Research in our lab focuses on integrating tools (e.g. prevention; chemical, mechanical, and biological control; prescribed fire, revegetation) to manage invasive plants on rangeland in Montana.  We aim to find ecologically-based, economically viable means to control invasive plants while maintaining or restoring desirable vegetation that meets management objectives.

Research: in progress

cattle grazing on rangeland in Montana

Noxious weeds and Montana grazing lands: An economic perspective

Collaborators: Kate Fuller (MSU) and Matt Rinella (USDA-ARS)

We developed a 16-question survey concerning noxious weed management and associated costs. The target audience for the survey was livestock producers who were grazing their livestock on privately-owned rangeland in Montana. See our article in a recent issue of the Montana IPM bulletin for results.

Canada thistle and field bindweed flowers

A meta-analysis of previous Canada thistle (Cirsium arvense) and field bindweed (Convolvulus arvensis) control and mangement studies

Collaborators: Fabian Menalled (MSU) and Zach Miller (MSU)

We are using meta-analysis, to 1) provide land managers with effective control measures for Canada thistle and field bindweed based on current knowledge, 2) systematically compile methods to manage impacted sites, and 3) identify existing knowledge gaps in the management of these two species.

seeds of hoary alyssum on white paper

The effect of herbicide application and soil texture on hoary alyssum (Berteroa incana) seed biology and control

Southwestern MT

Hoary alyssum can be difficult to manage, possibly due to its prolonged flowering period when populations are simultaneously flowering and producing seeds, in addition to the fact that it often grows on coarsely textured soils where control with herbicides may be reduced. Our objectives of this project are to 1) quantify hoary alyssum seed production and viability as influenced by herbicide application and 2) determine the influence of soil texture on efficacy of herbicides applied to hoary alyssum. This project started  summer 2016.

bluebunch wheatgrass

Mitigating priority effects of invasive plants during revegetation by altering perennial grass planting date

Bozeman, MT

Modifying seeding date may be one ecologically-based management tool to increase establishment of seeded species by giving them an initial size advantage over weedy species that emerge later. This project will explore how timing of planting of desirable perennial grasses (bluebunch wheatgrass) might overcome the priority effects of seedlings of the invasive plants spotted knapweed and cheatgrass. It is our hope that this research will improve efficacy of revegetation efforts on lands dominated by spotted knapweed and cheatgrass in Montana and other semi-arid regions. This project started fall 2015.

narrowleaf hawksbread

Management strategies for control of narrowleaf hawksbeard

Collaborators: Shelley Mills and Bobbie Roos (MSU Extension Agents)

Narrowleaf hawksbeard is not a state listed noxious weed, but it is becoming increasingly problematic in Montana cropland and CRP lands, especially in the northeastern part of the state. We are working with MSU Extension Agents to test various management strategies for control of narrowleaf hawksbeard. This project started in 2015, with mowing and herbicide treatments being applied to two sites in Daniels County and Valley County.

medusahead closeup

Monitoring a new invader: medusahead (Taeniatherum caput-medusae) in Sanders County

Sanders County

The presence of medusahead, an invasive annual grass, was confirmed in Montana for the first time in 2013. Medusahead is not on the Montana state noxious weed list, but has been added to the county noxious weed list in Sanders and Lake Counties. In 2014, 2015, and 2016, MSU researchers from the Mangold lab have surveyed frequency of medusahead, along with other plant functional groups, at the confirmed site. This monitoring project will allow us to track the rate and spread of medusahead. Click here to download a MSU Extension bulletin on medusahead.


Integrating Pyrenophora semeniperda into cheatgrass management in range and croplands

Krista Ehlert, Current PhD Student

I am investigating the effect of P. semeniperda on target (Bromus tectorum) and non-target species in a greenhouse study. Future studies will evaluate if a fungicide seed treatment can prevent or reduce P. semeniperda infection and mortality of non-target species. I am also determining which combination of three cheatgrass plant stages (early flowering, peak flowering, and after seed maturation) and three inoculation timings (morning, evening, none) enhance P. semeniperda infection. I am finally seeing if cultural, chemical, and biological practices can be integrated to improve cheatgrass management in crop and rangeland settings.

Rangeland resiliency sampling

Rangeland resilience - when is revegetation necessary?

Central and western MT

The objective of this project is to determine how an herbicide application for target weeds affects abundance of rangeland plant functional groups one and two years post-spraying. Aminopyralid (MilestoneĀ®) was applied at two spotted knapweed infested rangeland sites and two sulfur cinquefoil infested rangeland sites, while picloram (TordonĀ®) was applied at two Dalmatian toadflax infested rangeland sites. We have collected data in 2014 and 2015, one and two years post-treatment.

Research: completed

Rangeland revegetation revisited plots

Rangeland revegetation revisited: are short-term trends indicative of long-term outcomes?


PDF (Copyright by the Ecological Society of America)


Joint effects of biotic and abiotic stressors on winter wheat suppression of Bromus tectorum

Noelle Orloff, Former MS Graduate Student
site specific effects field work

Site-specific effects of exotic annual grass control integrated with revegetation

Noelle Orloff, Former MS Graduate Student
greenhouse pots

Role of size and nitrogen in competition between annual and perennial grasses

Noelle Orloff, Former MS Graduate Student
pollinator on spotted knapweed

Temporal- and density-dependent impacts of an invasive plant on pollinators and pollination services to a native plant

Christina Herron-Sweet, Former MS Graduate Student
Christina sampling

Native parasitoids associated with the biological control agents of Centaurea stoebe in Montana

Christina Herron-Sweet, Former MS Graduate Student
Hally spraying plots

Testing Integrated Management Strategies for Tall Buttercup (Ranunculus acris) in Irrigated Hayfield Meadows

Hally Strevey, Former MS Graduate Student
Pyrenophora semeniperda growth

Integrating the herbicide imazapic and the fungal pathogen Pyrenophora semeniperda to control Bromus tectorum

Krista Ehlert, Former MS Graduate Student
cheatgrass site

Imazapic activity in a semiarid climate in downy brome (Bromus tectorum)-infested rangeland and CRP sites

Krista Ehlert, Former MS Graduate Student
Jane and western salsify

Testing control options for western salsify (Tragopogon dubius) on Conservation Reserve Program Lands