Treesearch

Carbon–climate (CC) feedbacks — arising from response of land and ocean carbon sinks to elevated CO2 and climate warming — are critical yet highly uncertain drivers of Earth’s climate trajectory. Processes such as permafrost thaw, tropical forest dieback, reduced ocean uptake, and intensifying climate extremes are already weakening natural carbon sinks, with potential to amplify warming and accelerate crossing of tipping points. Detecting and quantifying these dynamics requires sustained, high-resolution, spatially-comprehensive Earth Observations. Drawing on outcomes from a 2024 community...

Tree canopy height is a key indicator of forest biomass, productivity and structure, yet measuring it accurately at regional or larger scales, whether from the ground or remotely, remains challenging. The objective of this study is to generate the first complete canopy height map of the Amazon forest at
4.78m resolution using Planet NICFI imagery and deep learning. Specifically, we (i) trained a U-Net regression model with canopy height models (CHMs) derived from tropical airborne LiDAR and their corresponding Planet NICFI images to estimate canopy height, (ii) evaluated the accuracy of...

It is unclear how plants respond to increasing temperatures. Leaf heat tolerance (LHT) is often at its upper limit in tropical forests, suggesting that climate change might negatively impact these forests. We hypothesized that intraspecific variation in LHT might be associated with changes in the soil microbiome, which might also respond to climate. We hypothesized that warming would increase LHT through changes in the soil microbiome: we combined an in situ tropical warming experiment with a shade house experiment in Puerto Rico. The shade house experiment consisted of growing seedlings...

Hurricanes strongly regulate vegetation structure and dynamics in coastal tropical forests by causing tree mortality and damaging the crowns of surviving trees. Despite the importance of this damage for long-term forest demography and carbon dynamics, the patterns and drivers of variation in hurricane-induced damage across heterogeneous landscapes remain poorly quantified. Here, we integrate field inventory data with repeated airborne LiDAR measurements to quantify tree crown damage following Hurricane María (Category 4) in the Luquillo Experimental Forest, Puerto Rico. We applied two...

Improved forest management (IFM), particularly the transition of even-aged forests to continuous cover forestry (CCF), is gaining attention as a management approach that may contribute to climate change mitigation by enhancing forest carbon sequestration and maintaining soil carbon storage. CCF aims to maintain continuous tree cover over time by using selective harvesting and natural regeneration instead of clear-cutting (CC), and is promoted as a forest management method that enhances productivity, ecological, and social benefits. Using a Scots pine stand management in Poland, we evaluated...

Microbial nitrogen (N) fixation accounts for c. 97% of natural N inputs to terrestrial ecosystems. These microbes can be free-living in the soil and leaf litter (asymbiotic) or in symbiosis with plants. Warming is expected to increase N-fixation rates because warmer temperatures favor the growth and activity of N-fixing microbes.We investigated the effects of warming on asymbiotic components of N fixation at a field warming experiment in Puerto Rico. We analyzed the function and composition of bacterial communities from surface soil and leaf litter samples.Warming significantly increased...

The Black-crowned Night Heron (Nycticorax nycticorax) is one of the most widely distributed heron species worldwide, absent only from Australasia and the far northern Holarctic. Notable for its pronounced phenotypic and genetic variability in plumage, the species occasionally exhibits rare chromatic aberrations such as melanism, leucism and albinism. These phenomena provide valuable insights into adaptability, underlying genetic mechanisms and ecological and evolutionary implications. Here, we summarize the frequency and geographic distribution of documented plumage aberrations of the...

The balance between methane producing and methane consuming microorganisms is partially responsible for the magnitude and direction of soil-atmosphere methane fluxes. Therefore, understanding the effects of vegetation and land use on relative abundance, community structure and vertical distribution of methane cycling microorganisms should help us interpret patterns of net emissions of methane. Mountain peatlands in the tropics areabundant and are important in global carbon cycling, but little is known about the communities of methane cycling microorganisms in these ecosystems. We sampled...

Accurately monitoring forest canopy height is crucial for sustainable forest management, particularly in southeastern North Carolina, USA, where dense forests and limited accessibility pose substantial challenges. This study presents an explainable machine learning framework that integrates sparse GEDI LiDAR samples with multi-sensor remote sensing data to improve both the accuracy and interpretability of forest canopy height estimation. This framework incorporates multitemporal optical observations from Sentinel-2; C-band backscatter and InSAR coherence from Sentinel-1; quad-polarization...

Convolutional neural networks (CNNs), specifically U-Nets, successfully detect and segment individual tree crowns when applied to high spatial resolution remotely sensed data. However, much of the prior work for individual tree detection and segmentation has been in arid climates such as the western United States and the African Sahel. In this study, we used the U-Net-id CNN architecture and National Agriculture Imagery Program (NAIP) imagery to investigate forest-cover-specific training on individual tree crown detection in Virginia, U.S. We trained three models using hand-delineated...