Guidelines for Planning Afforestation of Former Arable Land

Abstract

Afforestation objectives vary from one country to another and even within countries. Apart from the objectives, the specific conditions from a biophysical, environmental and socioeconomic point of view should always be considered throughout the entire afforestation process, from policy decisions through location of the new forest, establishment and management, and the final utilisation of the forest. Decisions on how and where to afforest, and how much these decisions will affect the environmental impacts should ultimately be a compromise between the site quality in terms of climate, soil and preceding land-use, the initial goals set by planners and managers, and the stakeholders' preferences. The focus of AFFOREST has been on building knowledge and capacity to support decisions regarding afforestation of former arable land with respect to changes in C and N pools and fluxes and changes in 250 K. HANSEN ET AL. water recharge. The guidelines in this chapter are based on literature reviews, the experimental data from chronosequences of afforested stands in Denmark, Sweden, and the Netherlands (described in Chapter 2, 3 and 4), and on the developed mechanistic metamodel (METAFORE) and the spatial Decision Support System (AFFOREST-sDSS) (Chapter 7, 8, 9 and 10). The structure of the guidelines is based on questions and corresponding answers under the main themes of water recharge, nitrate leaching, C sequestration, diversity of understory vegetation and complex questions involving more than one of the first three issues. Hopefully, the guidelines will be helpful and inspire landscape and forest planners in planning how and where afforestation should take place.

Deep ploughing increases agricultural soil organic matter stocks

“…In the USA, the effects of deep ploughing on crop growth have been studied since the 1960s (Burnett & Hauser, ). Although deep ploughing has become less common since the 1970s, it is still applied for hard pan or plough pan break‐up, to enlarge the rooting zone or as a preparation measure for afforestation in countries such as Canada (Unger, ), Denmark (Hansen et al ., ), the Netherlands (Van Ouwerkerk & Raats, ), Sweden (Nordborg & Nilsson, ), China (Cai et al ., ) and the USA (Zobeck & Schillinger, ).…”

Sezoninė C apykaita žolių ir kviečių agroekosistemose

“…Agroekosistemos aktyviai dalyvauja klimato formavime, augalams ir dirvožemiui kaupiant anglies atsargas (Hansen, Vesterdal, 2004). Agrarinių teritorijų dirvožemio organinėje medžiagoje, kaip natūralia-me CO 2 absorbente, kaupiamos pagrindinės C atsargos, kurias reikia XX • Botanikos sodo raštai / Scripta Horti Botanici issn 1392-3714 (Print), issn 2345-0215 (Online), http://dx…”

Deep soil ploughing for afforestation: a review of potential impacts on soil and vegetation

“…Soil cultivation is an important process that affects the physical, chemical, and biological properties of the soil, and leads to different plant growth responses, regardless of where it is applied (i.e. in agricultural or forest land) (Matthesen and Damgaard 1997, Akinci et al 2004, Hansen et al 2007, Alcántara et al 2017, Schneider et al 2017. Deep ploughing or subsoil ploughing has been widely used to reduce soil strength in agricultural soils (Akinci et al 2004), but there is little data on the effectiveness of this method for tree growth, especially in habitats with different soil conditions.…”

“…For many years, soil cultivation was rec-ommended as best practice for the establishment of tree plantations on all soil types. Deep ploughing is rarely used due to environmental concerns; however, it should be carefully considered as an alternative technology when planning afforestation of former agricultural land (Matthesen and Damgaard 1997, Hansen et al 2007, Malinauskas and Urbaitis 2010, Smal et al 2019. Owners of newly established forest plantations may have questions about the suitability of former agricultural land for the forest because soil has been ploughed for many years.…”

“…A layer of compacted soil (ploughpan), which has been formed on former agricultural soil due to intensive and repeated ploughing, can hamper successful afforestation by slowing down root penetration and water penetration (Malinauskas and Urbaitis 2008). Some authors argue that soil ploughing up to 60 cm deep before afforestation of agricultural land could be preferred because it provides better weed control compared with other technologies (Hansen et al 2007). However, many other issues remain unaddressed.…”