| OCR Text |
Show projections, Oregon's present land use regulations, and adaptability of individual farm crops to increased population pressures. The probability of farmland loss is estimated based on characteristics of individual parcels projected for the 2050 Willamette Valley agricultural landscape. The Researchers and Technical Advisory Committee decided that we should establish a plausible "control total" farm land loss estimate based on historical patterns of farmland loss, conditioned with subsequent regulatory changes in resource land zoning. The historical trend approximates patterns from the past 25 years, and the Land-Conserving Alternative assumes a growth plan eliminating any further loss or development of farmland beyond 2010. Under the Land-Conserving Alternative, we assume 150,000 acres are converted. Under the Historical Trend, we assume 300,000 acres are converted. The probability of farmland loss is estimated based on characteristics of individual parcels projected for the 2050 Willamette Valley agricultural landscape. These estimates incorporate population densities on agricultural lands, crop history, parcel size, and county. Total farmland losses reflect probabilities of conversion, bounded by the control totals. The relationship between density and probability of farmland conversion depends not just on open space, but also on the crop produced. Inherently, some crops require greater acreage than others to achieve productive and economic efficiency due to farming practices, yield, and returns per acre. Those crops that require large contiguous blocks of farmland are more sensitive to increases in population density. Analysis of the patterns of individual crop categories reveals that there are generally three relationships, identified here as land-intensive, neutral, and land-extensive crops. Land-intensive crops, including Christmas trees, nurseries, orchards, and small fruits, appear relatively insensitive to population density at ranges of 80 acres or more per dwelling. These crops are typically produced on small acreage, and may better survive modest increases in density. A second category of crops including pasture, woodlots, hay, irrigated annual row crops, and hybrid poplar plantations reflects an almost linear distribution of farm numbers by farm size. The implication is that farmland conversion in this category of intermediate crops will be roughly proportional to increases in density. Large, medium and small operations alike will bear proportional increases in the probability of conversion as densities increase. Land-extensive crops including irrigated field crops, grains, and grass seed show evidence of much greater sensitivity to parcel size. The probability of conversion is significant even at relatively low population densities. This category of crops appears least adaptable to the pressures of urbanization. DRAFT Summary Report ECONorthwest December 2000 Page 11 |
