I'm working on the ecological assessment of one herb species, which basically entails its status assessment from nearly 30 different study locations using the quadrat sampling method. When we do phytosociology of herbaceous species, which includes all of the plants in that particular forest, we proceed like 10x10 for trees, then 5x5 for shrubs, and then 1x1 for herbs. But how many quadrats/sites will be needed to evaluate the status of a single herb?
I appreciate the suggestions in advance. Thank you
Kindly refer to this given link for the previously asked question, I hope you will get some relevant answers in it from the experts in the field.
https://www.researchgate.net/post/How_many_sampling_quadrats_are_sufficient_to_study_a_particular_forest_stand_or_ecosystem#:~:text=It%20definitely%20has%20to%20be,to%20a%20normal%20distribution%20%3A)&text=If%20it%20is%20pure%20forest,must%20be%20bigger%20and%20numerous.
Hello Kalpana; In studies of ants asking the same general question a common practice is to continue sampling until your species-area curve draws to an asymptote. At that point you "have sampled enough". Except in the most uniform communities, I've never reached an asymptote. That is, there there are many, very rare species that are unlikely to be sampled at all.
It is likely that your tree and shrub sampling will become uninteresting long before you have " sampled enough" of the herb stratum.
Best regards, Jim Des Lauriers
James Des Lauriers thank you for the suggestions, Sir.
As the species-area curve explains the relationship between the area and the number of species present there, we analyse this relationship to get a sense of precisely how many quadrats will be needed for all the species in the random sampling approach. However, I'm not sure if we should use the same approach to assess the ecological status of a particular species.
Hello Kalpana; I don't know what you mean by "ecological status". Can you characterize the term for me? Perhaps then I'll know something to say. Cheers, Jim Des Lauriers
James Des Lauriers Sir, in my research, Iam using the term ecological status to determine a species' status. Its density, frequency, and abundance in the specific forest type, which will eventually reveal information about its status, including whether the species is present in large numbers or low, whether its population is declining in a particular habitat, or increasing with the association of other associated species. Such kind of relations only.
Therefore, the minimal number of quadrats needed for sampling a single herb species is required because the study is focused on one particular plant species.
Thank you for your responses, Sir.
Regards, Kalpana Rautela
Kalpana; OK! Constructing a "Performance curve" of your accumulating quadrate data will answer your question. Make a graph with the X-axis being the sequence of 1 m quadrates from the first to the last. The Y-axis is the cumulative mean number of individuals in a plot. The plotted line will jump around for a while but will eventually settle on a value that varies little. When the mean stops fluctuating, you can stop sampling. Best regards, Jim Des Lauriers