Wambo Coal AEMR 2010-2011 - Peabody Energy

species specific herbicide), no control actions are currently recommended for thisspecies.• Spot herbicide spraying for African Boxthorn (Lycium ferocissimum) was undertakenduring 2010 along North Wambo Creek and has resulted in the death of almost allAfrican Boxthorn plants. Due to the low frequency of occurrence within flora quadrats(recorded in one quadrat in 2010) and the success of the 2010 spraying program, nofurther control measures are currently recommended.2.3.4 Vegetation Heights• Increases in the height ranges of the canopy and mid-storey one layers are likely aresult of:» Observer bias:• Several increases in height range were beyond a realistic amount of growthfor any of the species present;• Different observers recorded vegetation heights in 2009 and 2010;• Visual estimates, as opposed to measured values, are more prone tovariation and a lack of repeatability;• Measured values are not a feasible option as several measurements wouldbe required per vegetation strata and the resulting time requirement wouldlikely exceed the benefit of more accurate data; and• Observer bias is an inherent factor of annual surveys that generally is onlyavoidable in the short term.» Natural growth of species within each strata. However as mentioned above thedegree of growth is most likely a result of observer bias.2.4 RecommendationsThe following recommendations are suggested to maintain the quality and diversity offlora species within the RWEP areas of Wambo Coal:• Continue the exclusion of domestic stock from RWEP areas.• Continue the annual flora monitoring program in future years.• Undertake weed control measures where-ever weed species occur at high densities(not all areas were covered during the annual monitoring program).2.5 ConclusionCurrent management practises within the RWEP areas of Wambo Coal Mine appear to beappropriate for the conservation of flora species. Variation evident in the results from thefive years of monitoring is most likely related to natural variation in species distribution,natural variation in species abundance and variation inherent in the sampling design, andnot to current management practises. There was no evidence to suggest that current2010 Annual Ecological Monitoring Report, Draft Report, January 2011 Page 11