Hi, we are in the Botanical Garden of Barcelona. Botanical gardens have many important roles for society and an important role is the role that they have for environmental education and outreach. Another goal is conservation, but in the botanical gardens all over the world, we can find important seed bank collections. The seed bank collections are important for conservation actions, like for example, reintroduction of a species in the natural environment. Another important objective is the research, so that we will find important researchers in different botanical gardens all over the world. But we are not going to visit this botanical garden, but the Botanical Institute of Barcelona and there we can see the oldest herbarium of Spain. We will meet Dr. Neus Nualart, who is one of the curators of this herbarium and her research is focused on Taxonomy, Biodiversity, and Ecological Niche Modeling. Hi Neus. Now, we are in the herbarium of the Botanical Institute of Barcelona. Could you explain to us what can we find here and what is an herbarium? Hi Sandra, here in an herbarium, we can find the specimens of dried and pressed plants. An herbarium is very important to preserve all these specimens because this collection constitute permanent records of the distribution of factors through the space and the time. Here in this herbarium, this is the BC herbarium and we have 800,000 specimens. We have all the specimens arranged by alphabetic order, but also a specimen can be arranged by region, like this one, and also by families in our herbarium. Here in this herbarium, we have mostly plants of the west Mediterranean region and mostly of vascular plants. And why are herbariums important? Herbarium specimens are very important in botanical research. First of all, because we can study the morphology and the variability of plants between regions and between different periods and so we can study the phylogeny of plants by molecular analysis of DNA. Also, we can study changes in phenology due to climate change and we can study the flora of a territory and for instance, we can find some possible extinctions like this one. This is a specimen from Salvatore's family collection from 17th and 18th century. This plant, Stachys maritima, is from Barcelona and now, this plant is extinct here in Barcelona. Also, we can study the date of introduction of alien plants in some territory. What is the process to make an herbarium specimen? Okay. Sandra, first of all, we have to collect the plant correctly with all the parts and characters that are important for each identification, like leaves, flowers, and fruits, and roots if it's possible. Then once collected, we have to press during a few weeks and we have to change the dry paper each two or three days. The pressing process is done for two objectives, the first one because the loss of the water prevents the degradation of the sample and also because by pressing, we reduce the space of the sample and the storage is more efficient. Then, when the sample is pressed, we have to mount it in a cardboard and we have to add a label with all the information of the collection. The data most important is the location, the place, and the date. We can also add other additional information like the ecology of the place and who has collected the plant. Once the specimen is mounted, then we have to freeze it during three weeks before the final storage inside the herbarium because in the herbarium, we have controlled climatic conditions, 20 degrees of temperature, and 50 percent of humidity. In botanical, a part of herbarium specimens, there is very important illustrations like this one. Illustrations are an image more faithful of the plant in the field and we can see some characters that may be in an herbarium specimen can be lost due to the pressing, like the color of the flowers or maybe hidden, and this illustration is done by Susan David. Susan David was an illustrator here in the Botanical Institute that has also collaborated with other research institutes. Neus, how can we identify plants? We identify plants by dichotomous keys, normally, the dichotomous keys are in books like these In a dichotomous key, normally we have two options, and we have to decide which option is better in function of the characters of all the plants and deciding for different two options in each case. Then finally, we arrive at the name of the species. To use a dichotomous keys like this, we have to identify some parts of the plant and sometimes, we need a binocular magnifier like this one to see some parts of the flower that can be very small, or glands or hairs in the stem. In some cases, it's important also to use a microscope if we need to know how is the pollen or the spores or other tissues of the plant. All this knowledge about plant anatomy and morphology are also very important because it allows plant physiologist to know how the plant is functioning. So in this sample, we have section of a leaf where we can see stomata. The stomata are responsible for the exchange of gases. So a plant through these spores of stomata can absorb CO2 and convert the CO2 to sugars and another cell constituent and this process is called photosynthesis. There is a very well-known woman called Elisabeth Gantt and she was studying organelles in red algae and cyanobacteria responsible or the collection of the light from the sun, which is necessary for photosynthesis. These measure of antenna complexes she was studying, she named them Phycobilisomes. This woman was also very interesting because she was the first president of the American Society of Plant Biologists. So she opened a path for women to take leadership roles in the society and after, her there were several more women presidents in that society. Are there other techniques to help in identifying plants? Yes. Now, all the classical technique to identify plants, we use only morphological characters, but we can use also DNA to identify the plants. For this, we have to sequence some part of the DNA of a plant that we don't know the species and then we can compare with other plants that we know that they are correctly identified, and then we can identify a plant by the DNA. But now, it's not used so much because we don't have the older portions of the DNA of all the plants of the world, then in the future is to have a DNA bank of all the plants. This large project is called DNA barcode and it will be a project to have this DNA bank and maybe with this DNA bank, the identification of plants will be possible with the DNA. Thank you Neus for being so kind to show us the Institute. You're welcome. Thank you also for coming here.
