Long-term fire effects of the drained open fen on organic soils

Abstract

Keywords: wetland fi re, peat fi re, fen, wildfi re. Abstract:Fire has considerable impact on vegetation and organic soils properties. As we observed that the differences between vegetation of burnt and unburnt areas on the rich fen are visible 11 years after the fi re, we assumed that the post-fi re changes are long lasting, yet limited exclusively to the burnt areas. In order to check this hypothesis we studied spatial differentiation of physical and chemical properties of soils, and productivity capacities of burnt and unburnt areas in the fen in Biebrza National Park. We took soil samples from the neighboring burnt and unburnt areas, from the depth of 0-30 cm and 30-50 cm. We analyzed 21 parameters of the soils including: pH, ash content, moisture, bulk density, exchangeable K, Na, Ca, available P, N-NH 4 + , N-NO 3 -, total N, C, K, Na, Ca, Mg, Fe, P; and calculated C:N, C:P ratios. Surface layer of the burnt soils differed signifi cantly from the unburnt soils in respect of 17 out of 21 parameters. The most pronounced difference was observed for available phosphorous (on average 6 times higher for the burnt soils). The differences in the deeper layer were mostly insignifi cant. The burnt areas were also characterized by twofold higher plant productivity than recorded for the unburnt areas. The infl uence of fi re on peaty soils was long lasting but mostly limited to the surface layer of the soils. In the case of particular soil features, the post-fi re differences were modifi ed by advanced muck formation (moorshing) processes in the unburnt areas. Since the fi re led to long lasting increase of fertility, the recovery of fen vegetation is unlikely.Unauthenticated Download Date | 5/11/18 2:35 PM 12 M. Sulwiński, M. Mętrak, M. Suska-Malawska of burnt soils. The duration of these changes depends on i.e. the amount and chemical composition of ashes. Elements released from peat and plant biomass during the fi re may be lost via volatilization (e.g. C, N, S) or with ashes transported with smoke by convection forces. After the fi re, remaining ashes can be removed by wind, water runoff, leaching downward soil profi le or by plant uptake. They may be also transformed into insoluble compounds or remain in exchangeable form (Neary et al. 1999, Certini 2005, Dikici and Yilmaz 2006, Qian et al. 2009a, Qian et al. 2009b.To the typical post-fi re changes of soils we may include: increase in pH, decrease in total amounts of nitrogen and carbon, and higher availability of P, K, Ca and Mg. The ranges of these alterations differ, depending on the type of soil and the fi re intensity (Neary et al. 1999, Marcos et al. 2007, Certini 2005, Ketterings and Bigham 2000, Arocena and Opio 2003, Dikici and Yilmaz 2006. Though the effects of fi re on mineral soils are well examined, there is not enough information on its infl uences on physical and chemical properties, especially long-term ones, of peaty soils (Dikici and Yilmaz 2006, Wang et al. 2015). Hence, we present a study carried out in the area of a burnt-out fen, 11 years a...

Increased Peatland Nutrient Availability Following the Fort McMurray Horse River Wildfire

“…Another significant finding of this study was the increase in available P after a fire. Similar to the work of Sulwiński et al [38], where a peatland 11 years post-fire had concentrations of available P that were 6 times higher. Our results show that available P was 5 times higher in the Burned areas compared to the Unburned area.…”

“…This study shows that burning had no effect on NH 4 + , and led to increases in both NO 3 − and P in the WBF. This concurs with previous findings on P, but contrasts with previous findings on N in other peatland studies that have generally shown a decrease in the total amounts of N, and an increase in the availability of P [38][39][40]. In a previous study [26] in the same fen (Poplar), pre-fire NH 4 + comprised 80-90% of the TIN concentrations in peat.…”

“…The relationship between fire and P supply are dependent on several interacting factors such as pH, redox conditions and the availability of ions (e.g., Ca 2+ , Mg 2+ , and/or Fe 3+ in fens) [38,43]. For instance, it is well documented in the literature that fire causes the release of P from organic matter, especially following partial combustion of organic matter, where bioavailable P is increased (i.e., sodium bicarbonate-extractable P), which is accompanied by an increase in pH.…”

“…The significant increase of P in these nutrient-poor peatlands has the potential to increase P loading to adjacent downstream aquatic ecosystems, or, local vegetation shifts [46]. Furthermore, vegetation shifts from post-fire regrowth can lead to the development of highly productive species, which have the ability to out-compete typical fen species, especially mosses that are critical for slow decomposition rates and net carbon sequestration function [38,47]. The effects of increased P availability can be long-lasting [48].…”

Peatlands Rehabilitation through Species Enrichment on Post-fire Oil Palm Plantation Area

“…Dampak negatif yang ditimbulkan jika lahan gambut terbakar atau dikonversi yaitu memancarkan sejumlah besar gas karbondioksida yang menjadi gas rumah kaca dan memperburuk pemanasan global, hal ini karena gambut merupakan sumber penyimpan dan penyerap karbon (Adinugroho et al 2005). Dampak lain dari segi ekologis yang di timbulkan yaitu penurunan kualitas tanah gambut, terganggunya siklus hidrologi, perubahan kapasitas tinggi muka air, menghancurkan struktur vegetatif bawah tanah, serta hilangnya regenerasi alami yang menyebabkan struktur dan komposisi vegetasi hutan menjadi terganggu, sehingga terjadi penurunan keanekaragaman hayati (Adinugroho et al 2005;Fitzherbert et al 2008;Posa et al 2011;Sulwinski et al 2017;Tonks et al 2017). Berdasarkan uraian tersebut, rehabilitasi pada lahan gambut terdegradasi merupakan kegiatan yang harus dilakukan untuk mengurangi dampak negatif yang di timbulkan.…”