Balancing economic costs and ecological outcomes of passive and active restoration in agricultural landscapes: the case of Brazil

Forest restoration requires strategies such as passive restoration to balance financial investments and ecological outcomes. However, the ecological outcomes of passive restoration are traditionally regarded as uncertain. We evaluated technical and legal strategies for balancing economic costs and ecological outcomes of passive versus active restoration in agricultural landscapes. We focused in the case of Brazil, where we assessed the factors driving the proportion of land allocated to passive and active restoration in 42 programs covering 698,398 hectares of farms in the Atlantic Forest, Atlantic Forest/cerrado ecotone and Amazon; the ecological outcomes of passive and active restoration in 2955 monitoring plots placed in six restoration programs; and the legal framework developed by some Brazilian states to balance the different restoration approaches and comply with legal commitments. Active restoration had the highest proportion of land allocated to it (78.4%), followed by passive (14.2%) and mixed restoration (7.4%). Passive restoration was higher in the Amazon, in silviculture, and when remaining forest cover was over 50 percent. Overall, both restoration approaches showed high levels of variation in the ecological outcomes; nevertheless, passively restored areas had a smaller percentage canopy cover, lower species density, and less shrubs and trees (dbh > 5 cm). The studied legal frameworks considered land abandonment for up to 4 years before deciding on a restoration approach, to favor the use of passive restoration. A better understanding of the biophysical and socioeconomic features of areas targeted for restoration is needed to take a better advantage of their natural regeneration potential.     

Is it really you,Orthotrichum acuminatum? Ascertaining a new case of intercontinental disjunction in mosses

Intercontinental disjunct distributions are a main issue in current biogeography. Bryophytes usually have broad distribution ranges and therefore constitute an interesting subject of study in this context. During recent fieldwork in western North America and eastern Africa, we found new populations of a moss morphologically similar to Orthotrichum acuminatum. So far this species has been considered to be one of the most typical epiphytic mosses of the Mediterranean Basin. The new findings raise some puzzling questions. Do these new populations belong to cryptic species or do they belong to O. acuminatum, a species which then has a multiple‐continent disjunct range? In the latter case, how could such an intercontinental disjunction be explained? To answer these questions, an integrative study involving morphological and molecular approaches was conducted. Morphological results reveal that Californian and Ethiopian samples fall within the variability of those from the Mediterranean Basin. Similarly, phylogenetic analyses confirm the monophyly of these populations, showing that O. acuminatum is one of the few moss species with a distribution comprising the western Nearctic, the western Palaearctic and Palaeotropical eastern Africa. Pending a further genetic and phylogeographical study to support or reject the hypothesis, a process of long‐distance dispersal (LDD) is hypothesized to explain this distribution and the origin of the species is suggested to be the Mediterranean Basin, from where diaspores of the species may have migrated to California and Ethiopia. The spore release process in O. acuminatum is revisited to support the LDD hypothesis, © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2016, 180 , 30–49.     

Effects of different arbuscular mycorrhizal fungal backgrounds and soils on olive plants growth and water relation properties under well‐watered and drought conditions

The adaptation capacity of olive trees to different environments is well recognized. However, the presence of microorganisms in the soil is also a key factor in the response of these trees to drought. The objective of the present study was to elucidate the effects of different arbuscular mycorrhizal (AM) fungi coming from diverse soils on olive plant growth and water relations. Olive plants were inoculated with native AM fungal populations from two contrasting environments, that is, semi‐arid – Freila (FL) and humid – Grazalema (GZ) regions, and subjected to drought stress. Results showed that plants grew better on GZ soil inoculated with GZ fungi, indicating a preference of AM fungi for their corresponding soil. Furthermore, under these conditions, the highest AM fungal diversity was found. However, the highest root hydraulic conductivity (Lp_r) value was achieved by plants inoculated with GZ fungi and growing in FL soil under drought conditions. So, this AM inoculum also functioned in soils from different origins. Nine novel aquaporin genes were also cloned from olive roots. Diverse correlation and association values were found among different aquaporin expressions and abundances and Lp_r, indicating how the interaction of different aquaporins may render diverse Lp_r values.