Indices of connectivity are critical means for moving from qualitative to (semi-)quantitative evaluations of material (e.g., water, sediment and nutrients) transfer across the building blocks of a terrestrial system. In geomorphology, compared to closely related disciplines like ecology and hydrology, the development of indices has only recently started and as such presents opportunities and challenges that merit attention. In this paper, we review existing indices of sediment connectivity and suggest potential avenues of development for meeting current basic and applied research needs. Specifically, we focus on terrestrial geomorphic systems dominated by processes that are driven by hydro-meteorological forcing, neglecting seismically triggered events, karstic systems and environments controlled by eolian processes. We begin by setting a conceptual framework that combines external forcings (drivers) and system (intrinsic) structural and functional properties relevant to sediment connectivity. This framework guides our review of response variables suitable for sediment connectivity indices. In particular, we consider three sample applications concerned with sediment connectivity in: (i) soil studies at the plot scale, (ii) bedload transport at the reach scale, and (iii) sediment budgets at the catchment scale. In relation to the set of response variables identified, we consider data availability and issues of data acquisition for use in indices of sediment connectivity. We classify currently available indices in raster based, object or network based, and indices based on effective catchment area. Virtually all existing indices address the degree of static, structural connectivity only, with limited attention for process-based, functional connectivity counterparts.

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The forest landscape across the Nordic and Baltic regions hosts numerous lakes and watercourses, which must be included in forest management. In this study, national policy designs regarding protection zones for surface waters on forest land were reviewed and compared for the Nordic countries, Estonia and Latvia. The focus was how each country regulates protection zones, whether they are voluntary or mandatory, and the rationale behind adopting a low or high degree of prescriptiveness. Iceland and Denmark had a low degree of policy prescriptiveness, whereas Norway, Estonia and Latvia had a high degree of prescriptiveness. Sweden and Finland relied to a large extent on voluntary commitments. The prescribed zone widths within the region ranged from 1 m to 5 km. The results indicated that land-use distribution, forest ownership structure and historical and political legacies have influenced the varying degrees of prescriptiveness in the region.

Restoration of wetlands is a high priority world-wide. Peat extraction areas can be restored by rewetting, however affecting the environment. It could be expected to turn the drained peat-cutover area from a source to a sink of most elements. This study examined effects of such rewetting on peat, hydrology and water chemistry over 15 years at two sites in Sweden; the nutrient-poor Porla peatland and the nutrient-rich Västkärr peatland. Rewetting caused minor changes to peat chemistry, but at the Västkärr site ammonium concentrations increased in superficial peat layers while nitrate decreased. In terms of hydrology, rewetting of the Porla site decreased annual runoff and both high and low discharges. Water pH at the Porla site stayed fairly stable, but at the Västkärr site pH, after an initial 4 years dip, gradually increased to higher values than before rewetting. Water colour and organic matter content were fairly stable, but slightly lower values were found after 15 years than in initial 4-5 years. The concentrations of base cations and of inorganic N were lower after rewetting, while total P was higher. However, these impacts could change from an initial phase as the wetlands in the long-term perspective develop into mires.

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Rewetted extracted peatlands are sensitive ecosystems and they can act as greenhouse gas (GHG) sinks or sources due to changes in hydrology, vegetation, and weather conditions. However, studies on GHG emissions from extracted peatlands after rewetting are limited. Methane (CH4) and nitrous oxide (N2O) emission fluxes were determined using the opaque closed chamber method along water level gradients from littoral zones to the open water body of constructed shallow lakes with different vegetation zones in a nutrient-rich rewetted extracted peatland in Sweden. Vegetation communities and their position relative to water level, together with short-term water level fluctuations, such as inundation events and seasonal droughts, and temperature had a significant impact on CH4 emissions fluxes. During “normal” and “dry” conditions and high soil temperatures, CH4 emissions were highest from Carex spp.-Typha latifolia L. communities. During inundation events with water levels > 30 cm, sites with flooded Graminoids-Scirpus spp.-Carex spp. emitted most CH4. Methane emissions from the water body of the constructed shallow lakes were low during all water level conditions and over the temperature ranges observed. Nitrous oxide emissions contributed little to the emission fluxes from the soil-plant-water systems to the atmosphere, and they were only detectable from the sites with Graminoids. In terms of management, the construction of shallow lakes showed great potential for lowering GHG emission fluxes from nutrient rich peatlands after peat extraction, even though the vegetated shore emitted some N2O and CH4.

There was no big influence of the used cell scales and algorithms on the mean topographical properties of the Nigula mire digital elevation models (DEMs). The DEMs, generated using the Triangulated Irregular Network and Inverse Distance Weighted algorithms, revealed the closest mire surface properties from all used generation algorithms. The subtracted MAX–MIN DEMs layer revealed a well visible net of ditches and possible plant cover pattern differentiated in vertical scale. In the Nigula mire 58% of the mire surface basins have S–SW orientation, followed by the levelled and less fractionated N–NE basin region (23% coverage), and the most fractionated but with steeper sloping W-orientated basin region (8% coverage)