Monday, October 16, 2017

Creating technical profiles for native tree species in the Orinoco River basin


 by Dexter B. Dombro



Colombia is blessed with 8% of the planet’s biodiversity, something that is very evident in the Orinoco River basin, which is home to numerous species and ecosystems. This biodiversity is readily visible to visitors thanks to the large number of native tree species in the region’s gallery forests, morichals (heavily treed savanna drainage creeks) and caños. Ironically, almost all plantation forestry in the country cultivates introduced tree species and not native tree species. Visitors to Colombia’s capital of Bogotá are often shocked to realize that the trees planted in the hills surrounding Bogotá are Eucalypts, with almost no native tree species represented. This sad reality impacts biodiversity, as native trees support local wildlife, birds and insects that have specific niche requirements for food and shelter, which are not available to those animals with introduced tree species. The result is a loss of biodiversity.

Caraipa llanorum seed collection.
The Colombian government has a subsidy program to encourage commercial tree planting, called the Certificado Incentivo Forestal or CIF for short (Forestry Incentive Certification program in English), but amazingly the program includes almost no native tree species in its list of approved tree types, and none which are native to the Orinoco River basin. The Ministry of Agriculture and Rural Development in Colombia has a simple excuse: There are no technical profiles for native tree species, so we don’t know if they can be cultivated. Secondly, there are no certified sources for seeds for native tree species, so we don’t want to waste the taxpayer’s money on subsidies that won’t produce commercially acceptable results.

Setting up germination tables at La Pedregoza.
At a public event in which La Pedregoza promoted the planting of native tree species, a bureaucrat from the Ministry of Agriculture and Rural Development, referring to plantation forestry, stated in public: “The problem is that native trees don’t grow in Colombia!” Besides this being a ridiculous and absurd statement, it is not really supported by the facts. The real problem is that there is a lack of knowledge regarding native tree species and how best to cultivate them. As a result, La Pedregoza has been working to create technical profiles or specifications for native tree species for some time now. Unfortunately, the process of creating a technical profile for the commercial cultivation of a tree species can be a 10 year long process, so having adequate funding and investigative continuity is often a problem.

Investigating densities and species behavior in the Reserva Natural La Pedregoza.

Why is this important? There are several answers to this that should help one to understand the issues:

  1. It makes sense to cultivate trees for commercial use, rather than to continue to chop down natural forests. Would you rather have your coffee table made out of plantation lumber, or out of old growth rainforest wood? In our opinion the answer is a no-brainer.
  2. Plantation forestry allows natural forests to recover, with all of the added benefits of biodiversity conservation, ecosystem services and protection against climate change. 
  3. Commercializing a tree species is often the best way to conserve and protect a tree, which otherwise is at risk of extinction due to over-exploitation of the species in its natural setting. 
  4. Plantation forestry is virtually always a legal activity creating legal employment and socioeconomic development, whereas much of the planet’s forestry is illegal, with little benefit to local communities. For example, the World Bank estimates that 60% of the lumber and wood produced in Colombia comes from illegal sources.
  5. Commercial tree plantations are a structured and easy way to increase the tree-based carbon capture in a country. Planting trees is a proactive strategy, whereas simply trying to preserve an existing forest does not result in increased carbon capture in the struggle against climate change.
There are numerous other benefits, but for the purpose of this article the ones listed above should help the reader to understand the main issues.
 
Germination of Aceite or Copaifera pubiflora at La Pedregoza.



So what exactly is required to create a useful technical profile for a tree species? Much of it involves simple experimentation and observation, while some of it does require laboratory analysis. What follows is a list of some of the issues that require investigation when creating a technical profile for a tree:
Preparing the soil at a planting site.
  1. What is the best manner of collecting the seeds and how should they be stored? How long do the seeds last before they start to decay?
  2. Do the seeds need any kind of special processing to enhance germination? For example removing a shell, or using sandpaper to thin the seed shell in order to make germination easier, or soaking the seeds for 24 hours to encourage germination.
  3. Germination tables are used to closely watch how fast germination occurs. Some species germinate in 3 or 4 days, others take 3 or 4 weeks. Statistics are kept of the germination rate. Some species have a low germination rate of 50%, others as high as 99%.
  4. Some seedlings are sacrificed to observe root development. Some species have a tap root that is twice as long as the above ground plant. This dictates the type of planting bag or tube that is used. It also helps determine the optimum time for managing the seedling in a tree nursery before planting in the field.
  5. Regardless, it is sometimes useful to learn how to manage the seedling over a long period of time in a tree nursery setting. For example, some restoration of degraded areas projects in difficult conditions, such as a strong current during the inundation season, may require the seedlings to be larger and more robust before they can be planted, something that wouldn’t matter in a cultivation setting.
  6. There are many ways of managing seedlings in a tree nursery, all of which require investigation to determine which have higher mortality rates, and which cause additional economic costs before planting in the field.
  7. There are different ways of preparing the soil at the final planting site, all of which need to be tried to see how the tree responds. For example, some trees need a deep ploughed furrow that allows roots to penetrate downward quickly, whereas others are only superficial rooters and respond better to small hillocks. 
  8.  Soil samples need to be taken at planting sites and analyzed, to see how the trees respond to different conditions, and whether the tree needs anything special added to some soils, but not to others. For example, some trees are happy in sandy or rocky soils, but do not respond well to soils with high clay content. Some are happy in wet soils, while others need well-drained soils. 
  9. Some trees need formation pruning in order to establish a primary tree trunk that is commercially attractive. Others need sanitary pruning, for example in order to avoid low handing branches touching the ground, causing fungal infections. Some trees need almost no maintenance, but it is important to understand the tree’s requirements for budget purposes and for maintenance and care purposes.
  10. The tree needs to be observed to determine in what densities it should be planted and what types of culls may be needed, depending on the objective of the cultivation.
  11. Other investigations are need to determine when it is best to fertilize the tree, and whether 1 or 2 fertilizations a year are needed, as that can be important in terms of growth, but also costly in terms of labour requirements.
  12. How a tree responds to different types of fertilizers is recorded, whether that be agrochemical or organic. Does a tree have special requirements, for example does a tree need more phosphorus or sulfur in the soil that say another species? Many fruit trees need extra silica, whereas most lumber and wood trees don’t. 
  13.  Average growth of a tree species is measured and monitored. This allows a commercial planter to determine how many years the cultivation needs to be maintained and what the expected financial returns might be. 
  14.  Analysis of a native tree’s woody biomass provides information on wood quality, color and attractiveness, shows how much carbon the tree can capture, whether the fiber content of the wood can be used for pulp and paper, whether its kilo-calorie content makes it suitable for bio-energy uses like pellets, what its wood density and resistance to termites or rot is like, as well as information on its suitability for structural strength or use in applications that need elasticity. 
  15. The tree is observed to see if it is social. For example, can it be planted as a shade tree for another species, like cacao, or is it aggressive killing other species that are nearby? 
  16. Good technical profiles include investigating traditional uses for the species, such as for medicinal or alimentary, arts and crafts, general or high end carpentry, ornamental or dozens of other possible uses and applications. 

Taking soil samples is a continuous process.
At La Pedregoza we have developed a form with more than 8 pages of questions that need to be answered, many of which require several years of investigation and observation. This explains in part why having reliable, long term funding is so crucial to the creation of useful technical profiles for native tree species.

Humans require wood for many reasons, but its production should support biodiversity and be sustainable.
One of the results of this work is the establishment of cultivations of native trees, which serve another purpose as well. Those cultivations allow us to select the trees with the best genetic characteristics, in order to start to offer certified seeds to other plantations and tree growers, thereby eliminating the Ministry of Agriculture and Rural Development’s excuses for not supporting native tree species. Tree-Nation members have indirectly supported our efforts with their purchases of native tree species, something for which we are very grateful. Technical profiles may sound boring, but they are important tools of biodiversity protection, of conservation and understanding of the world around us. For us the work we do at La Pedregoza is passion mixed with dedication and love for trees. What more can one say?

© 2017 Corporación Ambiental La Pedregoza

Saturday, May 13, 2017

The Sassafras: saving an endangered species


by Dexter B. Dombro

Preferred Sassafras habitat.


In the Orinoco River basin of Colombia there are several endangered tree species. One of them is the Sassafras or Ocotea cymbarum, a member of the Lauraceae family. It is listed in the IUCN’s Red List of vulnerable and endangered species. Its North American cousin was almost harvested to extinction, in order to make root beer, a beverage that was popular in the 19th and 20th centuries, and which is sold today as a type of soda pop, but thankfully without any Sassafras-based contents. 


Ecologists meet a Sassafras



The South American Sassafras has experienced similar uncontrolled extraction, primarily for its aromatic wood used in fine carpentry, but also in order to produce safrole oil for biofuel. In the 1960’s the use of safrole oil for human consumption was banned by the U.S. Food and Drug Administration, as studies suggested it is carcinogenic, with more bans that followed by European and other authorities. However, this did not stop the harvesting of Sassafras trees for carpentry uses.
 




Looking for Sassafras trees.

Ocotea cymbarum grows in the gallery forests and inundation forests of the Orinoco River basin. Its preferences make it a difficult species to work with. For starters, it prefers a lot of shade, which means that it cannot be cultivated in open settings. At the Reserva Natural La Pedregoza in Vichada, Colombia, planting experience shows that only those seedlings planted inside the rain forest survive, and that any attempts to establish the tree in non-shaded areas are a failure. This greatly limits the possible sites for restoration activities with this tree.

How to get up there?
Obtaining seeds from Sassafras trees is also a challenge. There are male and female trees, and only the  female trees have seeds. Due to past harvesting, this has caused further pressure on the species.  For example, when the natural reserve at La Pedregoza was established, only 4 mature Sassafras trees were found, 3 of which were males and 1 a female some 3 kilometers away from the males, making pollination extremely problematic. This low surviving density, more than anything else, encouraged the tree planters at La Pedregoza to make every effort to restore the tree to a self-propagating density inside the natural reserve.

Poor quality Sassafras seeds.
The seeds ripen in May and June, which coincides with the beginning of the wet season and the inundations. Since the trees have large, branchless and straight trunks and can grow to be over 25 meters in height, climbing the trees to collect the seeds is very dangerous. To add to the problem, the seeds are a favourite food for several types of fauna, especially macaws and parrots. This means that tree planters and birds are often in conflict when it is time to collect the seeds. Much relies on finding a compromise between the birds’ dinner plans and the needs of the tree planters when seed collecting time rolls around.

Good quality Sassafras seeds.
The seeds are quite large and very humid inside. This too causes a challenge, as only natural fiber cloth bags can be used to collect the seeds; otherwise they rot in the tropical heat. For that reason plastic bags are a complete no-no. For best germination results in the tree nursery, seeds should be no more than 1 week old from the time they are collected to the time that germination is attempted in the tree nursery. La Pedregoza has employed indigenous people to collect the seeds, a practice which has required considerable logistical support to get the seeds to the tree nursery in a timely manner.

Transporting Sassafras for planting.
There are only some 80 to 90 Ocotea cymbarum seeds in a kilogram (40 seeds per lbs.). Due to the many challenges already described the average cost of collecting a kilogram of Sassafras seeds works out to be about $100 USD, with no guarantee of germination. In addition, the manner in which the tree’s roots develop, means that larger planting bags are required in the tree nursery, each using a lot more substrate in order to fill each bag. The subsequent transport of the bags to a planting location is complicated due to the added weight caused by having large planting bags. Someone has to physically carry those bags into the rain forest, as vehicle access is not possible. 

Planting Sassafras in shaded spots.
 At La Pedregoza the average germination rate for Sassafras has been around 80% with good seeds. The  seedlings need about 4 months in the tree nursery, before they reach a viable size for transplanting in the forest. We use a 60% shading material while the seedlings are in the nursery, as they are quite sensitive to full sunlight even in their initial development. Since the seeds are collected quite late in the season, planting can´t really occur until October at the earliest, once flood waters start to recede from the inundation forest. La Pedregoza teams have planted Sassafras as late as December, when the final flood waters disappear.

Seeing if grasses will shade the tree.
Transplanting offers a further challenge, as any miscalculation in the selected planting site can result in a failure. Some natural predators seem to like to graze on the seedlings as well. In the past 3 years La Pedregoza has planted over 1,000 Sassafras trees in the rain forest, with only a 50% survival rate after one year. Working with Ocotea cymbarum is a labour of love, but considered by everyone to be well worth the effort, from seed collectors to tree nursery staff to the final tree planters, as well as the biologists and botanists supervising the process. The support of Tree-Nation members has been fundamental in this work, so everyone involved can truly state that they have helped save an endangered species.