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Much has been achieved by research into ecological restoration as a nature-based solution to the destruction of ecosystems, particularly in Canada. We conducted a national-level synthesis of Canadian restoration ecology research to understand strengths and gaps. This synthesis answers the following questions: Who is studying restoration? What ecosystem types are studied? Where is restoration studied? Which themes has restoration research focused on? Why is restoration happening? And how is restoration monitored and evaluated? We employed systematic searching for this review. Our results show that restoration research is conducted mainly by academics. Forest, peatland, grassland, and lake ecosystem types were the most commonly studied. There was a concentration of research in four provinces (Ontario, Quebec, Alberta, and British Columbia). Research into restoration has changed its thematic focus over time from reforestation to climate change. Legislation was the most common reason given for restoration. Restoration research frequently documented results of less than 5 years of monitoring and included one category of response variable (e.g., plant response but not animal response). Future research could investigate the outcomes of restoration prompted by legislation. At the dawn of the UN Decade on Ecosystem Restoration, this work demonstrates Canada's momentum and provides a model for synthesis in other countries.

Abstract:Our study found that a water level close to the surface and a seedbed composed of bare peat or a Sphagnumcarpet favored the germination of vascular species associated with pools in peatlands. A greenhouse experiment was conducted to study the impact of seedbed and water level on the germination and growth of 7 plant species associated with pools: Carex limosaL., C. magellanicaLam. ssp. irrigua (Wahlenb.) Hultén, C. oligospermaMichx., C. paucifloraLightf., and Rhynchospora alba(L.) Vahl from the Cyperaceae family as well as Drosera intermediaHayne (Droseraceae) and Scheuchzeria palustrisL. (Scheuchzeriaceae). The 3 seedbeds tested were 1) bare peat; 2) a carpet of Sphagnum cuspidatumEhrh. ex Hoffm. and S. fallax(Klinggr.) Klinggr. (Sphagnaceae); and 3) a carpet of Cladopodiella fluitans(Nees) H. Buch (Cephaloziaceae), common bryophytes along pool edges. Seedbeds were combined with 2 water levels (0 and 10 cm below the soil surface) in a complete factorial block design. Germination periods were generally longer when seeds were submitted to drier conditions and placed on C. fluitanscarpets. Conditions favoring biomass production were more variable among species. These results will facilitate the identification of the best ecological conditions for successful establishment of pool edge species in the context of restoration projects, thereby increasing biodiversity and ecological value of restored peatlands.

AbstractIn order to focus efforts towards specific vegetation groups in fen restoration, knowledge of the peat-accumulating function of dominant fen species is critical. The decomposition rates of 3 species typical to undisturbed fens and 3 species that spontaneously colonize harvested fens were assessed. These species were incubated in both a restoration site (harvested fen) and an undisturbed fen to compare decomposition according to different environmental conditions. The average exponential decay coefficient (k) for all material types was slightly higher (circa0.04·y−1higher) in the harvested fen than those observed in the undisturbed fen. However, the litter type (leaves, roots/rhizomes, or bryophyte fragments) had the largest impact on the decomposition rates. The 2 tested bryophytes had lower k-values (between 0.14 and 0.11 for Polytrichum strictumand 0.06 for Sphagnum centrale) than the vascular plant litter (between 0.25 and 0.50). The annual primary production of the tested species was also measured to estimate the peat-accumulating capacity of each species. Scirpus cyperinushad an annual primary production that was 3 times higher (1500 g·m−2.y−1) than the other species (between 300 and 550 g·m−2.y−1). Estimates show that the harvested fen has a high peat-accumulating potential due to the high biomass production observed at this site.

Peatlands may play an important role in global carbon cycles, and thus developing better estimates of carbon exchange in those ecosystems has become a main concern. In this study, the relationship between spectral indices and CO2fluxes was tested for different communities in a Sphagnum-dominated peatland. Fluxes were measured with a portable climate-controlled chamber while reflectance was simultaneously recorded using a hand-held spectroradiometer. A laboratory experiment was also conducted to select the water-related index most correlated with Sphagnumwater content to regulate the normalized difference vegetation index (NDVI) values obtained in the field. The laboratory experiment showed a strong correlation between Sphagnumwater content and all spectral indices, namely the water index (WI), normalized difference water index (NDWI), and relative depth index (RDI) (r= 0.753–0.993). WI was the index selected for regulating NDVI values. Indices tested in the field for CO2flux estimations were (i) NDVI, (ii) NDVI/WI, (iii) NDVI × sPRI (photochemical reflectance index), and (iv) the chlorophyll indices CI and CIm. NDVI alone was a poor predictor of net ecosystem exchange (NEE, r2= 0.12) and gross photosynthesis (PG, r2= 0.15), and NDVI × sPRI and NDVI/WI showed moderate adjustments to CO2fluxes (NEE, r2= 0.26 and 0.30; PG, r2= 0.38 and 0.43, respectively, for each index). The relationship between CO2fluxes and chlorophyll indices was reasonably well adjusted (CI and NEE, r2= 0.37; CI and PG, r2= 0.55; CIm and NEE, r2= 0.38; CIm and PG, r2= 0.57), and these indices may be the most promising for mapping the spatial distribution of CO2fluxes in the future.

The formation of many arctic wetlands is associated with the occurrence of polygon-patterned permafrost. Existing scenarios to describe and explain surface landforms in arctic wetlands (low-center and high-center polygons and polygon ponds) invoke competing hypotheses: a cyclic succession (the thaw-lake hypothesis) or a linear succession (terrestrialization). Both hypotheses infer the predictable development of polygon-patterned wetlands over millennia. However, very few studies have applied paleoecological techniques to reconstruct long-term succession in tundra wetlands and thereby test the validity of existing hypotheses. This paper uses the paleoecological record of diatoms to investigate long-term development of individual polygons in a High Arctic wetland. Two landform processes were examined: (1) the millennial-scale development of a polygon-pond, and (2) the transition from low-center to erosive high-center polygons. Diatom assemblages were quantified from habitats associated with contrasting landforms in the present-day landscape, and used as an analog to reconstruct past transitions between polygon types. On the basis of this evidence, the paleoecological record does not support either of the existing models describing the predictable succession of polygon landforms in an arctic wetland. Our results indicate a need for greater paleoecological understanding, in combination with in situobservations in present-day geomorphology, in order to identify patterns of polygon wetland development and elucidate the long-term drivers of these landform transitions.

AbstractIn order to restore peatlands after peat harvesting operations, Sphagnumdiaspores were reintroduced in combination with i) physical protection devices or ii) an irrigating system. The response of five Sphagnumspecies (Sphagnum angustifolium[C. Jens. exRuss.] C. Jens. inTolf, S. magellanicumBrid., S. papillosumLindb., S. fuscum[Schimp.] Klinggr. and S. capillifolium[Ehrh.] Hedw.) was investigated in relation to two types of peat substrates for two growing seasons. The physical protections consisting of plastic shade cloth (40% and 60% shade) improved the development of a greater number of capitula compared with control surfaces without protection or surfaces covered with a perforated polyethylene sheet. This stimulating effect could be caused by higher humidity created by a shade screen. Irrigation also enhanced the establishment success of Sphagnumbut the effect was less successful than expected. During a year with normal summer climatic conditions (1993), the sphagna of the sections Cuspidataand Acutifoliaestablished well with equal number of capitulum after 117 days of growth. In contrast, after a second year of growth which was much more humid because of abundant rainfalls, the sphagna of section Cuspidatawere maintained or multiplied while those of section Acutifoliaregressed. Since it is difficult to predict long-term climatic conditions, we suggest the reintroduction of a mixture of many species in order to favor the adaptation of the moss cover to diverse climatic conditions. In conclusion, we recommend the reintroduction of a variety of Sphagnumspecies under physical protections like plastic shade screen to favor an adequate microclimate during the restoration phase of a continuous moss carpet.

The article discusses the highlights of the International Symposium on Responsible Peatland Management and Growing Media Production held at Concorde Hotel, Québec, Canada on June 13-17, 2011. Posters and oral papers dealing with responsible peatland management and growing media productions were given over two days of the symposium. Two-hour roundtable discussions were done for each session at the end of the meeting and site visits were conducted after the symposium.