Late Holocene fire history and charcoal decay in subtropical dry forests of Puerto Rico

The late Holocene of south-eastern Australia was typified by stable climate, vegetation and sedimentary regimes, in relative equilibrium with Aboriginal land use and fire management. The arrival of Europeans, with the associated vegetation clearance, introduction of exotic plants and animals, notably for grazing and agriculture and a change in fire regimes, resulted in changes in vegetation and sedimentary patterns. Impacts varied in type and magnitude through the region and evidence of impacts that is preserved varies with sedimentary setting. Here we take a number of proxy measures of vegetation change, fire history, erosion and weathering from six sediment sections across south-eastern Australia and use an index to measure overall rate of change. This shows that the vegetation and environmental systems of south-eastern Australia have been very sensitive to human impact following European settlement.

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LATE HOLOCENE FIRE AND AGRICULTURE IN THE COPAN VALLEY, HONDURAS

Ancient Mesoamerica ◽

10.1017/s095653610213210x ◽

2002 ◽

Vol 13 (2) ◽

pp. 267-272 ◽

Cited By ~ 18

Author(s):

David Rue ◽

David Webster ◽

Alfred Traverse

Keyword(s):

Forest Fires ◽

Late Holocene ◽

Fire History ◽

Annual Rainfall ◽

Charcoal Analysis ◽

Maya Lowlands ◽

The Core ◽

Mean Annual Rainfall ◽

Copan Valley ◽

Agricultural Trends

Pollen and charcoal analysis of a 5.3-m sediment core from Aguada Petapilla, a peat bog, provides evidence of late Holocene vegetation and fire history in the Copan Valley, Honduras. Low concentration and preservation problems characterized the pollen flora, but there are taxa present indicative of major agricultural trends, including Zea mays. Microscopic charcoal fragments are well represented and record continued burning in the region since the lowest level of the core (5700 B.P. [3750 B.C.]). Presence of Zea indicates that maize farming was initiated by as early as 2300 B.C. Three peaks in charcoal-fragment frequencies occur in periods centered approximately at 900 B.C., 400 B.C., and A.D. 600. Fires in this relatively dry region of the southern Maya Lowlands (whose mean annual rainfall is about 1,400 mm) could have resulted from natural forest fires or human agricultural clearing at any time in the Holocene. This contrasts with wetter areas of tropical Central and South America (mean annual rainfall of about 2,500–4,000 mm) where significant climatic drying is required to ignite primary tropical forest.

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Land use legacy effects on structure and composition of subtropical dry forests in St. Croix, U.S. Virgin Islands

Forest Ecology and Management ◽

10.1016/j.foreco.2014.09.033 ◽

2015 ◽

Vol 335 ◽

pp. 270-280 ◽

Cited By ~ 12

Author(s):

Emily E. Atkinson ◽

Erika Marín-Spiotta

Keyword(s):

Land Use ◽

Virgin Islands ◽

Legacy Effects ◽

Dry Forests ◽

Subtropical Dry Forests

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Late Holocene extinction of Puerto Rican native land mammals

Biology Letters ◽

10.1098/rsbl.2006.0585 ◽

2007 ◽

Vol 3 (2) ◽

pp. 193-196 ◽

Cited By ~ 31

Author(s):

S.T Turvey ◽

J.R Oliver ◽

Y.M Narganes Storde ◽

P Rye

Keyword(s):

Puerto Rico ◽

Puerto Rican ◽

Late Holocene ◽

Close Agreement ◽

West Indian ◽

Indian Species ◽

Native Land ◽

Indian Land ◽

Mammal Faunas ◽

Radiometric Dates

West Indian land mammals have suffered the most severe extinctions of any Holocene mammal faunas. However, ‘last-occurrence’ dates based on radiometric or robust stratigraphic data remain unavailable for most West Indian species, making it impossible to identify factors responsible for these extinctions. Here, we present new radiometric dates from archaeological and palaeontological sites on Puerto Rico, the only Greater Antillean island to have lost all native land mammals. Although it has been suggested that these species died out earlier than other West Indian mammals, we demonstrate that Puerto Rican mammal last-occurrence dates are in close agreement with those from other Antillean islands, as several species in fact persisted for millennia following Amerindian arrival. Echimyid rodents and nesophontid ‘island-shrews’ were still present on Puerto Rico approximately 1000 years BP, and probably became extinct following European arrival. The large (13 kg) heptaxodontid rodent Elasmodontomys obliquus also appears to have survived for over 2000 years after Amerindian colonization, suggesting that at least some large West Indian mammals became extinct in protracted pre-European ‘sitzkrieg’-style events rather than ‘blitzkrieg’-style overkill.

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Novel dry forests in southwestern Puerto Rico

Forest Ecology and Management ◽

10.1016/j.foreco.2011.03.020 ◽

2011 ◽

Vol 262 (2) ◽

pp. 170-177 ◽

Cited By ~ 15

Author(s):

Sandra Molina Colón ◽

Ariel E. Lugo ◽

Olga M. Ramos González

Keyword(s):

Puerto Rico ◽

Dry Forests

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Holocene Carbon Accumulation, Wetness Shifts and Fire History at Three Threatened Peatlands in Carmarthenshire, SW Wales, UK

10.23889/suthesis.59169 ◽

2021 ◽

Author(s):

◽

Kristy Holder

Keyword(s):

Bronze Age ◽

Environmental History ◽

Late Holocene ◽

Fire History ◽

Developmental Change ◽

Management Strategies ◽

Carbon Accumulation ◽

Public Understanding ◽

Valuable Insight ◽

Holocene Thermal Maximum

This project studies three peatlands in Carmarthenshire, SW Wales, UK (Figyn Common, Pyllau Cochion and Mynydd Bach) that are threatened by the impacts of continued human interference and projected climate change. The threat that human and climatic forces pose on peatland carbon storage has become a significant global concern in the fight against greenhouse gas climate forcing. A record of their Holocene environmental and developmental history is obtained via a multi-proxy analysis, including carbon:nitrogen ratio (C:N), humification, charcoal and carbon accumulation. Potential drivers of developmental change and temporal carbon accumulation are also explored. Fen peat inception occurred at ca. 10800, ca. 9730 and ca. 7960 cal yrs. BP at Figyn Common, Pyllau Cochion and Mynydd Bach (respectively). The fen to bog transition (FBT) is dated to ca. 5120 cal yrs. BP at Pyllau Cochion and ca. 4480 cal yrs. BP at Figyn Common. The FBT does not take place at Mynydd Bach. Evidence of regional wet shifts during the late Holocene is found at ca. 2000 and ca. 850 cal yrs. BP and a dry shift is detected at ca. 2400 cal yrs. BP. All three sites demonstrate evidence of burning through the Mesolithic period and on-site burning increases at all sites after ca. 4500 cal yrs. BP. At Mynydd Bach, fire activity is linked to Bronze Age ritual practices. Long-term Apparent Rates of Carbon Accumulation (LARCA) for the three sites are 23.71, 13.09 and 42.55 g C m -2 yr -1 for Pyllau Cochion, Mynydd Bach, and Figyn Common (respectively). Carbon accumulation is high in the early Holocene, likely in response to the faster accumulation rates associated with early fen stages. However, in contrast to other northern peatlands carbon accumulation is lower during the Holocene Thermal Maximum and higher in the late Holocene when neoglacial cooling persisted. This is most likely because they sit close to the bioclimatic threshold of peatland formation in a UK context. Furthermore, an association between shorter-term wet shifts and higher carbon accumulation is found at several points in the Pyllau Cochion and Figyn Common record. The findings imply that the sites accumulate more carbon during wetter/cooler conditions and less when it is warmer/drier. Therefore, it is likely that they will experience reductions in carbon accumulation in response to projected warming during the 21st century. This adds support to the widely reported theory in the literature that peripheral peatlands will be the first to see losses in their carbon sequestration capacity because of predicted warming. This work contributes to the public understanding of the environmental history of these peatlands and the results provide valuable insight for conservation and future management strategies along with an assessment of carbon projections.

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RISING RIVERS AND SHIFTING SHORELINES: EXPLORING LANDSCAPE CHANGE IN MID TO LATE HOLOCENE PUERTO RICO AND IMPLICATIONS FOR ARCHAEOLOGY

10.1130/abs/2019am-339344 ◽

2019 ◽

Author(s):

L.M. Joyce Seals ◽

◽

Hernán Santos ◽

Hernán Santos

Keyword(s):

Puerto Rico ◽

Landscape Change ◽

Late Holocene

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Middle- to late-Holocene fire history and the impact on Mediterranean pine and oak forests according to the core RF93-30, central Adriatic Sea

The Holocene ◽

10.1177/0959683619846982 ◽

2019 ◽

Vol 29 (8) ◽

pp. 1362-1376 ◽

Cited By ~ 2

Author(s):

Anna Maria Mercuri ◽

Assunta Florenzano ◽

Rita Terenziani ◽

Elisa Furia ◽

Daniele Dallai ◽

...

Keyword(s):

Bronze Age ◽

Late Holocene ◽

Fire History ◽

Last Millennium ◽

Terrestrial Vegetation ◽

Fire Event ◽

Po River ◽

Good Correspondence ◽

Anthropogenic Fire ◽

The Impact

The high-resolution Adriatic RF93-30 core shows changes in its microcharcoal record, which correlate to terrestrial fires from the last 7000 years. Pollen and microcharcoals were transported by wind and fluvial transport from the sedimentary basin, including the Po River and other rivers flowing into the sea off the Italian east coast. Charcoal particles and pollen were counted in the same samples, and the maximum breadth and length of charcoal particles were measured. Microcharcoals with large dimensions were taken as fire indicators occurring along the near coast, as they probably arrived from short distances, the nearest being in Apulia, in southern Italy. The age–depth model was developed within the multidisciplinary PALICLAS project. Several potential fire activity increases (PFAIs) were visible as peaks in the diagram. The oldest PFAIs occurred at the middle Holocene (approximately dated to c. 6730, 5430, 4150 cal BP), others occurred at the late Holocene ( c. 3760, 2660, 2240, 2030, 1930, 1510 cal BP) and during the last millennium ( c. 900–865, 530, 120–96 cal BP). The two oldest peaks in the diagram, occurring in the 7th–6th millennia, showed the highest contribution of charcoal corresponding to the highest values of arboreal pollen (AP) in the sedimentary record. Although the CHAR peaks did not represent a single fire event, the diagram suggests a good correspondence between paleofire activity and terrestrial vegetation biomass during this early phase. Pollen containing black particles was observed, which suggested some grains were transported in suspension with winds from burned woods. The main unambiguous anthropogenic fire causation would have occurred during the last four millennia. From 4.2 ka, it became hard to disentangle climate and Bronze Age actions. Technology and human activity probably improved the pace of fire events, especially involving oak woods, with evidence of an increase of CHAR during the last millennium.

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