The effects of competition and herbicide drift on non-target plant populations

Abstract

Herbicide drift is the movement of herbicide away from its intended target. The effect of drift on non-target plants is considered in environmental risk assessments, where the goal of the assessment is to protect plant populations and communities. The aim of this study was to evaluate the assumption that the single species tests used in risk assessments are fully protecting wild plant populations, as they do not account for interspecific interactions. In a greenhouse two-species competition experiment, it was found that the competitive interactions between the model species, Centaurea cyanus and Silene noctiflora, were affected by low doses of glyphosate representing drift. These changes could affect both of their populations in the long-term, and would not be detected using current test guidelines. As interspecific competition is an important determinant of plant community structure, competitive interactions may need to be included in risk assessment to make more credible predictions on the effects of herbicide drift on non-target plants.

Massive neutrinos and cosmology

“…for modes which are outside the Hubble radius at the time of the non-relativistic transition, the density contrast δ ν is timeindependent and of the same order as (φ, δ cdm ) on super-Hubble scales. After horizon crossing, the solution is dominated again by (123) and becomes rapidly equal to δ cdm .…”

“…The recent third-year release (WMAP3) improves the TT and TE power spectra [114], and adds a detection of the E-polarization self-correlation spectrum (EE) [115]. The WMAP experiment measured with high precision the TT spectrum on large angular scales (l < ∼ 900), while at similar or smaller scales we have results from experiments that are either ground-based such as the Arcminute Cosmology Bolometer Array Receiver (ACBAR) [116], the Very Small Array (VSA) [117], the Cosmic Background Imager (CBI) [118] and the Degree Angular Scale Interferometer (DASI) [119], or balloon-borne such as ARCHEOPS [120], BOOMERANG (TT [121], TE [122] and EE [123]) and MAXIMA [124]. When using data from different CMB experiments, one should take into account that they overlap in some multipole region, and not all data are uncorrelated.…”

Separating polarized cosmological and galactic emissions for cosmic microwave background B-mode polarization experiments

“…One of those regions is centred on the position (40°, −45°) in right ascension and declination. This region has been observed by BOOMERanG 2K (Montroy et al 2005) and is the target of the EBEx (Oxley et al 2004), QUEST at DASI (QUAD; Bowden et al 2004) and Q/U Imaging Experiment (QUIET) experiments 1 . However, low amplitude of the foreground emission in total intensity does not ensure that on a level of the anticipated cosmological B‐mode signal the polarized foregrounds can a priori be considered irrelevant.…”

“…We will consider a circular sky patch with a radius θ C = 10° and 20°, corresponding to about 0.76 and 3.04 per cent of the entire sky, respectively. The centre in Galactic coordinates is at l = 260°, b =−62°, within the region considered by different experiments (Bowden et al 2004; Oxley et al 2004; Montroy et al 2005). We take two frequency combinations, 40, 90 GHz, and 150, 350 GHz, where the dominant foreground emission is represented by the synchrotron and the thermal dust, respectively.…”

“…The B signal in the CMB polarization is more than one order of magnitude smaller than the ‘gradient’ mode (E) coming from all kinds of cosmological perturbations, and about two orders of magnitude lower if compared with the total intensity anisotropies ( T ). The CMB E mode and the TE cross‐correlation have been detected by the Wilkinson Microwave Anisotropy Probe ( WMAP ) satellite (Page et al 2006) as well as instruments operating on the ground (Kovac et al 2002; Readhead et al 2004) and from balloons (Montroy et al 2005). No glimpse of the B has been seen so far and it is apparent that its detection will represent an experimental and data analysis challenge in terms of control and treatment of systematics and instrumental noise needed to attain the required precision.…”