Vadakste Biodiversity forest in south-western Latvia is a partially fenced 50 hectares mostly forested area in flat terrain, on calcareous clay soils, surrounded by state-owned spruce monoculture plantations. Agnis Graudulis, a trained horticulturist and forester, began implementing his vision for his land in 2019; a seed source for biodiversity and trees for food and timber.
The ambition is to restore the vegetation to its original deciduous forest character, in combination with adopting the concept of PNV, “potentially natural vegetation”, in terms of reintroducing native vegetation and assisting the migration of new vegetation, as an increasingly warmer climate opens up new possibilities for planting nut trees. The land contains several systems of different types of vegetation.
Initially, what caught our interest from a Swedish perspective, to the point that we made a film about it, was several thinned out stands of pioneer grey alder (Alnus incana) grown on arable land with planted cherry (Prunus avium), linden (Tilia cordata), maple (Acer platanoides), walnut (Juglans nigra), sweet chestnut (Castanea sativa), larch (Larix decidua), wild pear (Pyrus pyraster), wild apple, (Malus sylvestris), beech (Fagus sylvatica), oak (Quercus petrea, palustris, rubra, robur) trees etc to provide nuts, timber, honey and sap.
PLANTING TREES IN THE FOREST
The trees planted in the forest are grown from seed and planted out with an earth auger, without fertilizers, wood chips or irrigation. Part of the forest plantings are done without fencing to compare possible browsing damage. Wildlife populations in the area are managed through agreements with local hunters.
Carefully establishing a food and timber system in an existing forest has several advantages:
Taller trees around favor lower evaporation, resulting in higher soil moisture. Thanks to surrounding native trees, air movement is also more even, compared to grasslands, where the variation between day and night temperatures, sun and shade is greater. This reduction of heat and water stress, seems to result in both stronger growth in an early stage and in better winter hardiness — the winters here can be really harsh. A late leaf-out and budding seems to favour young, frost sensitive nut trees.
A species rich vegetation with structural diversity and a variety of ages in different layers provides for habitats for beneficial animals that regulate the presence of insect pests. A diverse vegetation also extends the pollen and nectar season for honey-bees, compared to a monoculture landscape, and can offer a possible extra income. The trees provide a wind barrier for these hardworking pollinators and other insects.
Mycorrhiza collaborations with native trees efficiently help the planted trees find water and nutrients, while the constant production of organic matter from a diversity of roots, trunks and leaves contributes to a fertile soil, improving plant survival and stress tolerance.
Furthermore, the land includes;
An open field, sparsely
spread, orchard like alleycropping system with walnut (Juglans regia),
chestnut trees (Castanea sativa), hazel bushes (Corylus avellana), and
fruit trees with common/black alders (Alnus glutinosa) as nurse trees,
(without crops in between the tree lines). Urine is used to water around
these trees and on fence poles, in order to keep wild-life away. The
growth of the saplings in the open field, compared to in the forest
system, is somewhat slower.
A mixed pioneer forest on former forest
pastures with silver birch and weeping downy birch (Betula pendula, B.
pubescens), spruce (Picea abies) and patches of walnut trees in the
understorey.
A stand of spruce
ready for felling, which is gradually being thinned out to invite
natural, broadleaf vegetation. Part of the thinned out areas are planted
with linden, maple, black alder and seeded with linden, maple, sycamore
maple (Acer pseudoplatanus), oak, beech, apple, rowan (Sorbus
aucuparia) and a bush layer seeded with barberry (Berberis communis) and
European buckthorn (Rhamnus cathartica).
Several
scattered, old “landmarks” of oak, wild apple, maple, linden, ash and
pine, with an undergrowth that includes bird cherry (Prunus padus),
hazel, gray willow (Salix cinerea) and bracken (Frangula alnus).
A fenced polycyclic trial (with inspiration from this Italian system) with a mix of fast and slow growing trees (aspen, alder, poplar, willow, oak, beech and other hardwood species) supporting each other, and intended for continuous timber harvest.
A plant nursery established in raised sand beds, inspired by the Swedish gardener Peter Korn at Klinta trädgård, to enhance the plant robustness and to minimise the need for extensive maintenance.
Other experiments underway are a newly established “tiny-forest” trial and a breeding project for sweet chestnuts and walnuts.
The work is done to some extent with small forestry machinery and by hired labor.
The last three years were spent creating microhabitats in the forest, such as dead standing trunks, stone piles and ‘Mulmholks’ - a nest box filled with mulch resembling the conditions that can be found in hollow tree trunks, intended for insects, such as saproxylic beetles, that depend on dead and rotting wood for food and habitat. From 2022, it’s a demonstration site for privately owned, sustainable forest management in collaboration with WWF Latvia and LatViaNature.
FILM: “I’M A TREE, WHAT DO I NEED?”
“This
is an interesting example of how former arable land can be transformed
into a multi functional system. Instead of removing the native, pioneer,
nitrogen-fixing grey alders, they have been left to enrich the system.
Vadakste can be an inspiration for southern Swedish forest owners, with
suffering monoculture spruce plantations on former arable land, looking
for a way to secure the forest as an intergenerational investment, for
food security, timber and biodiversity”
– Maja Lindström Kling.