Drivers of vegetative dormancy across herbaceous perennial plant species

Abstract

Vegetative dormancy, that is the temporary absence of aboveground growth for ≥ 1 year, is paradoxical, because plants cannot photosynthesise or flower during dormant periods. We test ecological and evolutionary hypotheses for its widespread persistence. We show that dormancy has evolved numerous times. Most species displaying dormancy exhibit life-history costs of sprouting, and of dormancy. Short-lived and mycoheterotrophic species have higher proportions of dormant plants than long-lived species and species with other nutritional modes. Foliage loss is associated with higher future dormancy levels, suggesting that carbon limitation promotes dormancy. Maximum dormancy duration is shorter under higher precipitation and at higher latitudes, the latter suggesting an important role for competition or herbivory. Study length affects estimates of some demographic parameters. Our results identify life historical and environmental drivers of dormancy. We also highlight the evolutionary importance of the little understood costs of sprouting and growth, latitudinal stress gradients and mixed nutritional modes.

Precipitation and Minimum Temperature are Primary Climatic Controls of Alpine Grassland Autumn Phenology on the Qinghai-Tibet Plateau

“…The response of MSD to precipitation during the optimum period is predominantly positive, which is consistent with previous studies [7,11,18,19,42]. Namely, more precipitation in autumn could improve the soil moisture and relieve the drought stress of alpine grassland [17], resulting in a delayed senescence. Similarly, the response of MSD to daily minimum temperature is also positive, because the minimum temperature may trigger leaf senescence by decreasing the light-saturated photosynthetic rate [43,44].…”

“…The relationships between plant autumn phenology and climatic factors are more complicated than with the spring phenology [15] and its mechanisms are still not clear [14,16,17]. Based on partial correlation or regression analysis, temperature, precipitation, and insolation are considered to be important climatic factors affecting the autumn phenology of herbaceous plants on the QTP [7,8,18,19].…”

Mycorrhizal fungi affect orchid distribution and population dynamics

“…The extent to which OMFs contribute to the support of mature photosynthetic orchids is still an open question and likely varies among species and habitats (Girlanda et al ., ; Sommer et al ., ; Selosse & Martos, ; McCormick & Jacquemyn, ; Liebel et al ., ; Hynson et al ., ). Fungi almost certainly play an important role during periods of vegetative dormancy, a widespread phenomenon where plants, including many orchids, fail to produce any aboveground tissues, but remain physiologically active, during one or more growing seasons (Shefferson et al ., , , , ; Shefferson, ). Vegetative dormancy is associated with plant stress, often carbon limitation, and often has negative consequences on survival (Shefferson & Tali, ; Gremer et al ., , ; Shefferson et al ., ).…”

“…Review 1209 2012; Selosse & Martos, 2014;McCormick & Jacquemyn, 2014;Liebel et al, 2015;Hynson et al, 2016). Fungi almost certainly play an important role during periods of vegetative dormancy, a widespread phenomenon where plants, including many orchids, fail to produce any aboveground tissues, but remain physiologically active, during one or more growing seasons (Shefferson et al, 2003(Shefferson et al, , 2011(Shefferson et al, , 2014(Shefferson et al, , 2018Shefferson, 2009). Vegetative dormancy is associated with plant stress, often carbon limitation, and often has negative consequences on survival (Shefferson & Tali, 2007;Gremer et al, 2010Gremer et al, , 2012Shefferson et al, 2018).…”

“…Similarly, Vannette & Hunter (2013) demonstrated that the abundance of arbuscular mycorrhizal fungi impacted plant biomass and defense against herbivory in Asclepias syriaca, but few studies have examined plant performance as a function of separately manipulated mycorrhizal fungus abundance. That mature orchid performance can also be impacted by abundance of appropriate OMFs is suggested by the link between carbon supply and entering vegetative dormancy (Shefferson et al, 2018). Studies demonstrating that the manipulation of OMF abundance leads to greater seed germination (McCormick et al, 2012) and that OMF abundance in one year predicts emergence in the following year (Rock-Blake et al, 2017) suggest that the directionality of causation is from the OMFs to the orchid, more so than the reverse.…”