Small wetlands in silvopastoral landscapes

Key words: water reservoirs, extensive livestock breeding, abandonment of countryside, agro-environmental policies

Department of Forestry, Wood Sciences and Design, University of Thessaly, Greece ykazoglou@uth.gr

Water, whether stagnant or flowing, abundant or limited, is a landscape element that always attracts the attention of most living organisms. It is one of the three essential features of wetlands and essentially defines the other two, which are wetland vegetation and hydromorphic soils (Fitoka et al. 2020). But what exactly are wetlands? According to article 1 of the Ramsar Convention on Wetlands of International Importance, especially as Waterfowl Habitat, “wetlands are areas of marsh, fen, peatland or water, whether natural, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine waters the depth of which at low tide does not exceed six meters”. Despite its weaknesses, this is a broad, commonly accepted definition of wetlands, among many scientific and legal definitions found in the international literature. Keddy (2002) suggests a shorter definition which also manages to describe the majority of the planet’s wetlands: “A wetland is an ecosystem that arises when inundation by water produces soils dominated by anaerobic processes and forces the biota, particularly rooted plants, to exhibit adaptations to tolerate flooding”. The diversity of wetland definitions appears to follow the diversity of wetlands themselves in terms of types, sizes, conditions, locations, and characteristics, a fact that according to Mitsch and Gosselink (1986) leads to an unsurprising lack of a single, universally recognized definition of what a wetland is.

Wetlands may cover areas of thousands of square kilometers or be much smaller. For the purposes of the present article, we will limit the subject to small or even very small wetlands. The upper limit for “small wetlands” in Greek legislation and recent literature (Fitoka et al. 2020) is set to eight (8) hectares; however, in the case of wetlands in silvopastoral landscapes, they may even cover areas of a few square meters, as they include small natural or artificial water bodies (ponds) and even completely artificial structures, such as water troughs for farm animals. The role of these small wetlands in silvopastoral landscapes is manifold. In ideal conditions, natural small wetlands with stagnant or low-flowing water have smooth banks with low emergent vegetation and, possibly, visible color signs of fluctuating water levels, as well as a zone of relatively deeper water. Possible “residents” or users of these habitats, depending on the season, may be invertebrates such as dragonflies and other insects, tadpoles and mature frogs and toads, newts, small fish or larger animals that leave their tracks in the mud of the bank, probably because at some point they passed through the wetland to drink or feed. In streams and small rivers, the zonation includes the active bed (covered by running water at low and high flows), the banks, ponds or troughs in or near the active bed, which are refuges for fish fauna, and the riparian zone with the always interesting forest vegetation and flora. In this case, wildlife species (invertebrates, amphibians, reptiles and fish) are usually less numerous and more specialized compared to those dwelling in small wetlands with stagnant waters, a fact determined by the almost permanent shading and water flow, as well as the lower air and water temperatures (Zogaris et al. 2007).

Moving on to aesthetically less ideal conditions and images, the importance of artificial water bodies that are often found in silvopastoral or silvoarable landscapes should not be overlooked. These include either older soil structures or more modern ones with a concrete or plastic waterproof substrate and/or surrounding walls to retain and collect water, such as (a) small lakes created by excavations, fed by adjacent streams, often made in order to irrigate cultivated fields, (b) long and narrow concrete, wooden or metal water troughs fed by springs or surface waters, and

(c) ponds, small pools and reservoirs for watering livestock, supplying other water storage infrastructure or for other uses (Papanastasis et al. 2021). In practice, all these constructions resemble natural wetlands and apart from farm animals, they are also used by wildlife. Roe deer (Capreolus capreolus), brown bears (Ursus arctos), wild boars (Sus scrofa, which often use the mud as well as the meadows below or around the water sources in their characteristic way) and many birds including large raptors such as the lesser spotted eagle (Clanga pomarina), very specialized species like the black stork (Ciconia nigra) and dozens of passerines especially in dry islands and Mediterranean habitats, all utilize these constructions in different ways. Such artificial wetlands also attract bats, which fly over water troughs and ponds to catch insects on their nocturnal hunts. Amphibians also use such structures either within them or where water overflows and soaks the ground outside them. These muddy surfaces often provide the right conditions to some orchid species and concentrate groups of small butterflies (puddling areas), bees and various other wild pollinators and their predators.

In order to preserve the valuable silvopastoral landscapes of Greece, it is necessary to manage the infrastructures serving extensive livestock farming, including small natural and artificial water reservoirs

The aesthetic, environmental and economic value of these small natural or artificial wetlands, which are found in silvopastoral landscapes and are critical elements for the preservation of extensive livestock farming, highlights the need for the integrated management of this special category of rural landscapes. At the same time, it points out the important role of extensive animal husbandry for the preservation of such landscapes. Extensive livestock breeding is, however, declining or gradually abandoned, which results in the degradation of traditional agroforestry systems. Specific, well-targeted and implementable national and European policies are needed for the maintenance of existing traditional silvopastoral and silvoarable systems and the creation of new such systems, in combination with proper management of natural wetlands and artificial water reservoirs at areas that can still support extensive animal farms. Only through the implementation of such policies will active human populations be maintained and, possibly, revived in mountainous, semi-mountainous, insular and generally disadvantaged areas which usually host the magnificent cultural landscapes of Greece.

Part C

Management, restoration and creation of agroforestry landscaoes