West-Central Forage Association

Cattle & Timber Integration

Abstract

This report outlines a study designed to determine the potential effects of cattle grazing on deciduous regeneration following clear cutting of deciduous stands and under proper range management. It was accessed as to whether or not managed cattle grazing at two levels of cattle stocking rates two years after harvest causes damage to regenerating deciduous stands.

The regen stand density of the closed pre-harvest block (1021) was significantly higher than that of the open pre-harvest condition block (1086). Included within total regeneration density assessments were aspen, accounting for 83% of total regeneration, while balsam poplar saplings contributed 17%. The proportion of aspen sapling damage due to animal impacts increased as the stocking rate was increased, although, at a rate of less than 10%, the rate of damage remained relatively low, even under high stocking treatments.

At both low and high animal stocking rates, there was found to be negligible effect attributable to two-year deferred cattle grazing on the post harvested regeneration success at both a pre-harvested open canopy and pre-harvested closed canopy deciduous forest. While cattle are found to have an impact of tree regeneration, given appropriate management controls, these effects were not found to be severe enough to jeopardize sustainable integration of forest and range management systems.

Acknowledgements

This project was completed by West--‐Central Forage Association. We would like to acknowledge Jillian Kaufmann, MSc Candidate, University of Alberta for the dedication and commitment of time that she contributed to making this project possible. In addition we would like to thank Dr. Edward Bork, University of Alberta, Mike Alexander, Craig DeMaere, and Gerry Elhert, Alberta Sustainable Resource Development for their commitment to the design and supervision of the project in addition to field work. We would also like to thank Darwayne and Linda Claypool for the use of both their cattle and grazing lease as well as the time that they invested in carrying out this research. We would also like to acknowledge the Forest Resource Improvement Association of Alberta (FRIAA), the Environmental Sustainable Agriculture Initiatives Program (ESAIP) and the Agriculture Opportunity Fund, Alberta Agriculture and Rural Development (AOF) for the funding to complete this project in its entirety.

Conclusion & Recommendations

In regards to the research questions that were posed for this project, at the low stocking rates, there was found to be no effect attributable to two-year deferred cattle grazing on the post harvested regeneration success at both a pre-harvested open canopy and pre-harvested closed canopy deciduous forest. At the high stocking rate there is negligible effect in both closed and open canopies.

Injury to deciduous saplings as a result of grazing did increase with a doubling of stocking rate; however, the average proportion of damaged aspen saplings failed to exceed 10% even under high stocking rate conditions. Given these low levels of damage to saplings, with adequate regeneration density it appears that reforestation will not be compromised.

Over time as vegetation production increases and logging residue decomposes, cut blocks may become more preferred foraging areas for cattle. By that time it is anticipated that the majority of the regen stand will have frown in height and diameter, thus obtaining a size to maintain resiliency against tramping by cattle (Dock rill et al. 2006). As tree regeneration becomes well established, damage resulting from grazing is expected to decrease. Deferring grazing for 1 to 2  years following seedling establishment, in combination with mid to late summer grazing acts to promote successful reforestation of harvested areas. To avoid over use of cut blocks and subsequent damage to regeneration, adequate forage could be stockpiled to accommodate sustained grazing once the growing season has ended. In addition, maintaining suitable stocking rates will promote low to moderate use of cut blocks by cattle, thereby minimizing damage to saplings or seedlings as a result of grazing.

Grazing management has been found to be necessary to ensure sufficient regeneration of deciduous seedlings in working forests. Timing, stocking rate, distribution and forage seeding are all management tools that should be considered when designing a site  specific grazing plan. Fencing combined with deferred-rational grazing systems is deemed to be the most effective control of cattle movement within forested areas (Bhattacharyya, J. Page, H. 2004) While cattle are found to have an impact of tree regeneration, given appropriate management.

While cattle are found to have an impact of tree regeneration, given appropriate management controls, these effects were not found to be severe enough to jeopardize sustainable integration of forest and range management systems.

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