Phenological responses to nitrogen and water addition are linked to plant growth patterns in a desert herbaceous community

Abstract

Increases in nitrogen (N) deposition and variation in precipitation have been occurring in temperate deserts; however, little information is available regarding plant phenological responses to environmental cues and their relationships with plant growth pattern in desert ecosystems. In this study, plant phenology and growth of six annuals in response to N and water addition were monitored throughout two consecutive growing seasons in 2011 and 2012 in a temperate desert in northwestern China. The effects of N and water addition on reproductive phenology differed among plant species. N and water addition consistently advanced the flowering onset time and fruiting time of four spring ephemerals; however, their effects on two spring‐summer annuals were inconsistent, with advances being noted in one species and delays in another. N and water addition alone increased plant height, relative growth rate, leaf number, flower number, and individual biomass, while their combinative effects on plant growth and reproductive phenology were dependent on species. Multiple regression analysis showed that flowering onset time was negatively correlated with relative growth rate of two species, and negatively correlated with maximum plant height of the other four species. Our study demonstrates that phenological responses to increasing precipitation and N deposition varied in annuals with different life histories, whereby the effects of climate change on plant growth rate were related to reproductive phenology. Desert annuals that were able to accelerate growth rate under increasing soil resource availability tended to advance their flowering onset time to escape drought later in the growing season. This study promotes our understanding of the responses of temperate desert annuals to increasing precipitation and N deposition in this desert.

Water Addition Prolonged the Length of the Growing Season of the Desert Shrub Nitraria tangutorum in a Temperate Desert

“…Many studies have shown that water plays an important role in driving plant phenology, such as budburst ( Hayden et al., 2010 ), green-up ( Zhang et al, 2005 ; Liu et al., 2013 ), flowering ( Crimmins et al., 2010 ; Lesica and Kittelson, 2010 ; Crimmins et al., 2011 ; Crimmins et al., 2013 ; Kigel et al., 2013 ; Sakkir et al., 2014 ; Huang et al., 2018 ), and fruiting ( Lotfi and Mohamed, 2006 ; Galindo et al., 2014 ), in water-limited ecosystems. However, most of these studies are focused on natural conditions, while the relationship between water increase and phenological events based on water addition experiments has not been explored, nor has the effects of water addition on branch phenology of desert plants.…”

“…Precipitation increases likely impose substantial impacts on plant phenology in these deserts in response to climate change. Few studies examined the effects of water addition on reproductive phenology of six annuals on the southern fringe of the Gurbantunggut Desert in northwestern China and the results were only based on a short-time manipulative experiment (Huang et al, 2018). The results showed that water addition consistently advanced both the flowering and fruiting time of four spring ephemerals; however, their effects on two spring-summer annuals were inconsistent, where advances were found in one species, while delays were found in another (Huang et al, 2018).…”

“…The phenological responses of plants in desert ecosystems in particular are causing increasing concern (Ghazahfar, 1997;Ogle and Reynolds, 2004;Leeuwen et al, 2010;Kigel et al, 2013;Sakkir et al, 2014;Yan et al, 2016;Huang et al, 2018). Desert ecosystems cover approximately 30% of the land surface and are strongly controlled by water availability (Patrick et al, 2009).…”

“…Few studies examined the effects of water addition on reproductive phenology of six annuals on the southern fringe of the Gurbantunggut Desert in northwestern China and the results were only based on a short-time manipulative experiment (Huang et al, 2018). The results showed that water addition consistently advanced both the flowering and fruiting time of four spring ephemerals; however, their effects on two spring-summer annuals were inconsistent, where advances were found in one species, while delays were found in another (Huang et al, 2018). Since this study only focused on ephemerals, it remains unknown how the desert plant phenology of dominant perennials responds to an increase in precipitation, especially long-term precipitation increases.…”

Desert vegetation distribution and species-environment relationships in an oasis-desert ecotone of northwestern China

“…It also affects species distribution, community characteristics (Xu et al, 2007;Li et al, 2010), and plant zonation (Cooper et al, 2006;Rzepecki et al, 2011) by driving water availability (Liu et al, 2017). Precipitation patterns influence the aboveground net primary production of sand-fixing vegetation (Li and Zhao, 2017), community structure (Cheng et al, 2006), annual plant phenology (Huang et al, 2018), photosynthesis (Liu et al, 2012), and carbon cycle (Thomey et al, 2011). Dune mobility affects the settlement and expansion of desert plants (Hernández-Cordero et al, 2015).…”