Periodic Reporting for period 3 - ALPHA (Assessing Legacies of Past Human Activities in Amazonia)
Reporting period: 2023-01-01 to 2024-06-30
1. What is the problem/issue being addressed?
The ALPHA (Assessing Legacies of Past Human Activities) project is aimed at examining how human activities and land use practices that have occurred over the past hundreds or thousands of years result in changes in that persist in the landscape and are manifested in modern forests. We are particularly focused on Amazonian rainforests, which were previously thought to be pristine and have a light human footprint prior to European arrival to the American continent in AD 1492. Archaeological data collected over the past several decades have shown that this is not the case. In some regions of Amazonia, indigenous people had complex and thriving societies. They were modifying soils, cultivating crops, burning forests, and changing the abundances of many types of plants. In some cases, these activities changed the landscape to the point that they are still evident in today's forests. These changes of the past may affect our understanding of modern ecology in one of the most biodiverse and culturally diverse places in the world. The ALPHA project is assessing how these past human activities affect modern patterns of vegetation and carbon storage in the forests.
2. Why is it important for society?
Amazonia holds approximately 15% of Earth's biodiversity and 17% of terrestrial carbon stocks. Because these forests are so vast and hold so much carbon, they are important components of global carbon models that predict how atmospheric CO2 levels will change in upcoming decades to centuries. These models current assume that Amazonian forests are in equilibrium and are not changing. However, past human activities and their legacies may result in forests that are still undergoing successional change, which could greatly affect carbon dynamics. The ALPHA project is looking to determine the successional stage of forests that are measured for biodiversity and carbon, so that researchers can understand whether or not these forests are in equilibrium or still undergoing successional change. This also makes the outcomes of the ALPHA project relevant for all of society.
The ALPHA project and its outcomes will also provide important data that can be used locally in Amazonia. Land rights of indigenous people are currently being questioned and threatened in many regions. Our data can show that indigenous people have lived on these lands for hundreds or thousands of years before Europeans came to the continent, and these types of data can be used in currently policy decisions regarding the land rights and ownership of indigenous people in certain areas.
3. What are the overall objectives?
The overall objectives of the ALPHA project are to generate data on the types, timing, duration, and locations of past human activities in Amazonian forests, and how/whether these activities leave signals that are still present in modern forests. We also aim to link these findings with current ecological and biogeographical patterns and processes documented in Amazonian forests over the last several decades. We aim to integrate past and modern ecology because what we observe and monitor today is usually dependent on processes that have occurred in the past, particularly in systems where individual trees live for hundreds of years - much longer than modern observations can see.
The ALPHA (Assessing Legacies of Past Human Activities) project is aimed at examining how human activities and land use practices that have occurred over the past hundreds or thousands of years result in changes in that persist in the landscape and are manifested in modern forests. We are particularly focused on Amazonian rainforests, which were previously thought to be pristine and have a light human footprint prior to European arrival to the American continent in AD 1492. Archaeological data collected over the past several decades have shown that this is not the case. In some regions of Amazonia, indigenous people had complex and thriving societies. They were modifying soils, cultivating crops, burning forests, and changing the abundances of many types of plants. In some cases, these activities changed the landscape to the point that they are still evident in today's forests. These changes of the past may affect our understanding of modern ecology in one of the most biodiverse and culturally diverse places in the world. The ALPHA project is assessing how these past human activities affect modern patterns of vegetation and carbon storage in the forests.
2. Why is it important for society?
Amazonia holds approximately 15% of Earth's biodiversity and 17% of terrestrial carbon stocks. Because these forests are so vast and hold so much carbon, they are important components of global carbon models that predict how atmospheric CO2 levels will change in upcoming decades to centuries. These models current assume that Amazonian forests are in equilibrium and are not changing. However, past human activities and their legacies may result in forests that are still undergoing successional change, which could greatly affect carbon dynamics. The ALPHA project is looking to determine the successional stage of forests that are measured for biodiversity and carbon, so that researchers can understand whether or not these forests are in equilibrium or still undergoing successional change. This also makes the outcomes of the ALPHA project relevant for all of society.
The ALPHA project and its outcomes will also provide important data that can be used locally in Amazonia. Land rights of indigenous people are currently being questioned and threatened in many regions. Our data can show that indigenous people have lived on these lands for hundreds or thousands of years before Europeans came to the continent, and these types of data can be used in currently policy decisions regarding the land rights and ownership of indigenous people in certain areas.
3. What are the overall objectives?
The overall objectives of the ALPHA project are to generate data on the types, timing, duration, and locations of past human activities in Amazonian forests, and how/whether these activities leave signals that are still present in modern forests. We also aim to link these findings with current ecological and biogeographical patterns and processes documented in Amazonian forests over the last several decades. We aim to integrate past and modern ecology because what we observe and monitor today is usually dependent on processes that have occurred in the past, particularly in systems where individual trees live for hundreds of years - much longer than modern observations can see.
We have made significant progress on the goals and checkpoints of Work Package 1 (WP1), which develops new methodologies to analyse fire intensity and charcoal data, and we have produced three manuscripts on methodological development. We have also produced fire histories for several forest inventory plots from western Amazonia (WP1) and our supplemental sites. Four of these have been published to date, with more in preparation.
We have also made significant progress on the goals and checkpoints of WP2, which is to reconstruct past vegetation changes within forest inventory sites. We have produced three manuscripts that expand the capabilities of vegetation reconstructions using phytoliths, and we have published four manuscripts where we reconstruct past vegetation change from the soils collected within forest inventory sites.
WP3, which generates continuous fire and vegetation histories from lake sediment records, is also underway. We have published two of these to date, with more in preparation (the analysis time is longer for these records than for soils). As part of the COVID delays, we published two syntheses of existing datasets that fall within the scope of the project. One drawback is that not all of the lakes around the forest inventory sites were of sufficient age and quality for analysis, so we have used other sites instead. We collected paired forest inventory sites and high-quality lake sediment records from southern Peru in 2022, and analysis of those is underway.
We have also made significant progress on the goals and checkpoints of WP2, which is to reconstruct past vegetation changes within forest inventory sites. We have produced three manuscripts that expand the capabilities of vegetation reconstructions using phytoliths, and we have published four manuscripts where we reconstruct past vegetation change from the soils collected within forest inventory sites.
WP3, which generates continuous fire and vegetation histories from lake sediment records, is also underway. We have published two of these to date, with more in preparation (the analysis time is longer for these records than for soils). As part of the COVID delays, we published two syntheses of existing datasets that fall within the scope of the project. One drawback is that not all of the lakes around the forest inventory sites were of sufficient age and quality for analysis, so we have used other sites instead. We collected paired forest inventory sites and high-quality lake sediment records from southern Peru in 2022, and analysis of those is underway.
We have made progress beyond the state of the art in both the analysis of fire intensity (through spectral analysis), which is a part of WP1. We have published two manuscripts on this, and have one in review (see above).
We have also made progress beyond the state of the art in the ability to identify phytoliths, which is crucial for reconstructing past vegetation. These have been implemented in the publications listed in the previous section.
We are expecting to produce state of the art linkages between the paleoecological data and the modern vegetation data in the upcoming period.
We have also made progress beyond the state of the art in the ability to identify phytoliths, which is crucial for reconstructing past vegetation. These have been implemented in the publications listed in the previous section.
We are expecting to produce state of the art linkages between the paleoecological data and the modern vegetation data in the upcoming period.