9.0 Historical Changes in the Land-Use and Wetland Availability in Old Norfolk County

9.1 Land cover and land-use change in old Norfolk County

9.1.4.1 Potential problems associated with increased corn cultivation

1/ One of the most substantial effects of increased cereal grain production in old Norfolk County has probably been on the nesting habitat of birds. Increased size of farm machinery and associated debt loads, combined with the large acreage required for profitable cereal production, have prompted farmers to cultivate marginal farmland and to convert pasture and hayland to cereal grain production. This has in all likelihood decreased the amount of nesting habitat available to waterfowl and other ground-nesting birds. However, while the area probably was an important nesting area during post-glacial times when the sand plain would have been somewhat similar to the Hudson Bay lowlands, it certainly is not an important waterfowl production area today. This can be attributed to the fact that it is on the periphery of the breeding range of many waterfowl species, and that wetland densities are extremely low (see section 9.2). The most substantial effect of the declining availability of improved pasture and native grasslands has probably been on non-waterfowl grassland nesting bird populations and other species of wildlife. Cereal grain production requires larger fields with fewer fence rows and fewer "fringes" of weedy, wooded peninsulas, which would provide habitat for nesting songbirds.

2/ The Haldimand-Norfolk region has a relatively high percentage of forest cover compared to other areas within the Carolinian Zone (e.g., Essex County has less than 3% forest cover), and there are numerous significant natural areas throughout the region (Gartshore et al. 1987). However, there is evidence that Ontario's farm operations have been facing increasing financial pressures, as Ontario's total net farm income for 1994 was $451 million, compared to the 1985-1989 five-year average of $730 million. One problem associated with the conversion to cereal grains and the decline in the agricultural economy has been the apparent loss of forest cover. This can be attributed to farmers clearing away forest margins so that they can increase the number of acres in cereal grain production, and improve efficiency, in hopes of reducing their debt load. Also, while the strong tobacco economy enabled the preservation of many woodlots, farmers are starting to develop them for residential or other uses in order to supplement their income (Beazley and Nelson 1993). This rural residential development is particularly noticeable in old Norfolk County and it can also be attributed to the numerous natural amenities offered by the region (Orr 1997). This may be problematic, as large forests with interconnected forest corridors serve many vital ecological roles such as protecting aquifers and interconnected stream networks, sustaining viable populations of interior forest species of wildlife, and providing habitat and escape cover for several species of mammals (Forman 1995). Isolated fragments of forest cover are much less suitable for maintaining wildlife movements and the biodiversity of the landscape.

3/ The increased size of farms and farm machinery also results in increased stream channelization and the further implementation of drainage systems. This, and the loss of fence rows and other natural areas, would increase the level of soil erosion and the amount of nutrients and contaminants entering streams and wetlands, and eventually, Long Point Bay, as drainage systems act as conduits from farmland to the Bay. Municipal drains and stream channelization also increase the rate of run-off which often results in a net loss of wetlands and their associated functions.

4/ Since corn does not require a winter cover crop there is potential for increased soil erosion in those areas where tobacco has been converted to cereal grain production. However, the sandy soils in old Norfolk County provide good spring drainage, thereby enabling farmers to plow fields in the spring, compared to heavier clay soils which require farmers to plow in the fall (D. Reid, personal communication). This and the fact that several conservation organizations such as Ontario Land Care and the Long Point Region Conservation Authority have been advocating minimum till, while opposing fall plowing, have resulted in very few fields within the county being plowed in the fall. With the exception of the upper Grand River, the annual suspended sediment yield for those agricultural watersheds that drain into Long Point Bay are the lowest of all Canadian watersheds draining into lake Erie (Wall et al. 1982).