Thruster maintenance system Patent

System for removing and repairing spacecraft control thrusters by use of portable air lock

The impact of secondary forest regeneration on ground-dwelling ant communities in the Tropical Andes

Natural regeneration of abandoned farmland provides an important opportunity to contribute to global reforestation targets, including the Bonn Challenge. Of particular importance are the montane tropics, where a long history of farming, frequently on marginal soils, has rendered many ecosystems highly degraded and hotspots of extinction risk. Ants play crucial roles in ecosystem functioning, and a key question is how time since abandonment and elevation (and inherent temperature gradients therein) affect patterns of ant recovery within secondary forest systems. Focusing on the Colombian Andes across a 1300 m altitudinal gradient and secondary forest (2–30 years) recovering on abandoned cattle pastures, we find that over time ant community composition and species richness recovered towards that of primary forest. However, these relationships are strongly dependent on elevation with the more open and warmer pasturelands supporting more ants than either primary or secondary forest at a particular elevation. The loss of species richness and change in species composition with elevation is less severe in pasture than forests, suggesting that conditions within pasture and its remaining scattered trees, hedgerows and forest fragments, are more favourable for some species, which are likely in or near thermal debt. Promoting and protecting natural regenerating forests over the long term in the montane tropics will likely offer significant potential for returning ant communities towards primary forest levels

Impacts of selective logging management on butterflies in the Amazon

Selective logging for timber production affects vast areas across the tropics, yet we lack detailed understanding of the impacts of logging intensity on biodiversity. These impacts can be studied at two levels: the impacts of logging intensity on overall diversity and community composition; and how logging intensity affects individual species' abundance-logging yield relationships. The latter underpins whether land-sharing logging (i.e. low intensity throughout) or land-sparing logging (i.e. high intensity with retention of some primary forest) is the optimal strategy. We examine both levels to determine the impacts of local-scale logging intensity on butterflies in Rondônia, Brazil, the global epicenter of butterfly alpha-diversity. Overall butterfly abundance was highest at intermediate logging intensity, whereas species richness increased after logging but was not affected by logging intensity, and that species composition increasingly changed from the primary community composition at higher logging intensities. Using individual species' abundance-yield curves, we then simulated species responses to a suite of logging strategies, ranging from total sharing to total sparing. Logging simulations predicted that more butterfly species would benefit from low-intensity land-sharing logging, having higher abundances than under land-sharing scenarios. However, some butterfly clades benefited disproportionally from the retention of primary forest within land-sparing logging concessions. Butterflies overall may benefit from intermediate logging strategies that promote a combination of low and high intensity logged areas, with some protected primary forest