Effects of Plant Population Density
The Effect of Population Density Among Plants
Ilustre M.N. and Pianka A.J. 2014
Table of contents
Line your pages numbers up
Table of contents…………………………………………………………………2
Abstract…………………………………………………………………………………..3
Introduction……………………………………………………………………………….3-4
Question………………………………………………………………………………….4
Hypothesis…………………………………………………………………………………4
Control variable…………………………………………………………………………….4-5
Independent variable ………………………………………………………………………….5
Dependent variable …………………………………………………………………………..5
Procedure………………………………………………………………………………………5
Material list…………………………………………………………………………………….5-6
Charts…………………………………………………………………………………………6-8
-Growth Chart…………………………………………………………………..6-7
-Average/Final Biomass……………………………………………………………7
-Line Graph ………………………………………………………………………….7-8
Eliminate the above and below
Pictures ………………………………………………………………………………………9-10
Conclusion………………………………………………………………………………10-11
Sources of error…………………………………………………………………………….11
Literature Cited …………………………………………………………………………….12
Abstract: Population density is one of the manygeneral alimiting factorsexistentin many of the living organisms in the environment. whichinfluences the growth of organism population growth. If a population is gonegrows unchecked in a certain environment, the population density inof a species may swell and cause major problems for other members of the population such as a lack of food or reduction in living space. The same problem of density in a population is possible in organisms such as plants. To test this possibility, 3three groups of 8 eight green bean seeds were placed into casings in which they were planted at different distances (save for one) from the recommended spaces. Each group of plants were was subjected underto the same growing conditions, from amount of water given, to the amount of sunlight each plant received. Once the green bean seeds were fully grown, they were removed harvested and measured for their height and biomass and height. The results from each group were then used to calculate an average biomass for each. From these results, it is shown that plants grown at 5five centimeters closer to each other had a mass .625 grams two values? This confuses me. What’s going on? (4.375 g) less than that of the plants grown at the recommended distance. The plants grown at 10 centimeters further had an average mass of 5 grams, .125 grams less than that of the plants grown at the recommended spacing. OK, now give me your conclusions too.
Introduction: All experienced farmers know that weather and temperature does not just affect plant growth. There are many other factors that contribute to a successful harvest than just the simple weather and temperature. One in particular is plant population density. High population density is a common problem in forests. Efforts to combat fires have led 9.5 million acres of Oregon forest to become overgrown and more fire-prone, according to Russ Hoeflich, (have to have a date)director of the Nature Conservancy in Oregon. He said that many trees are competing for water and becoming susceptible to disease and insect infestation because wildfires have not been allowed to thin forests naturally. But, this raises questions for farmers and botanists about, "Does population density affect plant growth? Will planting certain species of plants farther apart actually make the plants grow better?" Knowing the answer to this question just could mean a better quality product for farmers and botanists about. Previous research and field observations have shown that some plants will not be affected by population density at all" Harper (1977): summary, p. xvi; Ch. 7, pp. 195-235. Some may have a high level of tolerance to certain tightly knit or loosely knit communities. But, this may not be true for most plants. Does varying population density for plants really affect their growth?
Question:Can space be a limiting factor in plant growth?
Hypothesis:If bean seeds are planted closer than the recommended distance, then bean plants will have a lower biomass. This was predicted because Commercial seed producers recommended specific planting distances on their seed packets. Presumably this is because they have researched ideal growing conditions, including distance between plants. Seeds that are planted closer than recommended should experience intense competition for resources and therefore should have a lower biomass.
Just state the hypothesis
Control Variables:
-Water
-Light
-Soil type
-Tray size
-Temperature
Independent variable: Space between seeds
Dependent variable:Plant biomass
Procedure:The procedure in this experiment consisted of these steps:
-Put the same amount of soil specify in each of the nine containers.
-Plant the seeds closer than the recommended distance, plant seeds the recommended -distance and plant seeds further than recommend distance. Specify the distances
-Give all the seeds the same exact amount of water specify
-Set up the florescent grow lights
-recorded the height and biomass of each plant every 7 days
- Give the all the plants the same amount of water each day. Didn’t you already say this?
-give all the plants the same amount of light each day. Expose the plants to the same amount of light
- When plants get to flowering stage pull them out by the roots.
-Allow the plants to dry
- Measure the final biomass and make conclusion
Material List:The materials used in order to orchestrate this experiment were:
-Green Bean seeds of the same phenotype
-9 containers 55 cm by 18 cm (3 for each spacing)
-Soil (to fill containers)specify soil type. Potting soil?
-Water (to water the plants)well it’s not for you to drink!!
-Florescent grow light (regulated sunlight)
-Measuring cup (to measure water given to plants)
-Scale (to measure biomass of plants) specify. Triple beam?
-data sheet
-pen or pencil to write
-Labels to label containers
-ruler in cm to make measurements cm ruler
The results of the experiment proved the hypothesis is plausible, but not solid enough to be true.
Results
Plant Height
Growth Chart
Date / Spacing (CM) / Heights(CM)October 5, 2013 / 5cm / N/a seeds planted not germinated
October 5, 2013 / 10cm / N/a seeds planted not germinated
October 5, 2013 / 20cm / N/a seeds planted not germinated
October 12, 2013 / 5cm / 2,3,1,3,3,2,1,2
October 12, 2013 / 10cm / 3,2,2,1,2,3,2,3
October 12, 2013 / 20cm / 1,3,2,3,3,1,1,3
October 19, 2013 / 5cm / 2,5,4,4,6,5,4,7
October 19, 2013 / 10cm / 6,4,3,3,5,6,8,6
October 19, 2013 / 20cm / 4,6,7,5,8,6,4,7
October 26, 2013 / 5cm / 10,12,9,14,10,11,2,13
October 26, 2013 / 10cm / 12,11,12,13,17,16,14,21
October 26, 2013 / 20cm / 13,13,14,19,23,16,19,14
November 2, 2013 / 5cm / 24,2,13,10,19,11,25,19
November 2, 2013 / 10cm / 16,17,16,30,15,15,18,17
November 2, 2013 / 20cm / 15,23,26,14,14,18,20,17
November 9, 2013 / 5cm / 2,20,17,9,21,13,27,25
November 9, 2013 / 10cm / 20,32,21,21,19,19,18,17
November 9, 2013 / 20cm / 23,19,24,21,23,21,23,21
November 16, 2013 / 5cm / 2,19,22,17,12,22,26,29
November 16, 2013 / 10cm / 35,21,23,23,24,23,22,21
November 16, 2013 / 20cm / 26,24,30,22,20,22,20,20
November 23, 2013 / 5cm / 28,14,26,29,16,23,31,2
November 23, 2013 / 10cm / 22,22,25,23,22,24,22,32
November 23, 2013 / 20cm / 20,20,21,22,23,29,18,22
November 30, 2013 / 5cm / 27,22,29,23,23,16,20,2
November 30, 2013 / 10cm / 21,21,22,25,24,23,19,34
November 30, 2013 / 20cm / 24,19,24,22,24,28,7,23
December 7, 2013 / 5cm / 15,30,21,7,27,24,27,27
December 7, 2013 / 10cm / 29,20,24,27,14,23,23,36
December 7, 2013 / 20cm / 22,21,23,21,29,20,6,22
December 14, 2013 / 5cm / 15,31,22,7,28,24,28,27
December 14, 2013 / 10cm / 30,21,24,27,15,23,23,38
December 14, 2013 / 20cm / 22,21,23,29,21,6,22,39
Final Biomass Charts
Plant Spacing(CM) / Masses( in Grams)5cm / 4,4,4,4,4,5,5, 5
10cm / 5,5,5,5,5,5,5,6
20cm / 4,5,5,5,5,5,5,6
Final Average Biomass Average Chart
Plant Spacing (CM) / Mass Average( in Grams)5cm / 4.375
10cm / 5.125
20cm / 5.000
Plant Length height?Average
Week 1 / Week 2 / Week 3 / Week 4 / Week 5 / Week 6 / Week 7 / Week 8 / Week 9 / Week 10 / Week 11
5 cm / 0 / 2.215 / 4.625 / 12.125 / 15.375 / 16.75 / 18.625 / 21.125 / 20.25 / 20.5 / 21.375
10 cm / 0 / 2.215 / 5.125 / 14.5 / 18 / 20.875 / 24 / 24 / 23.625 / 23.25 / 23.625
20 cm / 0 / 2.215 / 11.375 / 16.315 / 18.375 / 21.875 / 23 / 21.1875 / 21.375 / 22.25 / 20.25
You need to label the x and y axis
This is a picture of plants a few days after planting. Plants after specific number of days
These are pictures of the plants after 3 weeks.
This is a picture after 11 weeks after the plants were pulled out and weighed for their biomass. Plants drying prior to measuring biomass
Conclusion:Although the Green Bean plants show that there would be a slight difference in plant growth when it comes to population density, the numbers seem to be too close to actually show that giving more space to a plant doesn’t actually benefit it. Yikes! Quite the run on sentence! Fix it! And you do not really tell me anything! However, the difference in the average biomasses of the plants grown at the recommended spacing of 10 cm and spacing at 5 cm shows that a densely populated area hinders growth in plants. beans
However, research shows by whom? that corn is heavily dependent on a rising population density and depending on the hybrid and the population density, the plants will yield a larger biomass and/or height. This evidence may point to the carrying capacity of Green Beans green beans to be smaller due to a different demand in nutrients necessary for growth. Competition due to population density is also evident in other members of the kingdom Plantae. For example, trees in densely packed forests are in competition for the most sunlight. Those who are blocked out by other trees that have already grown won’t no contractions survive or grow as much. The same can be said for other members of the Plant kingdom. Lower case
In conclusion, the test results were not solid enough what the heck does this mean?? Solid as in ice??? Lead?? Give me values!!! to prove that plant populations face pressures in Population Density, why are you capitalizing ? but evidence in nature, such as tightly packed forests show that population density has certain limits.
Sources of Error:
- Sample size is too small
- Beets, and Basil never fully germinated like the Green Beans.
- The conditions were suitable, but not beneficial for plant growth
- Plants started to die during the later weeks and were still measured after.???
Literature Cited
Dekker.J, 2011, Plant Density, Plant Form and Community Diversity, December 5, 2013,
Martin.P, 2013, What Plants Grow the Fastest From Seeds?, December 5, 2013
Anonymous, 2013, U.S. Corn Yields Growth Dependent On Increasing Plant Population Density, December 5, 2013
Lyon J.D.2009, How Do Plant Populations Affect Yield?, December 5, 2013,
Hakeet.K,et al,1991,Plant Population, December 5, 2013,