Course Name, Course Number
Intra and Interspecific Competition in Plants
Plant competition encompasses a form of struggle due to exceedingly inadequate resources including nutrients, water, and sunlight. Competition is a type of interaction that is considered disadvantageous to elements involved. This is because plants have different methods of obtaining resources. While there are plants that can adapt well to the surrounding and the forces surrounding the environment, there are also plants that take a while before they can fully adapt. Adaptation is any structure or behavior that enables an organism to survive in its environment. It is an inherited trait that increases a population`s chance of survival and reproduction in a certain environment. Plants that are able to easily adapt to the place tend to acquire resources faster compared to other plants. Consequently, plants that are able to adapt well tend to maintain their development. These plants can continue to evolve despite the competition and if there be any effects on them, these are only minor.
In this study, interspecific and intraspecific competition among plant species was observed in order to identify the best possible arrangement of panting including the most favorable thickness of seeds and the most favorable combination of varied plant species. The main objective of this experiment is to seek balance between healthy growth and competition. Competition is an extremely vital portion of interaction among plants. There are basically two forms of competition that exist among plants – intraspecific and interspecific. Intraspecific competition is a type of competition that exists among plants of their own kinds while interspecific competition is a type of competition that exists among plants of different species. These two forms of competitions vary in terms of their impacts on plants. In an intraspecific completion, plants belonging to the same species will also require the same demands and will have the same structures that is used in obtaining resources. Under intraspecific competition, there are three major effects being considered including the average plant size (as plant density increases, the plant size decreases), the population size structure (hierarchical), and density mortality reliance. In an interspecific competition, various experimental designs have already been used in the past. One of these approaches is the replacement series in which proportionality is constantly altered while the overall density of the plant is kept constant. Additive design is another method used in which the proportionality and density of plants are altered thereby resulting to basic hyperbolic association amid the number of weeds and the total crop damage.
Materials and Methods
To study intraspecific and interspecific competition among plants, this experiment makes use of three kinds of plants – corn (Zea), sunflower (Helianthus), and barley (Hordeum). The experiment is divided into three parts: part 1 is solely for planting, part 2 is measurement of plant growth, and part 3 is dedicated to harvesting.
Part 1 – Planting
For the first part of this experiment, sunflower is used for intraspecific competition study and for interspecific competition – sunflower (Helianthus), corn (Zea), and barley (Hordeum) is used. For intraspecific competition, the sunflower is planted according to the following distances: 2 cm. (17 rows of 21 plants) 4 cm. (9 rows of 11 plants) 8 cm. (5 rows of 5 plants) and 16 cm. (3 rows of 3 plants). In an interspecific competition, the three plant species is planted with 4 cm space in between them and each species is planted alternately following this arrangement: Barley and Corn (9 rows of 11 plants) Barley and Sunflower (9 rows of 11 plants) Corn and Sunflower (9 rows of 11 plants) Barley only (9 rows of 11 plants) Corn only (9 rows of 11 plants) Corn, Sunflower, and Barley (9 rows of 11 plants).
Part 2 – Measurement of Plant Growth
For the second part of this experiment, plants that did not germinate during the first week are replaced and if the plant did not germinate, the marker is moved to the closest germinated conspecific prior to replacement. The germinated conspecific is measured for the entire experiment duration. The plants are continually measured in centimeters and recorded at weekly intervals. The height is measured from the surface of the soil to the apical part of the meristem. Average growth rate will then be calculated.
Part 3 – Harvesting
During harvest time, the sunflower in intraspecific completion is initially measured according to its height. Following this, 5 plants are cut off from soil and the measurement of each plant is taken and recorded as follows: length of first internode length of second internode length of third internode length of the fourth internode (if present) and width of widest leaf. The rest of the plants are cut and counted and placed in a paper bag with label of the type of competition. The bags will then be placed inside the oven for a week in order for plant productivity to be compared according to its dry weight. For interspecific competition, all plants used is measured and harvested. The plants are grouped according to their species. Plants of each species are kept in separate paper bags with label of the type of competition applied. The number of plant species is recorded to be able to get the average dry weight of each plant. The plants will then be dried in the oven for a week n order for plant productivity to be compared according to its dry weight.
Fargione, J., and Tilman, D. 2002. Competition and coexistence in terrestrial plants. In Competition and coexistence. Edited by Ulrich Sommer, and Boris Worm. Springer-Verlag New York Inc. USA Springer-Verlag, Berlin,Germany. Pages 165-206.
Grace, James B. Tilman, David. Perspectives on plant competition. Academic Press: San Diego. USA.
Lambers, H. Chapin., F Pons, Thijs L. Plant Physiological Ecology. Springer New York: New York. USA. Chapter 9E
Molles, Manuel Cahill, James F. Ecology: concepts and applications. Mcgraw-Hill Ryerson: New York. USA. Chapter 13
Morin, Peter J. 2011. Community Ecology (Second Edition).Wiley-Blackwell: West Sussex, UK. Chapters 2 & 3
Neal, Dick. 2004. Introduction to population biology. Cambridge University Press: New York. USA. Chapters 5 & 17