1 Although fossil pollen from forest hollows (~ 5 m in diameter) is often interpreted as a record of stand-scale changes, this assumption has not previously been tested by comparing percentages modern sediment to vegetation range sampling radii. I compared surface with distance-weighted basal area trees radii 10 l00 m, test model (Sugita 1994) that predicts the 'relevant source area' for 50-100 and about 40 % comes growing within radius. 2 Maximum likelihood estimates productivity, based on...

Cause of patch formation was investigated on a 7.2 ha study area in Sylvania Wilderness Area, primary forest remnant Upper Michigan comprising mosaic hemlock, sugar maple, and mixed—forest patches. Spatial autocorrelation analysis the stem map indicated that, although most species pairs have neutral association between canopy trees understory other species, hemlock maple both strong positive self negative reciprocal with each other. No regeneration MOSAIC, Markov simulation model which...

Abstract The Landscape Reconstruction Algorithm (LRA) overcomes some of the fundamental problems in pollen analysis for quantitative reconstruction vegetation. LRA first uses REVEALS model to estimate regional vegetation using data from large sites and then LOVE composition within relevant source area (RSAP) at small by subtracting background estimated composition. This study tests training forest hollows northern Michigan (35 sites) northwestern Wisconsin (43 sites). In Michigan, surface...

The record of forest invasion by eastern hemlock (Tsuga canadensis) during the course Holocene migration provides useful information about processes in temperate forest, a system that has been invaded few exotic species. We used fossil pollen preserved small hollows, which composition on scale 1–3 ha, to study forests Sylvania Wilderness upper peninsula Michigan, where there is now mosaic 3–30 ha stands dominated either or sugar maple (Acer saccharum) and basswood (Tilia americana). Fossil...

We describe five common charcoal morphotypes observed in late-Holocene lake sediments from northern Wisconsin and compare them with produced by burning modern plant material. Our experiments show that grass cuticle, conifer wood leaves of some broadleaved taxa all produce recognizable types are preserved sediments. use the identification to enhance our interpretation a previously published record Ferry Lake, Wisconsin. The occurrence different changed as vegetation fire regimes over past...

Historical information spanning different temporal scales (from tens to millions of years) can influence restoration practice by providing ecological context for better understanding contemporary ecosystems. Ecological history provides clues about the assembly, structure, and dynamic nature ecosystems, this improve forecasting how restored systems will respond changes in climate, disturbance regimes, other factors. History recorded humans be used generate baselines assessing communities,...

Methods of interpreting pollen assemblages in sediment were examined using surface samples from 66 small forest hollows Michigan and Wisconsin. All canopy trees the surrounding 50 m measured to provide detailed information about source vegetation each assemblage. Basal area sample was used classify them into six stand types: hemlock-dominated, sugar maple/hemlock mixed, maple-dominated, ash-, oak-, pine-dominated stands. Various statistical procedures tested learn which most successful...

Abstract: We reconstruct Holocene climate history ( last 10,000 years) for each of the U.S. National Park Service units in western Great Lakes region order to evaluate their sensitivity global warming. Annual precipitation, annual temperature, and July January temperatures were reconstructed by comparing fossil pollen lake sediment with surface samples, assuming that ancient climates similar modern near analogous samples. In early Holocene, most parks experienced colder winters, warmer...

To investigate the influence of regional pollen inputs on reconstructing local vegetation, we compared modem assemblages deposited in forest hollow sediments from two study areas, Michigan and Wisconsin. Local forest-stand composition (within 50 m) at all sites is dominated by hemlock northern hardwood trees, but abundance tree taxa areas not same. Modern differ between corresponding with differences vegetation. Oak pine are more abundant Wisconsin samples, whereas sugar maple, birch...

Eastern hemlock (Tsuga canadensis) expanded rapidly across Upper Peninsula Michigan from ~6500 to 5500 cal. yr BP, followed by a sudden decline of pollen percentages that lasted over 1000 years. Hemlock declined throughout its range, apparently due insect/pathogen outbreaks, which may have been affected regional climatic shifts. Modern analogues were used reconstruct submillennial trends fossil sites spanning the western range limit hemlock. Reconstructions eight inside at time (5400 BP) are...

Terrestrial plant communities have the potential to respond climate change rapidly, if dominant species are killed by a series of extreme events, or slowly, cumulative effects shorter-term fluctuations result in long-term compositional change. We used pollen and charcoal records from lake testate amoebae-derived history water-table depth nearby peatland assess response jack pine-dominated forests northwestern Wisconsin variability last ~2000 years. The hydrology record indicate that near...

The record of forest invasion by eastern hemlock (Tsuga canadensis) during the course Holocene migration provides useful information about processes in temperate forest, a system that has been invaded few exotic species.We used fossil pollen preserved small hollows, which composition on scale 1-3 ha, to study forests Sylvania Wilderness upper peninsula Michigan, where there is now mosaic 3-30 ha stands dominated either or sugar maple (Acer saccharum) and basswood (Tilia americana).Fossil was...

We reconstructed vegetation and fire histories from four sites located on a sandy outwash plain in northwestern Wisconsin (USA) to test whether lakes wetlands have influenced how regimes pine–oak forests responded late-Holocene climatic changes. Because of positive feedbacks between jack pine (Pinus banksiana Lamb.) fire, communities with few breaks should be more resilient changing conditions. Pollen charcoal lake-sediment cores were used reconstruct changes at 50- 100-year intervals forest...

We used charcoal and fossil pollen to investigate how fire, vegetation climate have interacted over the past 2300 years at Ferry Lake, located on a sand plain in northwestern Wisconsin. Pollen analysis shows rapid transition from oak (Quercus spp.)-dominated woodland relatively open pine (Pinus spp.) forest 1450 cal. yr BP, more closed-canopy beginning about 700 BP. calculated accumulation rates of 125-250 ųm fragments (CHAR) contiguous 0.5 cm thick sediment samples, each representing 7-10...

The ‘Qualitative Assessment of Difference’ method (QAD) is proposed to objectively detect differences in the relative abundance vegetation between paired sites using pollen percentages. This corrects for intertaxonomic productivity and neutralizes influences background on representation vegetation, an inverse form Extended R-value model. We test modern pollen-vegetation data from small hollows northern Michigan (6 taxa; 45 sites) northwestern Wisconsin (7 43 USA. Compared with percentages,...

Landscape-scale vulnerability assessment from multiple sources, including paleoecological site histories, can inform climate change adaptation. We used an array of lake sediment pollen and charcoal records to determine how soils landscape factors influenced the variability forest composition over past 2000 years. The forests in this study are located northwestern Wisconsin on a sandy glacial outwash plain. Soils local vary across area. Natural Resource Conservation Service's Soil Survey...

Abstract We show how sedimentary charcoal records from multiple sites within a single landscape can be used to compare fire histories and reveal small scale patterns in regimes. Our objective is develop strategies for classifying comparing late-Holocene Midwestern oak- pine-dominated sand plain ecosystems where regimes include mix of surface crown fires. Using standard techniques the analysis lake sediments, we compiled 1000- 4000-yr-long accumulation peak frequencies 10 lakes across...

Fossil pollen assemblages are widely used to reconstruct past vegetation community composition at time scales ranging from centuries millennia. These reconstructions often based on the observed relationships between proportions of plant taxa in source and corresponding types collected surface sediments. Pollen-vegetation models rely upon parameters whose values typically assumed be stable through time, but this assumption is largely unevaluated, due part rarity comprehensive forest data,...

Records of century-scale climate variability in the Upper Midwest generally agree that moisture availability increased between 4000 and 3000 cal. yr BP (calendar years before present = 1950 CE), there were large, frequent droughts 1000–700 followed by wetter/cooler conditions. Variability among regional sites, however, remains problematic. In this study we reconstruct on Northwest Wisconsin Sand Plain (NWSP), USA, to identify potential climatic drivers previously documented changes...