How predictable are evolutionary responses to environment? Comparing trait-environment relationships among three species of Asteraceae forbs in the Great Basin

Restoring native forbs in the Great Basin Desert is an important part of regenerating a healthy landscape that benefits wildlife, plant communities, and humans. Despite their importance and contribution to plant diversity, forbs have been understudied relative to grasses and shrubs. To begin bridging this knowledge gap, we examined three Asteraceae species (Chaenactis douglasii, Dieteria canescens, Erigeron pumilus) collected from a wide geographic area and grown in common garden experiments, asking how variable these species and populations are, how their traits were associated with environment of origin, and how two of the three species responded to water addition in direct-seeding environments. We also asked if trait-environment relationships were similar among these three species. As expected, we found that populations were extremely variable, and that much of this variation was significantly different among populations, with some variation explained by the ecoregion where populations were gathered. All three species had at least one trait strongly correlated with an environmental variable, sometimes in similar ways. For example, we found a consistent relationship where plants from higher elevation locations flowered earlier across all species, as well as a relationship with plant height and mean annual temperature, with taller plants sourced from warmer areas. Across species, the strongest trait-environment relationships we found were found for plant height, flowering phenology, and flower production, though there was variation in which environmental variables were most correlated with these responses. Our results suggest that approaches that generalize across species, even closely related ones, may not be adequate when determining whether a potential seed-source is well-matched to a target restoration site. Instead, our results support the idea that species-specific seed zones (areas where seeds can be moved without loss of performance) should be developed to help make this decision. Additionally, we found that environmental variables such as mean annual temperature and elevation were highly associated with traits that are typically considered important in restoration, i.e. phenology, number of inflorescences, and plant size. Therefore, before species-specific seed zones are available, we may be able to use these environmental factors as proxies to help us better match seed sources to target restoration sites. Finally, we also found that at least one species (C. douglasii) emerged from seed more readily when it was sourced from a drier origin, in both ambient and water addition conditions. Although more research needs to be done in this area, this suggests that seeds sourced from drier locations may be better suited for restoration projects that are being direct-seeded

Description and performance of track and primary-vertex reconstruction with the CMS tracker

A description is provided of the software algorithms developed for the CMS tracker both for reconstructing charged-particle trajectories in proton-proton interactions and for using the resulting tracks to estimate the positions of the LHC luminous region and individual primary-interaction vertices. Despite the very hostile environment at the LHC, the performance obtained with these algorithms is found to be excellent. For tbar t events under typical 2011 pileup conditions, the average track-reconstruction efficiency for promptly-produced charged particles with transverse momenta of p(T) > 0.9GeV is 94% for pseudorapidities of |η| < 0.9 and 85% for 0.9 < |η| < 2.5. The inefficiency is caused mainly by hadrons that undergo nuclear interactions in the tracker material. For isolated muons, the corresponding efficiencies are essentially 100%. For isolated muons of p(T) = 100GeV emitted at |η| < 1.4, the resolutions are approximately 2.8% in p(T), and respectively, 10μm and 30μm in the transverse and longitudinal impact parameters. The position resolution achieved for reconstructed primary vertices that correspond to interesting pp collisions is 10–12μm in each of the three spatial dimensions. The tracking and vertexing software is fast and flexible, and easily adaptable to other functions, such as fast tracking for the trigger, or dedicated tracking for electrons that takes into account bremsstrahlung