Competition Between Species Lab
Audrey Umwali
Ecology Lab Report 10
Section 7649
Competition Data
November 28, 2012
INTRODUCTION Competition, whether it is for food, water, shelter or a mate occurs between any living organisms in a mutual habitat. They are likely to be in close proximity and this interaction could either be harmful or helpful to each organism. When the interaction is beneficial, it is considered to be mutualism, either being obligate or facultative. However, interactions between different species may take different forms, such as commensalism, parasitism, amensalism etc. Competition often results in reduced growth and/or lower seed production of one or both individuals or species when compared to the yield of either when grown alone. There …show more content…
are two types of competition; intraspecific and interspecific competition. Intraspecific competition refers to competition within a specific species and intraspecific competition is competition between different species.
Interspecific competition between different species may not be observed, if the resource requirements of the species are different. Interspecific competing species may also co-exist because no one species is competitive enough to drive out the other species. When one type of specie is a much better competitor compared to the other species, it is possible for competitive exclusion to occur, eliminating the other species from the community. Individuals of the same species may avoid competition by partitioning the resources (guild). Small species that mature rapidly are suitable for intraspecific and interspecific competition experiments. This laboratory exercise focuses both types on interactions using wheat and mustard seeds. Our goal was to observe intraspecific competition in mustard and in wheat by varying the density of plants and observing plant growth. We will also examine interspecific competition between mustard (Brassica) and wheat (Triticum) plants by planting a variety of mixtures of the two species together in the same pot. Variation in plant density can have a profound effect on yield …show more content…
per plant. This experiment gives us the opportunity to gain precision and statistically meaning predications.
MATERIALS & METHODS
The seeds were planted using planting pots and they were evenly spaced in order to avoid crowding. The seeds were then covered with a thin layer of soil. Each pot was numbered with respect to the number and type of seeds it contains. The pots were placed in the green house garden and watered routinely. Extra fertilizers were not added to the planting pots. The plants were allowed to grow for about 5-8 weeks. At around the eighth week, the plants were harvested and dried in an oven at 70 C0 for 24 hours. Then, they were weighed and the biomass of each species was recorded.
RESULTS
Tables 8.2, 8.3, 8.4 and 8.5 depicts the master summary tables including # of seeds of each specie planted, # of plants harvested, total mustard biomass, standardized per plant biomass and the averaged on the standardized biomass. The figures accounts for the number of seeds planted versus the average standard per plant biomass. The R² values for figures 8.2, 8.3, 8.4 and 8.5 were 0.9621, 0.843, 0.9649 and 0.7267 respectively. The baseline per plant biomass for mustard was determined to be 0.16525 and 0.175 for wheat.
Table 8.2 Master Summary Table: Effect of Intraspecific Competition on Mustard Pot # | # Mustard Seeds Planted | # Mustard Plants | Total Mustard Biomass (g) | Per Plant Biomass for Mustard (g) | Standardized Per Plant Biomass for Mustard | Average of Treatment Standardized Per Plant Biomass for Mustard | | | Harvested | | | (%) | (%) | 1 | 1 | 1 | 0.06 | 0.06 | Notapplicable | 100 | 2 | 1 | 1 | 0.155 | 0.155 | | | 3 | 1 | 1 | 0.325 | 0.325 | | | 4 | 1 | 1 | 0.121 | 0.121 | | | 5 | 2 | 1 | 0.175 | 0.175 | 105.9001513 | 81.896117 | 6 | 2 | 2 | 0.342 | 0.171 | 103.4795764 | | 7 | 2 | 2 | 0.12 | 0.06 | 36.3086233 | | 8 | 2 | 0 | 0 | 0 | 0 | | 9 | 4 | 2 | 0.205 | 0.1025 | 62.02723147 | 78.10136157 | 10 | 4 | 4 | 0.376 | 0.094 | 56.88350983 | | 11 | 4 | 1 | 0.195 | 0.195 | 118.0030257 | | 12 | 4 | 4 | 0.499 | 0.12475 | 75.49167927 | | 13 | 8 | 5 | 0.57 | 0.114 | 68.98638427 | 52.56213529 | 14 | 8 | 7 | 0.52 | 0.074285714 | 44.95353361 | | 15 | 8 | 8 | 0.55 | 0.06875 | 41.60363086 | | 16 | 8 | 5 | 0.452 | 0.0904 | 54.70499244 | | 17 | 12 | 11 | 0.533 | 0.048454545 | 29.32196397 | 31.66567338 | 18 | 12 | 11 | 0.682 | 0.062 | 37.51891074 | | 19 | 12 | 10 | 0.473 | 0.0473 | 28.62329803 | | 20 | 12 | 9 | 0.464 | 0.051555556 | 31.19852076 | | 21 | 16 | 15 | 0.716 | 0.047733333 | 28.88552698 | 30.69051221 | 22 | 16 | 15 | 0.74 | 0.049333333 | 29.85375693 | | 23 | 16 | 14 | 0.654 | 0.046714286 | 28.26885671 | | 24 | 16 | 12 | 0.709 | 0.059083333 | 35.75390822 | | 25 | 24 | 18 | 0.801 | 0.0445 | 26.92889561 | 23.39187606 | 26 | 24 | 21 | 0.821 | 0.039095238 | 23.65823788 | | 27 | 24 | 19 | 0.708 | 0.037263158 | 22.54956605 | | 28 | 24 | 21 | 0.709 | 0.033761905 | 20.4308047 | |
Table 8.3 Master Summary Table: Effect of Intraspecific Competition on Wheat Pot # | # Wheat Seeds Planted | # Wheat Plants Harvested | Total Wheat Biomass (g) | Per Plant Biomass for Wheat (g) | Standardized Per Plant Biomass for Wheat (%) | Average of Treatment Standardized Per Plant Biomass for Wheat (%) | | | | | | | | 29 | 1 | 1 | 0.081 | 0.081 | Not Applicable | 100 | 30 | 1 | 1 | 0.159 | 0.159 | | | 31 | 1 | 1 | 0.231 | 0.231 | | | 32 | 1 | 1 | 0.229 | 0.229 | | | 33 | 2 | 2 | 0.267 | 0.1335 | 76.28571429 | 123.6428571 | 34 | 2 | 2 | 0.47 | 0.235 | 134.2857143 | | 35 | 2 | 1 | 0.27 | 0.27 | 154.2857143 | | 36 | 2 | 1 | 0.227 | 0.227 | 129.7142857 | | 37 | 4 | 3 | 0.464 | 0.154666667 | 88.38095238 | 76.16666667 | 38 | 4 | 3 | 0.354 | 0.118 | 67.42857143 | | 39 | 4 | 2 | 0.213 | 0.1065 | 60.85714286 | | 40 | 4 | 4 | 0.616 | 0.154 | 88 | | 41 | 8 | 7 | 0.929 | 0.132714286 | 75.83673469 | 63.68112245 | 42 | 8 | 7 | 0.821 | 0.117285714 | 67.02040816 | | 43 | 8 | 8 | 0.797 | 0.099625 | 56.92857143 | | 44 | 8 | 7 | 0.673 | 0.096142857 | 54.93877551 | | 45 | 12 | 11 | 0.862 | 0.078363636 | 44.77922078 | 49.44083694 | 46 | 12 | 9 | 0.714 | 0.079333333 | 45.33333333 | | 47 | 12 | 12 | 0.994 | 0.082833333 | 47.33333333 | | 48 | 12 | 9 | 0.95 | 0.105555556 | 60.31746032 | | 49 | 16 | 14 | 0.963 | 0.068785714 | 39.30612245 | 38.9307954 | 50 | 16 | 16 | 0.945 | 0.0590625 | 33.75 | | 51 | 16 | 13 | 0.995 | 0.076538462 | 43.73626374 | | 52 | 0 | 0 | 0 | 0 | 0 | | 53 | 0 | 0 | 0 | 0 | 0 | 38.39285047 | 54 | 24 | 20 | 1.068 | 0.0534 | 30.51428571 | | 55 | 24 | 21 | 1.55 | 0.073809524 | 42.17687075 | | 56 | 24 | 17 | 1.264 | 0.074352941 | 42.48739496 | |
Table 8.4 Master Summary Table: Effect of Interspecific Competition on Mustard Pot # | # of Wheat Seeds Planted | # of Mustard Seeds Planted | # of Mustard Plants Harvested | Total Mustard Biomass | Per Plant Biomass for Mustard (g) | Standard. Per Plant Biomass for Mustard | Avg. of Treatment Stand. Per Plant Biomass for Mustard | | | | | (g) | | (%) | (%) | 57 | 1 | 1 | 1 | 0.203 | 0.203 | 122.844175 | 91.9062027 | 58 | 1 | 1 | 1 | 0.18 | 0.18 | 108.92587 | | 59 | 1 | 1 | 2 | 0.243 | 0.1215 | 73.5249622 | | 60 | 1 | 1 | 1 | 0.103 | 0.103 | 62.3298033 | | 61 | 2 | 2 | 3 | 0.33 | 0.11 | 66.5658094 | 70.4992436 | 62 | 2 | 2 | 15 | 0 | 0 | 0 | | 63 | 2 | 2 | 1 | 0.123 | 0.123 | 74.4326778 | | 64 | 2 | 2 | 0 | 0 | 0 | 0 | | 65 | 4 | 4 | 2 | 0.086 | 0.043 | 26.02118 | 36.2581947 | 66 | 4 | 4 | 3 | 0.257 | 0.08566667 | 51.8406455 | | 67 | 4 | 4 | 4 | 0.18 | 0.045 | 27.2314675 | | 68 | 4 | 4 | 5 | 0.33 | 0.066 | 39.9394856 | | 69 | 6 | 6 | 4 | 0.281 | 0.07025 | 42.5113464 | 34.1578417 | 70 | 6 | 6 | 6 | 0.188 | 0.03133333 | 18.9611699 | | 71 | 6 | 6 | 5 | 0.242 | 0.0484 | 29.2889561 | | 72 | 6 | 6 | 5 | 0.379 | 0.0758 | 45.8698941 | | 73 | 8 | 8 | 8 | 0.09 | 0.01125 | 6.80786687 | 12.6323752 | 74 | 8 | 8 | 6 | 0.18 | 0.03 | 18.1543116 | | 75 | 8 | 8 | 9 | 0.153 | 0.017 | 10.2874433 | | 76 | 8 | 8 | 8 | 0.202 | 0.02525 | 15.279879 | | 77 | 12 | 12 | 10 | 0.264 | 0.0264 | 15.9757943 | 12.5707147 | 78 | 12 | 12 | 11 | 0.263 | 0.02390909 | 14.4684363 | | 79 | 12 | 12 | 12 | 0.205 | 0.01708333 | 10.3378719 | | 80 | 12 | 12 | 10 | 0.157 | 0.0157 | 9.50075643 | |
Table 8.5 Master Summary Table: Effect of Interspecific Competition on Wheat
Pot # | # of Mustard Seeds Planted | # of Wheat Seeds Planted | # of Wheat | Total Wheat Biomass | Per Plant Biomass for Wheat (g) | Standard.
Per Plant Biomass for Wheat | Avg. of Treatment Stand. Per Plant Biomass for Wheat | | | | Plants Harvested | (g) | | (%) | (%) | 57 | 1 | 1 | 1 | 0.089 | 0.089 | 50.85714286 | 93.85714286 | 58 | 1 | 1 | 1 | 0.122 | 0.122 | 69.71428571 | | 59 | 1 | 1 | 1 | 0.151 | 0.151 | 86.28571429 | | 60 | 1 | 1 | 1 | 0.295 | 0.295 | 168.5714286 | | 61 | 2 | 2 | 2 | 0.46 | 0.23 | 131.4285714 | 120.2142857 | 62 | 2 | 2 | 2 | 0.273 | 0.1365 | 78 | | 63 | 2 | 2 | 1 | 0.244 | 0.244 | 139.4285714 | | 64 | 2 | 2 | 2 | 0.462 | 0.231 | 132 | | 65 | 4 | 4 | 4 | 0.78 | 0.195 | 111.4285714 | 85.31746032
| 66 | 4 | 4 | 3 | 0.41 | 0.136666667 | 78.0952381 | | 67 | 4 | 4 | 8 | remove | 0 | 0 | | 68 | 4 | 4 | 4 | 0.465 | 0.11625 | 66.42857143 | | 69 | 6 | 6 | 5 | 0.54 | 0.108 | 61.71428571 | 61.86904762 | 70 | 6 | 6 | 6 | 0.603 | 0.1005 | 57.42857143 | | 71 | 6 | 6 | 6 | 0.65 | 0.108333333 | 61.9047619 | | 72 | 6 | 6 | 4 | 0.392 | 0.098 | 56 | | 73 | 8 | 8 | 11 | remove | 0 | 0 | 54.66836735 | 74 | 8 | 8 | 8 | 0.765 | 0.095625 | 54.64285714 | | 75 | 8 | 8 | 7 | 0.67 | 0.095714286 | 54.69387755 | | 76 | 8 | 8 | 16 | remove | 0 | 0 | | 77 | 12 | 12 | 12 | 0.963 | 0.08025 | 45.85714286 | 40.40584416 | 78 | 12 | 12 | 10 | 0.81 | 0.081 | 46.28571429 | | 79 | 12 | 12 | 11 | 0.782 | 0.071090909 | 40.62337662 | | 80 | 12 | 12 | 12 | 0.606 | 0.0505 | 28.85714286 | |
Figure 8.2: Effect of Intraspecific Competition on Mustard
Figure 8.3: Effect of Intraspecific Competition on Wheat
Figure 8.4: Effect of Interspecific Competition on Mustard
Figure 8.5: Effect of Interspecific Competition on Wheat
DISCUSSION Plants that is more competitive than other plants will get most of the essential nutrients in the soil. This includes having deep roots to extract water in the lower level during seasons of low precipitations (dry season). Plants which grow healthier have a larger biomass i.e. the mass of the specie is a given area or ecosystem. Based on tables 8.2 and 8.3, pots 1-4 for mustard and 29-32 for wheat were used as a baseline for each species because it only had one seed of the specie in each pot, resulting in every yield. This is because it has all nutrients at its disposal and doesn’t have to compete with other species or individuals of the same species. It is important to have this baseline because it’s a standard and can be used to compare the per plant biomass of the experimental pots, and helps us determine if any form of competition leading to negative or positive effect was present. The treatment average was calculated because mustard and wheat species do not tolerate competition to the same degree. There was an intraspecific competition between individual species of mustard according to figure 1, since the per plant biomass based on the density of seeds was decreasing as the number of mustard plants in a pot increased. Hence, the high R2 value of 0.9621. This value is significant because it’s >0.5 indicating that there is correlation between the seed densities and the average standardized per plant biomass. The closer the R2 value is to 1, the higher the correlation between two variables. As a result, our data indicates that there is an intraspecific competition between individuals of mustard. Also, intraspecific competition is evident in wheat. Figure 8.3 depicts a decreasing trend of plant growth as the densities of seeds planted increases. This means that that the higher the wheat seeds in a pot, the lower the yield because each plant is competing for the same resource. I believe there was a decrease in biomass yield because there is exclusion occurring because competition is taking place within the same specie family. None is better than or more competitive than the other, which reduces the amount of resource each plant gets leading to reduced growth. The average standardized per plant biomass of wheat baseline pot is greater than the average standardized per plant biomass of wheat pots with 4,8,12, 16 and 24 seeds (Figure 8.3). In addition, the R2 value is 0.843, which indicates a correlation between seed density and the average standardized per plant biomass. Generally, intraspecific competition among plant species leads to plant growth reduction as the density of plant species growing in the same location increases. However, the average standardized per plant biomass of a treatment with high plant density can be greater than the baseline per plant biomass of the species. When plant species have access to more water, light source and essential nutrients, they demonstrate growth. This is the case with both the mustard and wheat species. Pots with 2 wheat seeds respectively have higher average standardized per plant biomass, when compared to the wheat baseline pot, which have only one seed each, according to table 8.3. This may be due to the fact that the baseline pots did not get enough water and light source, whereas pots with 2 seeds have sufficient water and light source available to them. Hence, the baseline pots would show less growth, when compared to pots with varying plant density as shown in Figure 8.3. Wheat and mustard do not only compete among individuals of their specie, but they also compete with other species for the essential nutrients, water and access to light. Based on Figure 8.4 and 8.5 compared to figures 8.2 and 8.3, the nature of interaction between wheat and mustard is interspecific (-,-) competition because there is a decrease in the average of treatment standardized per plant biomass for each species. For example, table 8.2 depicts that the average standardized biomass for mustard when planted with 4 seeds alone is approximately 52.6%. This value compared to 36.3% for 2 mustard seeds planted along side with 2 wheat sides for a total of 4 seeds in the pot. Even when compared to 4 mustard seeds planted with 4 wheat seeds, the average standardized biomass is 12.6%. This is still lower than the average standardized biomass of 52.6% when grown exhibiting intraspecific competition. We compared the 4 mustard seeds from intraspecific competition to the 2 mustard seeds from the interspecific because the 2 mustard seeds where planted with 2 wheat seeds for a total of 4 seeds in the pot. As a result, it’s appropriate that we compare it to the same amount of total seeds in the pot because the resources are going to be divided by 4 for both pot types. When we look at wheat plants too, we notice the same trend here. For example, table 8.3 shows that the standardized biomass is approximately 123.6% for 2 wheat seed planted by itself, and table 8.5 shows 120.2% and 85.3% for 1 wheat seed and 2 wheat seeds planted with mustard seeds respectively. However, we observed that as the seed density for wheat increased the biomass increased also. This is note clearly seen in the figures but the values are noticeable in tables 8.3 and 8.5. When 4 wheat seeds were grown with mustard seeds, the standardized biomass was 85.3% compared to the standardized biomass of 63.7% for 8 wheat seeds. Hence, interaction is more beneficial when the density of seeds planted per pot is increased. Based on this data, mustard plant can be excluded from the area if the wheat plant is at a number where the biomass yield is at its largest. Also, wheat plants are more competitive that mustard plants as shown in table 8.4 and 8.5. For both types of interspecific competition, the standardized biomass for both mustard and wheat is comparatively lower than the 100% baseline biomass. The treatment average was calculated because it was the most balanced value from the replicates and used as a representative of what is going on in pots with that number of seeds. This is the value used for comparison both and within and between species rather than comparing each pot because conclusions based on such comparative evaluation are more accurate. Also, a lot of variables affect the growth in each pot which makes the data less accurate which is why you need to take the average especially for an experiment with 4replicates of a sample. Based on the data presented in the tables and figures, it is clear that the plants compete more intensely with conspecifics compared to heterospecifics. This is because the same species require the same resources for optimal growth and can noticed with the close range of standardized biomass yield between the pots with different mustard and wheat seeds in figure 8.2 and figure 8.3. Based on the results of this experiment, interspecific is not as intense; thus the species have different resource requirements because wheat plants have a stronger negative effect on mustard plants. When varying number of mustard and wheat species that were planted in the same pot, both species have shown growth. This clearly indicates that the two species have different resources requirements. If the two species would have competed intensely, they would not have plant growth. The data is reported in tables 8.4 and 8.5 and also depicted in figures 8.4 and 8.5. Looking at the interspecific data tables, wheat seeds tend to have a higher standardized biomass when treated with mustard plants compared to mustard plants when planted with wheat plants. For example, in table 8.4, pots containing 8 mustard seeds had a standardized biomass of 12.6% compared to 54.7% for 8 wheat seeds in table 8.5. The same trend is evident within the rest of the pots. Therefore we can conclude that wheat plants are more competitive than mustard plants.
APPENDIX
A. Conspecifics # Mustard seed | Avg. std per | planted | plant biomass | 1 | 100 | 2 | 81.896117 | 4 | 78.10136157 | 8 | 52.56213529 | 12 | 31.66567338 | 16 | 30.69051221 | 24 | 23.39187606 | # wheat seed | Avg. std per | planted | plant biomass | 1 | 100 | 2 | 123.6428571 | 4 | 76.16666667 | 8 | 63.68112245 | 12 | 49.440803694 | 16 | 38.9307954 | 24 | 38.39285047 |
# wheat seed | Avg. std per | planted | plant biomass | 1 | 93.85714286 | 2 | 120.2142857 | 4 | 85.31746032 | 6 | 61.86904762 | 8 | 54.66836735 | 12 | 40.40584416 | B. Heterospecifics. # Mustard seed | Avg. std per | planted | plant biomass | 1 | 91.9062027 | 2 | 70.4992436 | 4 | 36.2581947 | 6 | 34.1578417 | 8 | 12.6323752 | 12 | 12.5707147 |
Ecology Lab Report 10
Section 7649
Competition Data
November 28, 2012
INTRODUCTION Competition, whether it is for food, water, shelter or a mate occurs between any living organisms in a mutual habitat. They are likely to be in close proximity and this interaction could either be harmful or helpful to each organism. When the interaction is beneficial, it is considered to be mutualism, either being obligate or facultative. However, interactions between different species may take different forms, such as commensalism, parasitism, amensalism etc. Competition often results in reduced growth and/or lower seed production of one or both individuals or species when compared to the yield of either when grown alone. There …show more content…
are two types of competition; intraspecific and interspecific competition. Intraspecific competition refers to competition within a specific species and intraspecific competition is competition between different species.
Interspecific competition between different species may not be observed, if the resource requirements of the species are different. Interspecific competing species may also co-exist because no one species is competitive enough to drive out the other species. When one type of specie is a much better competitor compared to the other species, it is possible for competitive exclusion to occur, eliminating the other species from the community. Individuals of the same species may avoid competition by partitioning the resources (guild). Small species that mature rapidly are suitable for intraspecific and interspecific competition experiments. This laboratory exercise focuses both types on interactions using wheat and mustard seeds. Our goal was to observe intraspecific competition in mustard and in wheat by varying the density of plants and observing plant growth. We will also examine interspecific competition between mustard (Brassica) and wheat (Triticum) plants by planting a variety of mixtures of the two species together in the same pot. Variation in plant density can have a profound effect on yield …show more content…
per plant. This experiment gives us the opportunity to gain precision and statistically meaning predications.
MATERIALS & METHODS
The seeds were planted using planting pots and they were evenly spaced in order to avoid crowding. The seeds were then covered with a thin layer of soil. Each pot was numbered with respect to the number and type of seeds it contains. The pots were placed in the green house garden and watered routinely. Extra fertilizers were not added to the planting pots. The plants were allowed to grow for about 5-8 weeks. At around the eighth week, the plants were harvested and dried in an oven at 70 C0 for 24 hours. Then, they were weighed and the biomass of each species was recorded.
RESULTS
Tables 8.2, 8.3, 8.4 and 8.5 depicts the master summary tables including # of seeds of each specie planted, # of plants harvested, total mustard biomass, standardized per plant biomass and the averaged on the standardized biomass. The figures accounts for the number of seeds planted versus the average standard per plant biomass. The R² values for figures 8.2, 8.3, 8.4 and 8.5 were 0.9621, 0.843, 0.9649 and 0.7267 respectively. The baseline per plant biomass for mustard was determined to be 0.16525 and 0.175 for wheat.
Table 8.2 Master Summary Table: Effect of Intraspecific Competition on Mustard Pot # | # Mustard Seeds Planted | # Mustard Plants | Total Mustard Biomass (g) | Per Plant Biomass for Mustard (g) | Standardized Per Plant Biomass for Mustard | Average of Treatment Standardized Per Plant Biomass for Mustard | | | Harvested | | | (%) | (%) | 1 | 1 | 1 | 0.06 | 0.06 | Notapplicable | 100 | 2 | 1 | 1 | 0.155 | 0.155 | | | 3 | 1 | 1 | 0.325 | 0.325 | | | 4 | 1 | 1 | 0.121 | 0.121 | | | 5 | 2 | 1 | 0.175 | 0.175 | 105.9001513 | 81.896117 | 6 | 2 | 2 | 0.342 | 0.171 | 103.4795764 | | 7 | 2 | 2 | 0.12 | 0.06 | 36.3086233 | | 8 | 2 | 0 | 0 | 0 | 0 | | 9 | 4 | 2 | 0.205 | 0.1025 | 62.02723147 | 78.10136157 | 10 | 4 | 4 | 0.376 | 0.094 | 56.88350983 | | 11 | 4 | 1 | 0.195 | 0.195 | 118.0030257 | | 12 | 4 | 4 | 0.499 | 0.12475 | 75.49167927 | | 13 | 8 | 5 | 0.57 | 0.114 | 68.98638427 | 52.56213529 | 14 | 8 | 7 | 0.52 | 0.074285714 | 44.95353361 | | 15 | 8 | 8 | 0.55 | 0.06875 | 41.60363086 | | 16 | 8 | 5 | 0.452 | 0.0904 | 54.70499244 | | 17 | 12 | 11 | 0.533 | 0.048454545 | 29.32196397 | 31.66567338 | 18 | 12 | 11 | 0.682 | 0.062 | 37.51891074 | | 19 | 12 | 10 | 0.473 | 0.0473 | 28.62329803 | | 20 | 12 | 9 | 0.464 | 0.051555556 | 31.19852076 | | 21 | 16 | 15 | 0.716 | 0.047733333 | 28.88552698 | 30.69051221 | 22 | 16 | 15 | 0.74 | 0.049333333 | 29.85375693 | | 23 | 16 | 14 | 0.654 | 0.046714286 | 28.26885671 | | 24 | 16 | 12 | 0.709 | 0.059083333 | 35.75390822 | | 25 | 24 | 18 | 0.801 | 0.0445 | 26.92889561 | 23.39187606 | 26 | 24 | 21 | 0.821 | 0.039095238 | 23.65823788 | | 27 | 24 | 19 | 0.708 | 0.037263158 | 22.54956605 | | 28 | 24 | 21 | 0.709 | 0.033761905 | 20.4308047 | |
Table 8.3 Master Summary Table: Effect of Intraspecific Competition on Wheat Pot # | # Wheat Seeds Planted | # Wheat Plants Harvested | Total Wheat Biomass (g) | Per Plant Biomass for Wheat (g) | Standardized Per Plant Biomass for Wheat (%) | Average of Treatment Standardized Per Plant Biomass for Wheat (%) | | | | | | | | 29 | 1 | 1 | 0.081 | 0.081 | Not Applicable | 100 | 30 | 1 | 1 | 0.159 | 0.159 | | | 31 | 1 | 1 | 0.231 | 0.231 | | | 32 | 1 | 1 | 0.229 | 0.229 | | | 33 | 2 | 2 | 0.267 | 0.1335 | 76.28571429 | 123.6428571 | 34 | 2 | 2 | 0.47 | 0.235 | 134.2857143 | | 35 | 2 | 1 | 0.27 | 0.27 | 154.2857143 | | 36 | 2 | 1 | 0.227 | 0.227 | 129.7142857 | | 37 | 4 | 3 | 0.464 | 0.154666667 | 88.38095238 | 76.16666667 | 38 | 4 | 3 | 0.354 | 0.118 | 67.42857143 | | 39 | 4 | 2 | 0.213 | 0.1065 | 60.85714286 | | 40 | 4 | 4 | 0.616 | 0.154 | 88 | | 41 | 8 | 7 | 0.929 | 0.132714286 | 75.83673469 | 63.68112245 | 42 | 8 | 7 | 0.821 | 0.117285714 | 67.02040816 | | 43 | 8 | 8 | 0.797 | 0.099625 | 56.92857143 | | 44 | 8 | 7 | 0.673 | 0.096142857 | 54.93877551 | | 45 | 12 | 11 | 0.862 | 0.078363636 | 44.77922078 | 49.44083694 | 46 | 12 | 9 | 0.714 | 0.079333333 | 45.33333333 | | 47 | 12 | 12 | 0.994 | 0.082833333 | 47.33333333 | | 48 | 12 | 9 | 0.95 | 0.105555556 | 60.31746032 | | 49 | 16 | 14 | 0.963 | 0.068785714 | 39.30612245 | 38.9307954 | 50 | 16 | 16 | 0.945 | 0.0590625 | 33.75 | | 51 | 16 | 13 | 0.995 | 0.076538462 | 43.73626374 | | 52 | 0 | 0 | 0 | 0 | 0 | | 53 | 0 | 0 | 0 | 0 | 0 | 38.39285047 | 54 | 24 | 20 | 1.068 | 0.0534 | 30.51428571 | | 55 | 24 | 21 | 1.55 | 0.073809524 | 42.17687075 | | 56 | 24 | 17 | 1.264 | 0.074352941 | 42.48739496 | |
Table 8.4 Master Summary Table: Effect of Interspecific Competition on Mustard Pot # | # of Wheat Seeds Planted | # of Mustard Seeds Planted | # of Mustard Plants Harvested | Total Mustard Biomass | Per Plant Biomass for Mustard (g) | Standard. Per Plant Biomass for Mustard | Avg. of Treatment Stand. Per Plant Biomass for Mustard | | | | | (g) | | (%) | (%) | 57 | 1 | 1 | 1 | 0.203 | 0.203 | 122.844175 | 91.9062027 | 58 | 1 | 1 | 1 | 0.18 | 0.18 | 108.92587 | | 59 | 1 | 1 | 2 | 0.243 | 0.1215 | 73.5249622 | | 60 | 1 | 1 | 1 | 0.103 | 0.103 | 62.3298033 | | 61 | 2 | 2 | 3 | 0.33 | 0.11 | 66.5658094 | 70.4992436 | 62 | 2 | 2 | 15 | 0 | 0 | 0 | | 63 | 2 | 2 | 1 | 0.123 | 0.123 | 74.4326778 | | 64 | 2 | 2 | 0 | 0 | 0 | 0 | | 65 | 4 | 4 | 2 | 0.086 | 0.043 | 26.02118 | 36.2581947 | 66 | 4 | 4 | 3 | 0.257 | 0.08566667 | 51.8406455 | | 67 | 4 | 4 | 4 | 0.18 | 0.045 | 27.2314675 | | 68 | 4 | 4 | 5 | 0.33 | 0.066 | 39.9394856 | | 69 | 6 | 6 | 4 | 0.281 | 0.07025 | 42.5113464 | 34.1578417 | 70 | 6 | 6 | 6 | 0.188 | 0.03133333 | 18.9611699 | | 71 | 6 | 6 | 5 | 0.242 | 0.0484 | 29.2889561 | | 72 | 6 | 6 | 5 | 0.379 | 0.0758 | 45.8698941 | | 73 | 8 | 8 | 8 | 0.09 | 0.01125 | 6.80786687 | 12.6323752 | 74 | 8 | 8 | 6 | 0.18 | 0.03 | 18.1543116 | | 75 | 8 | 8 | 9 | 0.153 | 0.017 | 10.2874433 | | 76 | 8 | 8 | 8 | 0.202 | 0.02525 | 15.279879 | | 77 | 12 | 12 | 10 | 0.264 | 0.0264 | 15.9757943 | 12.5707147 | 78 | 12 | 12 | 11 | 0.263 | 0.02390909 | 14.4684363 | | 79 | 12 | 12 | 12 | 0.205 | 0.01708333 | 10.3378719 | | 80 | 12 | 12 | 10 | 0.157 | 0.0157 | 9.50075643 | |
Table 8.5 Master Summary Table: Effect of Interspecific Competition on Wheat
Pot # | # of Mustard Seeds Planted | # of Wheat Seeds Planted | # of Wheat | Total Wheat Biomass | Per Plant Biomass for Wheat (g) | Standard.
Per Plant Biomass for Wheat | Avg. of Treatment Stand. Per Plant Biomass for Wheat | | | | Plants Harvested | (g) | | (%) | (%) | 57 | 1 | 1 | 1 | 0.089 | 0.089 | 50.85714286 | 93.85714286 | 58 | 1 | 1 | 1 | 0.122 | 0.122 | 69.71428571 | | 59 | 1 | 1 | 1 | 0.151 | 0.151 | 86.28571429 | | 60 | 1 | 1 | 1 | 0.295 | 0.295 | 168.5714286 | | 61 | 2 | 2 | 2 | 0.46 | 0.23 | 131.4285714 | 120.2142857 | 62 | 2 | 2 | 2 | 0.273 | 0.1365 | 78 | | 63 | 2 | 2 | 1 | 0.244 | 0.244 | 139.4285714 | | 64 | 2 | 2 | 2 | 0.462 | 0.231 | 132 | | 65 | 4 | 4 | 4 | 0.78 | 0.195 | 111.4285714 | 85.31746032
| 66 | 4 | 4 | 3 | 0.41 | 0.136666667 | 78.0952381 | | 67 | 4 | 4 | 8 | remove | 0 | 0 | | 68 | 4 | 4 | 4 | 0.465 | 0.11625 | 66.42857143 | | 69 | 6 | 6 | 5 | 0.54 | 0.108 | 61.71428571 | 61.86904762 | 70 | 6 | 6 | 6 | 0.603 | 0.1005 | 57.42857143 | | 71 | 6 | 6 | 6 | 0.65 | 0.108333333 | 61.9047619 | | 72 | 6 | 6 | 4 | 0.392 | 0.098 | 56 | | 73 | 8 | 8 | 11 | remove | 0 | 0 | 54.66836735 | 74 | 8 | 8 | 8 | 0.765 | 0.095625 | 54.64285714 | | 75 | 8 | 8 | 7 | 0.67 | 0.095714286 | 54.69387755 | | 76 | 8 | 8 | 16 | remove | 0 | 0 | | 77 | 12 | 12 | 12 | 0.963 | 0.08025 | 45.85714286 | 40.40584416 | 78 | 12 | 12 | 10 | 0.81 | 0.081 | 46.28571429 | | 79 | 12 | 12 | 11 | 0.782 | 0.071090909 | 40.62337662 | | 80 | 12 | 12 | 12 | 0.606 | 0.0505 | 28.85714286 | |
Figure 8.2: Effect of Intraspecific Competition on Mustard
Figure 8.3: Effect of Intraspecific Competition on Wheat
Figure 8.4: Effect of Interspecific Competition on Mustard
Figure 8.5: Effect of Interspecific Competition on Wheat
DISCUSSION Plants that is more competitive than other plants will get most of the essential nutrients in the soil. This includes having deep roots to extract water in the lower level during seasons of low precipitations (dry season). Plants which grow healthier have a larger biomass i.e. the mass of the specie is a given area or ecosystem. Based on tables 8.2 and 8.3, pots 1-4 for mustard and 29-32 for wheat were used as a baseline for each species because it only had one seed of the specie in each pot, resulting in every yield. This is because it has all nutrients at its disposal and doesn’t have to compete with other species or individuals of the same species. It is important to have this baseline because it’s a standard and can be used to compare the per plant biomass of the experimental pots, and helps us determine if any form of competition leading to negative or positive effect was present. The treatment average was calculated because mustard and wheat species do not tolerate competition to the same degree. There was an intraspecific competition between individual species of mustard according to figure 1, since the per plant biomass based on the density of seeds was decreasing as the number of mustard plants in a pot increased. Hence, the high R2 value of 0.9621. This value is significant because it’s >0.5 indicating that there is correlation between the seed densities and the average standardized per plant biomass. The closer the R2 value is to 1, the higher the correlation between two variables. As a result, our data indicates that there is an intraspecific competition between individuals of mustard. Also, intraspecific competition is evident in wheat. Figure 8.3 depicts a decreasing trend of plant growth as the densities of seeds planted increases. This means that that the higher the wheat seeds in a pot, the lower the yield because each plant is competing for the same resource. I believe there was a decrease in biomass yield because there is exclusion occurring because competition is taking place within the same specie family. None is better than or more competitive than the other, which reduces the amount of resource each plant gets leading to reduced growth. The average standardized per plant biomass of wheat baseline pot is greater than the average standardized per plant biomass of wheat pots with 4,8,12, 16 and 24 seeds (Figure 8.3). In addition, the R2 value is 0.843, which indicates a correlation between seed density and the average standardized per plant biomass. Generally, intraspecific competition among plant species leads to plant growth reduction as the density of plant species growing in the same location increases. However, the average standardized per plant biomass of a treatment with high plant density can be greater than the baseline per plant biomass of the species. When plant species have access to more water, light source and essential nutrients, they demonstrate growth. This is the case with both the mustard and wheat species. Pots with 2 wheat seeds respectively have higher average standardized per plant biomass, when compared to the wheat baseline pot, which have only one seed each, according to table 8.3. This may be due to the fact that the baseline pots did not get enough water and light source, whereas pots with 2 seeds have sufficient water and light source available to them. Hence, the baseline pots would show less growth, when compared to pots with varying plant density as shown in Figure 8.3. Wheat and mustard do not only compete among individuals of their specie, but they also compete with other species for the essential nutrients, water and access to light. Based on Figure 8.4 and 8.5 compared to figures 8.2 and 8.3, the nature of interaction between wheat and mustard is interspecific (-,-) competition because there is a decrease in the average of treatment standardized per plant biomass for each species. For example, table 8.2 depicts that the average standardized biomass for mustard when planted with 4 seeds alone is approximately 52.6%. This value compared to 36.3% for 2 mustard seeds planted along side with 2 wheat sides for a total of 4 seeds in the pot. Even when compared to 4 mustard seeds planted with 4 wheat seeds, the average standardized biomass is 12.6%. This is still lower than the average standardized biomass of 52.6% when grown exhibiting intraspecific competition. We compared the 4 mustard seeds from intraspecific competition to the 2 mustard seeds from the interspecific because the 2 mustard seeds where planted with 2 wheat seeds for a total of 4 seeds in the pot. As a result, it’s appropriate that we compare it to the same amount of total seeds in the pot because the resources are going to be divided by 4 for both pot types. When we look at wheat plants too, we notice the same trend here. For example, table 8.3 shows that the standardized biomass is approximately 123.6% for 2 wheat seed planted by itself, and table 8.5 shows 120.2% and 85.3% for 1 wheat seed and 2 wheat seeds planted with mustard seeds respectively. However, we observed that as the seed density for wheat increased the biomass increased also. This is note clearly seen in the figures but the values are noticeable in tables 8.3 and 8.5. When 4 wheat seeds were grown with mustard seeds, the standardized biomass was 85.3% compared to the standardized biomass of 63.7% for 8 wheat seeds. Hence, interaction is more beneficial when the density of seeds planted per pot is increased. Based on this data, mustard plant can be excluded from the area if the wheat plant is at a number where the biomass yield is at its largest. Also, wheat plants are more competitive that mustard plants as shown in table 8.4 and 8.5. For both types of interspecific competition, the standardized biomass for both mustard and wheat is comparatively lower than the 100% baseline biomass. The treatment average was calculated because it was the most balanced value from the replicates and used as a representative of what is going on in pots with that number of seeds. This is the value used for comparison both and within and between species rather than comparing each pot because conclusions based on such comparative evaluation are more accurate. Also, a lot of variables affect the growth in each pot which makes the data less accurate which is why you need to take the average especially for an experiment with 4replicates of a sample. Based on the data presented in the tables and figures, it is clear that the plants compete more intensely with conspecifics compared to heterospecifics. This is because the same species require the same resources for optimal growth and can noticed with the close range of standardized biomass yield between the pots with different mustard and wheat seeds in figure 8.2 and figure 8.3. Based on the results of this experiment, interspecific is not as intense; thus the species have different resource requirements because wheat plants have a stronger negative effect on mustard plants. When varying number of mustard and wheat species that were planted in the same pot, both species have shown growth. This clearly indicates that the two species have different resources requirements. If the two species would have competed intensely, they would not have plant growth. The data is reported in tables 8.4 and 8.5 and also depicted in figures 8.4 and 8.5. Looking at the interspecific data tables, wheat seeds tend to have a higher standardized biomass when treated with mustard plants compared to mustard plants when planted with wheat plants. For example, in table 8.4, pots containing 8 mustard seeds had a standardized biomass of 12.6% compared to 54.7% for 8 wheat seeds in table 8.5. The same trend is evident within the rest of the pots. Therefore we can conclude that wheat plants are more competitive than mustard plants.
APPENDIX
A. Conspecifics # Mustard seed | Avg. std per | planted | plant biomass | 1 | 100 | 2 | 81.896117 | 4 | 78.10136157 | 8 | 52.56213529 | 12 | 31.66567338 | 16 | 30.69051221 | 24 | 23.39187606 | # wheat seed | Avg. std per | planted | plant biomass | 1 | 100 | 2 | 123.6428571 | 4 | 76.16666667 | 8 | 63.68112245 | 12 | 49.440803694 | 16 | 38.9307954 | 24 | 38.39285047 |
# wheat seed | Avg. std per | planted | plant biomass | 1 | 93.85714286 | 2 | 120.2142857 | 4 | 85.31746032 | 6 | 61.86904762 | 8 | 54.66836735 | 12 | 40.40584416 | B. Heterospecifics. # Mustard seed | Avg. std per | planted | plant biomass | 1 | 91.9062027 | 2 | 70.4992436 | 4 | 36.2581947 | 6 | 34.1578417 | 8 | 12.6323752 | 12 | 12.5707147 |