Abstract Detail

Ecology

Super, Laura [1], Ye, Tong [1], Low, Caitlin [1], Tsai, Kyne [1], Simard, Suzanne [1].

The impact of anthropogenic nitrogen and warming on plants and their associated organisms .

In spite of the importance of understanding multiple factors on plants, less is known about the impact of multiple anthropogenic drivers on plants and associated organisms. This growth chamber study involved simulating nitrogen deposition (10 kg N per hectare per year) and climate change warming (three degrees Celsius increase) on tree seedlings to assess impacts on the plants above- and below-ground as well as associated organisms. Each tree seedling received one of the following treatments: control (C), warming (W), nitrogen (N), or nitrogen and warming (NW). This research focused on coastal Douglas-fir (Pseudotsuga mensiezii) for most subsequent analyses given large enough sample sizes (pilot data was still collected for the other species, with at least 3 replicates per treatment). For change in height data, there was enough to report on western red cedar (Thuja plicata, N=119, n=29 to 30 per treatment) and western hemlock (Tsuga heterophylla, N=120, n=29 to 31 per treatment) as well as Douglas-fir (N=340, n=83 to 86 per treatment). Preliminary analyses show that above-ground plant growth for shoot height change (week eight minus week one height) was the most for T. plicata on average, with T. plicata at the control temperature having the largest change in height. The P. mensiezii height change under NW was similar to that of T. plicata and was greater than the other treatments (C, N, W) for these species. T. heterophylla did not seem to show this response. With respect to above- and below-ground measures, analyses with Douglas-fir (N=48, n=12 per treatment) were conducted to assess shoot and root biomass, shoot height, root collar diameter, rooting depth, specific leaf area (SLA) and specific root length (SRL). In general, these did not differ between the treatments, but results suggest that average rooting depth was greater for N; root and shoot biomass and root collar diameter were greater for NW; and SRL was lower for NW. Preliminary pilot study analyses on the other species showed high variability given sample size (n= 3 per treatment). Additional trees are currently being assessed for soil food webs and above-ground organisms, and this data is forthcoming and hopefully will be ready by the conference. This research is part of Laura Super’s PhD project examining the impact of anthropogenic change on plant-microbe-invertebrate interactions, and has significance for applied and basic scientific research.

1 - The University of British Columbia (Vancouver Campus) , Forest and Conservation Sciences, Main Office (Room 3041), 2424 Main Mall , Vancouver, BC, V6T 1Z4, Canada

Keywords:
Nitrogen deposition
Climate change
Anthropogenic drivers
Tree seedlings
Microbes
Invertebrates
Soil food webs
Above- and below-ground ecology.

Presentation Type: Oral Paper
Session: 2, Ecology Section - Functional Traits and Responses
Location: 104/Mayo Civic Center
Date: Monday, July 23rd, 2018
Time: 8:45 AM
Number: 2004
Abstract ID:532
Candidate for Awards:Ecological Section Best Graduate Student Paper,Cinq Mars Award