An experiment to investigate the population size and age structure of plant populations
Source: Experiments in Botany
Operation method
basic program
Principle
Population is a group of individuals of a certain plant in a certain time and space, which is a whole with independent characteristics, structure and function, and is a biological unit that exists objectively. Populations have their quantitative characteristics, age structure, spatial pattern, interactions between individuals and populations within a population, so each population must occupy a certain ecological position in its community, and populations also have the ability to regulate their own density according to environmental conditions.
Materials and Instruments
Benthic and herbaceous plant populations in areas of high concentration of plant species. Move 1 Survey on the number and age structure of woody plant populations Select a representative section of a woody plant population to be investigated, use GPS to measure the sample plot and record the latitude, longitude and altitude. Several sample squares are circled with sample ropes. Depending on the specific conditions of the population, the size of the sample squares can range from 10mx10m to 20mx25m, but the size of each sample square should be the same, and the corners of the sample squares are fixed with iron sticks and stakes. Investigate the following aspects and record the results in the population sample questionnaire: (1) Number of plants: Only the number of plants (including young plants) of the plants to be investigated in each sample plot will be counted, and the number of other species will not be counted most. (2) Plant height: Measure the height of the above-ground part of each plant of the investigated species, young plants and shorter plants are measured with a tape measure, and taller plants are measured with a height meter or visually inspected. (3) Diameter at breast height (DBH): Measure the circumference of the trunk at a height of 1.3 m of each plant in the surveyed population with a tape measure and convert it to diameter. This data is not required for young plants. (4) Age: To determine the age of each plant in the population under investigation, young plants can be judged according to bud scale scars, and adult plants can be judged according to the annual rings by taking wood cores with a perforator, or to make a rough guess according to the diameter at breast height and plant height. 2 Determination of biomass of herbaceous plant populations Select a representative sample plot in the herbaceous plant community to be measured, and measure the latitude, longitude and altitude of the sample plot with a GPS locator. A number of 1mx1m or 0.5mx0.5m sample plots were circled with sample ropes, and their corners were fixed with iron sticks or wooden stakes. Determine the biomass of the aboveground part according to the following steps (1) Mowing and weighing the fresh weight: Use scissors to quickly cut off the above-ground portion of the plant of the population in the sample square, weigh the fresh weight as soon as possible, and put the sample into a paper bag with a number. (2) Splitting of samples: If the stratified weight of the above-ground part is required to be determined, cut the samples according to the specified length (e.g., 5cm or 10cm) and place them in strict order. If the biomass is required to be calculated by organ, the samples should be divided according to stems, leaves, reproductive branches and so on. (3) Drying and weighing: Place the divided samples in a constant-temperature drying oven at 65℃ for 8-10h in time, and weigh the dry weight of each part of the plant on the ground. Based on the measured data, the biomass structure of the aboveground part of the population can be drawn. For more product details, please visit Aladdin Scientific website.
GPS or altimeter Altimeter Constant temperature drying oven Balance Sample rope Tape measure (30m 5m) Scissors Paper bag, etc.