Papers by Kristine Averill
Weed Science
Managing agricultural pests with an incomplete understanding of the impacts that tactics have on ... more Managing agricultural pests with an incomplete understanding of the impacts that tactics have on crops, pests, and other organisms poses risks for loss of short-term profits and longer-term negative impacts, such as evolved resistance and nontarget effects. This is especially relevant for the management of weeds that are viewed almost exclusively as major impediments to crop production. Seldom considered in weed management are the benefits weeds provide in agroecosystems, which should be considered for optimal decision-making. Integration of weed costs and benefits will become increasingly important as management for pests transitions away from nearly complete reliance on herbicides and transgenic crop traits as the predominant approach for control. Here, we introduce a weed-management decision framework that accounts for weed benefits and exemplify how in-crop weed occurrence can increase crop yields in which a highly damaging insect also occurs. We highlight a case study showing h...
Unconventional gas development facilitates plant invasions
Journal of Environmental Management
Vegetation removal and soil disturbance from natural resource development, combined with invasive... more Vegetation removal and soil disturbance from natural resource development, combined with invasive plant propagule pressure, can increase vulnerability to plant invasions. Unconventional oil and gas development produces surface disturbance by way of well pad, road, and pipeline construction, and increased traffic. Little is known about the resulting impacts on plant community assembly, including the spread of invasive plants. Our work was conducted in Pennsylvania forests that overlay the Marcellus and Utica shale formations to determine if invasive plants have spread to edge habitat created by unconventional gas development and to investigate factors associated with their presence. A piecewise structural equation model was used to determine the direct and indirect factors associated with invasive plant establishment on well pads. The model included the following measured or calculated variables: current propagule pressure on local access roads, the spatial extent of the pre-development road network (potential source of invasive propagules), the number of wells per pad (indicator of traffic density), and pad age. Sixty-one percent of the 127 well pads surveyed had at least one invasive plant species present. Invasive plant presence on well pads was positively correlated with local propagule pressure on access roads and indirectly with road density pre-development, the number of wells, and age of the well pad. The vast reserves of unconventional oil and gas are in the early stages of development in the US. Continued development of this underground resource must be paired with careful monitoring and management of surface ecological impacts, including the spread of invasive plants. Prioritizing invasive plant monitoring in unconventional oil and gas development areas with existing roads and multi-well pads could improve early detection and control of invasive plants.
AoB PLANTS
Herbivores can profoundly influence plant species assembly, including plant invasion, and resulti... more Herbivores can profoundly influence plant species assembly, including plant invasion, and resulting community composition. Population increases of native herbivores, e.g. white-tailed deer (Odocoileus virginianus), combined with burgeoning plant invasions raise concerns for native plant diversity and forest regeneration. While
The influence of white-tailed deerand landscape composition and structure on exotic plant success
Photosynthetic performance of invasive Vincetoxicum species (Apocynaceae)
Invasive Plant Science and Management, 2016
Knowledge of photosynthetic capacity is crucial for fully understanding a species’ invasive poten... more Knowledge of photosynthetic capacity is crucial for fully understanding a species’ invasive potential and for the development of appropriate control strategies. Although growth and reproductive data are available for the invasive swallowwort vines Vincetoxicum nigrum and V. rossicum, photosynthetic data are wanting. These herbaceous, perennial congeners were introduced from separate European ranges during the late 19th century and became invasive during the following century in the northeastern United States and southeastern Canada. Vincetoxicum nigrum has been observed growing mainly in high light environments, whereas V. rossicum occurs across a wide range of light environments, suggesting niche divergence and that different management strategies might be needed for the two species. In this work, we investigated whether the differing habitat associations of these species is reflected in their photosynthetic capacities and leaf morphology. Photosynthetic parameters and specific lea...
Http Dx Doi Org 10 1614 Ipsm 07 036 1, Jan 19, 2009
Pale swallow-wort is a nonnative vine, invading natural areas across much of the northeastern Uni... more Pale swallow-wort is a nonnative vine, invading natural areas across much of the northeastern United States and southeastern Canada. Control of this clump-forming herbaceous perennial has been difficult. We conducted a 2-yr study (2005-2006) in a heavily infested site in Chaumont, NY to assess the response of swallow-wort to triclopyr applied once as a foliar treatment (1.9 kg ae/ha) (2005 only) alone or in combination with clipping 4 wk later, followed by a single clipping in 2006. We also evaluated the response of swallow-wort to one or two clippings during each of the 2 yr. Two yr after treatments began, swallow-wort cover was lower in plots treated with triclopyr (20 6 5%) compared with plots subjected to clipping-only (56 6 6%) or unmanaged controls (76 6 6%). Stem densities were also lower in triclopyr-treated plots (25 6 5 stems/m 2) than in clipping-only (188 6 9 stems/m 2) and control (178 6 10 stems/m 2) plots across three different sample dates. Seedling densities were lower in triclopyr-treated plots (160 6 50 seedlings/m 2) relative to clipping-only (1,120 6 180 seedlings/m 2) and control (960 6 50 seedlings/m 2) plots after the 2005 growing season. The cover of other plant species was negatively correlated with swallow-wort cover and was higher in triclopyr-treated plots (75 6 3%) than in clipping-only (5 6 1%) and control (7 6 4%) plots in 2006. Across both years, swallow-wort in control and clipped plots produced follicles, but not in triclopyr-treated plots. Regardless of clipping frequency, clipping in June or July was not effective in reducing swallow-wort stem density, cover, or follicle production. Although a single application of triclopyr provided considerable suppression of swallow-wort after two growing seasons, application of triclopyr in subsequent years is likely required to achieve long-term control.
Deer feeding selectivity for invasive plants
Biological Invasions, 2016
Http Dx Doi Org 10 1614 Ipsm D 10 00034 1, Jun 16, 2011
Black and pale swallowwort (BSW and PSW, respectively) are perennial, herbaceous vines in the Apo... more Black and pale swallowwort (BSW and PSW, respectively) are perennial, herbaceous vines in the Apocynaceae that are native to Europe. The species are becoming increasingly abundant in the northeastern United States and southeastern Canada and are difficult to manage. However, we know little about the demographic parameters of these species. We determined the survival, annual rate of vegetative growth, and fecundity of mature clumps of these swallowwort species. We selected four PSW sites (three of which comprised both old-field and forest habitats) in central New York and three BSW old fields in southeastern New York. BSW is largely restricted to higher light habitats in its introduced range. In each habitat, we followed the growth of 30 to 32 randomly selected clumps of similar size (2 to 5 stems clump 21 in the initial year) for 3 to 4 yr. Yearly survival was 99.6 6 0.3% [mean 6 standard error] for PSW and 100 6 0% for BSW. In old fields, vegetative expansion varied from 20.01 6 0.1 to 4.6 6 0.4 stems clump 21 yr 21 for BSW and 20.02 6 0.2 to 2.1 6 0.5 stems clump 21 yr 21 for PSW. In forests, PSW growth was lower with vegetative expansion ranging from 20.01 6 0.1 to 0.8 6 0.2 stems clump 21 yr 21. Fecundity of PSW in 2007 and 2008 (130 6 10 viable seeds stem 21 yr 21) was similar to BSW (100 6 10 viable seeds stem 21 yr 21). Fecundity of PSW in forests was generally lower than PSW in old fields, but it varied greatly among sites (0 to 170 viable seeds stem 21 yr 21). We found that stem growth and fecundity did not vary with clump size (stems per clump). Since vegetative expansion and fecundity rates were high in old-field habitats, but were generally low or nonexistent in forest habitats, we suggest that management of these two invasive vines be focused in higher light environments to reduce overall seed production and its subsequent spread to surrounding areas.
Invasive Plant Science and Management, 2014
Japanese hedgeparsley is an annual (or sometimes biennial) forb introduced from Eurasia and found... more Japanese hedgeparsley is an annual (or sometimes biennial) forb introduced from Eurasia and found throughout much of the eastern United States and parts of extreme southern Canada. In North America, Japanese hedgeparsley is commonly found in ruderal habitats, such as roadsides, railroad rights-of-way, forest edges, and urban waste spaces. This species has not yet been listed as a noxious invasive, but its expanding populations have caused concern in several Midwestern states. The primary threat from Japanese hedgeparsley is its vigorous growth habit, which creates dense patches, and its dispersal ability, facilitated by its clinging, burr-like fruits. Some confusion on identification exists within the Torilis genus, with similar species (particularly T. arvensis) frequently misidentified in herbaria and the literature. Here, we review aspects of the etymology, taxonomy, biology, distribution, and management of Japanese hedgeparsley with the objective of increasing awareness of the p...
Invasive Plant Science and Management, 2008
Pale swallow-wort is a nonnative vine, invading natural areas across much of the northeastern Uni... more Pale swallow-wort is a nonnative vine, invading natural areas across much of the northeastern United States and southeastern Canada. Control of this clump-forming herbaceous perennial has been difficult. We conducted a 2-yr study (2005-2006) in a heavily infested site in Chaumont, NY to assess the response of swallow-wort to triclopyr applied once as a foliar treatment (1.9 kg ae/ha) (2005 only) alone or in combination with clipping 4 wk later, followed by a single clipping in 2006. We also evaluated the response of swallow-wort to one or two clippings during each of the 2 yr. Two yr after treatments began, swallow-wort cover was lower in plots treated with triclopyr (20 6 5%) compared with plots subjected to clipping-only (56 6 6%) or unmanaged controls (76 6 6%). Stem densities were also lower in triclopyr-treated plots (25 6 5 stems/m 2) than in clipping-only (188 6 9 stems/m 2) and control (178 6 10 stems/m 2) plots across three different sample dates. Seedling densities were lower in triclopyr-treated plots (160 6 50 seedlings/m 2) relative to clipping-only (1,120 6 180 seedlings/m 2) and control (960 6 50 seedlings/m 2) plots after the 2005 growing season. The cover of other plant species was negatively correlated with swallow-wort cover and was higher in triclopyr-treated plots (75 6 3%) than in clipping-only (5 6 1%) and control (7 6 4%) plots in 2006. Across both years, swallow-wort in control and clipped plots produced follicles, but not in triclopyr-treated plots. Regardless of clipping frequency, clipping in June or July was not effective in reducing swallow-wort stem density, cover, or follicle production. Although a single application of triclopyr provided considerable suppression of swallow-wort after two growing seasons, application of triclopyr in subsequent years is likely required to achieve long-term control.
Nutritional and consumer preference tests of "Liberty" apples grown under organic and integrated fruit production systems /
Honors thesis (Plant Sciences)--Cornell University, May 2005. Includes bibliographical references... more Honors thesis (Plant Sciences)--Cornell University, May 2005. Includes bibliographical references (leaves 18-20).
Invasive non-native plant colonization on Marcellus Shale well pads predicted by local road density and drilling intensity
Background/Question/Methods Disturbed plant communities with newly available resources are ideal ... more Background/Question/Methods Disturbed plant communities with newly available resources are ideal habitats for invasive plant colonization. In the last decade, development associated with Marcellus Shale gas extraction has brought new networks of roads and pipelines, and high-volume traffic, into forests and agricultural landscapes. We hypothesize that within the development footprint in Pennsylvania forests invasive non-native plants (INNP) would be present on the well pads (~3 acres) used to stage gas extraction. In addition, we hypothesize that invasion severity on well pads would depend on the extent of disturbance in the area of the pad prior to construction. To determine the presence and extent of invasion we surveyed 128 well pads and access roads across the PA State Forest system and the Allegheny National Forest for 23 INNP in the summers of 2012 and 2013. Using ArcMap we calculated road density prior to well pad construction (31 acre circular polygon) as a measure of landsc...
Matrix population models to guide swallow-wort (Vincetoxicum spp.) biological control
Background / Purpose: High numbers of herbivores cause a reduction in the abundance of palatable ... more Background / Purpose: High numbers of herbivores cause a reduction in the abundance of palatable plant species and an increase in unpalatable species. Many exotic plant species are thought to invade because they are unpalatable to generalist herbivores. Main conclusion: Consumer preference experiments revealed that while some invasive exotic plant species are avoided by deer, others are just as palatable as the most preferred native species.
Invasive Plant Science and Management, 2011
Black and pale swallowwort (BSW and PSW, respectively) are perennial, herbaceous vines in the Apo... more Black and pale swallowwort (BSW and PSW, respectively) are perennial, herbaceous vines in the Apocynaceae that are native to Europe. The species are becoming increasingly abundant in the northeastern United States and southeastern Canada and are difficult to manage. However, we know little about the demographic parameters of these species. We determined the survival, annual rate of vegetative growth, and fecundity of mature clumps of these swallowwort species. We selected four PSW sites (three of which comprised both old-field and forest habitats) in central New York and three BSW old fields in southeastern New York. BSW is largely restricted to higher light habitats in its introduced range. In each habitat, we followed the growth of 30 to 32 randomly selected clumps of similar size (2 to 5 stems clump−1in the initial year) for 3 to 4 yr. Yearly survival was 99.6 ± 0.3% [mean ± standard error] for PSW and 100 ± 0% for BSW. In old fields, vegetative expansion varied from −0.01 ± 0.1 ...
Weed Technology, 2007
Although many of us fondly associate parsnips with a rustic, home-cooked meal, there is also a wi... more Although many of us fondly associate parsnips with a rustic, home-cooked meal, there is also a wild variety that is increasingly causing problems as a weed in North America. The cultivated variety is a subspecies of Pastinaca sativa (Pastinaca sativa ssp. sativa) and contains lower amounts of the problematic furanocoumarins than the wild version. Wild parsnip (Pastinaca sativa L. PAVSA) is an introduced facultative biennial from Eurasia. It has spread throughout the United States and southern Canada and is now colonizing old fields, railroad embankments, roadsides, and waste areas. Wild parsnip contains furanocoumarins, which deter herbivores from eating its foliage. These compounds can also cause phytophotodermatitis in humans and livestock, a condition that results in patches of redness and blisters on the skin when they come into contact with the sap or ingest parts of the plant in the presence of sunlight. Few people, including medical professionals, recognize the plant or assoc...
Plant Ecology, 2010
Vincetoxicum rossicum (pale swallowwort) is a non-native, perennial, herbaceous vine in the Apocy... more Vincetoxicum rossicum (pale swallowwort) is a non-native, perennial, herbaceous vine in the Apocynaceae. The species' abundance is steadily increasing in the northeastern United States and southeastern Canada. Little is known about Vincetoxicum species recruitment and growth. Therefore, we conducted a field experiment in New York State to address this knowledge gap. We determined the establishment, survival, and growth of V. rossicum during the first 2 years after sowing in two old fields subjected to four disturbance regimens. We hypothesized that establishment and survival would be higher in treatments with greater disturbance. At the betterdrained location, overall establishment was 15 ± 1% [mean ± standard error] and did not differ among treatments. At the poorly drained location, establishment varied by treatment; mowed and control plots had greater establishment [10 ± 2%] than herbicide ? tillage and herbicide-only plots [1.6 ± 0.5%]. Of those seedlings that emerged, overall survival was high at both locations (70-84%). Similarly, total (above ? belowground) biomass was greater in herbicide ? tillage and herbicide-only plots than in mowed and control plots at both locations. Thus, V. rossicum was successful in establishing and surviving across a range of disturbance regimens particularly relative to other old field species, but growth was greater in more disturbed treatments. The relatively high-establishment rates in old field habitats help explain the invasiveness of this Vincetoxicum species in the northeastern U.S. and southeastern Canada.
American Journal of Botany, 2010
Determining which traits may allow some introduced plant species to become invasive in their new ... more Determining which traits may allow some introduced plant species to become invasive in their new environment continues to be a key question in invasion biology. Vincetoxicum rossicum is an invasive, perennial vine colonizing natural and seminatural habitats primarily in the northeastern United States and southeastern Canada. More than half its seeds exhibit polyembryony, a relatively uncommon condition in which a single seed produces multiple seedlings. For evaluating the potential consequences of polyembryony on invasiveness, V. rossicum plants derived from seeds of three embryonic classes-singlets, doublets, and triplets (one, two, and three seedlings per seed, respectively)-were paired in all combinations intraspecifi cally and with the co-occurring native herbs Solidago canadensis and Asclepias syriaca in a greenhouse study. Vincetoxicum rossicum biomass was 25-55% greater and follicle production 55-100% greater under intraspecifi c competition compared with interspecifi c competition. However, within a competitive environment, follicle production varied little. Regardless of competitive environment, V. rossicum originating from seeds with a greater number of embryos typically performed no better than plants arising from seed with fewer embryos (singlets = doublets = triplets)-except intraspecifi cally where doublets outperformed singlets, and with S. canadensis where triplets outperformed singlets. Our fi ndings suggest that overall performance and fi tness of V. rossicum is higher in monocultures than in mixed stands and that its ability to invade new habitats may not be attributable to the production of polyembryonic seeds.
(162) Multi-level Comparisons of Organic (OFP) and Integrated Fruit Production (IFP) Systems for `Liberty' Apple in a New York Orchard
Hortscience, Jul 1, 2006
Uploads
Papers by Kristine Averill