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III. RESULTS |
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FLORA & FAUNA: ECOSYSTEM STRUCTURE |
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Mapping the ecosystem boundaries yielded several distinct ecosystems (Figure 3.1). Two distinct forest areas were present, one cultivated and one relatively untouched. Within the untouched forested area (D), two large areas of windfall were present (E). Similar to the forested area, two distinct agricultural areas were present on the property. The first area was used primarily for pastureland for cattle (A). The second area was used primarily for hayfields (F). Finally, two wetland areas were found. A freshwater wetland (G) is present near the southern border. Part of this wetland is now used for a commercial cranberry operation. The second wetland area (H) is a marine saltmarsh. |
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Figure 3.1: Aerial photograph showing relative ecosystem boundaries, based on GPS data |
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FLORA & FAUNA: SPECIES LIST |
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Examining the species list developed from systematic and incidental sampling revealed several types of organisms present on the property: ferns, flowers, grasses (including grasses, sedges and rushes), fungi, shrubs, trees, birds and mammals. Flowers showed the most taxa with 127 species. The least abundant were the mammals with 6 species (Mammals were recorded as incidental sightings and not rigorously sampled for). Grasses, trees and birds showed similar numbers of species with 29, 33 and 34 respectively. Finally, the ferns, fungi and shrubs showed similar numbers of species with 14, 20 and 18 respectively. |
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Figure 3.2: Summary of numbers of taxa observed on the Morton Centre property (May until September 2002) |
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FLORA & FAUNA: FOREST DENSITY PATTERNS |
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Figure 3.3 shows density patterns of the forested area of the property. The majority of this area falls into moderate and sparse categories with 48.98% and 36.10% respectively constituting 85.08% of the total forested area. The smallest area was categorized as open, with 0.24% of the forest falling into this category. The heavy and dense areas of forest showed similar percentages, with 7.33% and 7.35% respectively. |
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Figure 3.3: Property schematic showing density distribution of the forested area of the property |
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FLORA & FAUNA: FOREST DIVERSITY PATTERNS |
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Figure 3.4 shows diversity patterns of the forested area of the property. The largest percentage of forested area, 55.73%, was characterized by balsam fir as the primary species. Red Spruce was second with 17.94% of forested area but concentrated in more distinct patterns. White spruce was third with a total of 9.69% of the forest having a primary species of this type. The majority of white spruce was concentrated in the cultivated forest area (C in Figure 3.1). Some isolated areas of primarily yellow birch (4.58%) and white birch (4.76%) were present with the remainder (7.31%) composed of other species like speckled alder, tamarack, red maple, quaking aspen and large-tooth aspen. |
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Figure 3.4: Property schematic showing primary species distribution of the forested area of the property |
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WATER: CHEMISTRY & QUALITY |
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Sampling of wells between 1999 and 2002 showed a consistent decrease in the pH between all wells (Figure 3.5). Although there is no maximum or minimum acceptable pH value, the Canadian Drinking Water guidelines do present a pH objective range of 6.5 to 8.5. |
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In 1999, samples from wells 1 and 2 fell below the guideline recommendations with mean pH values of 6.40 and 6.43. Wells 3, 4 and 5 fell within the recommended aesthetic objectives with mean pH values of 6.69, 6.67 and 8.29. |
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Examining samples from 2002 revealed that only well 5 fell within the aesthetic objectives for pH with a mean pH of 6.48. Wells 1, 2, 3 and 4 all fell below the aesthetic objectives with mean pH values of 5.83, 5.67, 5.80 and 6.64. |
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Figure 3.5: Comparison of mean pH values of all wells between 1999 and 2002 with error bars representing standard error |
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Similar to mean pH values, mean alkalinity (Figure 3.6) from samples collected in 2002 exhibited consistently lower mean alkalinity at each sample site. Comparing sample sites between years revealed similar trends. Well 5, drilled into the aquifer, was consistently higher in alkalinity when compared to wells 1 through 4 in both 1999 and 2002. In both years and in all sample sites, alkalinity values were low, indicating poor buffering capacity. Buffering capacity is the ability to resist pH changes. |
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 Figure 3.6: Comparison of mean alkalinity values of all wells between 1999 and 2002 with error bars representing standard error |
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The mean hardness of water collected (Figure 3.7) exhibited variability between sample sites within sample year, and slight variability between sample years. In 1999, wells 2, 3 and 5 fell within the moderate range for total hardness with values of 62.8 ppm, 61.3 ppm and 68.5 ppm CaCO3 respectively. In contrast, wells 1 and 4 exhibited low levels of hardness with mean values of 49.1 ppm and 35.7 ppm respectively. |
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Three wells in 2002 also yielded water samples within the moderate range for hardness. The mean total hardness of wells 1, 3 and 5 were 80.8 ppm CaCO3, 60.3 ppm CaCO3 and 77.6 ppm CaCO3 respectively. Wells 2 and 4 showed a mean total hardness of 47 ppm CaCO3 and 35.0 ppm CaCO3 respectively, within the limits for soft water. |
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 Figure 3.7: Comparison of mean total hardness values of all wells between 1999 and 2002 with error bars representing standard error |
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The Canadian Drinking Water Guidelines suggest aesthetic objectives of ≤ 5 nephelometric turbidity units (NTUs). In 1999, only one well, well 1, met this standard with a mean turbidity of 3.0 NTU (Figure 3.8). Wells 2, 3, 4 and 5 all exceeded the aesthetic standards with mean values of 15.00, 24.85, 28.30 and 10.50 respectively. |
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In 2002, these trends changed noticeably. Well 4, with a mean turbidity of 8.22 was the only sample site to exceed aesthetic objectives. Wells 1, 2, 3 and 5 all exhibited mean turbidity values less than the aesthetic objectives of the Canadian Drinking Water Guidelines with mean values of 2.60 NTUs, 1.56 NTUs, 1.67 NTUs and 1.94 NTUs respectively. |
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 Figure 3.8: Comparison of mean turbidity values of all wells between 1999 and 2002 with error bars representing standard error |
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Tests for total nitrates (Figure 3.9) detected low levels present in water from all sample sites in both sample years. The mean total nitrates in water from well 1 increased from 0.0398 ppm in 1998 to 0.058 ppm in 2002. Similarly, water from well 2 contained mean total nitrates of 0.0475 ppm in 1992, less than the 2002 mean of 0.0900 ppm. Well 3 remained relatively consistent with trend established by wells 1 and 2, with mean total nitrates increasing from 0.0456 ppm to 0.0700 ppm. In contrast, the mean total nitrates of water from well 4 remained relatively constant with values of 0.0688 ppm in 1999 and 0.0600 ppm in 2002. |
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It should be noted that values range from 0.0338 ppm to 0.1400 ppm, a small difference of 0.1062 ppm. Due to the small range of values, the scale is misleading and variance appears artificially inflated. When compared to the maximum acceptable concentration of nitrates in the Canadian Drinking Water Guidelines (45 ppm), all samples fall well below this maximum. |
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 Figure 3.9: Comparison of mean total nitrate values of all wells between 1999 and 2002 with error bars representing standard error |
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It should also be noted that nitrates are quite volatile and breakdown relatively quickly in aerated water (Hem, 1985). Time elapsed from sampling to analysis could result in the underestimation of the actual nitrates present in the groundwater system, although consistency between both sample years suggests otherwise. |
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It is also important to realize that a limitation does exist when comparing water quality data collected in 1999 versus data collected in 2002. Data was collected by two different researchers using different protocols. As a result, inherent error exists in this comparison. |
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WATER: WATER TABLE HYDROLOGY |
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Previous work by Morse (1999) revealed a complex groundwater system (Figure 3.10). The presence of Hartland Till and Lawrencetown Till (clay phase) act as an aquiclude. This confining layer results in a perched aquifer, accessed by the dug wells (Wells 1, 2, 3 and 4). |
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Although low mean pH was found, preliminary chemical indicators suggest that this water is of good quality. The water is "young" however. In addition, Morse (1999) found the soil has very low hydraulic conductivity. As a result, water recharge is not rapid suggesting that large volume removal is not feasible. Additionally, in times of high precipitation there is propensity for overland flow as infiltration capacity is diminished due to the low hydraulic conductivity. |
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The impermeable till also acts as a confining layer for the bedrock aquifer. Initial chemical indicators suggest that the quality of this water is good, however there are concerns related to the composition of the Halifax Slates. These slates contain pyrite, and therefore, high iron. High iron concentrations can result in poor odour, taste and can result in stained laundry (Hem, 1985). |
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Figure 3.10: Schematic of the Morton Centre groundwater system (modified from Morse, 1999) |
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GEOMORPHOLOGY |
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Several important features revealed in the examination of aerial photos (Figure 3.11). The asymmetrical drumlin comprising the property appears to have two parallel axes. The western axis has a maximum elevation of 25 m above sea level. There is relatively shallow relief to the northeast with steeper relief to the southwest. The eastern axis of the drumlin shows shallow relief to the southwest with steeper relief to the northeast. The consequence of this relief pattern is that water tends to collect in the depression between the two axes (A, Figure 2.6), resulting in an area in which the water can re-enter the water table. In addition, due to the low infiltration capacity of the till, overland flow tends to occur in heavy precipitation events and an ephemeral drainage channel occurs. |
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Another area for water recharge is the the bog to the southeast of the property (B, Figure 3.11). Since this photograph was taken, a commercial cranberry bog has been completed by the adjacent land owner in this area. This operation consists of two large artificial bogs and a large irrigation reservoir. |
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Figure 3.11: Aerial photo (1992) of the Morton Centre property illustrating coastal processes, drumlin axes and relief, areas of water recharge and drainage patterns |
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Examination of the coastline revealed areas of erosion, transportation and deposition. The most significant of coastal processes is transportation with 82.8% of the total coastline (Figure 3.11). A small area of deposition occurs where the ephemeral drainage channel meets the marine environment (C, Figure 3.11). Depositional coast constitutes a mere 5.2% of the total shoreline. Areas of erosion also constitutes a small portion of the total coastline with 12% over 3 main areas with significant erosion (Figure 3.11). Only one of these erosional areas falls within property boundaries but is an area for concern as visual evidence suggests regular slumping events. |
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Further examination of coastal features reveals important features of sea level change. The northern portion of the property is believed to be a remnant of a wave-cut platform (D, Figure 3.11). This platform suggests isostatic rebound has occurred in the past. To the east of the wave-cut platform is a remnant salt marsh (E, Figure 3.11). The submergence of this salt marsh suggests a rise in relative sea level in the recent past. |
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An embayment occurs to the east of the property. At the head of this embayment is a small salt marsh (F, Figure 3.11). Near the salt marsh are several outcrops of Halifax formation slates, indicating strike and dip of the underlying bedrock. |
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Equidistant, parallel cross-sections (Figure 3.12) show topographical change from north to south of the property. Elevation increases from the A to A' cross section until peak elevation is reached in cross section D to D'. Figure 3.12 illustrates the asymmetrical nature of the property. |
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Figure 3.12: Topographical cross sections of the Morton Centre property |
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