I’m not sure where to begin writing about all that I have experienced so far in just the two weeks that I’ve been a part of the CLM Internship at San Diego Zoo Global, so I’ll just start from the beginning. It was not the usual first day, in that I was lucky enough to be able to go out in the field with my co-workers and assist with a current restoration project that was started two years ago. We went out to Lake Skinner County Reserve east of Temecula in Riverside County to water bunchgrass seedlings (10,000 of them!) that were planted one month ago. This season has been a dry one, so we needed to water the plants by hand. The bunchgrass, with its more open form, has been planted because invasive grasses have taken over the area. This has been problematic for Stephen’s Kangaroo Rat since the thick cover of invasive annual grass makes it difficult for the Stephen’s kangaroo rats to get around. After we successfully watered all the plots we were done with the field-work, for that week.
Then, back at the Institute of Applied Plant Ecology I began learning about the processing of seeds, which is fabulous once you complete a whole seed lot! The process varies, depending on the species and the seeds. The overall take on processing the seeds is to first make a separation based on differences in size. This is done by rubbing the seeds through several different screens in order to divide out the debris from the seeds. Once this is done the seeds are put into an air separator, which further divides out the seeds from the debris, based on differences in weight. The air separator can be a tricky thing because you want to make sure you are getting rid of debris, not seeds. So one must be sure to check the debris canister under the microscope to make sure there aren’t any seeds. If there are seeds, then you have to check the seeds to see if they are full or empty. Sometimes the seeds in the debris canister can be full, that is why it is important to check by cutting them open under the microscope. Once the seed lot has been passed through the air separator, it is ready to be hand-cleaned. The air separator does a good job getting rid of small twigs, branches, etc, but it can’t get everything so that is why hand-cleaning is necessary for seedlots that will be stored for gene conservation. (Seedlots used for restoration generally are not hand-cleaned. I’ve been hand-cleaning a seed lot for a few days now, and it is very rewarding seeing the clean seed lot increase in size!) After hand-cleaning the seeds are placed into a drying room where their moisture content is greatly reduced. We have to dry the seeds properly so they can be frozen for proper long-term storage. After the seeds have been in the freezer for a month, germination trials are done on the seeds, because what is the point of storing seeds if we don’t know how to “wake” them up, overcoming their dormancy mechanisms? I’ve also had an introduction to the theory behind the germination trials and the different techniques, but next week I will actually get to do one! I’m really looking forward to “waking up” seeds that have been in storage!
This last week I also did my first voucher on a couple Ceanothus species! It wasn’t as hard as I thought, but I’ve been told that Ceanothus’ are easier to voucher, compared to vouchering wildflowers. Afterwards, another intern and myself keyed out the plants to make sure what we vouchered was what we thought it was, Ceanothus tomentosus and C. crassifolius.