Fire suppression and ecosystem carbon storage
TL;DR: A 35-year controlled burning experiment in Minnesota oak savanna showed that fire frequency had a great impact on ecosystem carbon (C) stores, with most carbon stored in woody biomass.
Abstract: A 35-year controlled burning experiment in Minnesota oak savanna showed that fire frequency had a great impact on ecosystem carbon (C) stores. Specifically, compared to the historical fire regime, fire suppression led to an average of 1.8 Mg·ha−1·yr−1 of C storage, with most carbon stored in woody biomass. Forest floor carbon stores were also significantly impacted by fire frequency, but there were no detectable effects of fire suppression on carbon in soil and fine roots combined, or in woody debris. Total ecosystem C stores averaged ∼110 Mg/ha in stands experiencing presettlement fire frequencies, but ∼220 Mg/ha in stands experiencing fire suppression. If comparable rates of C storage were to occur in other ecosystems in response to the current extent of fire suppression in the United States, fire suppression in the USA might account for 8–20% of missing global carbon.
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TL;DR: The recent literature is reviewed, drawing parallels between fire and herbivores as alternative consumers of vegetation, and pointing to the common questions and some surprisingly different answers that emerge from viewing fire as a globally significant consumer that is analogous to herbivory.
Abstract: It is difficult to find references to fire in general textbooks on ecology, conservation biology or biogeography, in spite of the fact that large parts of the world burn on a regular basis, and that there is a considerable literature on the ecology of fire and its use for managing ecosystems. Fire has been burning ecosystems for hundreds of millions of years, helping to shape global biome distribution and to maintain the structure and function of fire-prone communities. Fire is also a significant evolutionary force, and is one of the first tools that humans used to re-shape their world. Here, we review the recent literature, drawing parallels between fire and herbivores as alternative consumers of vegetation. We point to the common questions, and some surprisingly different answers, that emerge from viewing fire as a globally significant consumer that is analogous to herbivory.
1,942 citations
Cites background from "Fire suppression and ecosystem carb..."
...In these instances, consumer control, rather than resource competition, determines tree cover [ 33 ]....
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TL;DR: Comparison of global 'fire off' simulations with landcover and treecover maps show that vast areas of humid C(4) grasslands and savannas, especially in South America and Africa, have the climate potential to form forests.
Abstract: This paper is the first global study of the extent to which fire determines global vegetation patterns by preventing ecosystems from achieving the potential height, biomass and dominant functional types expected under the ambient climate (climate potential). To determine climate potential, we simulated vegetation without fire using a dynamic global-vegetation model. Model results were tested against fire exclusion studies from different parts of the world. Simulated dominant growth forms and tree cover were compared with satellite-derived land- and tree-cover maps. Simulations were generally consistent with results of fire exclusion studies in southern Africa and elsewhere. Comparison of global 'fire off' simulations with landcover and treecover maps show that vast areas of humid C(4) grasslands and savannas, especially in South America and Africa, have the climate potential to form forests. These are the most frequently burnt ecosystems in the world. Without fire, closed forests would double from 27% to 56% of vegetated grid cells, mostly at the expense of C(4) plants but also of C(3) shrubs and grasses in cooler climates. C(4) grasses began spreading 6-8 Ma, long before human influence on fire regimes. Our results suggest that fire was a major factor in their spread into forested regions, splitting biotas into fire tolerant and intolerant taxa.
1,664 citations
Cites background from "Fire suppression and ecosystem carb..."
...In reality, both sites burnt at intervals of 2–5 yr (San Jose et al., 1998; Tilman et al., 2000)....
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TL;DR: In this article, the importance of land-use history and its legacies in most ecological systems has been recognized as a legitimate and essential subject of environmental science, and recognition of these historical legacies adds explanatory power to our understanding of modern conditions at scales from organisms to the globe and reduces missteps in anticipating or managing for future conditions.
Abstract: Recognition of the importance of land-use history and its legacies in most ecological systems has been a major factor driving the recent focus on human activity as a legitimate and essential subject of environmental science. Ecologists, conservationists, and natural resource policymakers now recognize that the legacies of land-use activities continue to influence ecosystem structure and function for decades or centuries—or even longer—after those activities have ceased. Consequently, recognition of these historical legacies adds explanatory power to our understanding of modern conditions at scales from organisms to the globe and reduces missteps in anticipating or managing for future conditions. As a result, environmental history emerges as an integral part of ecological science and conservation planning. By considering diverse ecological phenomena, ranging from biodiversity and biogeochemical cycles to ecosystem resilience to anthropogenic stress, and by examining terrestrial and aquatic ecosyst...
1,069 citations
TL;DR: A clear negative relationship between precipitation and changes in soil organic carbon and nitrogen content when grasslands were invaded by woody vegetation is found, with drier sites gaining, and wetter sites losing, soilorganic carbon.
Abstract: The invasion of woody vegetation into deserts, grasslands and savannas is generally thought to lead to an increase in the amount of carbon stored in those ecosystems. For this reason, shrub and forest expansion (for example, into grasslands) is also suggested to be a substantial, if uncertain, component of the terrestrial carbon sink1,2,3,4,5,6,7,8,9,10,11,12,13,14. Here we investigate woody plant invasion along a precipitation gradient (200 to 1,100 mm yr-1) by comparing carbon and nitrogen budgets and soil δ13C profiles between six pairs of adjacent grasslands, in which one of each pair was invaded by woody species 30 to 100 years ago. We found a clear negative relationship between precipitation and changes in soil organic carbon and nitrogen content when grasslands were invaded by woody vegetation, with drier sites gaining, and wetter sites losing, soil organic carbon. Losses of soil organic carbon at the wetter sites were substantial enough to offset increases in plant biomass carbon, suggesting that current land-based assessments may overestimate carbon sinks. Assessments relying on carbon stored from woody plant invasions to balance emissions may therefore be incorrect.
952 citations
Cites background from "Fire suppression and ecosystem carb..."
...Many biotic and abiotic factors determine SOC storag...
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TL;DR: In insect communities, insect species richness increased as plant species richness and plant functional group richness increased, and both factors may explain how the loss of plant diversity influences higher trophic levels.
Abstract: We experimentally separated the effects of two components of plant diversity—plant species richness and plant functional group richness—on insect communities. Plant species richness and plant functional group richness had contrasting effects on insect abundances, a result we attributed to three factors. First, lower insect abundances at higher plant functional group richness were explained by a sampling effect, which was caused by the increasing likelihood that one low‐quality group, C4 grasses, would be present and reduce average insect abundances by 25%. Second, plant biomass, which was positively related to plant functional group richness, had a strong, positive effect on insect abundances. Third, a positive effect of plant species richness on insect abundances may have been caused by greater availability of alternate plant resources or greater vegetational structure. In addition, a greater diversity of insect species, whose individual abundances were often unaffected by changes in plant spec...
479 citations
Cites background from "Fire suppression and ecosystem carb..."
...At Cedar Creek, for instance, the diversity of prairies and savannas is determined to a great extent by the diversity of forbs....
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...Department of Fisheries and Wildlife, Utah State University, Logan, Utah 84322-5210...
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...In addition, in a review of the history of fire at Cedar Creek, Tilman et al. (2000) found evidence for annual to biennial burn frequency....
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References
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Book•
06 Mar 1997
TL;DR: In this paper, the authors present a perspective of the global cycle of nitrogen and phosphorous, the global water cycle, and the global sulfur cycle from a global point of view.
Abstract: Part 1 Processes and reactions: origins the atmosphere the lithosphere the terrestrial biosphere biogeochemical cycling on land biogeochemistry in freshwater wetlands and lakes rivers and estuaries the sea. Part 2 Global cycles: the global water cycle the global carbon cycle the global cycle of nitrogen and phosphorous the global sulfur cycle a perspective.
3,871 citations
TL;DR: Slowing deforestation, combined with an increase in forestation and other management measures to improve forest ecosystem productivity, could conserve or sequester significant quantities of carbon.
Abstract: Forest systems cover more than 4.1 x 109 hectares of the Earth9s land area. Globally, forest vegetation and soils contain about 1146 petagrams of carbon, with approximately 37 percent of this carbon in low-latitude forests, 14 percent in mid-latitudes, and 49 percent at high latitudes. Over two-thirds of the carbon in forest ecosystems is contained in soils and associated peat deposits. In 1990, deforestation in the low latitudes emitted 1.6 ± 0.4 petagrams of carbon per year, whereas forest area expansion and growth in mid- and high-latitude forest sequestered 0.7 ± 0.2 petagrams of carbon per year, for a net flux to the atmosphere of 0.9 ± 0.4 petagrams of carbon per year. Slowing deforestation, combined with an increase in forestation and other management measures to improve forest ecosystem productivity, could conserve or sequester significant quantities of carbon. Future forest carbon cycling trends attributable to losses and regrowth associated with global climate and land-use change are uncertain. Model projections and some results suggest that forests could be carbon sinks or sources in the future.
3,175 citations
"Fire suppression and ecosystem carb..." refers background or methods in this paper
...…biomass creates ;20–25% of annual anthropogenic CO2 (Andreae 1991, Schimel 1995), modifications of fire frequency may significantly change regional and global C budgets (e.g., Fahenstock and Agee 1983, Andreae 1991, Stocks 1991, Dixon and Krankina 1993, Dixon et al. 1994, Sohngen and Haynes 1997)....
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...This work was supported by National Science Foundation Grant 9411972 and by the Andrew Mellon Foundation....
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...Our work supports the proposal that increased fire suppression and decreased anthropogenic burning of vegetation could significantly influence global carbon dynamics (Dixon et al. 1994, Sampson and Clark 1995, Sohngen and Haynes 1997, San Jose et al. 1998)....
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...Dixon et al. (1994) calculated that fire management in Russia could lead to long-term C storage of 0.6 3 1015 g C/yr....
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TL;DR: The terrestrial biosphere plays an important role in the global carbon cycle as mentioned in this paper, which is the fluxes of carbon among four main reservoirs: fossil carbon, the atmosphere, the oceans, and the terrestrial Biosphere.
Abstract: The terrestrial biosphere plays an important role in the global carbon cycle. In the 1994 Intergovernmental Panel Assessment on Climate Change (IPCC), an effort was made to improve the quantification of terrestrial exchanges and potential feedbacks from climate, changing CO2, and other factors; this paper presents the key results from that assessment, together with expanded discussion. The carbon cycle is the fluxes of carbon among four main reservoirs: fossil carbon, the atmosphere, the oceans, and the terrestrial biosphere. Emissions of fossil carbon during the 1980s averaged 5.5 Gt y−1. During the same period, the atmosphere gained 3.2 Gt C y−1 and the oceans are believed to have absorbed 2.0 Gt C y−1. The regrowing forests of the Northern Hemisphere may have absorbed 0.5 Gt C y−1 during this period. Meanwhile, tropical deforestation is thought to have released an average 1.6 Gt C y−1 over the 1980s. While the fluxes among the four pools should balance, the average 198Ds values lead to a ‘missing sink’ of 1.4 Gt C y−1 Several processes, including forest regrowth, CO2 fertilization of plant growth (c. 1.0 Gt C y−1), N deposition (c. 0.6 Gt C y−1), and their interactions, may account for the budget imbalance. However, it remains difficult to quantify the influences of these separate but interactive processes. Uncertainties in the individual numbers are large, and are themselves poorly quantified. This paper presents detail beyond the IPCC assessment on procedures used to approximate the flux uncertainties.
Lack of knowledge about positive and negative feedbacks from the biosphere is a major limiting factor to credible simulations of future atmospheric CO2 concentrations. Analyses of the atmospheric gradients of CO2 and 13 CO2 concentrations provide increasingly strong evidence for terrestrial sinks, potentially distributed between Northern Hemisphere and tropical regions, but conclusive detection in direct biomass and soil measurements remains elusive.
Current regional-to-global terrestrial ecosystem models with coupled carbon and nitrogen cycles represent the effects of CO2 fertilization differently, but all suggest longterm responses to CO2 that are substantially smaller than potential leaf- or laboratory whole plant-level responses. Analyses of emissions and biogeochemical fluxes consistent with eventual stabilization of atmospheric CO2 concentrations are sensitive to the way in which biospheric feedbacks are modeled by c. 15%. Decisions about land use can have effects of 100s of Gt C over the next few centuries, with similarly significant effects on the atmosphere.
Critical areas for future research are continued measurements and analyses of atmospheric data (CO2 and 13CO2) to serve as large-scale constraints, process studies of the scaling from the photosynthetic response to CO2 to whole-ecosystem carbon storage, and rigorous quantification of the effects of changing land use on carbon storage.
1,510 citations
"Fire suppression and ecosystem carb..." refers background or methods in this paper
...2680 Key words: carbon storage; fire suppression; missing carbon; oak savanna....
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...San Jose et al. (1998) calculated that fire suppression, by causing the transformation of the 2.8 3 107 ha Venezuelan Orinoco Llanos from grassland to semideciduous forest, could lead to a C sink of 0.08 3 1015 g C/yr....
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...Atmospheric CO2 is currently accumulating at ;3.2 3 1015 g C/yr (Schimel 1995)....
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...Dixon et al. (1994) calculated that fire management in Russia could lead to long-term C storage of 0.6 3 1015 g C/yr....
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...Because the burning of ecosystem biomass creates ;20–25% of annual anthropogenic CO2 (Andreae 1991, Schimel 1995), modifications of fire frequency may significantly change regional and global C budgets (e.g., Fahenstock and Agee 1983, Andreae 1991, Stocks 1991, Dixon and Krankina 1993, Dixon et al.…...
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TL;DR: The first edition of Schlesinger's Biogeochemistry in 1991 was an early entry in the field of Earth system science/global change, and has since gained sufficient popularity and demand to merit a second, extensively revised edition.
Abstract: Compared to the well-established disciplines, the field of Earth system science/global change has relatively few books from which to choose. Of the small subset of books dealing specifically with biogeochemical aspects of global change, the first edition of Schlesinger's Biogeochemistry in 1991 was an early entry. It has since gained sufficient popularity and demand to merit a second, extensively revised edition.
The first part of the book provides a general introduction to biogeochemistry and cycles, and to the origin of elements, our planet, and life on Earth. It then describes the functioning and biogeochemistry of the atmosphere, lithosphere, biosphere, and hydrosphere, including marine and freshwater systems. Although system function and features are stressed, the author begins to introduce global change topics, such as soil organic matter and global change in Chapter 5, and landscape and mass balance in Chapter 6.
1,075 citations
"Fire suppression and ecosystem carb..." refers background or methods in this paper
...This work was supported by National Science Foundation Grant 9411972 and by the Andrew Mellon Foundation....
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...Moreover, the immense global extent of tropical savanna and woodland, 2.45 3 109 ha (Schlesinger 1997), suggests that even moderate fire suppression in this ecosystem type could provide a globally significant C sink....
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TL;DR: The rates at which lands in the United States were cleared for agriculture, abandoned, harvested for wood, and burned were reconstructed from historical data for the period 1700-1990 and used in a terrestrial carbon model to calculate annual changes in the amount of carbon stored in terrestrial ecosystems, including wood products.
Abstract: The rates at which lands in the United States were cleared for agriculture, abandoned, harvested for wood, and burned were reconstructed from historical data for the period 1700-1990 and used in a terrestrial carbon model to calculate annual changes in the amount of carbon stored in terrestrial ecosystems, including wood products. Changes in land use released 27 +/- 6 petagrams of carbon to the atmosphere before 1945 and accumulated 2 +/- 2 petagrams of carbon after 1945, largely as a result of fire suppression and forest growth on abandoned farmlands. During the 1980s, the net flux of carbon attributable to land management offset 10 to 30 percent of U.S. fossil fuel emissions.
1,035 citations
"Fire suppression and ecosystem carb..." refers background or methods in this paper
...Houghton et al. (1999) estimated various sources of C storage in the United States....
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...Because fire suppression might lead to a period of C accumulation (Houghton et al. 1999), current fire suppression in the United States (Fig....
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...This work was supported by National Science Foundation Grant 9411972 and by the Andrew Mellon Foundation....
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...2680 Key words: carbon storage; fire suppression; missing carbon; oak savanna....
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