The CIFOR-ICRAF Dendroecology Laboratory for forests, trees, climate change and landscapes

Climate change is one of the biggest threats to nature and humanity today. The world is experiencing extreme weather events such as floods, droughts and dry spells of increased frequency and intensity. These are having devastating impacts on the vitality, productivity and quality of ecosystems and ecosystem services. To ensure progress towards attaining the Sustainable Development Goals (SDGs), it is crucial that the negative impacts of climate change on trees and forests, and on forest-dependent communities be addressed. Furthermore, agroforestry and the restoration of forest landscapes are increasingly prominent global concerns, as is acknowledging the roles they play in supporting climate change adaptation. However, there is a lack of basic information on how climate and ecological processes operated in the past to help in determining which tree species will be resilient to future climate, and how the ecosystems they form part of will be affected.

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Aster Gebrekirstos

Scientist

At the CIFOR-ICRAF Dendroecology Lab, we look at what trees, forests and forest-dependent communities have to say in order to address climate change issues and the effects of forest use and climate change on biodiversity and ecosystems. We seek to disentangle the effects of climate change and other kinds of disturbances, and generate knowledge and data on how climate and ecological processes impacted trees in the past, and how they are doing so now, to characterize how trees will respond under future climate conditions, and how sustainable their future ecosystems will be.

This is crucial to minimize risk and avoid undesirable effects of increasingly frequent and severe droughts, floods and heat waves on trees and forest ecosystems, and on people’s livelihoods. By reconstructing the past performance of trees in terms of their drought tolerance, growth dynamics, productivity and water use efficiency, we can assess how productive and resilient different tree species are under different environmental conditions, and how they are likely to respond in the face of climate change to come. This can inform the development of climate smart restoration options for agricultural and forest land. As their productivity can be modelled, they can be valued economically to create sound business cases to inform policies surrounding land, forest management and landscape restoration.

What we do

We use a combination of methods and interdisciplinary approaches to address spatiotemporal changes across scales. The applied methods include tree-ring, wood anatomy, plant-water relation and stable isotope analyses, and use of dendrometers.

Dendrochronology is defined as tree-ring dating, or the analysis of patterns of tree growth rings to specify the time and conditions under which each growth ring was formed. Trees are history books. They tell us so much about themselves; about us and how we treat them and their landscapes; and about what we are doing to our Earth. Like crime scene investigators use trace evidence to solve mysteries; we use tree rings to decode minutes, decades and even centuries of information stored in trees to shed light on an area’s shrouded and elusive climate history, and how it has changed and will impact us. Since such changes are recorded in the wood produced during a certain time period, the wood’s anatomical features, tree rings and stable isotopes in its tree rings are key terrestrial archives providing insight into past climate and environmental variability at annual resolution, and from local to regional scales. Tree ring proxies are also important as indicators of plant physiological responses to changing climatic conditions from cells to ecosystems, and for further understanding of long-term ecological processes that are needed for developing appropriate tree-based systems, management actions and policy decisions that benefit people’s livelihoods and health as well as the environment.

Our services

• Sample collection and sample preparation
• Micro-sectioning using microtomes
• Tree-ring width measurement and analysis
• Monitoring growth of living trees (including urban trees)
• Wood anatomical preparation and wood anatomy analyses
• Modeling: model calibration and verification
• Providing wood density and dendrometer data

Our tools

• Microtomes
• Tree-ring width – Lintab measuring device
• Scanners
• Dendrometers
• Leaf plant water potential gauges to measure water stress

Our goals

Climate smart ecosystem restoration and management options

• To adapt trees and forests to future climate by evaluating climate-growth relationships and the effects of a changing climate on tree growth, wood anatomy and hydraulic conductivity at different spatial and temporal resolutions in provenances, agroforestry systems and forest ecosystems;
• To develop climate smart restoration and agroforestry options – we provide evidence and data to a broad variety of questions related to how to plant the right trees at the right site for the right purpose; which species are productive; how to make them productive; which species are resilient; when is the optimum time to cut; which species sequester more carbon; which species are drought tolerant; which species compete with crops; and which ones are beneficial for crops.

Hydroclimate reconstructions

• To develop cost-effective adaptation measures using tree ring data for proxy-based reconstructions of past climate conditions beyond the period of instrumental meteorological records by generating data/information on natural climate variability, climatic trends, frequency of extreme events, likely future climate scenarios, and proxy evidence of past variations in the El Niño Southern Oscillation and other large-scale atmospheric circulation patterns;
• To develop better water management options by reconstructing changes in river flow, source of water and hydrological fluctuations in relation to climate change;

Carbon and water cycle

• To quantify the roles of forests and trees in carbon sequestration and the carbon cycle by analyzing cambial dynamics, carbon allocation patterns and changes, and soil-plant water interactions;
• To provide a better understanding of the role of trees and forests in the hydrological cycle at local and regional scale, by understanding the ecological relationships between stable isotopes (measured in our partners’ labs in Europe) of the wood, climate and site conditions;

Fire, natural hazards and insect dynamics

• To develop better forest management strategies by studying past and present forest ecological dynamics and function, including issues such as fire and/or insect dynamics and forest composition history;
• To link scientific with local knowledge (e.g., drought histories and frequencies), and to provide evidence which is meaningful to policymakers (e.g., to improve access to index insurance, Normalized Difference Vegetation Index (NDVI) and length of growing season);

Capacity development

• To develop capacity – since this approach is still a new frontier in the tropics, particularly in Africa, we train and host postdoc, PhD and MSc students to do their research and raise awareness on the roles of trees, and their stories using citizen science.

Where we are located

The CIFOR-ICRAF Dendrochronology Laboratory is housed within the World Agroforestry Centre climate change unit in Nairobi, Kenya. Our approach is an innovative, cost effective and reliable tool for generating tree-based data and evidence, since such information is scant in the tropics, especially in Africa.