Joseph Mascaro

• PhD
• Managing Director at Planet Labs

Tropical forests are crucial for mitigating climate change, but many forests continue to be driven from carbon sinks to sources through human activities. To support more sustainable forest uses, we need to measure and monitor carbon stocks and emissions at high spatial and temporal resolution. We developed the first large-scale very high-resolution...

The PlanetScope constellation consists of ∼150 optical cubesats that are evenly distributed like strings of pearls on two orbital planes, scanning the Earth's land surface once per day with an approximate spatial image resolution of 3 m. Subsequent cubesats on each of the orbital planes image the Earth surface with a nominal time lag of approximate...

Accurate bathymetric mapping of shallow waters (above 15 m) is essential for a wide range of scientific research, government, transport, and industry globally. Satellite-based bathymetry estimation approaches offer an alternative to traditional shipborne measurements, especially given advancements in their spatial and temporal resolution of satelli...

The PlanetScope constellation consists of ~ 150 optical cubesats that are evenly distributed like strings of pearls in two orbital planes and scan the Earth's land surface once per day with ~ 3 m spatial image resolution. Subsequent cubesats in each of the orbital planes image the Earth surface with a nominal time lapse of ~ 90 s between each other...

Remote sensing data have increasingly been employed in combination with field plot data to estimate aboveground carbon (C) stocks across heterogeneous forested landscapes around the world. The Forest Inventory and Analysis (FIA) program of the US Forest Service offers a gridded network of field plots which potentially can be linked to airborne Ligh...

Near–real-time monitoring and response are possible

Recent deployments of CubeSat imagers by companies such as Planet may advance hydrological remote sensing by providing an unprecedented combination of high temporal and high spatial resolution imagery at the global scale. With approximately 170 CubeSats orbiting at full operational capacity, the Planet CubeSat constellation currently offers an aver...

Satellite-based remote sensing has generally necessitated a trade-off between spatial resolution and temporal frequency, affecting the capacity to observe fast hydrological processes and rapidly changing land surface conditions. An avenue for overcoming these spatiotemporal restrictions is the concept of using constellations of satellites, as oppos...

When Earth observation satellite systems are designed, one typically prefers a sun-synchronous orbit. However, the first generations of cubesats from Planet were deployed out of the International Space Station (ISS) and therefore do not obey such an orbit. Their configuration samples at different local times within the mid-latitudes. Consequently,...

When Earth observation satellite systems are designed, one typically prefers a sun-synchronous orbit. However, the first generations of cubesats from Planet were deployed out of the International Space Station (ISS) and therefore do not obey such an orbit. Their configuration samples at different local times within the mid-latitudes. Consequently,...

Satellite measurements of coseismic displacements are typically based on synthetic aperture radar (SAR) interferometry or amplitude tracking, or based on optical data such as from Landsat, Sentinel-2, SPOT, ASTER, very high-resolution satellites, or air photos. Here, we evaluate a new class of optical satellite images for this purpose – data from c...

Coral reefs of the Spratly archipelago in the South China Sea are undergoing rapid transformation through military base and outpost development, destructive fishing practices and other factors. Despite increasing pressure on the ecologically unique reefs throughout this region, limited direct access to them has made it difficult to monitor reef cov...

Satellite measurements of coseismic displacements are typically based on Synthetic Aperture Radar (SAR) interferometry or amplitude tracking, or based on optical data such as from Landsat, Sentinel-2, SPOT, ASTER, very-high resolution satellites, or airphotos. Here, we evaluate a new class of optical satellite images for this purpose – data from cu...

Tropical forests store large amounts of carbon in tree biomass, although the environmental controls on forest carbon stocks remain poorly resolved. Emerging airborne remote sensing techniques offer a powerful approach to understand how aboveground carbon density (ACD) varies across tropical landscapes. In this study, we evaluate the accuracy of the...

Liana abundance and species diversity are higher in tropical than temperate forests, but substantial variation exists in liana community structure within tropical forests, particularly among biogeographical regions and along gradients in altitude, precipitation, and edaphic characteristics. We used liana surveys from across the world, which we comp...

The reality confronting ecosystem managers today is one of heterogeneous, rapidly transforming landscapes, particularly in the areas more affected by urban and agricultural development. A landscape management framework that incorporates all systems, across the spectrum of degrees of alteration, provides a fuller set of options for how and when to i...

In a recent paper (Mitchard et al. 2014, Global Ecology and Biogeography, 23, 935–946) a new map of forest biomass based on a geostatistical model of field data for the Amazon (and surrounding forests) was presented and contrasted with two earlier maps based on remote-sensing data Saatchi et al. (2011; RS1) and Baccini et al. (2012; RS2). Mitchard...

Significance Land use is a principal driver of carbon emissions, either directly through land change processes such as deforestation or indirectly via transportation and industries supporting natural resource use. To minimize the effects of land use on the climate system, natural ecosystems are needed to offset gross emissions through carbon seques...

Treefall gaps are the “engines of regeneration” in tropical forests and are loci of high tree recruitment, growth, and carbon accumulation. Gaps, however, are also sites of intense competition between lianas and trees, whereby lianas can dramatically reduce tree carbon uptake and accumulation. Because lianas have relatively low biomass, they may di...

Treefall gaps are the "engines of regeneration" in tropical forests and are loci of high tree recruitment, growth, and carbon accumulation. Gaps, however, are also sites of intense competition between lianas and trees, whereby lianas can dramatically reduce tree carbon uptake and accumulation. Because lianas have relatively low biomass, they may di...

For tropical forest carbon to be commoditized, a consistent, globally verifiable system for reporting and monitoring carbon stocks and emissions must be achieved. We call for a global airborne LiDAR campaign that will measure the 3-D structure of each hectare of forested (and formerly forested) land in the tropics. We believe such a database could...

Tropical forests are important storehouses of carbon and biodiversity. In isolated island ecosystems such as the Hawaiian Islands, relative dominance of native and nonnative tree species may influence patterns of forest carbon stocks and biodiversity. We determined aboveground carbon density (ACD) across a matrix of lava flows differing in age, tex...

Mapping aboveground carbon density (ACD) in tropical forests can enhance large-scale ecological studies and support CO2 emissions monitoring. Light Detection and Ranging (LiDAR) has proven useful for estimating carbon density patterns outside of field plot inventory networks. However, the accuracy and generality of calibrations between LiDAR-assist...

Accurate and spatially-explicit maps of tropical forest carbon stocks are needed to implement carbon offset mechanisms such as REDD+ (Reduced Deforestation and Degradation Plus). The Random Forest machine learning algorithm may aid carbon mapping applications using remotely-sensed data. However, Random Forest has never been compared to traditional...

An understanding of the spatial variability in tropical forest structure and biomass, and the mechanisms that underpin this variability, is critical for designing, interpreting, and upscaling field studies for regional carbon inventories. We investigated the spatial structure of tropical forest vegetation and its relationship to the hydrological ne...

Background/Question/Methods Old growth tropical rainforests play a large role in the global carbon (C) cycle by storing about 350 Pg C in aboveground tree biomass, a reservoir that is shrinking due to widespread forest clearing and degradation. A shifting climate may also cause substantial changes in intact forest C stocks. And yet, our understan...

High fidelity carbon mapping has the potential to greatly advance national resource management and to encourage international action toward climate change mitigation. However, carbon inventories based on field plots alone cannot capture the heterogeneity of carbon stocks, and thus remote sensing-assisted approaches are critically important to carbo...

Recent evidence suggests that liana abundance and biomass are increasing in Neotropical forests, representing a major structural change to tropical ecosystems. Explanations for these increases, however, remain largely untested. Over an 8-yr period (1999–2007), we censused lianas in nine, 24 × 36 m permanent plots in old-growth and selectively logge...

This chapter focuses on the biodiversity-ecosystem function paradigm. Shahid Naeem demonstrated that while extinction may not initially destabilize ecosystem function, continued extinction will do so inevitably. The analogy to a computer was apt for the decade. In the 1980s, the analogy chosen by Paul and Anne Ehrlich was an airplane. By drawing th...

This chapter begins by reviewing the foundational principles that point to the existence and importance of novel ecosystems. It provides a brief review of previous formulations of the novel ecosystem concept. The chapter then steps into synthesis and presents a new framework for the novel ecosystems concept. Using the original Hobbs components of n...

Islands have much to offer our understanding of novel ecosystems, for it is there that novel assemblages of species have developed most rapidly and dramatically. This chapter on island ecosystem novelty considers non-continental land masses currently surrounded by ocean, whether that has been true throughout their geological history or not. It brie...

That a continuum best models the concept of novel ecosystems – that its boundaries are not clear lines but gray areas – raises the possibility that a novel ecosystem may not be a distinct entity. This chapter explores that possibility. In doing so, the chapter presents many instinctively appealing definitions, upon careful consideration, which turn...

Background/Question/Methods Non-native species are a pervasive component of global change, often interrupting ecosystem services upon which humans depend; falling water tables in South Africa, clogged drains in the Great Lakes, endemic species extinctions, and widespread timber and crop diseases are key examples. However, as I review here, non-na...

Abstract. High-resolution mapping of tropical forest carbon stocks can assist forest management and improve implemen- tation of large-scale carbon retention and enhancement pro- grams. Previous high-resolution approaches have relied on field plot and/or light detection and ranging (LiDAR) sam- ples of aboveground carbon density, which are typically...

Accumulation of aboveground carbon is one of the most important services provided by tropical secondary forests—a land-cover type that is increasing in importance globally. Carbon accumulates rapidly for the first 20 years of succession, but few studies have considered forests older than 20 years, and the available data do not yield a consistent pa...

The positive relationship between species diversity (richness and evenness) and critical ecosystem functions, such as productivity, carbon storage, and nutrient cycling, is often used to predict the consequences of extinction. At regional scales, however, plant species richness is mostly increasing rather than decreasing because successful plant sp...

High-resolution mapping of tropical forest carbon stocks can assist forest management and improve implementation of large-scale carbon retention and enhancement programs. Previous high-resolution approaches have relied on field plot and/or Light Detection and Ranging (LiDAR) samples of aboveground carbon density, which are typically upscaled to lar...

Accurate, high-resolution mapping of aboveground carbon density (ACD, Mg C ha-1) could provide insight into human and environmental controls over ecosystem state and functioning, and could support conservation and climate policy development. However, mapping ACD has proven challenging, particularly in spatially complex regions harboring a mosaic of...

Appendices. The appendix contains text, figures and tables that provide detail on satellite, aircraft, and field data collection, processing and analysis.

Nonlinear regression is increasingly used to develop allometric equations for forest biomass estimation (i.e., as opposed to the traditional approach of log-transformation followed by linear regression). Most statistical software packages, however, assume additive errors by default, violating a key assumption of allometric theory and possibly produ...

Airborne light detection and ranging (LiDAR) is fast turning the corner from demonstration technology to a key tool for assessing carbon stocks in tropical forests. With its ability to penetrate tropical forest canopies and detect three-dimensional forest structure, LiDAR may prove to be a major component of international strategies to measure and...

Current markets and international agreements for reducing emissions from deforestation and forest degradation (REDD) rely on carbon (C) monitoring techniques. Combining field measurements, airborne light detection and ranging (LiDAR)-based observations, and satellite-based imagery, we developed a 30-meter-resolution map of aboveground C density spa...

Background/Question/Methods Recent evidence suggests that liana abundance and biomass are increasing in Neotropical forests, representing a major structural change to these ecosystems. However, putative explanations for these increases remain largely untested. Over an 8-year period (1999 - 2007), we censused lianas in nine, 24 x 36 m permanent pl...

Many ecosystems are now dominated by introduced species, and because dominant species drive ecosystem properties, these changes lead to increased uncertainty in estimates of carbon storage and cycling. We examined aboveground biomass in forests dominated by the introduced tree Rhamnus cathartica (common buckthorn) relative to forests dominated by n...

Skole et al. (1) claim that we do not make a case for high-resolution carbon stock and emissions mapping in tropical forests. Specifically, they argue that (i) our Intergovernmental Panel on Climate Change (IPCC) Tier 1 estimates for the Peruvian Amazon study are biased, (ii) our plot-level carbon estimates used to calibrate airborne Light Detectio...

Hawai‘i’s forest ecosystems are changing rapidly due to a high level of species introductions, and it is an open question whether native species will be maintained. Several studies have explored the potential for native species to succeed in future communities dominated by introduced species in Hawai‘i, but the results have been conflicting and mos...

Despite the importance of tropical forests to the global carbon cycle, ecological controls over landscape-level variation in live aboveground carbon density (ACD) in tropical forests are poorly understood. Here, we conducted a spatially comprehensive analysis of ACD variation for a mainland tropical forest – Barro Colorado Island, Panama (BCI) – an...

Efforts to mitigate climate change through the Reduced Emissions from Deforestation and Degradation (REDD) depend on mapping and monitoring of tropical forest carbon stocks and emissions over large geographic areas. With a new integrated use of satellite imaging, airborne light detection and ranging, and field plots, we mapped aboveground carbon st...

We test the hypotheses proposed by Gentry and Schnitzer that liana density and basal area in tropical forests vary negatively with mean annual precipitation (MAP) and positively with seasonality. Previous studies correlating liana abundance with these climatic variables have produced conflicting results, warranting a new analysis of drivers of lian...

Ecological invasions are a major driver of global environmental change. When invasions are frequent and prolonged, exotic species can become dominant and ultimately create novel ecosystem types. These ecosystems are now widespread globally. Recent evidence from Puerto Rico suggests that exotic-dominated forests can provide suitable regeneration sit...

Recent work on exotic species in island ecosystems has revealed that many exotic woody plants are capable of dominating forests in which they occur, substantially altering forest structure and nutrient cycling. In mainland forests, however, few empirical examples of exotic dominance exist. The invasive shrub Rhamnus cathartica L. (common buckthorn)...

Among their effects on forest structure and carbon dynamics, hurricanes frequently create large-scale canopy gaps that promote secondary growth. To measure the accumulation of aboveground biomass (AGBM) in a hurricane damaged forest, we established permanent plots 4 mo after the landfall of Hurricane Joan on the Atlantic coast of Nicaragua in Octob...

Lianas can have a large impact on the diversity, structure, and dynamics of tropical forests, yet they remain essentially unknown even in some of the most intensely studied tropical forests, such as La Selva Biological Station in Costa Rica. We quantified the diversity, abundance, and mortality of lianas in primary and selectively logged forest at...

Lianas can have a large impact on the ecology, diversity, and architecture of tropical forests, yet lianas remain virtually unknown even in some of the most intensely studied tropical forests in the world (e.g., La Selva Biological Station in Costa Rica). We quantified the abundance, diversity, and mortality of lianas in primary and selectively log...