Owing to the methane (CH 4 ) produced by rumen fermentation, ruminants are a source of greenhouse gas (GHG) and are perceived as a problem. We propose that with appropriate regenerative crop and grazing management, ruminants not only reduce overall GHG emissions, but also facilitate provision of essential ecosystem services, increase soil carbon (C) sequestration, and reduce environmental damage. We tested our hypothesis by examining biophysical impacts and the magnitude of all GHG emissions from key agricultural production activities, including comparisons of arable-and pastoral-based agroecosystems. Our assessment shows that globally, GHG emissions from domestic ruminants represent 11.6% (1.58 Gt C y -1

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As a result of water-level regulation, cattails have invaded sedge/grass meadow in all wetlands on Lake Ontario. Even with a change in water-level-regulation to a more natural hydrologic regime, restoration requires methods for active cattail management without the ability to manipulate water depths and without imperiling other vegetation. We conducted replicated studies at a wetland site with an active invasion front in zones of nearly mono-dominant cattail and transitional invasion. We tested various combinations of cutting cattail ramets when carbohydrate reserves were minimized, spraying cut stems with herbicide, slicing rhizomes to mimic tilling, and hand-wicking resprouted ramets with herbicide. We also collected companion environmental data. The most effective treatment in both zones was cutting during the period with reduced rhizome carbohydrates followed by handwicking resprouted ramets with herbicide in late summer, which allows the herbicide to be absorbed by the rhizomes. Two years of treatment provide the best results, reducing cattail stem counts and cover by more than 50%, but follow-up applications in ensuing years may be warranted to treat surviving cattails. Given the widespread problem of cattail invasion, these treatments may have broad application in wetlands where water levels cannot be manipulated.

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A life cycle assessment with carbon (C) as the reference unit was used to balance the benefits of land preparation practices of establishing tall-grass prairies as a crop for reclaimed mine land with reduced environmental damage. Land preparation and management practices included disking with sub-soiling (DK-S), disking only (DK), no tillage (NT), and no tillage with grazing (NT-G). To evaluate the C balance and energy use of each of the land preparations, an index of sustainability (I s = C O /C I , Where: C O is the sum of all outputs and C I is the sum of all inputs) was used to assess temporal changes in C.Of the four land preparation and management practices, DK had the highest I s at 8·53. This was due to it having the least degradation of soil organic carbon (SOC) during land-use change (À730 kg ha À1 y À1 ) and second highest aboveground biomass production (9,881 kg ha À1 ). The highest aboveground biomass production occurred with NT (11,130 kg ha À1 ), although SOC losses were similar to DK-S, which on average was 2,899 kg ha À1 y À1 . The I s values for NT and DK-S were 2·50 and 1·44, respectively. Grazing from bison reduced the aboveground biomass to 8,971 kg ha À1 compared with NT with no grazing, although stocking density was low enough that I s was still 1·94. This study has shown that converting from cool-season forage grasses to tall-grass prairie results in a significant net sink for atmospheric CO 2 3 years after establishment in reclaimed mine land, because of high biomass yields compensating for SOC losses from land-use change.

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