Treesearch

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...

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...

Models project that climate change is increasing the frequency of severe storm events such as hurricanes. Hurricanes are an important driver of ecosystem structure and function in tropical coastal and island regions and thus impact tropical forest carbon (C) cycling. We used the DayCent model to explore the effects of increased hurricane frequency on humid tropical forest C stocks and fluxes at decadal and centennial timescales. The model was parameterized with empirical data from the Luquillo Experimental Forest (LEF), Puerto Rico. The DayCent model replicated the well-documented cyclical...

Tropical forests are a dominant regulator of the global carbon cycle, exchanging more carbon dioxide with the atmosphere than any other terrestrial biome. Climate models predict unprecedented climatic warming in tropical regions in the coming decades; however, in situ field warming studies are severely lacking in tropical forests. Here we present results from an in situ warming experiment in Puerto Rico, where soil respiration responses to +4 oC warming were assessed half-hourly for a year. Soil respiration rates were 42- 204% higher in warmed relative to ambient plots, representing some...

Understanding thermal stress in tropical forests has taken on new urgency in light of accelerating climate change and expansion of deforestation and forest degradation. Degraded tropical forests in particular may be approaching critical temperature thresholds even more rapidly than intact forests, with implications for tree survival and ecosystem recovery. We investigate thermal stress in degraded tropical forests within the Brazilian Amazon Arc of Deforestation. Using land surface temperature data from the ECOsystem Spaceborne Thermal Radiometer Experiment on the international Space...

We studied the stoichiometry of 6 forest stands dominated by Spathodea campanulata (African Tulip Tree; hereafter Spathodea) on alluvial (n = 3) and karst (n = 3) substrates in the north-central region of Puerto Rico. The stands were on lands previously used for Saccharum officinarum (Sugar Cane) cultivation, subsistence agriculture, and grazing, and are representative of novel forest emergence and secondary succession in the study region. The functioning of these novel forests is poorly understood, and we sought to improve our understanding by studying the stoichiometry of forest stands...