Implications of applied best management practice for peatland forest harvesting

Abstract

organic) and returned to pre-clearfelling levels, or below, within 6 months of the 33 commencement of clearfelling. Exports of TP and DRP from the study site were 0.9 and 0.4 34 2 kg ha -1 yr -1 , which were greater than the study control (0.6 and 0.2 kg ha -1 yr -1 , respectively). 35This indicated that the mitigation practices employed on site were not effective in phosphorus 36 retention. 37 38

Forest clearfelling effects on dissolved oxygen and metabolism in peatland streams

“…Simultaneously, grab water samples were taken and analysed for total reactive phosphorus ( Water samples were also taken as part of two complementary studies on a monthly basis in the pre-felling study period and weekly in the post-felling period using an automated ISCO sampler, the findings of which are published in O' Driscoll et al (2014c) and Finnegan et al (2014). Storm events were targeted as Rodgers et al (2010) found that nutrient concentrations were low during base flow conditions.…”

“…O' Driscoll et al (2014b) examined the efficiency of a buffer zone on ameliorating nutrient and suspended sediment export arising from clearfelling. Finnegan et al (2014) investigated the implications of applied best management practice for peatland forest harvesting incorporating phosphorus, nitrogen, suspended sediment, DO, electrical conductivity, pH and stream water temperature. This study examines in more depth the DO and temperature impacts arising from clearfelling by considering a longer pre-felling period and investigating flow regimes and metabolic processes.…”

“…A harvester machine was used to clearfell the 9.4 ha GS catchment. Clearfelling at the GS was carried out in accordance with best management practices (BMPs) (Forest Service, 2000a, b), as far as practicable (see Finnegan et al, 2014 for more detail).The crown of the tree and associated residues (i.e. needles, twigs and branches) were collected to form windrows and brash mats which were used for machine travel thus protecting the soil surface and reducing erosion.…”

“…More recently studies have begun to examine the pathways and mechanisms of nutrient and sediment release (Asam et al, 2012(Asam et al, , 2014O'Driscoll et al, 2014b). While some studies have reported a reduction in DO concentrations in aquatic ecosystems following forest clearfelling activities on blanket peat (Drinan et al, 2013;Finnegan et al, 2014), the potential causes and effects on ecological processes have not been investigated.…”

“…Commercial, non-native coniferous forestry was clearfelled from the catchment of one of these streams, while the forestry was left intact in the catchment of the control stream. Based on the findings of earlier studies of forestry clearfelling effects on receiving streams (Drinan et al,2013;Finnegan et al, 2014) we hypothesised that following clearfelling: (H 1 ) there would be significant decreases in DO concentrations; (H 2 ) periphytic biomass would increase in the stream due to increased light, temperature and nutrients, (H 3 ) both water temperatures and stream flow rates would increase; and; (H 4 ) metabolic rates would rise post-clearfelling due to increased nutrients, light and temperature in the study stream. From a global perspective this study provides a unique opportunity to develop our understanding of the impacts of forest clearfelling on stream functional ecology.…”