Biogeochemistry is the scientific discipline that involves the study of the chemical, physical, geological, and biological processes and reactions that govern the composition of the natural environment. In particular, biogeochemistry is the study of biogeochemical cycles, the cycles of chemical elements such as carbon and nitrogen, and their interactions with and incorporation into living things transported through earth scale biological systems in space and time. The field focuses on chemical cycles which are either driven by or influence biological activity. Particular emphasis is placed on the study of carbon, nitrogen, oxygen, sulfur, iron, and phosphorus cycles. Biogeochemistry is a systems science closely related to systems ecology.
Ecosystem ecology is the integrated study of living (biotic) and non-living (abiotic) components of ecosystems and their interactions within an ecosystem framework. This science examines how ecosystems work and relates this to their components such as chemicals, bedrock, soil, plants, and animals.
Afforestation is the establishment of a forest or stand of trees (forestation) in an area where there was no recent tree cover. In comparison, reforestation means re-establishing forest that have either been cut down or lost due to natural causes, such as fire, storm, etc. There are three types of afforestation: Natural regeneration, agroforestry and tree plantations. Afforestation has many benefits. In the context of climate change, afforestation can be helpful for climate change mitigation through the route of carbon sequestration. Afforestation can also improve the local climate through increased rainfall and by being a barrier against high winds. The additional trees can also prevent or reduce topsoil erosion, floods and landslides. Finally, additional trees can be a habitat for wildlife, and provide employment and wood products.
Carbon sequestration is the process of storing carbon in a carbon pool. It plays a crucial role in limiting climate change by reducing the amount of carbon dioxide in the atmosphere. There are two main types of carbon sequestration: biologic and geologic.
Human impact on the nitrogen cycle is diverse. Agricultural and industrial nitrogen (N) inputs to the environment currently exceed inputs from natural N fixation. As a consequence of anthropogenic inputs, the global nitrogen cycle (Fig. 1) has been significantly altered over the past century. Global atmospheric nitrous oxide (N2O) mole fractions have increased from a pre-industrial value of ~270 nmol/mol to ~319 nmol/mol in 2005. Human activities account for over one-third of N2O emissions, most of which are due to the agricultural sector. This article is intended to give a brief review of the history of anthropogenic N inputs, and reported impacts of nitrogen inputs on selected terrestrial and aquatic ecosystems.
Soil carbon is the solid carbon stored in global soils. This includes both soil organic matter and inorganic carbon as carbonate minerals. It is vital to the soil capacity in our ecosystem. Soil carbon is a carbon sink in regard to the global carbon cycle, playing a role in biogeochemistry, climate change mitigation, and constructing global climate models. Natural variation such as organisms and time has affected the management of carbon in the soils. The major influence has been that of human activities which has caused a massive loss of soil organic carbon. An example of human activity includes fire which destroys the top layer of the soil and the soil therefore get exposed to excessive oxidation.
A Dynamic Global Vegetation Model (DGVM) is a computer program that simulates shifts in potential vegetation and its associated biogeochemical and hydrological cycles as a response to shifts in climate. DGVMs use time series of climate data and, given constraints of latitude, topography, and soil characteristics, simulate monthly or daily dynamics of ecosystem processes. DGVMs are used most often to simulate the effects of future climate change on natural vegetation and its carbon and water cycles.
A peatland is a type of wetland whose soils consist of organic matter from decaying plants, forming layers of peat. Peatlands arise because of incomplete decomposition of organic matter, usually litter from vegetation, due to water-logging and subsequent anoxia. Like coral reefs, peatlands are unusual landforms that derive mostly from biological rather than physical processes, and can take on characteristic shapes and surface patterning.
The CO2 fertilization effect or carbon fertilization effect causes an increased rate of photosynthesis while limiting leaf transpiration in plants. Both processes result from increased levels of atmospheric carbon dioxide (CO2). The carbon fertilization effect varies depending on plant species, air and soil temperature, and availability of water and nutrients. Net primary productivity (NPP) might positively respond to the carbon fertilization effect. Although, evidence shows that enhanced rates of photosynthesis in plants due to CO2 fertilization do not directly enhance all plant growth, and thus carbon storage. The carbon fertilization effect has been reported to be the cause of 44% of gross primary productivity (GPP) increase since the 2000s. Earth System Models, Land System Models and Dynamic Global Vegetation Models are used to investigate and interpret vegetation trends related to increasing levels of atmospheric CO2. However, the ecosystem processes associated with the CO2 fertilization effect remain uncertain and therefore are challenging to model.
Carbon farming is a set of agricultural methods that aim to store carbon in the soil, crop roots, wood and leaves. The technical term for this is carbon sequestration. The overall goal of carbon farming is to create a net loss of carbon from the atmosphere. This is done by increasing the rate at which carbon is sequestered into soil and plant material. One option is to increase the soil's organic matter content. This can also aid plant growth, improve soil water retention capacity and reduce fertilizer use. Sustainable forest management is another tool that is used in carbon farming. Carbon farming is one component of climate-smart agriculture. It is also one way to remove carbon dioxide from the atmisphere.
Thomas Ward Crowther is a professor of ecology at ETH Zürich and founding co-chair of the Advisory Board for the United Nations Decade on Ecosystem Restoration. At ETH Zurich, he started Crowther Lab, an interdisciplinary group of scientists exploring the role of biodiversity in regulating the Earth's climate. Crowther is the founder of Restor, an online platform that supports thousands of community-led restoration projects around the world. In 2021, the World Economic Forum named Crowther a Young Global Leader.
Whendee Silver is an American ecosystem ecologist and biogeochemist.
Pamela H. Templer is an ecosystem ecologist and professor at Boston University who focuses on plant-microbial interaction and their effect on carbon exchange and nutrient cycling. She is also interested in examining how urban ecosystems function, how human actions influence nutrient cycling, atmosphere-biosphere interactions, and other ecosystem processes.
Erika Marín-Spiotta is a biogeochemist and ecosystem ecologist. She is currently Professor of Geography at the University of Wisconsin-Madison. She is best-known for her research of the terrestrial carbon cycle and is an advocate for underrepresented groups in the sciences, specifically women.
Elisabeth Holland is an American climate scientist who focuses on how the carbon and nitrogen cycles interact with earth systems. She has become a key player in the international climate debate. She is currently a professor of climate change at the University of the South Pacific. She is also the director of the Pacific Center for Environmental and Sustainable Development.
M. Francesca Cotrufo is a soil ecologist who focuses her work on litter decomposition and the dynamics of soil organic matter. She is currently a Professor and Associate Head in the Department of Soil and Crop Sciences, as well the Senior Scientist at the Natural Resource Ecology Lab, at Colorado State University.
Christine Goodale is an ecosystem ecologist and an Associate Professor in the Department of Ecology and Evolutionary Biology at Cornell University. Goodale conducts research that studies the cycling of water, carbon, nitrogen and other nutrients through forest ecosystems.
Tana Elaine Wood is a biogeochemist and ecosystem scientist with a focus in land-use and climate change. Her research is focused on looking into how these issues affect tropical forested ecosystems and particularly focuses on soil science and below ground research efforts.
David Edward Reichle is an American ecologist who worked at the Oak Ridge National Laboratory (ORNL). He is known for his pioneering research on the movement of radionuclides in the environment and the carbon metabolism of forest ecosystems. From 1967 to 1981 he was co-chair of Woodlands for the International Biological Programme. He served as Director of ORNL’s Environmental Sciences Division (1986-1990) and retired in 2000 as Associate Director.
Dan Yakir is an Israeli Ecophysiologist and a Professor in the Department of Earth and Planetary Sciences at the Weizmann Institute of Science. Yakir is a 2019 recipient of the Israel Prize for Research in Geology, Earth Sciences and Atmospheric Sciences.
