October 22, 2014

New CTFS-ForestGEO Program Manager

We are pleased to welcome Dr. Kristin Powell as the Center for Tropical Forest Science-Forest Global Earth Observatory (CTFS-ForestGEO) network Program Manager.  Kristin recently completed a postdoctoral fellowship at the National Socio-Environmental Synthesis Center, where she researched biodiversity and ecosystem functioning in tropical forests. Prior to her fellowship, she earned her doctoral degree in Ecology and Evolution and her bachelor’s degree in Environmental Science from Washington University in St. Louis, Missouri. Kristin’s interest in science coordination and management stems from her past work on several education and plant research initiatives with the Chicago Botanic Garden and Morton Arboretum, the Botanical Society of America, and the Center for the Integration of Research, Teaching, and Learning.  When she is not helping to run the CTFS-ForestGEO network at the National Museum of Natural History in Washington, D.C., you can find her wandering the forest in Shenandoah National Park, running through the D.C. city streets, and rooting for the St. Louis Cardinals during baseball season. Kristin can be reached at PowellK@si.edu. 

To learn more about CTFS-ForestGEO, click here.

October 9, 2014

Review: CTFS-ForestGEO: a worldwide network monitoring forests in an era of global change

CTFS-ForestGEO Scientists, along with 78 global collaborating institutions and global partners published "CTFS-ForestGEO: a worldwide network monitoring forests in an era of global change" in Journal Global Change Biology. The publication highlights the impacts of global climate change on the worlds forests, and the monitoring methods used to collect climate change data. The CTFS-ForestGEO network now monitors 60 plots in 24 countries, monitoring approx. 4.5 million trees. “We look forward to using the CTFS-ForestGEO network to continue to understand how and why forests respond to change, and what this means for the climate, biodiversity conservation and human well-being,” said Stuart Davies, CTFS-ForestGEO network director. 

Below is the abstract of the review: 

Global change is impacting forests worldwide, threatening biodiversity and ecosystem services including climate regulation. 

Understanding how forests respond is critical to forest conservation and climate protection. This review describes an international network of 59 long-term forest dynamics research sites (CTFS-ForestGEO) useful for characterizing forest responses to global change. 

Within very large plots (median size 25 ha), all stems >1 cm diameter are identified to species, mapped, and regularly recensused according to standardized protocols. 

CTFS-ForestGEO spans 25°S–61°N latitude, is generally representative of the range of bioclimatic, edaphic, and topographic conditions experienced by forests worldwide, and is the only forest monitoring network that applies a standardized protocol to each of the world’s major forest biomes.

Supplementary standardized measurements at subsets of the sites provide additional information on plants, animals, and ecosystem and environmental variables.

CTFS-ForestGEO sites are experiencing multifaceted anthropogenic global change pressures including warming (average 0.61 °C), changes in precipitation (up to !30% change), atmospheric deposition of nitrogen and sulfur compounds (up to 3.8 g N m"2 yr"1 and 3.1 g S m"2 yr"1), and forest fragmentation in the surrounding landscape (up to 88% reduced tree cover within 5 km). 

The broad suite of measurements made at CTFS-ForestGEO sites makes it possible to investigate the complex ways in which global change is impacting forest dynamics. 

Ongoing research across the CTFSForestGEO network is yielding insights into how and why the forests are changing, and continued monitoring will provide vital contributions to understanding worldwide forest diversity and dynamics in an era of global change.

For the full review, click here

Email CTFS-ForestGEO program assistant, Delaney Rakosnik at rakosnikd@si.edu if you would like the supplemental information.

Click here to learn more about the CTFS - ForestGEO network.

September 23, 2014

CTFS-ForestGEO grant project report from KC Cushman at Barro Colorado Island, Panama

CTFS-ForestGEO Grants Program recipient, KC Cushman, has been researching her grant proposal “Improving estimates of biomass change in buttressed trees using site-specific tree taper models" in Panama, Thailand, Singapore and Colombia. She recently completed her project and the following is her report:
KC with a buttressed tree in Khao Chong, Thailand
"The amount of biomass stored in any tropical forest can change over time as trees grow, produce new seedlings, and die. Measuring how tropical forest biomass changes over time is important for understanding the global carbon cycle; if tropical forests increase in biomass over time they act as a carbon sink (if trees are growing more than they are dying, on average), but if tropical forests decrease in biomass over time they act as a carbon source (if trees are dying more than they are growing, on average).

CTFS plot in Amacayacu, Colombia.
The diameter measurement height of
each tree is marked in yellow paint.
One tool for studying biomass change is measuring tree diameters in forest plots, such as those in the Center for Tropical Forest Science network. Diameter measurements taken at 1.3 m height are converted to an estimate of total biomass using equations developed in previous research. All trees in a plot are remeasured regularly to determine changes in biomass.
Picture of a tree, a 3-D model
of the same tree constructed
from 43 pictures using
Agisoft PhotoScan, and
trunk outlines extracted from
the 3-D model point using the
program Cloud Compare

However, the prevalence of buttressed trees in tropical forests presents some challenges for this approach. Trees with buttresses are not cylindrical at 1.3 m height, so their diameters are measured higher on the trunk. This practice creates a bias because tree trunks tend to decrease in diameter with height, or taper. Therefore, diameter measurements taken above 1.3 m height will be smaller and yield a lower value for biomass. The magnitude of biomass underestimation in a forest can change over time because measurement heights are often moved up a tree as it grows. This is problematic because biomass appears to change, but the change is not caused by real forest processes. In a previous study on Barro Colorado Island, Panama, we found that biomass trends change significantly after correcting for changing measurement heights in diameter data. Biomass decreased over time in uncorrected data but increased over time in corrected data (Cushman et al. 2014).

Walking to the plot in
Huai Kha Khaeng, Thailand
This year, I had the opportunity to follow up on our preliminary study on BCI through research supported by the CTFS-ForestGEO Research Grants Program. I visited four other CTFS plots to compare tree taper in different forests: Amacayacu (Colombia), Bukit Timah (Singapore), Huai Kha Khaeng (Thailand), and Khao Chong (Thailand). In this study, I am also using a novel tool to measure trees by creating 3-D models from digital pictures using Agisoft PhotoScan. I took 30-60 photos of each of approximately 100 trees per plot to create a model of each tree.  I am using these models to measure characteristics of trunk shape at each site, such as how diameter and trunk circularity change with height. Results from trunk shape measurement can then be used to improve estimates of biomass change when diameter measurement heights change over time.
Field Station at
Huai Kha Khaeng, Thailand

I am thankful to have had the opportunity to visit these plots and meet other researchers through the CTFS-ForestGEO network. This work would not have been possible without the support and guidance of collaborators Helene Muller-Landau, Stuart Davies, Sarayudh
Bunyavejchewin, Alvaro Duque, Somboon Kiratiprayoon, and Shawn Lum, and the assistance of Pablo Ramos, Paulino Villareal, Emily Francis, Juan Sebastian Barreto Silva, Gabriel, Pitoon Kongnoo, Mohamah Fairoz, Jonathan, and Reuben in the field."

To learn more about CTFS-ForestGEO, click here

September 5, 2014

2014 CTFS-ForestGEO Dimensions of Biodiversity Workshop

The 2014 NSF-funded CTFS-ForestGEO Workshop was held last month at the Xishuangbanna Tropical Botanical Garden (XTBG) in Yannan Provine in China . It was the fourth of five annual research workshops over the period 2011 to 2015 focused on "Diversity and Forest Change: Characterizing functional, phylogenetic and genetic contributions to diversity gradients and dynamics in tree communities". The program is co-supported by the Dimensions of Biodiversity Program of the US National Science Foundation (DEB-1046113) and the National Science Foundation of China.

Over 55 scientists from 20 countries worked in small groups to address specific research topics. The focus was on both individual plot analyses and cross-plot comparisons, and included studies of forest carbon dynamics, spatial patterns in species diversity, and forest growth and mortality. The workshop culminated in the presentation of over 40 different research projects on the final day of the workshop. Manuscripts derived from the work are now being prepared.

The gathering of many partners from across the CTFS-ForestGEO network also provided an important opportunity to advance current and future collaborations on the science of the world’s forests. While in China, scientists also enjoyed a tour of the Xishuangbanna Plot and a canopy hike in Greestone Forest.

August 25, 2014

2014 Research Grant Program awardees

The 2014 cycle of the CTFS-ForestGEO Research Grant Program was competitive. Approximately 35 interesting and diverse proposals were submitted from all over of the globe. Each proposal was read by network scientists, and ranked according to scientific merit, contribution to the network, educational contribution, and status of the Principle Investor (PI) to determine an overall rank. 5 proposals were selected for funding. Find a summary of each funded proposal below.  

Carlos Jaramillo, a Staff Scientist at STRI, submitted Pollen flora of the Amacayacu 25 Ha Plot: adding a geological time scale dimension to SIGEO plots, The research will take place at Amacayacu National Park, Amazons, Colombia.

Matthew Craig, a PhD student at Indiana University submitted A new framework for quantifying drivers of soil carbon dynamics within and among forests. The research will take place at Lilly Dicky Woods, SCBI, SERC, Tyson Research Center,  Wind River.

Jan Ng, a PhD student at University of California-Davis submitted Assessing shifts in tree spatial patterns following reintroduction of fire disturbance in the Yosemite Forest Dynamics plot. The researched will take place at Yosemite Forest Dynamics Plot in California, USA.

Owen Lewis, an Associate Professor at Oxford University submitted Linking botanical and entomological datasets: A seed trap network for the Wanang 50-ha plot. The research will take place at Wanang, Papua New Guinea.

Jian Zhang, Postdoc at University of Alberta submitted See forests from drones: testing the potentials of drones in CTFS long-term monitoring network. The work will take place in Dinghushan, China.

To learn more about the CTFS-ForestGEO network, visit www.ctfs.si.edu

August 5, 2014

CTFS-ForestGEO Dimensions of Biodiversity USA - China Student Exchange Program

María Natalia Umaña is a student from Nathan Swenson's Lab who traveled to China to develop a Project in Xishuangbanna Tropical Botanical Garden (XTBG) funded by CTFS-ForestGEo Dimensions of Biodiversity USA-China Student Exchange Program. The following is a report she wrote about her trip when she returned: 

"Tropical forests, being important hot spots of biodiversity, harbor a significant number of rare species. Most of the plant species in tropical forests exhibit very restricted distributions and low abundances, while only few species are dominant. Why are so many species rare? Is it because rare spaces have different characteristics compared with common species? Are rare species ill-suited to the available habitats or specialized on rare habitats? These are classic questions in ecology and the main motivation of my PhD project.

In order to assess this question I am measuring the intraspecific variation in functional traits across several species with different relative abundances. Recently, as a part of my Ph.D. research, I traveled to the Xishuangbanna Forest Dynamics Plot (FDP) located in the south of Yunnan Province, China where I collected the functional trait data for seedlings in this tree community. In April 2013, 218 seedling plots were established near the 20-ha Xishuangbanna FDP. All the seedlings were monitored for growth and survival every two months. After one year, in April 2014, a team of 5 Chinese field assistants and I quantified functional trait data from every individual.
I stayed in the field station near the 20-ha FDP during my visit. This region, shaped by extensive mountains ranges, is home to a diverse tree community with over 400 species in the 20-ha plot with most of them being quite rare. During my visit I had the chance to share some time with local people who helped me with fieldwork. Although I arrived to China knowing only few words in Chinese, we were able to set up a nice team and work collaboratively in harmony. The people I met were always very kind and very hard-working. The field assistants have grown up in close partnership with nature and are very familiar with the hundreds of species located in and around the FDP. After our exhaustive field and lab work we now have an extensive data set including trait and demographic information at the individual level. With this data we will be able to evaluate how variable are traits across species with different relative abundances and how this individual level trait variation links with individual performance.

I would like to acknowledge the financial support of CTFS for this fieldwork. Specifically, the Dimensions of Biodiversity IRCN USA-China NSF grant awarded to Dr. Stuart Davies and Dr. Keping Ma funded my travel and this collaborative opportunity. I would also like to thank all of my new Chinese collaborators that were involved in this project from the laboratory of Dr. Min Cao. Specifically, t
his work would not have been possible without the help of Dr. Luxiang Lin, Cai Cai Zhang (a PhD student in Xishuangbanna Tropical Botanical Garden), Dr. Yang Jie, Zhigang Chen(field technician), Lang Ma (field technician), Zhilin Mu and Yongzheng Shen (field technician). Our time together yielded great new working relationships and friendships."

To learn more about Xishuangbanna Forest Dynamics Plot:


July 2, 2014

Harvard ForestGEO plot initial census completed!

Harvard Forest researchers, with the assistance of scientists from the Center for Tropical Forest Science (CTFS) and the Smithsonian Institute’s Forest Global Earth Observatory (ForestGEO), completed the census of woody stems within the 35 ha plot located on Prospect Hill in March 2014. Using standardized CTFS-ForestGEO methodology, Jay Aylward and field assistants Kyle Krigest and Sarah Myers have measured, tagged, painted, and mapped the final 4,400+ woody stems greater than 1 cm dbh in the remaining section of forest located in the beaver swamp in the north-central portion of the plot.
The swamp is particularly dense, containing over 29,000 stems of winterberry holly (Ilex verticillata), highbush blueberry (Vaccinium corymbosum), witherod (Viburnum cassinoides), and maleberry (Lyonia ligustrina).  The final plot tally from Dave Orwig, Jay, and 26 field assistants was over 116,000 woody stems!  The HF SIGEO plot is dominated by eastern hemlock (> 25,000 stems) and northern hardwood species in upland plots, and will make an excellent comparison with several other hardwood plots in North America and China at similar latitudes. 

This plot is part of a global array of large-scale plots established by CTFS, which recently expanded sampling efforts into temperate forests to explore ecosystem processes beyond population dynamics and biodiversity. 

The geography and size of the Harvard Forest plot (500 m x 700 m) was designed to include a continuous, expansive and varied natural forest landscape that will yield opportunities for the study of forest dynamics and demography while capturing a large amount of existing science infrastructure (e.g. eddy flux towers, gauged sections of a small watershed, existing smaller permanent plots) that will enable the integrated study of ecosystem processes (e.g., biogeochemistry, hydrology, carbon dynamics) and forest dynamics . Thus, the resulting data will integrate well with ongoing NSF-funded LTER (Long Term Ecological Research) and NEON (National Ecological Observation Network) studies.

To learn more about CTFS-ForestGEO, click here.