Temporal variation in temperature and rainfall differentially affects ectomycorrhizal colonization at two contrasting sites

Abstract

We examined the roles that seasonal shifts in precipitation and temperature played in the ectomycorrhizal (ECM) colonization of pinyon pine (Pinus edulis Engelm.) at two contrasting sites in northern Arizona. Pinyons growing in ash and cinder soils experienced much greater water and nutrient stress than pinyons growing nearby in sandyloam soils. Over a one year period, we obtained monthly measurements of ECM colonization, root zone soil moisture and temperature, and air temperature and precipitation. Four major patterns emerged. Firstly, although climate as measured by ambient temperature and precipitation did not vary between the two sites, soil temperature was significantly higher and soil moisture significantly lower at the cinder site than at the sandy-loam site. Secondly, ECM colonization was significantly higher at the cinder site for 5 of 12 months. Thirdly, although nearly 70 % of the variation in ECM colonization of pinyons growing in cinder soil was predicted by a combination of soil moisture and soil temperature, these same variables had little predictive power for pinyons growing in sandy-loam soils. Air temperature and precipitation were also significantly correlated with ECM colonization at the cinder site but not the sandy-loam site. Fourthly, a watering experiment showed that ECM colonization significantly increased with supplemental water at the cinder site, but not at the sandy-loam site. Thus, in two sites that did not differ in plant community or climate, ectomycorrhizas in cinder soils were far more sensitive to changes in moisture and temperature than ectomycorrhizas in sandy-loam soils.

Ectomycorrhizal colonization of Alnus acuminata Kunth in northwestern Argentina in relation to season and soil parameters

“…At the two seasons of sampling, no influence on the percentage of ECM colonization was observed, in contrast to other studies, where seasonal variation in temperature, soil moisture, physiological and phenological changes in the host plant affected both symbionts [22,52]. In this study climatic differences between the seasons were minimal (spring and autumn) [2]; which may be the reason for similar ECM colonization.…”

“…Studies that focus on the relationship between edaphic factors and mycorrhizas are lacking as stated by Swaty et al [52], Newbery et al [38], Moyersoen et al [34] and El Karkouri et al [16]. This work was carried out to determine the phenology and diversity of the ECM in natural forests of A. acuminata in relation to some soil parameters (field capacity, pH, electrical conductivity, available P, total N and organic matter) at two different seasons (spring and autumn).…”

Herbivory, plant resistance, and climate in the tree ring record: Interactions distort climatic reconstructions

“…The cinder fields on which our experimental trees grow are the result of a 200-yr-long series of volcanic eruptions at Sunset Crater that ended Ϸ800 years ago, and that covered 1,200 km 2 in lava, cinders, and ash (19). This cinder soil, which has been recolonized by the surrounding pinyon-juniper forest, has been demonstrated to be deficient in water availability (13,14).…”

“…Several attributes of the ecosystem at Sunset Crater make it ideally suited to address these issues. First, Sunset Crater is a hot, dry environment (13,14), making the region ideal for the selection of climatically sensitive trees. Yet, this water-stressed environment also supports several insect species, including the pinyon needle scale, (Margarodidae, Homoptera) Matsucoccus acalyptus, which reaches high population densities, and chronically attacks pinyon pine (Pinus edulis) (11)(12)(13).…”

Fine roots and ectomycorrhizal colonization in black spruce subjected to reductions in soil moisture

“…However, contrasting responses of the rate of mycorrhization to moisture stress have been observed (Lehto and Zwiazek 2011). Drought was reported to either enhance (Davies et al 1996;Swaty et al 1998) or reduce (Becker et al 1987) the proportion of mycorrhizal root tips. The aim of this study was thus to investigate how a reduction in soil moisture influences fine roots and ectomycorrhizas (ECM) in the boreal ecosystem.…”