Humans take control of fire-driven diversity changes in Mediterranean Iberia’s vegetation during the mid–late Holocene

Fire regime changes are considered a major threat to future biodiversity in the Mediterranean Basin. Such predictions remain uncertain, given that fire regime changes and their ecological impacts occur over timescales that are too long for direct observation. Here we analyse centennial- and millennial-scale shifts in fire regimes and compositional turnover to track the consequences of fire regime shifts on Mediterranean vegetation diversity. We estimated rate-of-change, richness and compositional turnover (beta diversity) in 13 selected high-resolution palaeoecological records from Mediterranean Iberia and compared these with charcoal-inferred fire regime changes. Event sequence analysis showed fire regime shifts to be significantly temporally associated with compositional turnover, particularly during the last three millennia. We find that the timing and direction of fire and diversity change in Mediterranean Iberia are best explained by long-term human–environment interactions dating back perhaps 7500 years. Evidence suggests that Neolithic burning propagated a first wave of increasing vegetation openness and promoted woodland diversity around early farming settlements. Landscape transformation intensified around 5500 to 5000 cal. yr BP and accelerated during the last two millennia, as fire led to permanent transitions in ecosystem state. These fire episodes increased open vegetation diversity, decreased woodland diversity and significantly altered richness on a regional scale. Our study suggests that anthropogenic fires played a primary role in diversity changes in Mediterranean Iberia. Their millennia-long legacy in today’s vegetation should be considered for biodiversity conservation and landscape management.

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Is Anthropogenic Pyrodiversity Invisible in Paleofire Records?

Fire ◽

10.3390/fire2030042 ◽

2019 ◽

Vol 2 (3) ◽

pp. 42 ◽

Cited By ~ 4

Author(s):

Roos ◽

Williamson ◽

Bowman

Keyword(s):

High Frequency ◽

Landscape Heterogeneity ◽

Fire Regime ◽

Fire Regimes ◽

Regime Shifts ◽

Cultural Changes ◽

Regime Changes ◽

Other Information ◽

Patch Burning ◽

The Impact

Paleofire studies frequently discount the impact of human activities in past fire regimes. Globally, we know that a common pattern of anthropogenic burning regimes is to burn many small patches at high frequency, thereby generating landscape heterogeneity. Is this type of anthropogenic pyrodiversity necessarily obscured in paleofire records because of fundamental limitations of those records? We evaluate this with a cellular automata model designed to replicate different fire regimes with identical fire rotations but different fire frequencies and patchiness. Our results indicate that high frequency patch burning can be identified in tree-ring records at relatively modest sampling intensities. However, standard methods that filter out fires represented by few trees systematically biases the records against patch burning. In simulated fire regime shifts, fading records, sample size, and the contrast between the shifted fire regimes all interact to make statistical identification of regime shifts challenging without other information. Recent studies indicate that integration of information from history, archaeology, or anthropology and paleofire data generate the most reliable inferences of anthropogenic patch burning and fire regime changes associated with cultural changes.

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Potentials and limitations for human control over historic fire regimes in the boreal forest

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2007.2205 ◽

2007 ◽

Vol 363 (1501) ◽

pp. 2351-2356 ◽

Cited By ~ 40

Author(s):

Anders Granström ◽

Mats Niklasson

Keyword(s):

Fire Regime ◽

Fire Regimes ◽

Fire Spread ◽

Fire Frequency ◽

Human Control ◽

Regime Changes ◽

Northern Fennoscandia ◽

Potential Impact ◽

Cattle Husbandry ◽

Different Cultures

Fire, being both a natural and cultural phenomenon, presents problems in disentangling the historical effect of humans from that of climate change. Here, we investigate the potential impact of humans on boreal fire regimes from a perspective of fuels, ignitions and culture. Two ways for a low technology culture to impact the fire regime are as follows: (i) by altering the number of ignitions and their spatial distribution and timing and (ii) by hindering fire spread. Different cultures should be expected to have quite different impacts on the fire regimes. In northern Fennoscandia, there is evidence for fire regime changes associated with the following: a reindeer herding culture associated with few ignitions above the natural; an era of cattle husbandry with dramatically increased ignitions and somewhat higher fire frequency; and a timber exploitation era with decreasing fire sizes and diminishing fire frequency. In other regions of the boreal zone, such schemes can look quite different, but we suggest that a close look at the resource extraction and land use of different cultures should be part of any analysis of past fire regimes.

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Planned and unplanned fire regimes on public land in south-east Queensland

International Journal of Wildland Fire ◽

10.1071/wf18213 ◽

2020 ◽

Vol 29 (5) ◽

pp. 326 ◽

Cited By ~ 2

Author(s):

Martyn Eliott ◽

Tom Lewis ◽

Tyron Venn ◽

Sanjeev Kumar Srivastava

Keyword(s):

Fire History ◽

Fire Regime ◽

Regional Scale ◽

Fire Regimes ◽

The Public ◽

Asset Protection ◽

Occurrence Data ◽

The Individual ◽

Service State ◽

Open Forests

Land management agencies in Queensland conduct planned burning for a variety of reasons, principally for management of fuels for human asset protection and biodiversity management. Using Queensland Parks and Wildlife Service’s archived manually derived fire reports, this study considered the individual components of the fire regime (extent, frequency and season) to determine variation between planned and unplanned fire regimes in south-east Queensland. Overall, between 2004 and 2015, planned fire accounted for 31.6% and unplanned fire 68.4% of all fire on Queensland Parks and Wildlife Service state-managed land. Unplanned fire was more common in spring (September–October), and planned fire was more common in winter (June–August). Unplanned fire affected 71.4% of open forests and woodlands (148563ha), whereas 58.8% of melaleuca communities (8016ha) and 66.6% of plantations (2442ha) were burnt with planned fire. Mapping fire history at a regional scale can be readily done with existing publicly available datasets, which can be used to inform the assessment of planned burning effectiveness for human asset protection and the management of biodiversity. Fire management will benefit from the continued recording of accurate fire occurrence data, which allows for detailed fire regime mapping and subsequent adaptive management of fire regimes in the public domain.

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Fire regime and vegetation change in the transition from Aboriginal to European land management in a Tasmanian eucalypt savanna

Australian Journal of Botany ◽

10.1071/bt16032 ◽

2016 ◽

Vol 64 (5) ◽

pp. 427 ◽

Cited By ~ 12

Author(s):

Louise M. Romanin ◽

Feli Hopf ◽

Simon G. Haberle ◽

David M. J. S. Bowman

Keyword(s):

Vegetation Change ◽

Fire Regime ◽

Plantago Lanceolata ◽

Sediment Cores ◽

Open Water ◽

Fire Regimes ◽

Ecological Impacts ◽

14C Dating ◽

Early 19Th Century ◽

European Settlement

Using pollen and charcoal analysis we examined how vegetation and fire regimes have changed over the last 600 years in the Midlands of Tasmania. Sediment cores from seven lagoons were sampled, with a chronology developed at one site (Diprose Lagoon) using 210Pb and 14C dating. Statistical contrasts of six cores where Pinus served as a marker of European settlement in the early 19th Century and showed significant changes in pollen composition following settlement with (a) influx of ruderal exotic taxa including Plantago lanceolata L., Brassicaceae, Asteraceae (Liguliflorae) and Rumex, (b) increase in pollen of the aquatics Myriophyllum spp. and Cyperaceae, (c) a decline in native herbaceous pollen taxa, including Chenopodiaceae and Asteraceae (Tubuliflorae) and (d) a decline in Allocasuarina and an initial decline and then increase of Poaceae. The presence of Asteraceae (Liguliflorae) in the pre-European period suggests that an important root vegetable Microseris lanceolata (Walp.) Sch.Bip. may have been abundant. Charcoal deposition was low in the pre-European period and significantly increased immediately after European arrival. Collectively, these changes suggest substantial ecological impacts following European settlement including cessation of Aboriginal traditions of fire management, a shift in hydrological conditions from open water lagoons to more ephemeral herb covered lagoons, and increased diversity of alien herbaceous species following pasture establishment.

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Frequent fires prime plant developmental responses to burning

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2019.1315 ◽

2019 ◽

Vol 286 (1909) ◽

pp. 20191315 ◽

Cited By ~ 3

Author(s):

Kimberley J. Simpson ◽

Jill K. Olofsson ◽

Brad S. Ripley ◽

Colin P. Osborne

Keyword(s):

Developmental Plasticity ◽

Fire Regime ◽

Fire Regimes ◽

Fire Frequency ◽

Fire Exposure ◽

Regime Changes ◽

Below Ground ◽

Developmental Responses ◽

In Fire ◽

Plastic Responses

Coping with temporal variation in fire requires plants to have plasticity in traits that promote persistence, but how plastic responses to current conditions are affected by past fire exposure remains unknown. We investigate phenotypic divergence between populations of four resprouting grasses exposed to differing experimental fire regimes (annually burnt or unburnt for greater than 35 years) and test whether divergence persists after plants are grown in a common environment for 1 year. Traits relating to flowering and biomass allocation were measured before plants were experimentally burnt, and their regrowth was tracked. Genetic differentiation between populations was investigated for a subset of individuals. Historic fire frequency influenced traits relating to flowering and below-ground investment. Previously burnt plants produced more inflorescences and invested proportionally more biomass below ground, suggesting a greater capacity for recruitment and resprouting than unburnt individuals. Tiller-scale regrowth rate did not differ between treatments, but prior fire exposure enhanced total regrown biomass in two species. We found no consistent genetic differences between populations suggesting trait differences arose from developmental plasticity. Grass development is influenced by prior fire exposure, independent of current environmental conditions. This priming response to fire, resulting in adaptive trait changes, may produce communities more resistant to future fire regime changes.

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Landscape-based fire scenarios and fire types in the Ayllón massif (Central Mountain Range, Spain), 19th and 20th centuries

Cuadernos de Investigación Geográfica ◽

10.18172/cig.3796 ◽

2020 ◽

Vol 46 (1) ◽

pp. 103-126

Author(s):

C.R. Sequeira ◽

C. Montiel-Molina ◽

F.C. Rego

Keyword(s):

Forest Management ◽

Fire History ◽

Driving Forces ◽

Fire Regime ◽

Fire Regimes ◽

Landscape Dynamics ◽

Mountain Range ◽

Regime Changes ◽

Fire Scenarios ◽

Fire Type

Wildfires have been a major landscape disturbance factor throughout history in inland mountain areas of Spain. This paper aims to understand the interaction of fire regimes and landscape dynamics during the last two centuries within a socio-spatial context. The study area selected for this historical and spatial analysis is the Ayllón massif, in the Central Mountain Range. The theoretical background used to identify the driving forces of fire regime changes over the 19th and 20th centuries in this mountain area includes landscape-based fire scenarios and fire-type concepts. Both concepts have been addressed in recent studies from a spatial planning and fire management approach in an attempt to understand current fire landscapes and wildfire risk. However, this is the first time that these concepts have been applied to show that both spatial and temporal scales are crucial for an understanding of the current wildfire panorama, and that fire history related to landscape dynamics is fundamental in socio-spatial differences in fire regimes.Four variables (fire history, land use, population and settlement system, and forest management) were assessed to define historical landscape-based fire scenarios, and three fire feature variables (fire extent, fire cause, and spatial distribution pattern) were considered to define historical fire-types. We found that the non-linear evolution of fire regimes during the 19th and 20th centuries was determined by fire-type changes according to landscape dynamics. Moreover, population and forest management have been the main driving forces of fire regime tipping points or pyrotransitions. This study validates the hypothesis that fire regime changes are the result of the interaction of fire history and landscape dynamics.

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Wildfire Impact and the “Fire Paradox” in a Natural and Endemic Pine Forest Stand and Shrubland

Fire ◽

10.3390/fire1030044 ◽

2018 ◽

Vol 1 (3) ◽

pp. 44 ◽

Cited By ~ 2

Author(s):

José Arévalo ◽

Agustín Naranjo-Cigala

Keyword(s):

Canary Islands ◽

Fire Regime ◽

Fire Suppression ◽

Regional Scale ◽

Fire Regimes ◽

Social Effects ◽

Nutrient Cycle ◽

Spatial And Temporal Variation ◽

Economic Damage ◽

Fire Occurrence

Fire is a powerful force that has shaped forests for thousands of years. It also provokes widespread social concern due to possible economic damage, social effects, impact on homes and properties, and other social effects including fatalities. Regions with seasonal variations in aridity have a fire regime dependent on climate resulting from the role of precipitation and temperature in fire occurrence, implying a synchrony of fire occurrence at regional scale. This spatial and temporal variation of fire regimes regulates the structure, diversity, regeneration dynamics, and nutrient cycle of an area. In the Canary Islands, fires are recurrent in pine forests, although their occurrence in the same area more than once within a 20-year period is rare. The main aim of this work is to reveal, over a 50-year period, fire occurrence and impact on the Canary Islands and how the islands are immersed in a “fire paradox”—a process typical of protected areas, where fire suppression becomes one of the main aims of forest management.

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Climate, not Aboriginal landscape burning, controlled the historical demography and distribution of fire-sensitive conifer populations across Australia

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2013.2182 ◽

2013 ◽

Vol 280 (1773) ◽

pp. 20132182 ◽

Cited By ~ 28

Author(s):

Shota Sakaguchi ◽

David M. J. S. Bowman ◽

Lynda D. Prior ◽

Michael D. Crisp ◽

Celeste C. Linde ◽

...

Keyword(s):

Fire Regime ◽

Fire Risk ◽

Fire Regimes ◽

Demographic Analysis ◽

Distribution Models ◽

Last Glacial ◽

Regime Changes ◽

Population Sizes ◽

The Impact ◽

The Last Glacial

Climate and fire are the key environmental factors that shape the distribution and demography of plant populations in Australia. Because of limited palaeoecological records in this arid continent, however, it is unclear as to which factor impacted vegetation more strongly, and what were the roles of fire regime changes owing to human activity and megafaunal extinction (since ca 50 kya). To address these questions, we analysed historical genetic, demographic and distributional changes in a widespread conifer species complex that paradoxically grows in fire-prone regions, yet is very sensitive to fire. Genetic demographic analysis showed that the arid populations experienced strong bottlenecks, consistent with range contractions during the Last Glacial Maximum ( ca 20 kya) predicted by species distribution models. In southern temperate regions, the population sizes were estimated to have been mostly stable, followed by some expansion coinciding with climate amelioration at the end of the last glacial period. By contrast, in the flammable tropical savannahs, where fire risk is the highest, demographic analysis failed to detect significant population bottlenecks. Collectively, these results suggest that the impact of climate change overwhelmed any modifications to fire regimes by Aboriginal landscape burning and megafaunal extinction, a finding that probably also applies to other fire-prone vegetation across Australia.

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Amazon fire regimes under climate change scenarios

10.32942/osf.io/nr23w ◽

2021 ◽

Author(s):

Leonardo Saravia ◽

Ben Bond-Lamberty ◽

Samir Suweis

Keyword(s):

Climatic Change ◽

Fire Regime ◽

Remote Sensing Data ◽

Biodiversity Loss ◽

Fire Regimes ◽

Climate Projections ◽

Climate Change Scenarios ◽

Regime Changes ◽

Critical Transitions ◽

In Fire

Fire is one of the most important disturbances of the earth-system, shaping the biodiversity of ecosystems and particularly forests. Anthropogenic drivers such as climatic change and other human activities could produce potentially abrupt changes in fire regimes, triggering more profound transformations like the transition from forests to savannah or grasslands ecosystems. Large biodiversity loss could be produced if these transitions occur. Climatic change could cause conditions that enhance fire ignition and spread, which may potentially produce more extensive, intense, and frequent fires. In this work, by considering climate projections for the 21st century, we evaluate the possible changes in the Amazon region's fire regime. We parametrize a fire model using remote sensing data on fire extension and temperature. In the context of our model, there are two possible regime changes: the critical regime that implies high variability in fire extension and mega-fires, and an absorbing phase transition which would produce the extinction of the forest and transition to a different vegetation state. The fitted model and the projections suggest that the Amazon region is not close to any of these regime changes, but other factors not included in the model could result crucial in determining such critical transitions.

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Climate and human influence on late Holocene fire regimes in the British Virgin Islands

Quaternary Research ◽

10.1017/qua.2018.123 ◽

2018 ◽

Vol 91 (2) ◽

pp. 679-690

Author(s):

Joshua R. Mueller ◽

Mitchell J. Power ◽

Colin J. Long

Keyword(s):

Fire Regime ◽

Global Climate ◽

Fire Regimes ◽

Virgin Islands ◽

Ecological Impacts ◽

Fire Disturbance ◽

British Virgin Islands ◽

Landscape Modification ◽

Anthropogenic Landscape ◽

European Settlement

AbstractGlobal climate change poses significant threats to the Caribbean islands. Yet, little is known about the long-term disturbance regimes in island ecosystems. This research investigates 2000 yr of natural and anthropogenic fire disturbance through the analysis of a latitudinal transect of sediment records from coastal salt ponds in the British Virgin Islands (BVI). The two research objectives in this study are (1) to determine the fire regime history for the BVI over the last 2000 yr and (2) to explore ecological impacts from anthropogenic landscape modification pre- and post-European settlement. The magnitude of anthropogenic landscape modification, including the introduction of agriculture, was investigated through a multiproxy approach using sedimentary records of fossil pollen and charcoal. Our results suggest fire regimes from Belmont Pond, Thatch Island, and Skeleton Pond have been influenced by human activity, particularly during the postsettlement era, from 500 cal yr BP to modern. Our results suggest that fire regimes during the Medieval Climate Anomaly were responding to changes in climate via dominant atmospheric drivers. The presettlement fire regimes from these islands suggest that fires occurred every 90 to 120 yr. This research represents a significant data contribution to a region with little disturbance and vegetation data available.

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