Abstract Detail

Ecological Section

Bijman, Alison [1], Landhausser, Simon [1], Macdonald, S. Ellen [1].

Vegetation development on poor reclamation sites: Impact of tree seedling presence, biochar and fertilizer amendments.

Re-vegetation of open pit mines can be challenging due to poor cover soil quality, a lack of propagules and suitable microsites for natural seed germination and establishment. This is particularly a problem on mine sites where there is a lack of salvaged surface soil materials that can be used to cover poor subsoil substrates. To explore the vegetation development under these limiting conditions, a blocked split-split plot design was set up in approximately 3 hectares of land on a former coal mine, creating 6 sites (experimental blocks; 0.50 ha each) that included all treatments. Two different soil amendments were tested at each site: (1) Biochar derived from Lodgepole pine (Pinus contorta) biomass applied at a rate of 1800 kg/ha in October 2011, and (2) a slow release fertilizer (15-9-12-6; N-P-K-S) which was applied at two levels in June 2012 (low (50 kg N/ha) and high (100 kg N/ha) and compared to an unamended control. Together these resulted in six treatment combinations: the unamended Control, Biochar only, High fertilizer only, Low Fertilizer only, High fertilizer + Biochar, and Low fertilizer + Biochar. To compare the impact of planting of tree seedlings on vegetation development, four of these treatments (excluding the high fertilizer combination) also had areas that were not planted with trees. The influence of these treatments on vegetation cover, species richness, and understory community development was assessed over two growing seasons (2013 and 2014). Across the site, total percent cover and species richness increased between 2013 and 2014 but overall vegetation cover remained very low. Both fertilizer and biochar were associated with an increase in total percent cover and species richness. Planted aspen trees were associated with significantly higher total cover of both forb and non-native plant species. These results show that presence of tree seedlings, and both fertilizer and biochar amendments can make site conditions more favourable for natural re-vegetation; however conditions continued to be poor and overall vegetation cover and species richness remained very low when qualitatively compared to areas within the mine that had been capped with a salvaged top soil.

1 - University Of Alberta, Dept Of Renewable Resources, Univ Of Alberta - ESB 4-42, Edmonton, AB, T6G 2E3, Canada

Keywords:
Land reclamation
Vegetation Development
biochar
Soil Amendments.

Presentation Type: Oral Paper:Papers for Sections
Session: 21
Location: Salon 17/18/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 2:00 PM
Number: 21003
Abstract ID:897
Candidate for Awards:None