Water requirements for emergence of buffelgrass (Pennisetum ciliare)

Abstract

The ability of an invasive species to acquire and use a limiting resource during critical life history stages governs its ability to establish and persist within an environment. Arid environments are generally considered more resistant to invasion and are defined by low and sporadic precipitation. Warm-season grasses are most susceptible to mortality during seedling emergence, but water requirements for emergence are rarely known. We examined the ability of the often invasive warm-season grass, buffelgrass, to emerge given a range of simulated precipitation delivered on 2, 3, and 4 consecutive days with the use of a line-source irrigation system in a glasshouse. The minimum amount of water required for buffelgrass emergence was observed to be 6.3 mm (3.14 mm on 2 consecutive days). With the use of probit analysis, the median emergence response (0.5 emergence probability) was predicted to require 17.4–19.9 mm of water. Emergence was concentrated within the first 5 days following initial simulated precipitation with the probability of new emergence highest on Days 3 and 4. Over the period from 1949–2001 in Tucson, Arizona within the Sonoran Desert, the total number of consecutive rainy-day sequences meeting the minimum per-day precipitation levels for a median and minimum emergence response was 27 and 92, respectively. Precipitation sufficient to result in emergence of 50% of viable buffelgrass caryopses has occurred in Tucson in about 1 of 2 years over this period. We compare the soil water requirements for emergence of buffelgrass to other perennial species in the Sonoran Desert and suggest that the invasion success of buffelgrass is due in part to its ability to emerge following relatively low precipitation levels.

Effects of flooding and shading on growth and gas exchange of Vochysia divergens Pohl (Vochysiaceae) of invasive species in the Brazilian Pantanal

“…In particular, traits associated with maximizing C gain, such as high leaf area production, maximum photosynthesis, and specific leaf area (projected leaf area/leaf dry mass), appear to be positively correlated with invasive performance (Funk, 2008). Expression of these traits may be highly dependent on resource availability (Sala et al, 1996;Siemann and Rogers, 2007) and/or developmental stage (Ward et al, 2006); however, invasive species often exhibit high phenotypic and physiological plasticity (Funk, 2008), which allows them to expand their distribution across spatially heterogenous landscapes.…”

Invasiveness of Cut-Leaf Ground-Cherry (Physalis angulata L.) Populations and Impact of Soil Water and Nutrient Availability

“…Moreover, understanding and identifying environmental resources that promote or restrict the success of invasive, alien species during the critical life stages can be used to focus on how to manage them (Ward et al, 2006;Speziale and Ezcurra, 2011).…”

Mapping Presence and Predicting Phenological Status of Invasive Buffelgrass in Southern Arizona Using MODIS, Climate and Citizen Science Observation Data

“…However, the invasive responds more quickly to moisture inputs than native grasses [28][29][30], resulting in an accelerated germination of new plant material after rainfall events. The response of one buffelgrass plant observed for this study to the 2014 monsoon is shown in the supplementary file.…”

“…We observed an especially strong spatial coincidence of the buffelgrass patches and the high correlation values for all years using this CLaRe metric. Given the results at Pima Canyon, which contains abundant buffelgrass, and knowing that buffelgrass can break dormancy to respond to water faster than native plants [28], we anticipated that areas with buffelgrass might exhibit stronger precipitation-greenness relationships than areas without. Our results confirmed this, showing that the presence of buffelgrass is indeed captured by the CLaRe metrics, including CLaRe-ppt123 displayed in Figure 6.…”