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Grupo BambuBrasil - Entrevistas

Dra. Lynn G. Clark
Iowa University - USA

BB - How started your interest about bamboo?
My interest in bamboo started when I was 16. My father knew many of the botanists at the Smithsonian Institution because of his work. One day my father mentioned to Dr. Thomas Soderstrom, who was a curator at the U. S. National Herbarium at the Smithsonian, that I was interested in plants. Tom replied, "Bring her in, we'll find something for her to do!" So I started as a volunteer at the Smithsonian during the summers, working as needed on the bamboo collection and helping Tom and Dr. Cleo Calderón, an Argentinian botanist who worked with Tom on bamboos. I learned a great deal about bamboo plants, bamboo classification, and bamboo literature from both Tom and Cleo, and eventually they gave me small research projects to work on. They helped me choose what university to attend, and then, when I wanted to attend graduate school, they recommended that I go to Iowa State University, to work with Dr. Richard Pohl, a well known expert on grasses. It was Tom who suggested that I study the bamboo genus Chusquea for my dissertation, and I have been working on Chusquea ever since.

BB - Is bamboo a primitive plant?
In the past, bamboo has been regarded as a primitive lineage within the grass family, primarily because bamboos have flower parts in multiples of three, which is generally thought to be a primitive feature. But we now know from molecular data that the true bamboos (woody bamboos of tribe Bambuseae and herbaceous bamboos of tribe Olyreae) are actually part of the major radiation of grasses and are not primitive at all. Bamboos retain a few primitive features, but they also exhibit many advanced features as well.

BB - In which continent bamboo has borned? How many years ago aproximately?
We can't identify on which continent the bamboos originated, but the evidence points to a tropical origin for bamboos, so it seems most likely that the bamboos arose somewhere in the southern hemisphere. Our best evidence indicates that this happened sometime between 30 and 5 million years ago, but so far we can't be more exact than that. As shown by fossil leaf material, bamboos definitely were in existence by approximately 5 million years ago.

BB - Why is there so many species of bamboo?
This is a very good question. There are about 1200-1300 species of bamboos worldwide. We think that one reason for this diversity is that many groups of bamboos have evolved in tropical or subtropical mountains where there are many different habitats and microclimates available, and where populations can easily become isolated and thus evolve unique characteristics. For example, there is great bamboo diversity in the Andes, the Serra do Mar of Brazil, the mountains of Central America, and the geologically complex mountain formations of south-east China and the Himalayas. There may be other factors involved too, but we don't fully understand them.

BB - Why is the flowering of bamboos a mistery?
The synchronous flowering of woody bamboos after long periods of vegetative growth is indeed mysterious. I think it is still a mystery because this is such a difficult phenomenon to study. We have many observations of flowering from many different sources, but the flowering cycle of a bamboo species may be 30 or 40 or 50 years or more, much longer than the active professional life of a researcher, so that one person cannot usually have the opportunity to observe a full cycle or conduct experiments. Another reason is that only recently have we developed techniques that enable us to study this phenomenon from the genetic or molecular levels, which I feel will be important in understanding bamboo flowering cycles. Ultimately the ability of bamboos to count time must be encoded in the genes. Another important, relatively recent development is the work in India on inducing flowering in bamboos cultivated in vitro--this should provide a way to produce material for experimental purposes.

BB - Which are the types of flowering that occurs in bamboo?
There are several types of flowering in bamboos. The herbaceous bamboos (tribe Olyreae) tend to flower for an extended period of time each year, usually for several months. I should point out that we know very little about reproductive biology in the herbaceous bamboos, so this is another interesting field of study. A few species of herbaceous bamboos appear to have long cycles like those of the woody bamboos. The woody bamboos are famous for flowering synchronously after long periods of vegetative growth, and probably a majority of woody bamboo species behave in this way. The notable thing about this type of flowering is that the plants usually die after flowering is finished and seeds are produced. However, we know that some woody bamboos flower sporadically, that is, some individuals will bloom at odd times, even if synchronous, cyclical blooming is also observed. In these cases, the plants still die after flowering even if it is out of the normal cycle. Some species, especially those from high altitudes, never seem to flower synchronously--instead, you will almost always find a few clumps in flower (which then die and presumably reseed) but a mass flowering is never observed. And there are a few reports of species that flower year after year without dying, and some bamboos appear to flower irregularly without any defined cycle. So there is actually a wide variation in flowering behavior in the bamboos.

BB - Have you seen many bamboo flowering events?
I have been very fortunate to see a number of bamboo flowering events. One memorable mass flowering of Chusquea valdiviensis occurred in Chile in 1992. Hundreds of hectares of this bamboo were in bloom at the same time, and you could see large brown patches on the mountain sides even in the distance. I saw the plants in late January of that year, and although the plants appeared brown, the flowers were just shedding pollen. Seed production probably occurred over the next several months, and I know that Chilean and Argentinian researchers observed seeds and seedlings early the following year. I have seen similar mass flowering in other species in Colombia and Ecuador and other countries. In Brazil, I have collected many species in flower but sporadic flowering appears to be more common among Brazilian species, at least within the genus Chusquea.

BB - Does the Smithsonian Institute always give resources to bamboo researchers?
The Smithsonian Institution does not have funds dedicated to bamboo research. However, it is possible for a researcher to collaborate with a staff member and in this way get support to visit the Smithsonian collections. But the bamboo collections at the Smithsonian (including the literature and photographs) are available for use by researchers even if they visit without Smithsonian support or collaboration.

BB - Who are your references in bamboo botanic study?
My main influences in bamboo botany were Tom Soderstrom, Cleo Calderón, and Richard Pohl. They taught me a lot about bamboos and also encouraged me to continue my research every step of the way. But I also have many valued colleagues who work on bamboos and who have also taught me a great deal. These colleagues include: Ximena Londoño of Colombia, Emmet Judziewicz, Gerald Guala and Peggy Stern of the U.S.A., Chris Stapleton of England, Tatiana Sendulsky, Luiz Sergio Sarahyba, and Tarciso Filgueiras of Brazil, and Dr. De-Zhu Li of China. I must also say that the late Agnes Chase (she died in 1963), who was well known for her work on grasses, has always been an inspiration to me, as was Dr. Floyd McClure (who died in 1970).

BB - Who created the idea of "American Bamboos"?
Emmet Judziewicz had the idea for the book 'American Bamboos'. He, Ximena Londoño and I met in the spring of 1993 to discuss the form the book would take, and what we each had to do. We also invited Dr. Peggy Stern to contribute her knowledge of bamboo ecology to the book. We worked on the manuscript for close to three years, and finally submitted it in the spring of 1996. At that point, the manuscript was reviewed by three different bamboo people, who gave us useful comments on how to improve the manuscript. We then revised the manuscript, and gave it back to the publisher (the Smithsonian Institution Press) in 1997. The book was then edited and designed, and we saw the page proofs in September of 1998. After approving this last version, we finally saw the finished book early in 1999.

BB - Can we say that Brasil has a great number of native bamboo species? Why are they so unknown?
Brazil definitely has a great number of native bamboo species--approximately 137 described species of woody bamboos, and 67 described species of herbaceous bamboos, giving a total of over 200 native species. We do know that there are a number of yet undescribed bamboo species in Brazil that will eventually increase this number. Bamboos in general are very difficult to study because they can be large and complex, and for the woody bamboos, often the flowering structures are not readily available. For Brazilian bamboos in particular, there are many species but there have been few botanists, either from Brazil or elsewhere, who have dedicated themselves to the study of Brazilian bamboos. The exceptions in Brazil are Tatiana Sendulsky, Tarciso Filgueiras, and the late Alisdair Burman. But because of the very great bamboo diversity in Brazil, and the need to go into the field to study the plants and collect herbarium specimens, it takes a lot of effort and a long time to adequately understand this diversity. Tatiana has worked for many years on Merostachys, a very beautiful and diverse group of primarily Brazilian bamboos, greatly increasing our knowledge of this genus, but the species of this genus seem to have relatively long flowering cycles, and complete collections are often not available, so of necessity it takes time. Tarciso has worked on the cerrado bamboos, and collaborated with Alisdair on a summary of the diversity of Brazilian bamboos. While these botanists have made significant contributions to Brazilian bamboo botany, it is also reassuring to know that there are at least two Brazilian students who are currently being trained in bamboo botany to carry on this work.

BB - Do you know the work of Dr. Tatiana Sendulsky, from Instituto de Botância de São Paulo?
Yes, I have known Dr. Sendulsky for many years. As mentioned above, she has studied the genus Merostachys for many years, and has described many new species of Merostachys for Brazil. She is recognized as the world authority on this group of bamboos, and of course is very knowledgeable about other bamboos and also the grasses in general.

BB - Do you see in vitro propagation as a good way to propagate bamboos?
In vitro propagation is certainly one extremely useful way to propagate bamboos. It is especially useful if you require many uniform plants, or if you do not have much space to work with. But in vitro propagation requires specialized techniques, trained personnel and a laboratory, so a greater initial investment is needed if such a facility is desired. More traditional propagation techniques may produce larger plants more quickly than in vitro, but then more space is needed. Both in vitro and traditional techniques have advantages and disadvantages.

BB - When you make an in vitro bamboo, it is in the beggining of its flowering cycle or can it flower at any time?
I do not have any expertise in in vitro propagation, but my understanding is that the process can start with an embryo from a bamboo seed, or it can start from vegetative material. If one starts with an embryo, then the resulting plant will be at or near the beginning of its flowering cycle (assuming that we know what the cycle is). If the process is started with vegetative material, then the resulting plant will be at the same point in the flowering cycle as its parent plant, whatever that is.

BB - Which is the best way to determine a bamboo species?
If you wish to identify a bamboo species, you need to have the appropriate reference books on hand (assuming that these exist!--for example, there is not yet a single reference that would allow you to identify all of the bamboos in Brazil) and you also have to examine the external form of the bamboo in question. For woody bamboos, the most important features to collect or photograph for identification are the culm leaves (the large bracts covering the new shoots), the pattern of vegetative branching from the main culm, and the branch leaves (size of the blade, are there any fimbriae on the sheath, and so on). If the bamboo is flowering, the flower structures are useful for identification, but the culm leaves might not be available because bamboos may not produce shoots the year before flowering, and the plant may have dropped its branch leaves too. But I want to emphasize that it is definitely possible to identify a bamboo without flowering structures. Other features that can be very useful for bamboo identification include the size of the culms, whether the culms are hollow or solid, the growth form of the plant (is it upright or scrambling onto nearby vegetation, for example), and the appearance of the internodes (color, do they have hair or not, etc.). Sometimes when we try to match a vegetative herbarium specimen with a flowering herbarium specimen it is like putting the pieces of a puzzle together. But once we connect this information, the species can be identified at any point in its flowering cycle.

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