Question

1. If you wanted to measure biodiversity in a grassland/meadow, which sampling method from the video would you use (quadrat or transect) and why?

2. If you wanted to measure diversity in a Douglas fir forest locally, which sampling method from the video would you use (quadrat or transect) and why?

3. What do you think is the biggest threat to species biodiversity in plant communities of the Pacific Northwest? Why?

Answer 1

ANSWER -

1) quadrat method is a kind of method in which a quadrat shaped frame is randomly laid down to mark out the specific area of the community to be sampled. within the quadrat the occurance of the plant is recorded with appropriate measures of abundance.

a grassland is a huge area of small grasses and shrubs, and in such areas the quadrat method is used, as in quadrat method random placement is fast and as being a frame it is not possible to measure random data in a doughlas type forest because of presence of huge trees which disrupts the frame , therefore, it is basically used in the grasslands. along with this, it is a good viable method.

2) transect method is a kind of method in which point sampling is being done to measure cover, in this method , point readings are taken up at either systematic or random locations along a tape that is extended to create a transact across the site

doughlas forest are a kind of forest which are occupiedwith huge trees and varied vegetations, in such ecosystem, transect method is successful, and not quadrat, therefore, it is used in doughals type, becasue the data provided by it is accurate, plus as the transect points can be taken up randomly anywhere in the forest, without being worried about the vegetation. also,it is comparitively a fast method . therefore, in doughlas forest transcet type sampling method is used

3)pacific northwest is regarded as the areas of the northern america which is surrounded by the pacific ocean, the pacific ocean, is the one of the region of america with high diversity and also prone to various threats .

few of the threats to the plant communities are as follows -

i) cutting down of the trees for commercial use on a large scale, golden paintbrush, water howellia , kincade lupines, marsh sandworts are the types of plants which are in the endangered list of the north west pacific

ii)the loss of habitat , through human activities, through encroachments of human population is another major threat to the area

iii) presence or introduction of invasive species which are non native in the area is another danger to the local ecosystem, as the invasive species fight for the same niche as that of the local plant species and compete for resources and in most cases , they overcome the host species and destroy them directly or indirectly, exmaple are - gypsy moth, they destroy the vegetation completely,another example is oregon noxious weed which destorys the native plant species and grows and spread rapidly.

iv) change in the climatic conditions over time is another reason for the loss of the habitat of plants in the region.

v) hunting down of predators, which leads to an increase in the preys in the area causes an extreme vegetation loss, as excess of herbivores destroys the native species.

vi) deforestation done by humans for self benefits is the other one, as this results into loss of forest area and also decrement of the plant species.

these are few of the reasons with some examples for the loss of plant species in the north west pacific