Anne McIntosh, Alberta Biodiversity Monitoring Institute
April 7, 2014
Executive Summary
There is uncertainty related to the long-term consequences of reconstructing landscapes on Alberta’s specified lands. Alberta has over 100,000 wellsites that have been certified under evolving reclamation criteria over the past 50+ years. These wellsites are not currently revisited post-certification to evaluate their long-term ecological recovery. Ecological recovery is achieved when the biological, physical and chemical properties (e.g., vegetation community composition, soil properties) of a reclaimed site are similar to the properties of an undisturbed reference or pre-disturbance site. With the lack of long-term monitoring of wellsites post-certification in Alberta, there is currently no way of knowing if or when ecological recovery will be achieved on these reclaimed sites. The absence of this information is a potential liability that detracts from government’s stewardship commitments, and from industry’s social license to operate on public lands.
The Ecological Recovery Monitoring (ERM) Project Team was established in November 2012. The overarching goals of the ERM are to: i) undertake a field study to assess historical wellsites to address key knowledge gaps that currently constrain the assessment of ecological recovery after reclamation, and ii) create a scientifically-robust, transparent, and financially-sustainable long-term monitoring program to assess the ecological recovery of reclaimed wellsites. The initial focus on wellsites will provide a foundation for future work on other energy sector footprints.
In the first stage of the project (November 2012 – March 2013), three main project activities were completed. Using a series of workshops, the strengths and weaknesses of three programs that could potentially be used to develop integrated long-term monitoring protocols were evaluated. Workshop participants, who included members from research institutions, industry and government, selected a set of soil and vegetation indicators that could be used to monitor ecological recovery of certified sites. Integrated monitoring protocols that incorporated the selected indicators were developed for use in evaluating the long-term success of reclamation on certified reclaimed wellsites (ABMI 2013a). A governance and funding model to implement and sustain this project in the long-term was also recommended (ABMI 2013b). An extensive review of the literature and existing sources of pertinent data illustrated a lack of long-term monitoring data for certified sites in Alberta (ABMI 2013c).
In the most recent stage of the project (April 2013-March 2014), our project focused on two research areas: i) using the newly developed integrated monitoring protocols to assess ecological recovery of historical wellsites on a single common ecosite type in native grasslands (see Chapter 1), and ii) developing a framework to support implementing a long-term monitoring program to track ecological recovery of certified sites in Alberta (see Chapter 2).
The first objective for this year was to compare ecological recovery for a set of vegetation and soil properties (i.e., indicators of recovery) on certified reclaimed wellsites with adjacent reference locations (i.e.,sites without industrial disturbance) across a range of age classes post certification (~10, 20, and 30 yrs) in native grasslands in the Dry Mixedgrass Natural Subregion (see Chapter 1).
We measured vegetation (percent cover by species and strata, species richness, Shannon diversity, and Sørensen’s similarity index) and soil (bulk density, electrical conductivity, LFH depth, pH, total nitrogen (TN), total organic carbon (TOC), TOC:TN) indicators for four soil depths (0-15 cm, 15-30 cm, 30-60 cm, and 60-100 cm), comparing them among 18 wellsites and adjacent reference locations. For each indicator we conducted two-way ANOVAs to test for differences among location (wellsite vs reference) and age class (10, 20, 30 yrs post certification). We also used non-metric multidimensional scaling (NMS) ordination and a multi-response permutation procedure to explore plant community composition patterns among sites.
Vegetation analyses highlighted differences among the wellsite and reference locations, including lower species richness, Shannon diversity, and total vegetation cover on the wellsites compared with the reference sites, regardless of age class. In contrast, wellsites had significantly higher cover of non-native vegetation compared with the reference sites across age classes. Several vegetation indicators only showed significant differences for the wellsite and reference locations in some age classes (i.e., forb (including non-native), graminoid (including non-native), clubmoss, and lichen cover, and Sørensen’s similarity index). There were no significant differences among wellsite and reference sites for shrub cover. The plant community composition ordination illustrated separation of the wellsite and reference locations among age classes, with the 10-yr wellsite community composition more similar to the composition of the reference sites compared with the 20- and 30-yr age classes. These differences among site locations and age classes were primarily correlated with the cover of plant species (e.g., crested wheatgrass in 20- and 30-yr wellsites).
For all soil indicators there were significant differences among the wellsite and reference locations for at least one soil depth. Bulk density (only measured for the two shallowest depths) and electrical conductivity were higher in the wellsites for all sampled depths. Compared with reference sites, wellsite pH was significantly higher at 15-30 cm depth and significantly lower at 60-100 cm depth. LFH depth was significantly deeper in the reference sites compared with the wellsites for the 20 and 30 yr age classes. Total nitrogen was significantly higher in the reference sites for the two shallowest depths and total organic carbon was significantly higher for the reference sites in the most shallow depth (0-15 cm). The ratio of total organic carbon: total nitrogen was significantly higher on wellsites in the deepest depth (60-100 cm).
Overall, it appears that for many vegetation and soil indicators, wellsites have not yet fully recovered to values similar to those found in adjacent reference locations. This lack of recovery was evident across the different age classes, although there was some support for increased recovery of plant communities in the youngest age class compared with the older age classes. We do not yet know how long it will take for these reclaimed wellsites to recover, and thus longer-term monitoring is needed to evaluate recovery trajectories over time.
Alberta is in the process of developing the Alberta Environmental Monitoring, Evaluation and Reporting Agency (AEMERA) with the goal of providing “accurate, trustworthy, and useful data and information to inform the work of policymakers, regulators, research organizations and others through the design, execution and supervision of environmental monitoring programs for air, land, water and biodiversity” (AEMP 2011, WGEM 2012). This over-arching provincial body could provide an administrative and regulatory framework for this long-term ecological recovery monitoring program several years down the road, however considerable work is required prior to this potential amalgamation to ensure that reclaimed sites are effectively monitored. Thus, the second study objective was to begin development of a framework to support the inclusion of long-term monitoring of reclaimed wellsites in Alberta as part of AEMERA. Towards achieving this objective we investigated the following areas of research: i) we used the historical wellsite study (see Chapter 1) as a pilot of our long-term monitoring protocols, reviewing information from the field study to inform sampling effort in native grasslands for the long-term monitoring program, and ii) we identified potential criteria to aid in development of a framework for selection of a subset of wellsites for inclusion in the long-term monitoring program. We initially planned to develop an implementation plan for the long-term monitoring program, but with the uncertainty related to the governance of AEMERA, we decided it would be more relevant to wait until the governance structure of AEMERA is decided before pursuing this avenue of research so that our results are cohesive with the structure the government plans to implement.
The piloting of the long-term monitoring protocols in the field study described in Chapter 1 provided significant learnings; improvements in technology and use of trained reclamation field crews contributed to significant increases in efficiencies throughout the field season. Analysis of variability among vegetation and soil indicators illustrated high variability both within and between wellsite and reference locations within and among sites. However, the statistical design of our study with paired locations of wellsite and reference locations within individual sites provided the statistical power to detect treatment differences. The statistical design of our study also allowed us to detect differences with a smaller number of sample sites than we would need if we did not use blocking in our design. Our statistical design and the hands on learning experience we gained in the field can be applied when implementing the long-term monitoring program for certified wellsites in native grasslands, thus ensuring efficient and cost effective wellsite monitoring in the future.
ERM advisory group members identified criteria that could potentially be used to classify/categorize both the current pool of certified reclaimed wellsites (>100,000) and future certified wellsites that have not yet been certified (>300,000 and growing). There was also discussion about the scope of the monitoring network, with two different potential approaches identified: i) sampling wellsites from all possible combinations of classes/criteria, or ii) sampling wellsites from only a subset of classes/criteria. Group members highlighted the complexities associated with site selection and its implementation as part of a long-term monitoring program. No final decisions related to site selection for long-term monitoring were made, as these decisions will depend on both the scope of the program and the budget available for establishment of the plot network, and we also need more information on sampling in forested and cultivated lands to help inform site selection.
Overall, our findings from the activities in this project year provided novel insights into the sampling and assessment of recovery of wellsites post-certification in native grasslands in the Dry Mixedgrass natural subregion. These findings will aid in the development of an integrated, scientifically robust and financially sustainable monitoring program to enable the assessment of ecological recovery of physical, chemical, and biological indicators at certified reclaimed wellsites across Alberta. In the next stage of our project we will be assessing ecological recovery of historical wellsites in forested lands and continue to develop the framework for establishing the long-term monitoring program for certified reclaimed wellsites in Alberta.
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