer spring temperatures generally prompt an earlier onset of gross primary production (GPP), but temperature effects on the termination of GPP are less clear. If the temporal relationship between NPP and GPP is altered as temperatures rise, then shifts in C source-sink relationships may, in turn, affect tissue NSC concentrations, an outcome that could have broad ecological consequences for the resilience of forest growth following disturbance or climatic stress [3,[24][25][26][27][28][29][30][31]. Forecasts of future plant tissue NSC have focused on the effects of rising atmospheric CO 2 [32].…”