Multiscale drivers of restoration outcomes for an imperiled songbird

Habitat restoration is a cornerstone of conservation, particularly for habitat‐limited species. However, restoration efforts are seldom rigorously monitored at meaningful spatial scales. Poor understanding of how species respond to habitat restoration programs limits conservation efficacy for habitat‐restricted species like the Golden‐winged Warbler (Vermivora chrysoptera, GWWA). We provide one of the first concerted assessments of a national conservation program aimed at restoring songbird habitat across its breeding range. We studied GWWA response to forest habitat restoration across two broad regions with opposing population trajectories and assessed factors driving species use of restored habitats across multiple spatial scales. From 2015 to 2017, we conducted 1,145 (n = 457 locations) and 519 point counts (n = 215 locations) across the Appalachian Mountains and Great Lakes (respectively) within restored habitats. Warbler abundance within restored habitats across the Great Lakes varied with latitude, longitude, elevation, forest type, and number of growing seasons. In the Appalachian Mountains, occupancy () varied with longitude, elevation, forest type, and number of growing seasons. Detections were restricted to areas within close proximity to population centers (usually <24 km) in the Appalachian Mountains, where GWWAs are rare ( = 0.22, 95% confidence interval [CI]: 0.20–0.25), but not in the Great Lakes, where GWWAs remain common ( = 0.87, 95% CI: 0.84–0.90). Our study suggests that, even when best management practices are carefully implemented, restoration outcomes vary within/across regions and with multiscale habitat attributes. Although assessments of concerted habitat restoration efforts remain uncommon, our study demonstrates the value of monitoring data in the adaptive management process for imperiled species.     

Insights into life history theory: a brood size manipulation on a southern hemisphere species,Tachycineta leucorrhoa,reveals a fast pace of life

Life history traits exhibit substantial geographical variation associated with the pace of life. Species with a slow pace are expected to invest more in their future/residual reproductive value and are more common at tropical latitudes, whereas species from high latitudes, with a faster pace, are expected to prioritize the current reproductive effort. Most evidence supporting this pattern comes from studies conducted in tropical and north temperate species; very little is known about patterns in southern South American species. Here, we describe the life history of a southern swallow Tachycineta leucorrhoa and use an experimental approach to test their breeding strategy over four breeding seasons. We manipulated brood size for 105 nests of white‐rumped swallows to measure whether costs of reproduction were borne by adults or nestlings as alternative selection strategies towards maintaining residual or current reproductive value. Adults increased their feeding effort in enlarged broods, at least enough to maintain nestlings’ development/growth. In addition, adults decreased the number of visits to the nest (without having a negative effect on nestlings) in reduced broods. We did not detect differences in fledging success among treatments, suggesting there were no differences in nestlings’ survival. However, enlarged broods more frequently incurred in complete nest failure, suggesting only some adults were able to cope with increased costs of reproduction. We conclude this species is characterized by a fast pace of life similar to their northern congeners and less like its tropical ones. This is one of the first studies to use an experimental approach to test a life history hypothesis of pace of life using data from a southern South American species. We encourage researches to include southern species when evaluating latitudinal variations as we still do not have enough evidence to assume all southern subtropical species are indeed similar to tropical ones.     

Remnants fragments preserve genetic diversity of the old forest lichen <Emphasis Type="Italic">Lobaria pulmonaria</Emphasis> in a fragmented Mediterranean mountain forest

Fragmentation represents a serious threat to biodiversity worldwide, however its effects on epiphytic organisms is still poorly understood. We study the effect of habitat fragmentation on the genetic population structure and diversity of the red-listed epiphytic lichen, Lobaria pulmonaria, in a Mediterranean forest landscape. We tested the relative importance of forest patch quality, matrix surrounding fragments and connectivity on the genetic variation within populations and the differentiation among them. A total of 855 thalli were sampled in 44 plots (400 m²) of 31 suitable forest fragments (beeches and oaks), in the Sierra de Ayllón in central Spain. Variables related to landscape attributes of the remnant forest patches such as size and connectivity and also the nature of the matrix or tree species had no significant effects on the genetic diversity of L. pulmonaria. Values of genetic diversity (Nei’s) were only affected by habitat quality estimated as the age patches. Most of the variation (76%) in all populations was observed at the smallest sampled unit (plots). Using multiple regression analysis, we found that habitat quality is more important in explaining the genetic structure of the L. pulmonaria populations than spatial distance. The relatively high level of genetic diversity of the species in old forest patches regardless of patch size indicates that habitat quality in a highly structured forest stand determines the population size and distribution pattern of this species and its associated lichen community. Thus, conservation programmes of Mediterranean mountain forests have to prioritize area and habitat quality of old forest patches.     

Colonization of Olive Inflorescences by Verticillium dahliae and its Significance for Pathogen Spread

Verticillium wilt of olive, caused by Verticillium dahliae Kleb., is the most severe disease affecting this crop in most olive growing countries. In this study, the presence of viable structures of V. dahliae in dried inflorescences from wilted olive shoots was investigated. The pathogen was found inside peduncles and flowers, by assessing the number of typical star‐shaped microsclerotial colonies formed onto the modified sodium polypectate agar medium. Microsclerotia of V. dahliae were observed inside the peduncles under the stereoscopic microscope. The presence of microsclerotia in these easily decomposable olive tissues shows that infected inflorescences can act as a source of inoculum for Verticillium wilt epidemics.     

Morphological and chemical leaf composition of Mediterranean evergreen tree species according to leaf age

Changes in morphology [leaf dry mass per unit area (LMA), thickness and density] and chemical composition (macronutrients and fibres content) in different age leaves of eight evergreen Mediterranean woody species were investigated. LMA and leaf thickness increased with leaf age increasing. Young tissues possessed higher concentrations of N, P, K, and Mg and lower Ca concentrations on a dry mass basis. However, mineral content was independent of age on leaf area basis (except for Ca content) suggesting that the changes in mineral concentration with leaf ageing are due to dilution in the larger dry mass accumulated in the oldest leaves. Leaf tissue density (LTD) increased during the first year of the leaf life. Lignin and hemicellulose concentrations did not vary along leaf life and the cellulose concentration increased with leaf age in most species between the current-year and the one-year old leaves. Our results suggested that physical leaf reinforcement with a higher cellulose concentration and density might be a leaf response to the unfavourable climatic conditions during the first winter.     

Delimitation of the genus Schizachyrium (Poaceae,Andropogoneae) based on molecular and morphological data

Schizachyrium (Poaceae, Andropogoneae) includes about 60 species distributed in tropical and subtropical regions of the world. In all recent molecular phylogenies of Andropogoneae, representatives of Schizachyrium appear closely related to Andropogon species. The objective of this study was to contribute to the delimitation of Schizachyrium. We performed a phylogenetic study including 38 taxa (>63%) of Schizachyrium, along with representatives of related genera, mainly of Andropogon, yielding a total of 49 taxa. This is the first phylogenetic analysis to include the type species of Schizachyrium, S. condensatum. DNA sequences of two plastid markers (ndhF and trnL-F) were analyzed under Bayesian methods. The results indicate that Schizachyrium is not monophyletic: 26 of the 38 Schizachyrium taxa analyzed are placed in a Schizachyrium s.s. clade that includes the type species of the genus, while 10 taxa are related to Andropogon species and two other species, S. delavayi (from China and India) and S. jeffreysii (from Africa), appear clearly separated. Additionally, 58 morphological characters (41 qualitative and 17 quantitative) were scored for the same 49 taxa and analyzed under the parsimony criterion. Character optimizations showed that (i) the reduced pedicellate spikelets, (ii) with lower glume less than or equal to 0.5 mm wide, (iii) awned, and (iv) without lemma and palea support the Schizachyrium s.s. clade. We propose these four characters as diagnostic features for the delimitation of Schizachyrium s.s.     

Dengue-3 Virus Entry into Vero Cells: Role of Clathrin-Mediated Endocytosis in the Outcome of Infection

The endocytic uptake and intracellular trafficking for penetration of DENV-3 strain H-87 into Vero cells was analyzed by using several biochemical inhibitors and dominant negative mutants of cellular proteins. The results presented show that the infective entry of DENV-3 into Vero cells occurs through a non-classical endocytosis pathway dependent on low pH and dynamin, but non-mediated by clathrin. After uptake, DENV-3 transits through early endosomes to reach Rab 7-regulated late endosomes, and according with the half-time for ammonium chloride resistance viral nucleocapsid is released into the cytosol approximately at 12 min post-infection. Furthermore, the influence of the clathrin pathway in DENV-3 infective entry in other mammalian cell lines of human origin, such as A549, HepG2 and U937 cells, was evaluated demonstrating that variable entry pathways are employed depending on the host cell. Results show for the first time the simultaneous coexistence of infective and non -infective routes for DENV entry into the host cell, depending on the usage of clathrin-mediated endocytosis.     

The Toluene o-Xylene Monooxygenase Enzymatic Activity for the Biosynthesis of Aromatic Antioxidants

Monocyclic phenols and catechols are important antioxidant compounds for the food and pharmaceutic industries; their production through biotransformation of low-added value starting compounds is of major biotechnological interest. The toluene o-xylene monooxygenase (ToMO) from Pseudomonas sp. OX1 is a bacterial multicomponent monooxygenase (BMM) that is able to hydroxylate a wide array of aromatic compounds and has already proven to be a versatile biochemical tool to produce mono- and dihydroxylated derivatives of aromatic compounds. The molecular determinants of its regioselectivity and substrate specificity have been thoroughly investigated, and a computational strategy has been developed which allows designing mutants able to hydroxylate non-natural substrates of this enzyme to obtain high-added value compounds of commercial interest. In this work, we have investigated the use of recombinant ToMO, expressed in cells of Escherichia coli strain JM109, for the biotransformation of non-natural substrates of this enzyme such as 2-phenoxyethanol, phthalan and 2-indanol to produce six hydroxylated derivatives. The hydroxylated products obtained were identified, isolated and their antioxidant potential was assessed both in vitro, using the DPPH assay, and on the rat cardiomyoblast cell line H9c2. Incubation of H9c2 cells with the hydroxylated compounds obtained from ToMO-catalyzed biotransformation induced a differential protective effect towards a mild oxidative stress induced by the presence of sodium arsenite. The results obtained confirm once again the versatility of the ToMO system for oxyfunctionalization reactions of biotechnological importance. Moreover, the hydroxylated derivatives obtained possess an interesting antioxidant potential that encourages the use of the enzyme for further functionalization reactions and their possible use as scaffolds to design novel bioactive molecules.