Mapping the first family tree for tropical forests

More than 100 researchers have collaborated to classify the world's tropical forests according to their evolutionary history, a process that will help researchers predict the resilience or susceptibility of different forests to global environmental changes.

The results, culled from almost 1 million different tree samples from 15,000 tree species, have uncovered a shared ancestry between tropical forests thousands of miles apart and previously believed to be unrelated. Published this week in the Proceedings of the National Academy of Sciences, the study describes an international, grassroots effort to collect and analyze data from more than 400 geographic coordinates across the tropics, a region that comprises 40 percent of the Earth's surface.

The study was led by Ferry Slik, an associate professor at the Universiti Brunei Darussalam in Brunei. Janet Franklin, a distinguished professor of biogeography at the University of California, Riverside, coordinated the interpretation and reporting of the data, which is publicly available as an open access article.

Franklin said the new classification scheme's value comes from the inclusion of ancestral information about the tree samples (gleaned from DNA analyses), rather than the "snapshot" of tree biodiversity that is obtained from recording a plant's species.

"When ecologists study biodiversity, they look at the present day by identifying the range of species in a particular forest. However, without going deeper into a plant's history by looking at its family tree, each species is considered separate and unrelated," Franklin said. "By adding the evolutionary relationships between species, however, we suddenly have a measure of how similar species are to each other. This means that we were able to do a much more detailed and realistic comparison between forest sites than previously possible."

The study revealed five major tropical forest regions: Indo-Pacific, Subtropical, African, American, and Dry Forests, which are found at the boundaries between tropical and dry climates.

The study also showed the evolutionary relationships between the forests. One surprising finding was that tropical forests in Africa and South America are closely related, with most of the differences between them occurring within the last 100 million years.

More information: J. W. Ferry Slik el al., "Phylogenetic classification of the world's tropical forests," PNAS (2018). www.pnas.org/cgi/doi/10.1073/pnas.1714977115 

Journal reference: Proceedings of the National Academy of Sciences  

Provided by: University of California - Riverside 

2,000 years ago, people domesticated these plants. Now they’re wild weeds. What happened?

"Adventurers and archaeologists have spent centuries searching for lost cities in the Americas. But over the past decade, they’ve started finding something else: lost farms.

Over 2,000 years ago in North America, indigenous people domesticated plants that are now part of our everyday diets, such as squashes and sunflowers. But they also bred crops that have since returned to the wild. These include erect knotweed (not to be confused with its invasive cousin, Asian knotweed), goosefoot, little barley, marsh elder, and maygrass. We haven’t simply lost a few plant strains: an entire cuisine with its own kinds of flavors and baked goods has simply disappeared.

By studying lost crops, archaeologists learn about everyday life in the ancient Woodland culture of the Americas, including how people ate plants that we call weeds today. But these plants also give us a window on social networks. Scientists can track the spread of cultivated seeds from one tiny settlement to the next in the vast region that would one day be known as the United States. This reveals which groups were connected culturally and how they formed alliances through food and farming."

Read full article at ArsTechnica: Hunting for the ancient lost farms of North America: 

Is Amazonian tree biodiversity / species distribution a product of past landscape domestication?

News of recent studies has revealed that an estimated 390 billion trees are growing in Amazonia today, consisting of an approximate 16,000 species. 227 of these species are termed “hyperdominant”, because they represent about half of the total number of trees, while the rarest 11.000 species make up only 0.12% of the total.

Why only 227 species make up such a disproportional percentage of overall trees remains unknown.

“We knew that, normally, a few species dominate ecosystems, but if you have a system that has 16,000 tree species but just 227 make up half of the trees, that was pretty surprising even for us,” said lead author Dr Hans ter Steege from the Naturalis Biodiversity Center in the Netherlands.”

“In the paper, Dr. ter Steege and the team of more than 100 scientists wrote that there was no evidence that two key functional traits for trees – seed mass and wood density – played a part in determining what species dominated the landscape.” Read full article on BBC

Although the long and highly-involved history of human-forest habitation/impact/modification in Amazonia was not mentioned in the article(s), I am curious if the researchers have begun to look into the possible correlation between the 227 hyperdominant species and their ethnobotanical significance among past and present populations of Amazonian indigenous peoples. My guess is that the 227 hyperdominant species also have a wide range of human uses.

With recent findings confirming that sophisticated human societies inhabited the Bolivian Amazon 10,400 years ago, and that human habitation of the region likely dates back as far as 30,000 years, coupled with our firmly established understanding that Amazonian peoples have managed highly complex, large-scale domesticated landscapes (massive agro-silvo-pastoral systems), it seems inevitable that long-term human presence in the Amazon has played significant role in determining present day biodiversity and species distribution.

We’ll see what answers science comes up with.

Here are a few relevant articles on the subject of pre-Colombian Amazonian history, Amazonian agroforestry, and anthropogenic landscapes in the Amazon:

Clark Erickson: Culture amidst the Pristing: The Anthropogenic Forests of the Bolivian Amazon

NPR Article: Amazon was once home to advanced civilizations

Discovery News: Did humans arrive in the Americas 30,000 years ago?

New York Times: Once Hidden by Forest, Carvings in Land Attest to Amazon’s Lost World

Science Daily: Pre-Colombian societies in the Amazon may have been much larger and more advance then thought

Agroforestry and the Built Environment by: Spencer Woodard (Anthropogen):

New Yorker: Under the Jungle by David Grann

PDF: Amazonian Agroforestry and Homegardens

Tropaeolum tuberosum - Mashua

OVERVIEW, ORIGIN, AND DISTRIBUTION

Closely related to the common nasturtium, T. tuberosum is a perennial plant domesticated and traditionally grown in the Peruvian and Bolivian Andes Mountains of South America. The plant is a creeper with fleshy stems and orange-red flowers similar to those of nasturtium. The plant is a creeper with fleshy stems and orange-red flowers.

 It was cultivated centuries before European Colonization for the edible root / tuber. Europeans brought the plant back home where it has since been propagated and selected for its ornamental traits. The tuber nasturtium is practically unknown outside of South America where it is still grown as a staple food in many high altitude areas where few other crops will grow

USES AND ETHNOBOTANY

The edible roots are white with purple spots, not dissimilar to the form of some potatoes. Traditionally the roots are not eaten fresh but are dried and eaten like potatoes. Pickled tubers have been used in Europe to garnish hors d’oeuvres and cold meats. Leaves are added to salads for their spicy taste and attractive colors. Young seeds and unopened flowers are pickled with tarragon and used as a substitute for capers.

Stelechocarpus burahol - Kepel fruit

DESCRIPTION, ORIGIN AND DISTRIBUTION

Stelechocarpus burahol is closely related to such species as guanabana (soursop), Biriba (Rollinia deliciosa), Paw-Paw (Asimina triloba) and Ylang Ylang. Burahol (kepel fruit, or keppel apple) is a rare and endangered member of the Anonaceae family, originating in southeast Asia, more specifically Indonesia where, it is said, cultivation is unfortunately becoming less and less common. The tree has been introduced into Honduras and Florida. In Indonesia the fruit is the object of investigation for eventual use as a perfume.

The fruit is born on the trunk of the tree. They take a while to ripen. You know the fruit is ready to harvest when you peel away some skin with your nail and it is orange underneath (rather than green). I have found one mature, productive tree growing in Panama, where it seems to do very well. Despite this it is by no means commonly grown. Whenever I have the opportunity, I collect and propagate seed.

The tree grows up to 20 meters tall, with a straight trunk, brilliant foliage, spectacular bright pink leaves that flush out all at once over the entire tree.

Pinkish cream colored flowers bloom in abundance directly out of the truck and develop into fruits the size of a small orange. The fruit has a brown, leathery skin and contains numerous, l0ng, oval seeds in a creamy, light orange flesh.

USES AND ETHNOBOTANY

Kepel fruit is edible and of a very agreeable flavor, aromatic, with undertones of coconut. It is said that the consumption of this fruit will perfume ones excretions (such as urine or sweat) with the smell of violets.

The Kepel tree is considered to be one of the most beautiful of all tropical ornamental/fruit trees.

PROPAGATION AND CULTIVATION

Kepel fruit grows in a hot, humid climate and can be planted at sea level, up to 300 m. It is propagated from seed, which typically germinate quickly, but can take up to 12 months to develop the seedling shoot. The tree will begin to bear fruit in around eight years and produces year round.

I am curious if there has been any success grafting this species? Any comments to that effect would be greatly appreciated.

Medicinal and Ritualistic Uses of Chocolate in Mesoamerica

Here’s a recent, relatively brief but interesting and thorough article on the Medicinal and Ritualistic Uses of Chocolate in Mesoamerica.

For a more in-depth read on the subject, I’ll recommend this book: Chocolate in Mesoamerica: A cultural history of Cacao

Rollinia delisiosa - Biriba

Unripe Biriba fruit.

OVERVIEW

ORIGIN AND DISTRIBUTION

Biriba can be found growing in the wild in the islands of the Caribbean and in northern South America, now more commonly found in cultivation. It is most widely cultivated in the Brazilian state of Para.

Two small ripe fruit (photo above). Below, immature fruit on tree.

USES AND ETHNOBOTANY

The fruit is consumed raw. It’s sweet pulp has a very agreeable flavor; a somewhat mucilaginous, custard-like texture. Many Brazilians consider the Biriba to be the best tasting fruit of the Anonaceae family. I would consider that possibility myself. It is eaten fresh, out of hand, or in smoothies, sorbets and ice creams.

Reportedly, the seeds of Biriba can/are used for their insecticidal properties. Macerated seeds, soaked in water and strained, might hold potential for a good organic foliar insecticide and fungicide.

PROPAGATION AND CULTIVATION

Biriba is a medium size tree from the hot, humid tropics and grows best in areas with more than 1,250 mm of annual rainfall. The tree and fruit develop best in clay soils, deep, well drained and rich in organic matter.

The seedling Biriba tree begins to produce fruit around the third year of growth reaching maximum production in the eighth year. A single tree can produce around eighty fruits a year weighing between .4 and 1 kilo. Here in Panama it is one of the most productive fruit trees I have seen, however it is also very uncommon. Virtually unknown. I cannot recall when I have seen it in this area of Central America outside of private botanical collections.

When collecting seed for propagation, collect only the largest seeds from the largest fruits harvested from the most healthy and disease resistant trees.

Don’t eat seeds from Biriba or any other Anonaceous seeds, they may poison and possibly kill you.

Psychotria viridis - Chacruna

OVERVIEW

Psychotria viridis is a perennial shrub of the Rubiaceae family. In the Quechua languages it is called chacruna or chacrona. In Quechua, chaqruy is a verb meaning "to mix". P. viridis grows to a height of approximately 5 m (16 ft). Its branches span a diameter of about 2 m (6 ft 7 in)

ORIGIN AND DISTRIBUTION

Neotropics. Amazon basin, South America. 

USES AND ETHNOBOTANY

This species of Psychotria is used by indigenous peoples of western Amazonia, primarily as an additive in the preparation of a hallucinogenic drink ayahuasca, also called yage, employed for healing and divination. Although in some instances ayahuasca can be prepared in the absence of Psychotria, the addition of the plant greatly enhances the visionary effect of the brew due to the significant amounts of DMT present in its leaves. DMT, or N, N-dimethyltryptamine, is a tryptamine alkaloid.

Other plants with significant quantities of DMT include: Mimosa tenuiflora (=M. hostilis), Anadenanthera peregrina, Acaciapolyacantha, A. cornigera, A. maidenii, A. nubica, A. plebophylla, A. polyantha, A. senegal, A. simplicifolia), Calliandra spp., Desmodium spp. Mucuna pruriens (Fabaceae), Virola peruviana, V. elongata (=V. heiodora) Epenña, Yakeé (Myristicaceae); Banisteriopsos argentea, B. rusbyana (Malpighiaceae); Prestonia amazonica (Apocynaceae); Psychotria peoppigiana, adn P. psychotriaefolia (Rubiaceae); Arundo donax, Phalaris arundinacea, Phragmites austraiis (Poaceae) and Zanthoxylum spp (Rutaceae).

PROPAGATION

Psychotria viridis is hardy in USDA zone 10 or higher. The plant is fairly easy to propagate from seeds, stem cuttings, or leaf cuttings. Some resources state that the plant is extremely difficult to propagate from seed (as low as 1%!), but I have not found this to be the case. I would probably note that treating the seeds in their own fermenting fruit pulp can improve germination. 

The plant does, however, reproduce most readily from fresh leaf cuttings. I have looked for evidence of leaves dropping off the plant and self-propagating as such. I have noticed that some plants will produce seed heavily for a while, then the bulk of the shrub will slowly die off, sending up a few new shoots in succession from the base of the trunk. 

P. viridis leaf cutting propagation.

Chiranthodendron pentadactylon - Devil's Hand, Mācpalxōchitl, Canac

OVERVIEW

The Genus Chiranthrodendron comprises a single species, C. pentadactylon. The tree is called the Devil's, monkey's or Mexican hand tree or the hand-flower in English, the árbol de las manitas (tree of little hands) in Spanish, and mācpalxōchitl (palm flower) in Nahuatl, all on account of its distinctive red flowers, which resemble open human hands.Common names include Arbol de las Manitas (Spanish), and mācpalxōchitl (palm flower) in Nahuatl.

Chiranthodendron leaf.

Origin and distribution

The tree is most common in the subtropical highlands of Mexico, less commonly found in Guatemala. I propagated the seed and planted it in Northern California just north of San Francisco. The tree seems to thrive in the cloud-forest-like redwood covered hills. The tree gave a few flowers in its fourth year, a few more in the fifth, and now on its sixth year from seed it is close to 50 feet tall and flowering profusely in June.

USES AND ETHNOBOTANY

From what limited ethnobotanical information I can find: solutions containing the tree’s flowers are used as remedy for lower abdominal pain and to treat heart ailments. Similar solutions are used to reduce edema and serum cholesterol levels and are used as diuretics. The flowers can still be found sold in markets in Mexico and Guatemala, commonly referred to as “Manitas” or little hands.

It has also been documented that parts of the plant were used to flavor the traditional cacao beverage by the Aztecs in the 16th century.

Apparently the leaves are edible, and traditionally used to wrap tamales and cheese, said to impart a distinct flavor.

The lower saucer portion of the flower contains up to a few tablespoons of sweet syrup with a flavor reminiscent of burn caramell / sugar.

The bark can be used to make rope.

Chiranthodendron has a seedpod not dissimilar in form to the Starfruit. This pod is, however, extremely durable, making it challenging to extract seeds from an unopened pod.

Chiranthodendron mature seedpod.Note the star form.

The bizarre and highly photogenic Chiranthodendron flower.

Chiranthodendron pentadactylon flowers on the branch in a tree I propagated from seed six years ago.

Pseudobombax ellipticum - Shaving Brush Tree, Amapolla

OVERVIEW

Pseudobombax ellipticum, is a species of plant in the Bombacoideae subfamily of the Malvaceae family. known in English as Shaving Brush tree (in reference to the flower) is native to Mexico and Central America where it is referred to variously as Acoque, amapola, árbol de doncellas, árbol de señoritas, calinchuche, jilinsuche, matías, pilinsuchil, pumpo, shaving bush, shilo, shilo blanco, shilo colorado. I took these photos in Jalsico, Mexico where it is called Clavelina.

Mature trees grow to about 60 ft developing an engorged, bottle-shaped trunk.

USES

Uses include firewood and wood for carving handicrafts.

The attractive flowers are used to decorate homes and churches in Central America. In Central America, a highly intoxicating drink is made from the tree.

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Pseudobombax ellipticum trunk.