With climate change projected to increase the frequency and severity of episodic insect outbreak events, assessing potential consequences for soil microbial communities and nutrient dynamics is of importance for understanding forest resilience. The forest tent caterpillar (Malacosoma disstria) is an important defoliator of deciduous tree species in temperate and mixed forests of eastern North America with an invasion cycle every 10-12 years and outbreak events that can last 3-6 years. Following a defoliation episode on trembling aspen (Populus tremuloides) from 2015 to 2017 in Abitibi-Témiscamingue, QC, Canada, we sought to test if defoliation resulted in changes to soil bacterial and fungal communities. We hypothesized an increase in soil microbial biomass due to increased caterpillar frass inputs and potential changes in community structure following the event. Soils were sampled in July 2018, May 2019 and July 2019 from sites that had been subject to defoliation during the outbreak and from sites where no defoliation had been recorded. We assessed soil microbial biomass and fungal to total microbial activity ratio on all sampling dates, and Community Level Physiological Profiles (CLPPs) for 2018 only using a substrate induced respiration method. Contrary to our hypothesis, we observed a significant 50% decrease in microbial biomass (g biomass-C g-1 soil hour-1) in defoliated stands suggesting tree carbon normally allocated towards root exudates was reallocated towards foliage regeneration. We noted a differentiated carbon-based substrate usage following defoliation, but no change in the fungal to total microbial activity ratio. The observed changes in the two years following the defoliation event suggest that defoliation episodes aboveground could trigger changes in soil chemistry belowground with effects on soil microbial communities that may, in turn, feedback to influence forest plant dynamics.

AbstraIncorporating knowledge of indigenous forage legumes or associated nutritional attributes in cultivated pastures has the potential to improve grazing conditions, rangeland conditions, and cattle productivity. Climate change and other site-specific factors such as land sizes and other grazing management practices play a significant role in food security, job creation, and environmental health. Several research results have reported that the utilization of forage legumes in most farming systems has proved to increase herbage yield and soil fertility. The major aim of this review is to elucidate the potential benefits of intercropping indigenous forage legumes such as cowpea (Vigna unguiculacta L.Walp) and Dolichols (Lablab purpureaus) intercropped with Chloris gayana, this is to assesses the principal advantages, productivity, and overall performance of forage legumes grown in conjunction with grasses. Moreover, this review seeks to provide insights into the optimal management practices for intercropping forage legumes with grasses. The promising feature of intercropping South African pastoral systems must target the ability of forage legumes in terms of performance and utilization of agro-symbiotic relationships of N2 fixation symbiotic relationship in pastures. Moreover, this review aims also to address this knowledge gap by assessing the effects of defoliation frequency on the biomass production of selected forage legumes when intercropped with Chloris gayana in different growing seasons. By examining how varying defoliation frequencies influence biomass production, this review aimed to provide practical recommendations for optimizing forage management practices and promoting sustainable forage production systems. Through this investigation, we can gain insights into the complex dynamics between the defoliation frequency, intercropping systems, and biomass production.

The largest impact of needle diseases in the recorded history of Pinus radiata and Pinus nigra plantations in the North of Spain, was from 2018 to 2019. The severity of the disease has led to a serious reconsideration of forest management in the area. The main pathogens involved in this historical outbreak were Lecanosticta acicola and Dothistroma septosporum. Three arboreta were established under the European project REINFFORCE in the Basque Country in recently harvested P. radiata plantations. The plants for the arboreta were produced in nurseries located in the Alps of Upper Provence (France). These arboreta were surrounded by plantations seriously damaged by L. acicola and D. septosporum. The Pinus species which were sampled in the arboreta included P. brutia (4 provenances), P. elliottii (2 provenances), P. nigra (8 or 9 provenances), P. pinaster (7 provenances), P. pinea (6 provenances), P. ponderosa (3 provenances), P. sylvestris (8 provenances) and P. taeda (3 provenances). Lecanosticta acicola is reported for the first time infecting Pinus brutia (Provenance: Alexandropolis, Greece and var. eldarica, Crimea), a new host species for this pathogen. Pinus elliottii (Provenance: Georgia, USA) and P. ponderosa (Provenance: Central California, USA) are new host reports of L. acicola for Spain. Dothistroma septosporum was found for the first time on P. brutia (Provenance: Marmaris, Turkey) and P. ponderosa (Provenance: Oregon, USA) in Spain and was also detected infecting P. nigra (Provenance: Slogne Vayrières, France).