Pollen Distribution Research Articles

Latitude, elevation, richness and hotspots of change across the Americas: a test of Orlóci’s plant compositional transition hypotheses throughout the Holocene

Our understanding of how plant communities will respond to current and future climate change has advanced considerably since the use of early climate models to predict specific local temperature and precipitation changes, and thereby plant transitions, at the beginning of climate change recognition and research. The collection, availability and spatial distribution of pollen records across the Americas has recently allowed us to investigate plant compositional transitions during climate change periods in the past. Results from these models and pollen record investigations have provided formulated hypotheses, led by Laszlo Orloci, in palynology and climate change ecology predicting that high latitude, high elevation and species-rich communities have shown greater plant compositional transitions during periods of climate change in the past, show greater change today, and will show greater change in the future. To address hypotheses for the past, and infer changes for the future, we used 238 pollen records across North and South America to test if latitude, elevation and taxa richness defined plant compositional transitions and their rates of change over the past 10,000 years, representing the majority of the Holocene (11.7k – 150 ybp), and if transitions were identifiable as hotspots of change. Contradicting Orloci’s hypothesis we found low latitude records to show greater transitions during the late Holocene, associated with increased aridity leading to Amazon, deciduous and Atlantic forest – Caatinga, Cerrado shifts at low latitudes. Higher elevations showed greater plant compositional transitions during the late Holocene, providing support for Orloci’s hypothesis of greater plant transitions at higher elevations, associated with Andean cooling over the past 5k years. Richness explained less of plant compositional transition than latitude and elevation and showed positive, negative and no relationships showing no clear conclusive pattern. Climate change research solely at high latitudes and high elevations overlooks consequences of climate shifts on other ecosystems, such as tropical forests of northeastern South America showing past increased aridity and predicted future drought probability of 80% by 2050 leading to predicted 20% forest loss by the end of the century.

Crossability of Pinus sibirica and P. pumila with their hybrids

Abstract Crossability of Pinus sibirica and P. pumila hybrids and their parental species was studied using the controlled pollination method. Pinus sibirica and its hybrids were represented by grafts at the “Kedr” field station southeast of Tomsk Oblast, Russia; the parental species was of local provenance, with its hybrids obtained from the Southern Baikal region. In the case of P. pumila, trees were pollinated in a wild stand located in the Upper Angara River delta. Parental species had the highest number of filled seeds under open pollination. When they were pollinated with hybrid pollen, the trees showed nearly two-fold reductions in the number of filled seeds. Hybrids tended to abort most ovules during the first year of female cone development, resulting in a high seed abortion rate and consequent low seed production. The number of filled seeds obtained from hybrids was low, with levels ranging from 8.2 to 24.3%. Because of weak reproductive isolation between hybrids and parental species, crosses are inevitable and lead to species introgression. The hybrids probably contribute to interspecies genetic exchange both through hybrid seed production following pollination by parental species and by hybrid pollen distribution.

Pollen quantitative distribution in marine and fluvial surface sediments from the northern South China Sea: New insights into pollen transportation and deposition mechanisms

In order to improve the understanding of pollen transportation and deposition mechanisms in northern South China Sea (SCS), 45 seafloor surface sediment samples from the SCS and nine surface sediment samples from the Pearl River mouth were analyzed palynologically. The spatial distributions of pollen and spore taxa suggest that various transport mechanisms and the production at the source. The dominant pollen Pinus, Poaceae, Cyperaceae and fern spores are most abundant in the river mouth and decrease with increasing distance from the land, suggesting they are mainly derived from the Pearl River drainage basin and strongly dispersed by river plume and ocean currents, which reflects a dominant pollen transportation pattern in the northern SCS. Podocarpus and temperate broad-leaved components pollen, such as evergreen Quercus and Castanopsis pollen, is common in marine samples and is scattered in the Pearl River samples, reflecting their extensive source areas and dispersal in more than one route. However, some pollen types of conifers are mostly deposited close to the shore, such as Dacrydium, Picea and Abies, which are restricted near Hainan Island and Taiwan Island. Excluding evergreen Quercus and Castanopsis pollen, the total tropical and subtropical components poorly reflect their parent plants, and fewer such pollen are transported over long distances. However, the source areas of some other pollen taxa (e.g., Phyllocladus, Artemisia and Chenopodiaceae) are unclear. Spatially varying ratios of spores to pollen indicate that spores are relatively easily transported by water over longer distances than are pollen grains. This study provides a sound basis for interpreting Quaternary pollen deposits from the northern SCS, and for further evaluation of pollen dispersal and deposition in marine and fluvial deposits.

The distribution of pollen and particulate matter in an urban agglomeration using the city of Berlin as an example

Background: The study shows the findings concerning the distribution of pollen and particulate matter (particles < 10 μm; PM10) within an urban agglomeration, using the example of the city of Berlin as an example.

The public health impacts of climate change in Macedonia

The public health impacts of climate change in Macedonia Vladimir Kendrovski1, Margarita Spasenovska2, Maria Kisman2, Allison Thorpe3, Bettina Menne4 1Medical faculty, Skopje, FYR Macedonia 2WHO-CO, Skopje, FYR Macedonia 3Brunel University, London 4WHO, ECEH, Bonn, Germany Background. Scenarios for Macedonia anticipate an average increase of 3.8 °? by 2100, more frequent and more intense heatwaves, droughts and flood events.Climate change adaption has been established as a priority within existing international and national policy instruments. Aims. The aims were to assess the health effects of climate change and to develop a national adaptation strategy and action plan. Methods.A variety of qualitative and quantitative methodologies were used: Literature reviews, interviews, focus group, time series and regression analysis, damage and adaptation cost estimation, scenario based assessment, and stakeholder engagement. The development of a national adaptation strategy followed a public health strategy process developed by the WHO Europe. Results. Climate change poses a significant threat to population health in the Former Yugoslav Republic of Macedonia. An increase in average monthly temperatures of only 1ºC compared to the period 1996–2000 significantly influences the monthly distribution of total mortality. Climate change-attributed costs of approximately € 2.6 million were calculated. Projected direct health impacts include 5-10% higher salmonellosis notifications for each degree increase in weekly temperature, an increase in pollen distribution in early spring (March), and a change in the presence of vectors. Conclusions. The generation of a robust evidence base, a coordinated and systematic approach to climate change research and the development of robust stakeholder engagement can be used to support the formulation and implementation of sustainable, multisectoral strategies and promote adaptive capacity.

Numerical simulation of allergic pollen over a coastal city in Korea

Background: The recent increase in prevalence of allergic diseases and climate change stimulate the interest in allergic pollen. Numerical modeling techniques can enhance our understanding about spatiotemporal pollen patterns and help to achieve a better management of pollen-related allergic diseases. Aims: This study aims to simulate oak pollen distributions in multiscale domain using a new model system developed by modifying the existing pollen emission and air quality models and to evaluate modeled concentrations for urban scale prediction with observations in Ulsan city, Korea. Methods: Gridded inventories of oak pollen sources were calculated by a pollen-emission model using the Weather Research and Forecasting (WRF) model-based meteorology fields and detailed land cover information. The emission model was incorporated into the modified Community Multiscale Air Quality (CMAQ) model which can address pollen dispersion and deposition in urban and regional scales. A 10 day-run for oak pollen simulation was conducted using the developed model during an episode of the 2011 spring pollen season. Results: Modeled pollen concentrations were evaluated against data collected at the Ulsan Environmental Health Center sampling site within the model domain. Overall, the simulated temporal patterns reasonably followed the measured profiles of oak pollen, but there were large differences between modeled and measured concentrations at certain times due to the discrepancy in winds. Some simulations indicated nighttime peak of oak concentration was closely associated with regional transport under strong wind condition and change in boundary layer structure. In addition, the inflow of marine air masses mainly contributed to decrease in surface oak concentrations in the city atmosphere. Conclusions: The present study describes the successful application of air quality modeling system to simulate oak concentration in urban scale. However, a better understanding of the pollen release and deposition processes will be needed to improve pollen prediction by numerical models.

Investigation of the diurnal pattern of the vertical distribution of pollen in the lower troposphere using LIDAR

Abstract. The diurnal pattern of the vertical distribution of biogenic pollen in the lower troposphere was investigated by LIDAR. Meteorological data were taken at the ground. Pollen concentrations were measured at the surface using a Burkard 7-day-recording volumetric spore sampler. Aerosol extinction coefficients and depolarization ratios at 532 nm were obtained from LIDAR measurements in spring (4 May–2 June) 2009 in Gwangju, South Korea. Linear volume depolarization ratios varied between 0.08 and 0.14 and were observed only during daytime (09:00–17:00 local time (LT)) during days of high pollen concentration (4 to 9 May). Daily average pollen concentrations ranged 1000–2500 cm−3 in the same period. The temporal evolution of the vertical distribution of the linear volume depolarization ratio showed a specific diurnal pattern. Linear volume depolarization ratios of more than 0.06, were measured near the surface in the morning. High depolarization ratios were detected up to 2 km aboveground between 12:00 and 14:00 LT, whereas high depolarization ratios were observed only close to the surface after 17:00 LT. Low values of depolarization ratios (≤0.05) were detected after 18:00 LT until the next morning. During the measurement period, the daily variations of the high depolarization ratios close to the surface showed correlation to number concentration measurements of pollen. This finding suggests that high depolarization ratios could be attributed to enhanced pollen concentrations. The diurnal characteristics of the high values of depolarization ratios are thought to be closely associated with turbulent transport. Diurnal and vertical characteristics of pollen, if measured continuously, could be used to improve the accuracy of pollen-forecasting models via data assimilation studies.

The spatial and temporal distribution of pollen in a room: Forensic implications

This paper presents two experimental studies that deal with the spatial and temporal distribution of pollen grains within a room of a domestic dwelling. The findings concur with the preliminary work of Morgan et al. [1] and provide greater detail as to the behaviour of pollen grains within indoor locations that are pertinent for forensic investigations. The spatial distribution of pollen in a room exhibits strong distance decay trends, with the majority of pollen recovered within 0.8m of its source. The pollen was found to persist in increasing quantities during the time the flowers were in the room. This study also shows that 20days after the flowers were removed, 25-32% of the original pollen was still present within the room. The influence of disturbance was investigated and whilst areas of high disturbance were found to retain less pollen than undisturbed locations, the influence of the proximity to source was a more dominant factor. These findings have significant implications for forensic investigation protocols, particularly the collection and interpretation phases of trace evidence analysis. The distribution of pollen around a room ensures that viable sources of trace pollen are available for transfer if contact is made between a location in the room and a suspect. The persistence of pollen many days after the flowers have been removed from a room indicates that many rooms in domestic dwellings will have distinctive assemblages that reflect the history of the flowers that have been displayed within that room in the past, and that these assemblages will persist and therefore be available for transfer. These preliminary findings indicate that investigation by forensic palynology in indoor domestic settings may well be an underutilised technique that has the potential to provide accurate and valuable intelligence and evidence for forensic enquiry.

Pollen–climate transfer functions intended for temperate eastern Asia

Pollen data of 646 surface samples from northern China and Mongolia and climatic data from the relevant meteorological stations were collected in this study to develop more reliable pollen–climate transfer functions for temperate eastern Asia. Canonical correspondence analysis (CCA) was used to examine the pollen–climate relationships, and mean summer precipitation (MSP) and mean January temperature (MJaT) were inferred to be the first and second important factors controlling the spatial distribution of the surface pollen in the study area. The original dataset was screened with CCA for MSP and MJaT separately to detect anomalous samples that show the extreme values. The first screened dataset was established after excluding those anomalous samples, and the initial transfer function was generated using the weighted averaging partial least squares (WAPLS) method. The jackknife test was then applied to the WAPLS model for determining the optimum transfer function and for detecting large-residual samples, and the final transfer function was generated after removing the large-residual samples from the first screened dataset. The final dataset for MSP and MJaT consists of 428 and 419 samples, respectively. The root mean square errors of prediction for both WAPLS models are 34 mm and 2.7 °C, and the coefficients of determination are 0.85 and 0.73. This study suggests that the values of climatic parameters could be better estimated and the reliability of pollen–climate transfer functions would be significantly improved through removing anomalous and large-residual samples from the original dataset with mathematical methods.

Аеропалінологічний спектр м. Дніпропетровськ як основа профілактики сезонної алергії

Hay fever is important allergenic complain with number of patients rising year by year. Ukraine holds the leading positions in Europe in accordance with pollinosis morbidity. Therefore, it’s important to determine regional pollen spectrum for all five climatic and geographical zones of the country having certain variety of plants’ allergens. There are just a few cities with a constant pollen monitoring carried out in Ukraine. They are Vinnytsia, Kyiv, Odessa and Lviv. Palynological range of other Ukrainian cities remains unknown or poorly studied. Dnipropetrovsk – Ukrainian city with location in the Central part of the country in the Steppe zone – isn’t exception as well. Thus, the aim of our study was to determine the pattern of airborne pollen distribution and pollen calendar creation for the city of Dnipropetrovsk. Pollen count obtained at Vinnytsia National Pirogov Memorial Medical University (VNMU) by Aerobiology Research Group. Study was held in 2010 from the 17th of March till the 20th of October on daily basis employed volumetric methods using the Burkard trap. It stands on the roof of the Dnipropetrovsk Municipal hospital at 20 meters of a relative height above ground. The air samples were sent by currier mail on weekly basis from Dnipropetrovsk to Vinnytsia for the research term. 51 pollen types were determined during the study period. The aeropalinological research was done for the Dnipropetrovsk at first. Study was conducted in association with the European Aeroallergen Network (EAN). The EAN tools and the software package “Statistica 5.5” were used for data statistical analysis. The study showed prevalence of the airborne herbal pollen types in Dnipropetrovsk. The “weeds : trees” pollen ratio was «88 : 12». Most abundant pollen rain (59% of total annual pollen count) was produced by Ambrosia. The second position with 6% was held by Amaranthus / Chenopodiaceae pollen group and Urtica dioica pollen. Artemisia and other representatives of Asteraceae constituted of 5% each. The most abundant tree pollen rain (4% from total annual count) was produced by the Populus species. Betula pollen was the next having up 2% of annual pollen rain in Dnipropetrovsk. As can be seen, the first arboreal spring-summer pollination wave was not massive in Dnipropetrovsk. It was represented by Populus, Betula, Acer, Fraxinus, Quercus, Ulmus, Pinus, Juglans pollen spread in the end of March, whole April and the first weeks of May mostly. However, the second wave was intensively seen from the mid of July till the mid of October. Important airborne pollen producing taxa were Artemisisia, Ambrosia, Asteraceae, Chenopodiaceae, Urtica, Plantago, Polygonaceae pollen at that time. Important airborne pollen allergens of Poaceae family (grasses) held the 7th position in the total annual pollen rain and were recorded between two pollination waves from the mid of May till the end of June mostly. The worst period for the patients was associated with the Betula, Acer and Quercus pollination from 13th of April till the mid of May and with Ambrosia and Artemisia pollination from 28th of July, till September, 30. The present airborne pollen calendar should be considered while diagnosing the hay fever symptoms in sensitive patients. It’s important to continue the pollen count and control in Dnіpropetrovsk due to constant changing of climatic and anthropogenic conditions impacting the pollen production and release.

Palynology and palynofacies of the Upper Cretaceous succession of the El-Noor-1X borehole, northwestern Egypt

Palynological and palynofacies analyses were carried out on some middle–upper Cretaceous samples from the El-Noor-1X borehole, northern Western Desert, Egypt. Palynological age has lead to a refinement of the original ages suggested by the drilling company. Upper Albian–Lower Cenomanian, Upper Cenomanian, and Turonian–Coniacian were recognized. The palaeoenvironment was interpreted on the basis of the ecological preferences of the palynomorphs. It was fluctuating between marginal to inner-middle shelf environment. Distribution of araucaroid pollen and xerophytes suggests that arid or semi-arid paleclimate prevailed during the deposition of the studied sediments. A warm tropical palaeoclimate is suggested on the basis of abundance of hygrophilous plants. Based on the recovered palynological organic matter, two palynofacies were recognized: palynofacies A for the Bahariya Formation, which suggests kerogen type III, and palynofacies B for the upper Bahariya and Abu Roash Formations, which suggests kerogen type IX. Data gathered from the theoretically estimated vitrinite reflectances, which are based on spore/pollen coloration, and visual pterographic kerogen analysis are used to define the source rock potentialities of the studied sediments.

Influence of environmental factors on measurements with Hirst spore traps

The study assesses differences in the results retrieved by Hirst samplers of the same model in order to determine their sampling variability. Five seven-day Burkard spore traps were compared. Four were located at ground level at the same site, separated by less than 2 m from each other. The fifth was placed on a terrace 16 m above ground, close to the other four samplers. An automatic meteorological station at ground level close to the spore traps was working simultaneously. Sampling was done for 51 days. The daily and hourly pollen concentration data were compared and the pollen distribution over the microscope slide surface was analysed. There were highly statistically significant strong positive correlations between spore traps themselves, with equivalent measurements of the daily and hourly patterns. Differences in hourly values between samplers were greater than differences in daily values, and the hourly peaks did not always match among samplers, with typically lags of two or more hours between traps. Analysis of the surface deposition of pollen on the slides showed pollen loss towards the edges and pollen appearing even outside the slit intake width. As hourly peaks indicated a degree of variability, this type of data requires to be interpreted with relative caution.

Analysis of airborne pollen grains in Denizli

Airborne pollen distribution in Denizli Province was measured volumetrically during 2 consecutive years, 2005 and 2006, on a weekly basis. A total of 11,981 pollen grains/m^3 belonging to 42 taxa were determined. In 2005 the total was 5368 pollen grains/m^3 and in 2006 it was 6613 pollen grains/m^3. Among the taxa recorded, 26 belonged to arboreal and 16 to nonarboreal taxa. At the end of the 2 years total pollen counts comprised 79.68% arboreal, 19.48% nonarboreal, and 0.84% unidentified taxa. The number of pollen grains/m^3 among arboreal plants was as follows: Pinaceae (24.19%), Cupressaceae/Taxodiaceae (15.99%), Olea europaea (11.35%), Quercus spp. (6.08%), Platanus orientalis (5.68%), Acer spp. (2.93%), Morus spp. (2.58%), Salix spp. (1.59%), and Eucalyptus camaldulensis (1.47%), and for nonarboreal representatives: Poaceae (6.63%), Asteraceae (3.08%), Chenopodiaceae/Amaranthaceae (2.27%), Plantago spp. (2.12%), Urticaceae (1.82%,) and Xanthium strumarium (1.52%). The distribution of pollen in the atmosphere of Denizli was highest in May, followed by June, April, and March.

Characteristics of modern pollen distribution in surface sediment samples for the northern South China Sea from three transects

The present study is an analysis of the distribution of pollen in surface sediments of the northern South China Sea (SCS) as recorded in 74 samples from the area 12.00–23.72°N, 108.57–120.00°E at water depths of 14–4410 m. The characteristics of the pollen distribution along north–south, northeast–southwest and northwest–southeast directions in the northern South China Sea are described below: (1) Based on PCA analysis, samples in the present study are mainly dominated by river transport (Component 1). Pollen Area I has samples with Component 1 > 0, located in the east and south part of the study area, with the dominant species of Poaceae, Pinus (water-transported), Monolete Spores, Podocarpus macrophyllus, Fungi, Rhizophoraceae, Artemisia, and Castanopsis, transported by Pearl River, rivers from Taiwan Island, Mekong River. Pollen Area II has samples with Component 1 < 0, they are located in the east and south around Hainan Island, with dominant Trilete Spores, transported by rivers from Hainan Island and summer monsoon forced marine current. (2) The characteristics of the percentages of pollen grains were influenced mainly by the geomorphology of the seafloor. Pollen percentages from sample sites on the continental shelf or near islands are different from those in the sea basin. The percentages of Trilete spores at continental shelf or island sites are higher than those at sea basin sites. (3) The pollen percentages and concentrations indicate that Castanopsis and Evergreen Quercus pollen are most abundant in the southwest. These pollen could be transported from Indochina by the Mekong River. The percentage of Castanopsis pollen decreased from north to south and from northwest to southeast, indicating that the Guangdong coast is a secondary source area. Monolete spores, Cyperaceae and Poaceae abundances decreased from northwest to southeast, related to input from the Pearl River or proximity to the Guangdong coast. In the north–south direction, Monolete spores and Poaceae decreased from the north and from the south to the middle of the basin, which can be attributed to inputs from the Pearl River or Guangdong coast in the north and Indochina in the south.

Modern pollen distributions in Qinghai-Tibetan Plateau and the development of transfer functions for reconstructing Holocene environmental changes

Modern pollen distributions in Qinghai-Tibetan Plateau and the development of transfer functions for reconstructing Holocene environmental changes

An Investigation of Airborne Allergenic Pollen at Different Heights

Background and Aims: Airborne pollen is an important source of allergens in a number of allergic diseases. Data on the concentrations of pollen at different heights in the air are scarce. The aim of the present study was to investigate different types and numbers of airborne pollen and their seasonal variation at different heights in the urban area of Shenzhen (China) and their associations with meteorological factors. Methods: The concentration of airborne pollen at different heights was monitored with Burkard traps from July 1, 2006, to June 30, 2007, in Shenzhen; the results were analyzed with SAS 9.13 software. Results: In total, 1,095 films (at 3 heights, 365 films at each height) were exposed throughout the year, and 48 families and 85 genera of pollen taxa were identified. The total pollen count was 55,830 grains (25,204 grains at 1.5 m; 16,218 grains at 35 m, and 14,408 grains at 70 m); pollen grains were present in the atmosphere throughout the year, with two peaks of airborne pollen: one peak in February to April and the other in September to November. Conclusions: On the basis of our local investigations, the pollen concentrations and the pollen types in the air decrease gradually with increasing height. The distribution and concentrations of airborne pollen at different heights in the atmosphere were influenced by composite factors such as the season and meteorological factors.

Recognition of Optical Microscopy Images Based on Shape and Texture

Airborne pollen is the main cause of pollen allergy, so statistic of the amount and distribution of pollen in the air is important. This paper presents a method to identify airborne pollen grains in optical microscopy images. After pollen region is segmented by thresholding, global shape descriptor and Fourier descriptor are used to extract shape features, gray level co-occurrence matrix is employed to extract texture features, and finally pollen grains are classified by a k-nearest neighborhood classifier. In the experiment with 55 cases ofPoaceae, 44 cases ofMoraceaeand 48 cases ofPinaceae, a classification rate of 82.31% can be obtained with an accuracy of 85.45%, 61.36%, and 97.91% for each family.

Modern pollen-vegetation relationship based on discriminant analysis across an altitudinal transect on Gongga Mountain, eastern Tibetan Plateau

Quantitative relationship between modern pollen assemblage and altitudinal vegetation belt is crucial for the reconstruction of paleovegetation in the mountain regions. Modern pollen analysis on 70 topsoil samples was conducted across an altitudinal transect (1100-4500 m) on the eastern slope of Gongga Mountain in the eastern Tibetan Plateau with an elevation interval of 50 m. Distributions of major pollen types along the transect indicated a weak correlation between Pinus pollen and the elevation. Distributions of Picea and Abies pollen (percentage sum of 2%-8%) could fairly indicate the elevation range of 2700-3700 m, as well as the subalpine dark coniferous forest and the timberline in the region. High percentage intervals of alpine types of Ericaceae, Cupressaceae and Cyperaceae were correlated to the high-elevation regions (3700-4500 m) dominated by alpine shrub meadow and alpine meadow. Seven altitudinal vegetation belts on the eastern slope of Gongga Mountain were well defined by discriminant analysis conducted on the modern pollen assemblages, as reflected by high values of probability of modern analog. Most of the modern pollen assemblages (88.5%) were typical for the vegetation types at their sampling locations. Thus, the relationship between the modern pollen assemblages and vegetation across the altitudinal transect based on discriminant analysis can be applied to the quantitative reconstruction of paleovegetation changes in the mountain regions of the eastern Tibetan Plateau.

Climate and vegetation history of western Portugal inferred from Albian near-shore deposits (Galé Formation, Lusitanian Basin)

AbstractThe late Early Cretaceous greenhouse climate has been studied intensively based on proxy data derived essentially from open marine archives. In contrast, information on continental climatic conditions and on the accompanying response of vegetation is relatively scarce, most notably owing to the stratigraphic uncertainties associated with many Lower Cretaceous terrestrial deposits. Here, we present a palynological record from Albian near-shore deposits of the Lusitanian Basin of W Portugal, which have been independently dated using Sr-isotope signals derived from low-Mg oyster shell calcite.87Sr/86Sr values fluctuate between 0.707373 ± 0.00002 and 0.707456 ± 0.00003; absolute values and the overall stratigraphic trend match well with the global open marine seawater signature during Albian times. Based on the new Sr-isotope data, existing biostratigraphic assignments of the succession are corroborated and partly revised. Spore-pollen data provide information on the vegetation community structure and are flanked by sedimentological and clay mineralogical data used to infer the overall climatic conditions prevailing on the adjacent continent. Variations in the distribution of climate-sensitive pollen and spores indicate distinct changes in moisture availability across the studied succession with a pronounced increase in hygrophilous spores in late Early Albian times. Comparison with time-equivalent palynofloras from the Algarve Basin of southern Portugal shows pronounced differences in the xerophyte/hygrophyte ratio, interpreted to reflect the effect of a broad arid climate belt covering southern and southeastern Iberia during Early Albian times.

The ice age ecologist: testing methods for reserve prioritization during the last global warming

ABSTRACTAim We play the role of an ice age ecologist (IAE) charged with conserving biodiversity during the climate changes accompanying the last deglaciation. We develop reserve‐selection strategies for the IAE and check them against rankings based on modern data.Location Northern and eastern North America.Methods Three reserve‐selection strategies are developed. (1) Abiotic: the IAE uses no information about species–climate relationships, instead maximizing the climatic and geographic dispersion of reserves. (2) Species distribution models (SDMs): the IAE uses boosted‐regression trees calibrated against pollen data and CCSM3 palaeoclimatic simulations from 21 to 15 ka bp to predict modern taxon distributions, then uses these as input to the Zonation reserve‐ranking program. (3) Rank‐and‐regress: regression models are used to identify climatic predictors of zonation rankings. All strategies are assessed against a Zonation ranking based on modern pollen distributions. Analysis units are ecoregions and grid cells.Results The abiotic strategy has a negative or no correlation between predicted and actual rankings. The SDM‐based strategy fares better, with a significantly positive area‐corrected correlation (r= 0.474, P &lt; 0.001) between predicted and actual rankings. Predictive ability drops when grid cells are the analysis unit (r= 0.217, P = 0.058). Predictive ability for the rank‐and‐regress strategy is similar to the SDM results.Main conclusions For the IAE, SDMs improve the predictive ability of reserve‐selection strategies. However, predictive ability is limited overall, probably due to shifted realized niches during past no‐analogue climates, new species interactions as species responded individually to climate change, and other environmental changes not included in the model. Twenty‐first‐century conservation planning also faces these challenges, and is further complicated by other anthropogenic impacts. The IAE's limited success does not preclude the use of climate scenarios and niche‐based SDMs when developing adaptation strategies, but suggests that such tools offer at best only a rough guide to identifying possible areas of future conservation value.