Methods for separating orchards from forest using airborne LiDAR

• Key message The aim of the study was to distinguish orchards from other lands with forest vegetation based on the data from airborne laser scanning. The methods based on granulometry provided better results than the pattern analysis. The analysis based on the Forest Data Bank/Cadastre polygons provided better results than the analysis based on the segmentation polygons. Classification of orchards and other areas with forest vegetation is important in the context of reporting forest area to international organizations, forest management, and mitigating effects of climate change. • Context Agricultural lands with forest vegetation, e.g., orchards, do not constitute forests according to the forest definition formulated by the national and international definitions, but contrary to the one formulated in the Kyoto Protocol. It is a reason for the inconsistency in the forest area reported by individual countries. • Aims The aim of the study was to distinguish orchards from other lands with forest vegetation based on the data from airborne laser scanning. • Methods The study analyzed the usefulness of various laser scanning products and the various features of pattern and granulometric analysis in the Milicz forest district in Poland. • Results The methods based on granulometry provided better results than the pattern analysis. The analysis based on the Forest Data Bank/Cadastre polygons provided better results than the analysis based on the segmentation polygons. • Conclusion Granulometric analysis has proved to be a useful tool in the classification of orchards and other areas with forest vegetation. It is important in the context of reporting forest area to international organizations, forest management, and mitigating effects of climate change.

Shrub richness is primarily driven by climate conditions in Southwestern European woodlands

• Key message The shrub species richness in Spanish forests is mainly linked to climatic variables and the importance of the groups of variables scarcely differs among forest types. Forest surrounding the Mediterranean Basin exhibit the highest levels of shrub richness. • Context Shrub species account for a high proportion of the plant diversity in Spanish forests and are a determinant factor in forest dynamics and ecosystem functionality. • Aims To investigate the relative importance of climatic, forest stand features, soil and topographic variables in explaining shrub richness in Spanish forests and if the relative importance of these four groups of variables reflects variations among forest types. • Methods We used the Spanish National Forest Inventory and a boosted regression trees approach to identify which climatic, soil, stand and topographic variables (N = 19 variables) are related to the richness of shrub species in Spanish woodlands. • Results The shrub species richness is mainly related to climatic variables followed by soil variables whereas stand and topographic variables play a minor role. The importance of the groups of variables scarcely differs among forest types although forests located around the Mediterranean Sea display the highest levels of shrub richness. • Conclusion Shrub richness in Spain is primarily driven by climatic and soil variables, both at country and forest-type scales. Forests surrounding the Mediterranean Basin account for the highest richness of shrub species but are also those most threatened by global change. Therefore, special attention must be paid to the monitoring and assessment of these forest ecosystems.

New appetite for the monitoring of European forests

Key message Future international forest monitoring should build upon the existing pan-European programs. There is a renewed interest in the monitoring of European forests. Future monitoring systems should build upon existing international programs, making use of their strengths and solving their weaknesses. This approach will result into win–win solutions for both the existing and future systems. The UNECE ICP Forests has a number of characteristics that makes it a very good and strong basis for developing an advanced international forest monitoring system.

Molecular control to salt tolerance mechanisms of woody plants: recent achievements and perspectives

Key message Woody plants have salt-tolerant mechanisms similar to those developed by non-woody plants. Among others, compartmentalization of ions, production of compatible solutes, synthesis of specific proteins and metabolites, and induction of transcriptional factors are the most relevant. Woody plant-associated microbial interactions as well as naturally stress-adapted trees are resources that deserve to be deepened to fully understand the tolerance mechanisms. Context The high variability of salinity responses found in woody plants implies a high potentiality for germplasm selection and breeding. Salt tolerance mechanisms of plants are regulated by numerous genes, which control ion homeostasis, production of compatible solutes and specific proteins, and activation or repression of specific transcription factors. Despite the fact that numerous studies have been done on herbaceous model plants, knowledge about salt tolerance mechanisms in woody plants is still scarce. Aims The present review critically evaluates molecular control of salt tolerance mechanisms of woody plants, focusing on the regulation and compartmentalization of ions, production of compatible solutes, activation of transcription factors, and differential expression of stress response-related proteins, including omics-based approaches and the role of plant-microbial interactions. The potential identification of genes from naturally stress-adapted woody plants and the integration of the massive omics data are also discussed. Conclusion In woody plants, salt tolerance mechanisms seem not to diverge to those identified in non-woody plants. More comparative studies between woody and non-woody salt tolerance plants will be relevant to identify potential molecular mechanisms specifically developed for wood plants. In this sense, the activation of metabolic pathways and molecular networks by novel genetic engineering techniques is key to establish strategies to improve the salt tolerance in woody plant species and to contribute to more sustainable agricultural and forestry systems.