Forest management can be used to increase the local abundance of species of conservation concern. To achieve this goal, managers must be sure that the relationships between the targeted forest attributes and the focal species abundance are based on robust data and inference. This is a critical issue as the same forest attributes could have opposing effects on species abundance and the detectability of individuals, impairing our ability to detect useful habitat quality surrogates and to provide correct forest management recommendations. Using spatially stratified capture-recapture models (a.k.a. multinomial N-mixture models), we evaluated the effects of stand-level forest attributes on detection probability and local abundance for the endangered Southern Darwin's frog (Rhinoderma darwinii), a forest-specialist and fully terrestrial amphibian endemic to the South American temperate forest. Our results show that an increase of stand basal area and a decrease of daily microclimatic fluctuation (i.e. an increase in structural complexity) were positively associated with the local abundance of R. darwinii. These stand-level forest attributes also explained the amongpopulation variation in detection probability, although the relationships were opposite to those for abundance. Consequently, an analysis of raw frog counts (i.e. not adjusted for imperfect detection) did not reveal all the factors associated with local abundance. Our results provide further support to previous claims that raw counts of individuals should not be used, generally, as a proxy of abundance in species inhabiting forest ecosystems and elsewhere. More importantly, the opposite effect of forest attributes on abundance and detectability observed in our study highlights the need to use methods that quantify species-habitat relationships in a robust way and which take habitat-specific imperfect detection into account.
This text is an introduction of Alternautas’ mini-dossier in tribute to the work of Hector Alimonda (1947-2017). Here, Facundo Martín, Gabriela Merlinsky and Catalina Toro Pérez present Alimonda’s unique contribution to the field of political ecology in Latin America. It is followed by the newly translated “In the key of south: Latin American political ecology and critical thinking”, the introduction of Alimonda’s latest book, Ecología Política Latinoamericana - Volumen 1 (2017), co-edited by Facundo Martín and Catalina Toro Pérez. In the next weeks, we will also publish a translation of “The coloniality of nature”, an article that appeared originally in La naturaleza colonizada (2011).
The negotiation of the Andean free-trade agreement consolidated the implementation phase of intellectual property regulation of biodiversity in Latin America, establishing new forms of control over societies and their strategic resources consistent with a strategy of territorial deployment of U.S. national security policies. Aspects of the agreement such as patents and public health, protection of information, patents for secondary uses, and the extension of patents to a 20-year period have become focal points of controversy in the specialized world of politicians, jurists, and economists.
The catalytic activity of systems of type [RuH(CO)(N-N)(PR 3 ) 2 ] + was evaluated in the hydroformylation reaction of 1-hexene. The observed activity is explained through a reaction mechanism on the basis of the quantum theory. The mechanism included total energy calculations for each of the intermediaries of the elemental steps considered in the catalytic cycle. The deactivation of the catalyst precursors takes place via dissociation of the polypyridine ligand and the subsequent formation of thermodynamically stable species, such as RuH(CO) 3 (PPh 3 ) 2 and RuH 3 (CO)(PPh 3 ) 2 , which interrupt the catalytic cycle. In addition, the theoretical study allows to explain the observed regioselectivity which is defined in two steps: (a) the hydride migration reaction with an anti-Markovnikov orientation to produce the alkyl-linear-complex (3.1a), which is more stable by 19.4 kJ/mol than the Markovnikov orientation (alkyl-branched-complex) (3.1b); (b) the carbon monoxide insertion step generates the carbonyl alkyl-linear specie (4.1a) which is more stable by 9.5 kJ/mol than the alternative species (4.1b), determining the preferred formation of heptanal in the hydroformylation of 1-hexene.
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