Masting in whitebark pine (Pinus albicaulis) depletes stored nutrients

Abstract

Summary• In masting trees, synchronized, heavy reproductive events are thought to deplete stored resources and to impose a replenishment period before subsequent masting. However, direct evidence of resource depletion in wild, masting trees is very rare. Here, we examined the timing and magnitude (local vs individual-level) of stored nutrient depletion after a heavy mast event in Pinus albicaulis.• In 2005, the mast year, we compared seasonal changes in leaf and sapwood nitrogen (N) and phosphorus (P) concentrations and leaf photosynthetic rates in cone-bearing branches, branches that never produced cones, and branches with experimentally removed cones. We also compared nutrient concentrations in cone branches and branches that had never had cones between 2005 and 2006, and measured tree ring width and new shoot growth during 2005.• During the mast year, N or P depletion occurred only in tissue fractions of reproductive branches, where photosynthetic rates were reduced. However, by the end of the following year, nutrients were depleted in all branches, indicating individual-level resource depletion. New shoot and radial growth were not affected by masting.• We provide direct evidence that mast events in wild trees deplete stored nutrients. Our results highlight the importance of evaluating reproductive costs over time and at the individual level.

Sex allocation, pollen limitation and masting in whitebark pine

“…1b). This occurred even though mast years deplete stored phosphorous and nitrogen in P. albicaulis (Sala et al 2012), consistent with the idea that mobile resources available for reproduction fluctuate through time in masting species (Isagi et al 1997). Our results suggest that increased reproductive success due to pollen coupling could outweigh benefits of changing resource allocation to male and female function in response to changing resource availability in masting species, although this remains to be tested for other species.…”

Temporal trends in the enhanced vegetation index and spring weather predict seed production in Mediterranean oaks

“…This latter hypothesis predicts that plant resources are depleted to sustain the masting episode, so that flowering and seed production are expected to be very low or absent in the next growing season, causing a negative autocorrelation between consecutive seed crops (Koenig and Knops 2000). The consequences of resource depletion after a masting episode may include signs such as a reduction in the leaf area due to self-thinning (Camarero et al 2010) or a decrease of nitrogen and phosphorous concentrations in branches (Sala et al 2012).…”

“…carbohydrates and nutrients) remains controversial (Koenig and Knops 2000;Kelly and Sork 2002;Sala et al 2012). On the one hand, the resource matching hypothesis (Sork et al 1993;Kelly and Sork 2002) states that plants produce large or poor seed crops in direct response to the immediate availability of resources, i.e.…”

Ecología evolutiva de la reproducción en dos pinos mediterráneos: Pinus pinaster Ait. y Pinus halepensis Mill.

“…All MCMC analyses 60 were run yielding in every case a total of 1,000 data points for each analysis and 61 ensuring autocorrelations below 0. Alla et al, 2011;Sala et al, 2012;Barringer et al, 2013;Żywiec & Zielonka, 2013) and a 50 review helping to define mechanistic links between both functions.…”

“…As before, treatment 165 was defined as fixed but we used no covariate. Population was included as a random factor as 166 well as an observation-level random factor in order to account for overdisperssion in our data 167 Sala et al, 2012) and carbohydrates (Ichie et al, 2013) . Such an example is also provided by our data at the phenotypic 228 level.…”