Jaconette Mirck

Agroforestry systems of high nature and cultural value in Europe: provision of commercial goods and other ecosystem services

Land use systems that integrate woody vegetation with livestock and/or crops and are recognised for their biodiversity and cultural importance can be termed high nature and cultural value (HNCV) agroforestry. In this review, based on the literature and stakeholder knowledge, we describe the structure, components and management practices of ten contrasting HNCV agroforestry systems distributed across five European bioclimatic regions. We also compile and categorize the ecosystem services provided by these agroforestry systems, following the Common International Classification of Ecosystem Services. HNCV agroforestry in Europe generally enhances biodiversity and regulating ecosystem services relative to conventional agriculture and forestry. These systems can reduce fire risk, compared to conventional forestry, and can increase carbon sequestration, moderate the microclimate, and reduce soil erosion and nutrient leaching compared to conventional agriculture. However, some of the evidence is location specific and a better geographical coverage is needed to generalize patterns at broader scales. Although some traditional practices and products have been abandoned, many of the studied systems continue to provide multiple woody and non-woody plant products and high-quality food from livestock and game. Some of the cultural value of these systems can also be captured through tourism and local events. However there remains a continual challenge for farmers, landowners and society to fully translate the positive social and environmental impacts of HNCV agroforestry into market prices for the products and services.

How is agroforestry perceived in Europe? An assessment of positive and negative aspects by stakeholders

Whilst the benefits of agroforestry are widely recognised in tropical latitudes few studies have assessed how agroforestry is perceived in temperate latitudes. This study evaluates how stakeholders and key actors including farmers, landowners, agricultural advisors, researchers and environmentalists perceive the implementation and expansion of agroforestry in Europe. Meetings were held with 30 stakeholder groups covering different agroforestry systems in 2014 in eleven EU countries (Denmark, France, Germany, Greece, Hungary, Italy, Netherlands, Portugal, Spain, Sweden and the United Kingdom). In total 344 valid responses were received to a questionnaire where stakeholders were asked to rank the positive and negative aspects of implementing agroforestry in their region. Improved biodiversity and wildlife habitats, animal health and welfare, and landscape aesthetics were seen as the main positive aspects of agroforestry. By contrast, increased labour, complexity of work, management costs and administrative burden were seen as the most important negative aspects. Overall, improving the environmental value of agriculture was seen as the main benefit of agroforestry, whilst management and socio-economic issues were seen as the greatest barriers. The great variability in the opportunities and barriers of the systems suggests enhanced adoption of agroforestry across Europe will be most likely to occur with specific initiatives for each type of system.

Mini-Review of Knowledge Gaps in Salt Tolerance of Plants Applied to Willows and Poplars

Salt tolerance of agricultural crops has been studied since the 1940, but knowledge regarding salt tolerance of woody crops is still in its initial phase. Salt tolerance of agricultural crops has been expressed as the yield decrease due to a certain salt concentration within the root zone as compared to a non-saline control. The most well-known plant response curve to salinity has been a piece-wise linear regression relating crop yield to root zone salinity. This method used the hypothesis that crops tolerate salt up to a threshold after which their yield decreases approximately linearly. Critique to this method included its lack of sensitivity to dynamic factors such as weather conditions. As a result, other classification indices have been developed, but none is as well accepted as the threshold-slope model. In addition to a mini-review of the key salt tolerance studies, our objective was to classify salt tolerance levels of poplars and willows. Initial classification showed that salt tolerance of these genera ranged from sensitive to moderately tolerant.

Farmers’ reasoning behind the uptake of agroforestry practices: evidence from multiple case-studies across Europe

Potential benefits and costs of agroforestry practices have been analysed by experts, but few studies have captured farmers’ perspectives on why agroforestry might be adopted on a European scale. This study provides answers to this question, through an analysis of 183 farmer interviews in 14 case study systems in eight European countries. The study systems included high natural and cultural value agroforestry systems, silvoarable systems, high value tree systems, and silvopasture systems, as well as systems where no agroforestry practices were occurring. A mixed method approach combining quantitative and qualitative approaches was taken throughout the interviews. Narrative thematic data analysis was performed. Data collection proceeded until no new themes emerged. Within a given case study, i.e. the different systems in different European regions, this sampling was performed both for farmers who practice agroforestry and farmers who did not. Results point to a great diversity of agroforestry practices, although many of the farmers are not aware of the term or concept of agroforestry, despite implementing the practice in their own farms. While only a few farmers mentioned eligibility for direct payments in the CAP as the main reason to remove trees from their land, to avoid the reduction of the funded area, the tradition in the family or the region, learning from others, and increasing the diversification of products play the most important role in adopting or not agroforestry systems.

Addressing farmer-perceptions and legal constraints to promote agroforestry in Germany

Agroforestry is receiving increasing attention in Germany because of its capacity to address some of the negative consequences of intensive agriculture. However the actual uptake and maintenance of agroforestry by farmers remains low. The aim of this study was to identify the opportunities and obstacles to agroforestry in Germany and to identify potential measures which could address the obstacles and increase agroforestry adoption. Qualitative interviews with 32 farmers indicated that the legal framework and administrative burden associated with agroforestry in Germany was a major obstacle. The farmers recognised that agroforestry provided environmental benefits, but these do not always increase farm profitability. Agroforestry was identified as a viable alternative to conventional farming systems, especially in less productive areas, not profitable when managed in a conventional way. To enhance the implementation of agroforestry the simplification of the legal framework is crucial. Modern agroforestry should be better recognized by existing policy measures providing payments for environmentally friendly farming. Ultimately, an integrated approach for environmental benefits and production objectives is required, which is based on rewarding farmers for providing ecosystem services (ESs) and a stronger public involvement in sustainable land use practices. Rewarding farmers for ESs could increase the interest in agroforestry in highly productive areas, enhancing sustainable land use in the long term.

Conductivity gradients as inferred by electromagnetic-induction meter (EM38) readings within a salt-affected wetland in Saskatchewan, Canada

The change from deep-rooted grass and shrub vegetation to annual-cropping dryland farming has contributed to serious soil salinization challenges on the semi-arid North American Great Plains. In some cases, cultivation of the Great Plains has increased the availability of water, causing dominant sulfate salts to travel from the uphill areas to depressions where it will surface when water evaporates at the soil surface. A potential solution could include the replanting of the native deep-rooted vegetation, which requires knowledge of the spatial distribution of soil salinity. This study tested the soil factors influencing electromagnetic-induction meter (EM38) readings of soil salinity distribution around wetlands. The objectives were to: (1) predict growth and survival of Salix dasyclados Wimm. (cv. ‘India’) along a salinity gradient in a small wetland, and (2) investigate whether newly established willows affected water-table fluctuations, which would indicate their phreatophytic nature or their ability to obtain their water supply from the zone of saturation. Results indicated significantly lower salinity values for sampling points with EM38 readings above 175 and 250 mS m−1 for height and survival, respectively. In addition, diurnal fluxes of the water table in areas of good willow growth and lower salinity indicated that cultivar ‘India’ was phreatophytic in these areas and therefore has great potential for being used to combat saline seeps.RésuméLa substitution d’un herbage à enracinement profond et d’une végétation arbustive par une agriculture de zone sèche avec récolte annuelle a contribué à des défis graves de salinisation du sol dans les Grandes Plaines semi-arides Nord-Américaines. Dans certains cas, la culture des Grandes Plaines a accru la disponibilité de l’eau, amenant les sels de sulfate dominants à migrer des hautes terres vers les dépressions où ils remontent à la surface quand l’eau s’évapore au niveau du sol. Une solution possible comporterait la replantation de la végétation d’origine à racines profondes, ce qui nécessite la connaissance de la répartition dans l’espace de la salinité du sol. La présente étude a testé les facteurs du sol qui influencent la mesure de l’induction électro-magnétique (EM38) relative à la distribution de la salinité des sols dans l’environnement des zones humides. Les objectifs étaienty: (1) de prédire la croissance et la survie de Salix dasyclados Wimm. (cv. ‘India’) selon le gradient de salinité dans une petite zone humide, et (2) d’examiner si les saules nouvellement installés ont influencé les fluctuations de la nappe phréatique, ce qui pourrait indiquer leur nature phréatophytique ou leur capacité à constituer leur réserve d’eau à partir de la zone saturée. Les résultats indiquent des valeurs de salinité significativement plus basses pour les points d’échantillonnage présentant des mesures EM38 au-dessus de 175 and 250 mS m−1 pour la taille et la survie respectivement. De plus, les fluctuations journalières de la surface piézométrique dans les zones de bonne croissance du saule et de basse salinité indiquent que le cultivar ‘India’ était phréatophytique dans ces zones et offre donc un grand potentiel d’utilization dans la lutte contre les remontées salines.ResumenEl cambio de una vegetación profundamente arraigada de pastizales y arbustos a una agricultura de secano de cultivos anuales contribuyó a serios desafíos en la salinización del suelo en las Grandes Llanuras semiáridas de América del Norte. En algunos casos, el cultivo en las Grandes Llanuras ha incrementado la disponibilidad de agua, haciendo que las sales de sulfato dominantes transiten desde las áreas altas hacia las depresiones donde aflorarán cuando el agua se evapore de la superficie del suelo. Una posible solución podría incluir la replantación de la vegetación autóctona de raíces profundas, lo cual requiere el conocimiento de la distribución espacial de la salinidad en el suelo. Este estudio verificó los factores del suelo que influyen en las lecturas de la distribución de la salinidad del suelo alrededor de los humedales en el medidor de inducción electromagnética (EM38). Los objetivos fueron: (1) predecir el crecimiento y la supervivencia de Salix dasyclados Wimm. (cv. ‘India’) a lo largo de un gradiente de salinidad en un pequeño humedal y (2) investigar si los sauces recién establecidos afectaron las fluctuaciones de la capa freática, lo que indicaría su naturaleza freatófita o su capacidad de obtener su suministro de agua desde la zona saturada. Los resultados indicaron valores de salinidad significativamente más bajos para los puntos de muestreo con lecturas del EM38 superiores a 175 y 250 mS m−1 para la altura y la supervivencia, respectivamente. Además, los flujos diurnos del nivel freático en áreas de buen crecimiento del sauce y menor salinidad indicaron que la variedad ‘India’ era freatófita en estas áreas y, por lo tanto, tiene un gran potencial para ser utilizado para combatir las filtraciones salinas.摘要从根深草地和灌木植被变化到每年种植旱地耕作对半干旱的北美大平原造成了严重的盐碱化挑战。在有些情况下,大平原的耕作增加了水的可用量,致使占主导地位的硫酸盐盐分从高坡地带迁移至地外地带,并且在水发后覆盖在土壤表面。可能的解决方案包括重新栽培本地根深植被,这就需要了解土壤盐度的空间分布。本研究测试了影响湿地周围土壤盐度电磁感应表读数的土壤因素。目标就是:(1)预测小型湿地沿盐分坡度毛枝柳的生长状况和生存情况,(2)调查重新栽植的柳树是否影响水位的波动,这种植物可表现出其深根吸水植物的特性或者其从饱和带获取供水的能力。结果表明,高度和生存情况的电磁感应表读数分别为175以上和250 mS m−1 时采样点盐度值非常低。另外,在柳树生长非常好及盐度低的地区水位的日通量表明,培育植物毛枝柳是这些地区的深根吸水植物,因此,有很大的潜力用来抗击盐分的渗出。ResumoA mudança de gramíneas de raízes profundas e vegetação de arbustos para plantação anual em áreas secas têm contribuído para a séria salinização do solo no semiárido das Grandes Planícies da América do Norte. Em alguns casos, o plantio nas Grandes Planícies aumentou a disponibilidade de água, fazendo com que os sais dominante de sulfato migrem das áreas mais altas para as áreas de depressão, onde chegam a superfície quando a água do solo evapora. Uma potencial solução poderia incluir o replantio da vegetação nativa de raízes profundas, o que requer o conhecimento das distribuição espacial da salinidade do solo. Este estudo testou fatores do solo que influenciam as leituras de indução-eletromagnética (EM38) na distribuição da salinidade do solo ao redor de áreas alagadas. Os objetivos foram: (1) prever o crescimento e sobrevivência da Salix dasyclados Wimm. (cv. ‘India’) ao longo de um gradiente de salinidade em uma pequena área alagada, e (2) investigar se os recentes estabelecidos salgueiros afetaram a flutuação do nível de água, que poderia indicar a sua natureza freatofítica ou sua habilidade de obter água da zona saturada. Os resultados indicaram significante diminuição dos valores de salinidade para pontes de amostragem com leituras de EM38 acima de 175 and 250 mS m−1 para altura e sobrevivência, respectivamente. Além disso, a flutuação diurna do nível de água em áreas de bom crescimento de salgueiros e baixa salinidade indicaram que a espécie ‘India’ era freatofítica nestas áreas e, portanto, tem grande potencial para serem usadas para combater nascentes salinas.