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Understanding the impact of management on the dispersal potential of forest tree species is pivotal in the context of global change, given the implications of gene flow on species evolution. We aimed to determine the effect of logging on gene flow distances in two Nothofagus species from temperate Patagonian forests having high ecological relevance and wood quality. Therefore, a total of 778 individuals (mature trees and saplings) of Nothofagus alpina and N. obliqua, from a single plot managed 20 years ago (2.85 hectares), were mapped and genotyped at polymorphic nuclear microsatellite loci. Historical estimates of gene dispersal distance (based on fine-scale spatial genetic structure) and contemporary estimates of seed and pollen dispersal (based on spatially explicit mating models) were obtained. The results indicated restricted gene flow (gene distance ≤ 45 m, both pollen and seed), no selfing and significant seed and pollen immigration from trees located outside the studied plot but in the close surrounding area. The size of trees (diameter at breast height and height) was significantly associated with female and/or male fertility. The significant fine-scale spatial genetic structure was consistent with the restricted seed and pollen dispersal. Moreover, both estimates of gene dispersal (historical and contemporary) gave congruent results. This suggests that the recent history of logging within the study area has not significantly influenced on patterns of gene flow, which can be explained by the silviculture applied to the stand. The residual tree density maintained species composition, and the homogeneous spatial distribution of trees allowed the maintenance of gene dispersal. The short dispersal distance estimated for these two species has several implications both for understanding the evolution of the species and for defining management, conservation and restoration actions. Future replication of this study in other Nothofagus Patagonian forests would be helpful to validate our conclusions.

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Pastoral systems worldwide secure rural livelihoods in the harshest environments on Earth. Their low productivity per area unit or head makes them the subject of much criticism with regard to their environmental impact, particularly in relation to global warming, desertification and land degradation. Such is the case of the traditional pastoral systems of Patagonia, a vast and isolated region where sedentary and mobile pastoralism coexist and contribute to shape landscapes and cultures. We argue that pastoral systems provide a wide range of ecosystem services that may compensate for their negative impact on the environment. We review the scarcely available evidence from Patagonia to identify ecosystem services and disservices associated with pastoralism, and pay special attention to the carbon balance: with C footprints between 10 to 40 kg CO2-eq.kg−1 carcass, pastoral systems in dry Patagonia are below or within the range of semi-extensive livestock systems worldwide (35–45 CO2-eq. kg−1 carcass). To inform development and policy, the assessment of trade-offs and synergies between ecosystem services needs to incorporate the intertwined social and ecological dynamics of complex pastoral systems, along resource regenerative trajectories.

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A condition called "cypress mortality" affects forest of Austrocedrus chilensis (D. Don) Pic. Ser et Bizarri in Argentina. Their classic groups of symptoms has been described as a slow process of defoliation that culminating in death of the tree; nevertheless, dying and recently dead trees with abundant foliage are frequently observed in which foliage changes to red. Cinara (Cupressobium) cupressi (Buckton) is considered the agent responsible for reddening this indigenous conifer in Chile. Therefore, the relationship between the presence of C. cupressi and the new aerial symptoms in A. chilensis from Argentina required evaluation. However, Cinara (Cupressobium) tujafilina (del Guercio) also has been reported from this host, and the differentiation of both species of Cinara is time consuming and requires a great expertise because they share many morphologic and microscopic characters. A rapid molecular method of identification of C. cupressi and C. tujafilina is desirable to detect and differentiate them. We report the development and evaluation of a polymerase chain reaction-restriction fragment length polymorphism method based on the mitochrondial cytochrome oxidase I gene to identify C. cupressi and C. tujafilina in colonies of aphids. The first detection of C. cupressi from A. chilensis in Argentina, is reported based on the new method.