Transgenerational effects of global environmental change: long-term CO2 and nitrogen treatments influence offspring growth response to elevated CO2

Abstract

Global environmental changes can have immediate impacts on plant growth, physiology, and phenology. Long-term effects that are only observable after one or more generations are also likely to occur. These transgenerational effects can result either from maternal environmental effects or from evolutionary responses to novel selection pressures and are important because they may alter the ultimate ecological impact of the environmental change. Here, we show that transgenerational effects of atmospheric carbon dioxide (CO(2)) and soil nitrogen (N) treatments influence the magnitude of plant growth responses to elevated CO(2) (eCO(2)). We collected seeds from Lupinus perennis, Poa pratensis, and Schizachyrium scoparium populations that had experienced five growing seasons of ambient CO(2) (aCO(2)) or eCO(2) treatments and ambient or increased N deposition and planted these seeds into aCO(2) or eCO(2) environments. We found that the offspring eCO(2) treatments stimulated immediate increases in L. perennis and P. pratensis growth and that the maternal CO(2) environment influenced the magnitude of this growth response for L. perennis: biomass responses of offspring from the eCO(2) maternal treatments were only 54% that of the offspring from the aCO(2) maternal treatments. Similar trends were observed for P. pratensis and S. scoparium. We detected some evidence that long-term N treatments also altered growth responses to eCO(2); offspring reared from seed from maternal N-addition treatments tended to show greater positive growth responses to eCO(2) than offspring from ambient N maternal treatments. However, the effects of long-term N treatments on offspring survival showed the opposite pattern. Combined, our results suggest that transgenerational effects of eCO(2) and N-addition may influence the growth stimulation effects of eCO(2), potentially altering the long-term impacts of eCO(2) on plant populations.

Short‐term effects of elevated precipitation and nitrogen on soil fertility and plant growth in a Neotropical savanna

“…Increased N deposition changes soil acidity and macronutrient availability (Vitousek et al 1997, Aber et al 1998) which alters plant biomass allocation, phenology, fitness, and competitive interactions (Cleland et al 2006, Clark and Tilman 2008, Lau et al 2008). The effects of N deposition on plant growth and soil fertility can affect ecosystem net primary production, plant diversity, and global climate via effects on carbon cycling (Vitousek et al 1997, Gruber 2008.…”

The effects of CO2 and nutrient enrichment on photosynthesis and growth of Poa annua in two consecutive generations

“…Decreased germination (Farnsworth and Bazzaz 1995;Andalo et al 1996) and seed weight (Wulff and Alexander 1985) have been reported for other plant species growing in elevated CO 2 , although enhanced seed weight has also been reported (Steinger et al 2000;Miyagi et al 2007). Although most studies point to CO 2 -induced effects on seed characteristics as the mechanism through which intergenerational differences occur, it may also be possible that these effects are driven by genetic changes in a plant's response to elevated CO 2 (Ward and Kelly 2004;Lau et al 2008;Leakey et al 2009). Genetic changes often occur over multiple generations, but recent epigenetic studies have shown that heritable changes in gene expression and function can also occur from one generation to the next.…”

“…A number of studies have now been published which show that a variety of plant species show intergenerational differences in their responses to conditions of elevated CO 2 (Andalo et al 1998;Bezemer et al 1998;Huxman et al 1998Huxman et al , 2001Derner et al 2004;Lau et al 2008). In our study, seed weight and germinability of P. annua were both significantly lower for plants grown in conditions of elevated CO 2 , and this might-at least partly-explain the differences observed in CO 2 responsiveness during the succeeding generation.…”

“…Curtis et al 1994;Farnsworth and Bazzaz 1995;Andalo et al 1996;Steinger et al 2000;Kinugasa et al 2003;Hikosaka et al 2011). By affecting the reproductive output of a plant, the effects of CO 2 on plants can extend beyond a single growth period (Steinger et al 2000;Lau et al 2008).…”

“…Bezemer et al 1998;Huxman et al 1998Huxman et al , 2001Steinger et al 2000;Ward et al 2000;Schulte et al 2002;Derner et al 2004;Lau et al 2008). For example, seedlings of the annual grass Bromus madritensis respond to elevated CO 2 by increasing their growth rate, but this increase is less when the parent plant was also grown at elevated CO 2 than when the parent plant was grown at ambient CO 2 (Huxman et al 1998).…”