Global climate changes have serious consequences on natural ecosystems and cause diverse environmental abiotic stressors that negatively affect plant growth and development. Trees are dependent on their symbiosis with mycorrhizal fungi, as the hyphal network significantly improves the uptake of water and essential mineral nutrients by colonized roots. A number of recent studies has enhanced our knowledge on the functions of mycorrhizal associations between fungi and plant roots. Moreover, a series of timely studies have investigated the impact and benefit of root symbioses on the adaptation of plants to climate change-associated stressors. Trees in temperate and boreal forests are increasingly exposed to adverse environmental conditions, thus affecting their durable growth. In this mini-review, we focus our attention on the role mycorrhizal symbioses play in attenuating abiotic stressors imposed on trees facing climatic changes, such as high temperatures, drought, salinity, and flooding.

Mycorrhizas are mutual beneficial associations between soil-borne fungi and plant roots.Mycorrhizal fungi provide their host plant with essential minerals in exchange for sugars and/or lipids. Traditionally, transport and translocation of macronutrients, including nitrogen and phosphorus, throughout the fungal mycelium and towards the host plant are well studied. However, the regulation of nutrient exchange and their contribution in the morphogenesis and development of mycorrhizas remains unclear. In this Opinion, we argue that including micronutrients in the current models of symbiotic transport is essential to fully understand the establishment, maintenance, and functioning of mycorrhizal associations. Homeostatic mechanisms at the cellular level and the first transport proteins involved have been recently documented for zinc (Zn) in arbuscular mycorrhizal, ectomycorrhizal, and ericoid mycorrhizal fungi. Mycorrhizal plants benefit from an improved Zn status in control conditions and are better protected from the devastating effect of low or high environmental Zn availability. These recent progresses are paving the way for a better understanding of micronutrient allocation in mycorrhizas. Revising our vision on the role of micronutrients, particularly of Zn, in these interactions will allow a better use of mycorrhizal fungi in sustainable agriculture and forestry, and will increase management practices in waste land, as well as in agricultural and natural ecosystems.

There is an increasing global demand for medicinal plants. Nevertheless, the nature and scale of processing in national-level medicinal plant production networks, and how this can contribute to sustainable development, are poorly understood. This study (i) uncovers and explains the emergence of the Nepalese medicinal plant secondary processing sector, (ii) characterises the enterprises and identify the obstacles they face, (iii) quantifies the volumes and values of processed species and end markets, and (iv) discusses the potential to contribute to sustainable economic development. Empirical data were generated from key informant interviews and qualitative (n = 13) and quantitative (n = 79) semi-structured surveys of medicinal plant processing enterprises. In 2014–15, the sector purchased 3679 metric tonnes of air-dry raw materials (across 67 products) for USD 4.0 million, producing 494 tonnes of end-products valued at USD 11.2 million. The sector is characterised by small enterprises. Rising domestic demand drove the increase in the number of enterprises. Key business obstacles were export barriers, low access to technology, infrastructure and service barriers, labour challenges, socio-economic and political instability, and the inefficient bureaucracy. The actions required to change from being a supplier of raw materials and producer of lower-value domestic consumer products to integrating into the global economy as an exporter of higher-value products that are sustainably sourced are discussed.