Conservation of aquatic landscapes: ponds, lakes, and rivers as integrated systems

Abstract

Although many wetlands have been lost, the European lowlands still hold a mosaic of aquatic habitats covering rivers, lakes, ponds, ditches, springs, and swamps. To effectively conserve this diverse and important resource, both scientific studies and management and restoration activities need to focus on all of the watery patches in the landscape and in turn on the linkages between them. Over recent years, catchment and landscape-based approaches to aquatic conservation have been on the rise. However, perhaps driven by a lack of legislative drivers, there remains a tendency to neglect small lakes, ponds, and headwater streams. With consideration of the current conservation scene in the UK, and using a small lowland river catchment (River Glaven, eastern England) as a case study, this paper outlines the strong need for an integrated approach to aquatic conservation that sees rivers, lakes, and ponds as habitat networks. It is proposed that river restoration needs to more fully embrace standing water habitats on floodplains (backwaters and ponds), frequently missing components in regulated rivers. Equally, is it argued that aquatic conservation strategies should focus more strongly on headwater areas where protecting/restoring networks of farmland ponds, ditches, and small streams should increase connectivity for aquatic species, while moderating floods and improving water quality for receiving systems. In this way, aquatic conservation should become a much more effective and sustainable activity with positive ecological consequences that cascade downstream and into the coastal zone.

Herbivore regulation of plant abundance in aquatic ecosystems

“…We used the habitat type reported by each study to classify the habitat type for our analysis. As there is no universally accepted distinction between pond and lake (Sayer, 2014), for the purposes of our study we included ponds within the lake category. Whilst herbivore consumption rates may increase with body mass to a power of <1.0 (van Gils, Gyimesi & Van Lith, 2007;Wood et al, 2012b), consumption is only one mechanism through which herbivores affect plant abundance, with others including trampling, and herbivore-induced changes in nutrient availability (e.g.…”

Artificial Aquatic Ecosystems

“…Deliberate examples of construction include fountains, many roadside ditches, rain gardens, stormwater treatment areas, many farm ponds, and all designer ecosystems [10]. Conservation-oriented water regulation typically exempts such constructs outright; they usually do not count as water [7,23,24]. Accidental examples include logging ruts, erosional gullies in building sites and agricultural fields, poorly drained impervious surfaces, and even bomb craters [25].…”

“…A future increase in the acceptance of novel ecosystems might allow the creation of new types of waterbodies designed to provide similarly novel suites of ecosystem services [10,150]. Even the tendency for less regulation of more highly and accidentally modified [23,29,30] and smaller waterbodies [7,8], particularly in the U.S., constitutes an opportunity; this quality could make them comparatively easy and low-cost systems in which to study, test, and implement novel ecological design ideas [148,151,152]. Together with the repetitive design and construction of many such waterbodies, like ditches and ponds, the manipulability of artificial aquatic ecosystems makes them prime sites for natural experiments [153] and designed experiments [148].…”

“…Indeed, it is often unclear which waterbodies even belong in the category of "artificial" or "anthropogenic". To date, the limited study of different artificial aquatic systems has been fragmented among various domains of ecology and other environmental sciences, and more often discussed on the margins of natural ecosystems than in conjunction with them, as part of a complete hydroscape [7]. Because science and management does not often focus on artificial aquatic ecosystems, their abundance and extent are poorly quantified, and their ecological statuses and causes thereof poorly understood.…”

Coupled Hydrological/Hydraulic Modelling of River Restoration Impacts and Floodplain Hydrodynamics

“…Nevertheless, the river flows through numerous habitat types that are of high conservation value (e.g. wet meadows, riparian woodlands, shallow lakes and coastal marshes), which support several important and protected freshwater species such as brook lamprey ( Lampetra planeri ), white‐clawed crayfish ( Austropotamobius pallipes ) and otter ( Lutra lutra ) (Sayer, ; Sayer and Lewin, ).…”