Relative contributions of plant traits and soil microbial properties to mountain grassland ecosystem services

Abstract

Summary 1. Plant functional diversity and soil microbial community composition are tightly coupled. Changes in these interactions may influence ecosystem functioning. Links between plant functional diversity, soil microbial communities and ecosystem functioning have been demonstrated in experiments using plant monocultures and mixtures, using broad plant and microbial functional groups, but have not been examined in diverse natural plant communities. 2. We quantified the relative effects of plant and microbial functional properties on key ecosystem functions. We measured plant functional diversity, soil microbial community composition and parameters associated with nitrogen (N) cycling and key nutrient cycling processes at three grassland sites in different parts of Europe. Because plant structure and function strongly influence soil microbial communities, we determined relationships between ecosystem properties, plant traits and soil community characteristics following a sequential approach in which plant traits were fitted first, followed by the additional effects of soil micro-organisms. 3. We identified a continuum from standing green biomass and standing litter, linked mostly with plant traits, to potential N mineralization and potential leaching of soil inorganic N, linked mostly with microbial properties. Plant and microbial functional parameters were equally important in explaining % organic matter content in soil. A parallel continuum ran from plant height, linked with above-ground biomass, to plant quality effects captured by the leaf economics spectrum, which were linked with the recycling of carbon (C) and N. 4. More exploitative species (higher specific leaf area, leaf N concentrations and lower leaf dry matter content) and taller swards, along with soil microbial communities dominated by bacteria, with rapid microbial activities, were linked with greater fodder production, but poor C and N retention. Conversely, dominance by conservative species (with opposite traits) and soil microbial communities dominated by fungi, and bacteria with slow activities, were usually linked with low production, but greater soil C storage and N retention. 5. Synthesis -Grassland production, C sequestration and soil N retention are jointly related to plant and microbial functional traits. Managing grasslands for selected, or multiple, ecosystem services will thus require a consideration of the joint effects of plant and soil communities. Further understanding of the mechanisms that link plant and microbial functional traits is essential to achieve this.

Grass strategies and grassland community responses to environmental drivers: a review

“…3 for species codes turn could rank grass species along gradients, such as from conservative-strategy to acquisitive one with, respectively, deep and coarse root system or shallow and thin root system (Fort et al 2013), or also could discriminate for drought tolerance (Craine et al 2012) or dehydration avoidance (Zwicke et al 2015). Going further on roots traits appears also promising in order to better understand below-ground processes as shown by recent studies (see Ke et al 2015;Legay et al 2014;Grigulis et al 2013). …”

Plant trait-based models identify direct and indirect effects of climate change on bundles of grassland ecosystem services

“…Because of the cold and, in some instances, dry climate, nitrogen is one of the most limiting elements for plants and soil microorganisms in subalpine grasslands, and thereby for carbon and nitrogen cycling (15,21,22). In our models, EPs were driven by two core sets of variables relating to fertility and plant traits, respectively (Fig.…”

“…1). Using semimechanistic models of ecosystem properties (EPs) based on plant and microbial functional traits (8), we simulate the impacts of combined climate and land-use changes on ESs (14,15).Using data from a grassland-dominated landscape in the French Alps, we analyzed the responses to four plausible scenarios of a set of EPs (8) identified by stakeholders as contributing to locally important ESs such as water quality, aesthetic value, and fodder quality and quantity (16).Considering that changes in ESs at the landscape scale result from changes in the landscape-scale patterns in management and their plot-scale effects on biodiversity and ecosystem functioning, we used an empirical model: (i) to predict the potential effects of climate change on the supply of individual ESs and on their bundles, both directly or indirectly through land-management adaptation; (ii) to quantify the relative contributions of direct and indirect climate effects on individual ESs and their bundles; and (iii) to identify the underpinning mechanisms involved. …”

“…1). Using semimechanistic models of ecosystem properties (EPs) based on plant and microbial functional traits (8), we simulate the impacts of combined climate and land-use changes on ESs (14,15).…”

A Review of Strong Evidence for the Effect of Functional Dominance on Carbon Stocks in Natural Forest Ecosystems

“…However, most of the studies focusing on the relationship between FTD and C stocks did not consider the whole plant coordination and root traits are particularly ignored due to technical difficulties and are often substituted by measurement of leaf functional traits (Conti and Diaz, 2013;Cavanaugh et al, 2014;Finegan et al, 2015). It is recommended to include root traits, in addition to leaf and stem traits, in further studies concerning FTD and C stocks in natural forest ecosystems (Orwin et al, 2010;Grigulis et al, 2013). Because, root traits have been recognized to have more direct ecosystem effects (Butterfield and Suding, 2013) and may not always be well associated with leaf traits (Orwin et al, 2010;Fortunel et al, 2012).…”