This dataset shows annual tree cover extent,gain, and loss from the year 2001 to 2014, at 30 meter resolution, as colored layers that can be seen together or one at a time as individual layers that can be toggled on and off. Green is used to represent tree cover in 2000, red shows tree cover loss between 2001-2014, blue shows tree cover gain between 2001-2014, and purple is gain and loss together due to replanting after loss has occurred.
“Tree cover” is defined as all vegetation greater than 5 meters in height, and may take the form of natural forests or plantations across a range of canopy densities. “Loss” indicates the removal or mortality of tree cover and can be due to a variety of factors, including mechanical harvesting, fire, disease, or storm damage. As such, “loss” does not directly equate to deforestation.
The dataset is a collaboration between by Global Forest Watch partners at GLAD (Global Land Analysis & Discovery) lab at the University of Maryland, Google, USGS and NASA. The data were generated using Landsat imagery and algorithms to measure where tree cover patterns extend, or are lost, each year. When the algorithm sees the pattern of tree cover is missing or existing after one year, it places a pixel where this occurred. The tree cover extent data is used to measure against the loss or gain, thus giving us a sense of where the trees were to begin with or where they have been planted.
Trees grow much faster in warmer, tropical regions than in colder, boreal regions. That is why there appears to be stronger overlap with loss and gain data (purple) in some parts of the world; trees are cut down, but they might grow back very quickly. This is also true of production forests and plantations; overlap in areas like Scandinavia and the southeast USA look particularly purple because these areas are logged then replanted with more timber trees, or in Indonesia areas are cleared then often replanted with oil palm plantations.
You can view of loss, gain, and extent as separate layers or one on top of each other. When the red loss and the blue gain layer are on top of one another or very close on a pixel-scale level, it looks like purple from afar. For visualizations purposes, we combined these layers into a separate purple layer.
The tree cover loss data is updated annually, but for visualization purposes, this was all aggregated into one layer. Therefore the yearly data from 2001-2014 is all mushed together into one “loss” layer. However, the gain and extent data remain static, as they have only been updated once.
C2 Cause and Effect. Students routinely identify and test causal relationships and use these relationships to explain change. They understand events that occur together with regularity might or might not signify a cause and effect relationship
C1 Patterns. Students recognize that macroscopic patterns are related to the nature of microscopic and atomic-level structure. They identify patterns in rates of change and other numerical relationships that provide information about natural and human designed systems. They use patterns to identify cause and effect relationships, and use graphs and charts to identify patterns in data.
C2 Cause and Effect. Students classify relationships as causal or correlational, and recognize that correlation does not necessarily imply causation. They use cause and effect relationships to predict phenomena in natural or designed systems. They also understand that phenomena may have more than one cause, and some cause and effect relationships in systems can only be described using probability.
C4 Systems and System Models. Students can understand that systems may interact with other systems; they may have sub-systems and be a part of larger complex systems. They can use models to represent systems and their interactions—such as inputs, processes and outputs—and energy, matter, and information flows within systems. They can also learn that models are limited in that they only represent certain aspects of the system under study.
C1 Patterns. Students observe patterns in systems at different scales and cite patterns as empirical evidence for causality in supporting their explanations of phenomena. They recognize classifications or explanations used at one scale may not be useful or need revision using a different scale; thus requiring improved investigations and experiments. They use mathematical representations to identify certain patterns and analyze patterns of performance in order to re-engineer and improve a designed system.
C2 Cause and Effect. Students understand that empirical evidence is required to differentiate between cause and correlation and to make claims about specific causes and effects. They suggest cause and effect relationships to explain and predict behaviors in complex natural and designed systems. They also propose causal relationships by examining what is known about smaller scale mechanisms within the system. They recognize changes in systems may have various causes that may not have equal effects.
C4 Systems and System Models. Students can investigate or analyze a system by defining its boundaries and initial conditions, as well as its inputs and outputs. They can use models (e.g., physical, mathematical, computer models) to simulate the flow of energy, matter, and interactions within and between systems at different scales. They can also use models and simulations to predict the behavior of a system, and recognize that these predictions have limited precision and reliability due to the assumptions and approximations inherent in the models. They can also design systems to do specific tasks.
C6 Structures and Functions. Students investigate systems by examining the properties of different materials, the structures of different components, and their interconnections to reveal the system’s function and/or solve a problem. They infer the functions and properties of natural and designed objects and systems from their overall structure, the way their components are shaped and used, and the molecular substructures of their various materials.
ESS2.A Earth Materials and Systems. Four major Earth systems interact. Rainfall helps to shape the land and affects the types of living things found in a region. Water, ice, wind, organisms, and gravity break rocks, soils, and sediments into smaller pieces and move them around
ESS3.A Natural Resources. Energy and fuels humans use are derived from natural sources and their use affects the environment. Some resources are renewable over time, others are not.
ESS3.B Natural Hazards. A variety of hazards result from natural processes; humans cannot eliminate hazards but can reduce their impacts.
ESS3.C Human Impact on Earth systems. Societal activities have had major effects on the land, ocean, atmosphere, and even outer space. Societal activities can also help protect Earth’s resources and environments.
ESS3.D Global Climate Change. If Earth’s global mean temperature continues to rise, the lives of humans and other organisms will be affected in many different ways.
LS4.D Biodiversity & Humans. Populations of organisms live in a variety of habitats. Change in those habitats affects the organisms living there
ESS2.A Earth Materials and Systems. Energy flows and matter cycles within and among Earth’s systems, including the sun and Earth’s interior as primary energy sources. Plate tectonics is one result of these processes.
ESS3.A Natural Resources. Humans depend on Earth’s land, ocean, atmosphere, and biosphere for different resources, many of which are limited or not renewable. Resources are distributed unevenly around the planet as a result of past geologic processes
ESS3.B Natural Hazards. Mapping the history of natural hazards in a region and understanding related geological forces can help forecast the locations and likelihoods of future events, such as volcanic eruptions, earthquakes and severe weather.
ESS3.C Human Impact on Earth systems. Human activities have altered the biosphere, sometimes damaging it, although changes to environments can have different impacts for different living things. Activities and technologies can be engineered to reduce people’s impacts on Earth.
ESS3.D Global Climate Change. Human activities affect global warming. Decisions to reduce the impact of global warming depend on understanding climate science, engineering capabilities, and social dynamics.
LS4.D Biodiversity & Humans. Changes in biodiversity can influence humans’ resources and ecosystem services they rely on.
ESS2.A Earth Materials and Systems. Feedback effects exist within and among Earth’s systems.The geological record shows that changes to global and regional climate can be caused by interactions among changes in the sun’s energy output or Earth’s orbit, tectonic events, ocean circulation, volcanic activity, glaciers, vegetation, and human activities.
ESS2.E Biogeology. The biosphere and Earth’s other systems have many interconnections that cause a continual co-evolution of Earth’s surface and life on it
ESS3.A Natural Resources. Resource availability has guided the development of human society and use of natural resources has associated costs, risks, and
ESS3.B Natural Hazards. Natural hazards and other geological events have shaped the course of human history at local, regional, and global scales. Human activities can contribute to the frequency and intensity of some natural hazards.
ESS3.C Human Impact on Earth systems. Sustainability of human societies and the biodiversity that supports them requires responsible management of natural resources, including the development of technologies that produce less pollution and waste and that preclude ecosystem degradation.
ESS3.D Global Climate Change. Global climate models used to predict changes continue to be improved, although discoveries about the global climate system are ongoing and continually needed.
LS4.D Biodiversity & Humans. Biodiversity is increased by formation of new species and reduced by extinction. Humans depend on biodiversity but also have adverse impacts on it. Sustaining biodiversity is essential to supporting life on Earth