Familiar soil conditions help Pinus ponderosa seedlings cope with warming and drying climate

Abstract

Changes in temperature and moisture as a result of climate forcing can impact performance of planted trees. Tree performance may also be sensitive to new soil conditions, for example, brought about by seeds germinating in soils different from those colonized by ancestral populations. Such “edaphic constraint” may occur with natural migration or human‐assisted movement. Pinus ponderosa seedlings, sourced from one location (“home” site), were grown across a field environmental gradient in either their original home soil or in soils from two different “away” sites. Seedlings were inoculated with site‐specific soil organisms by germinating seeds in living soil. After 6 months, the inoculated seedlings were transplanted into sterilized soils from the home or away sites. This experimental design allowed us to uncouple the importance of abiotic and biotic soil properties and test (1) how biotic and abiotic soil properties interact with climate to influence plant growth and stress tolerance, and (2) the role of soil biota in facilitating growth in novel environments. Seedlings grew least in hotter and drier away sites with away soil biota. Home soil biota ameliorated negative impacts on growth of hotter and drier away sites. Measurements of photosynthetic rate, stomatal conductance, and chlorophyll florescence (Fv/Fm) suggest that edaphic constraint reduced growth by increasing tree water stress. Results suggest that success of Ponderosa pine plantings into warming environments will be enhanced by pre‐inoculation with native soil biota of the seed source.

Sympatric pairings of dryland grass populations, mycorrhizal fungi and associated soil biota enhance mutualism and ameliorate drought stress

“…It is plausible that both population-and community-level forces are interacting to determine mycorrhizal allocation and function across resource gradients, and a better understanding of these determinants of fungal allocation is an intriguing next step. Some studies, including Remke, Hoang, et al (2020), have demonstrated that these patterns are likely to persist when soil resources are limited, however, patterns dissipate when soil resources are more abundant. For arid regions that are water limited, severe water stress from warming temperatures or prolonged drought might increase the importance and benefit of sympatric mycorrhizal associations in the future (Remke, Hoang, et al, 2020).…”

“…Additionally, AM fungi and plants that originated from a common location and potentially share a co-evolutionary history, tend to have a greater mutualistic function (Ji et al, 2013;Johnson et al, 2010). We call this the sympatric advantage hypothesis (Remke, Hoang, et al, 2020). Some evidence suggests that plants and co-occurring soil microbes, including mycorrhizal fungi, rapidly adapt to changes in the environment and thus co-adaptation creates greater mutualistic function (Lau & Lennon, 2011Vurukonda et al, 2016).…”

Assisted Migration Field Tests in Canada and Mexico: Lessons, Limitations, and Challenges

“…Camarretta et al [104] concluded in a study of species and provenance translocation into different community assemblages that performance was not affected by community context. Additionally, experimental evidence has suggested that migrating plants with the soil biota of the site of origin increases plant performance in the target site [105], and that assisted migration outside of range is possible along elevation gradients for some rare species [106]. These, and other studies, suggest that biotic interactions and the more complex set of interactions among biotic and abiotic factors will influence the outcome of assisted migration within or outside of range.…”

Restoration, soil organisms, and soil processes: emerging approaches

“…respiration, C and P exoenzyme activities), which may help to increase plant cover. Others experimented with inoculating restoration sites with soil microbial amendments (Koziol et al 2020; Lance et al 2020) or with intact soil containing desirable microbial communities (Grman et al 2020; Remke et al 2020).…”

“…Furthermore, Grman et al (2020) presented evidence that historic failure to establish desired plant species in a prairie ecosystem may be due to a lack of specific functional groups of mutualistic soil microbes (rhizobial bacteria and arbuscular mycorrhizal fungi). In a ponderosa pine forest, Remke et al (2020) also found that transplanted tree seedlings were more successful when the soil that contained site‐specific soil organisms was used, reinforcing the need to understand soil microbial communities at restoration sites to increase revegetation success.…”