Modern pollen rain in mangroves from San Andres Island, Colombian Caribbean

The precise characterisation of present-day mangrove ecosystems from modern pollen rain facilitates the accurate use of fossil pollen data for late Quaternary sea level and environmental reconstructions. Here, we investigate whether the analysis of pollen rain data corroborates existing floristic and structural characterisation of different mangrove types at the Caribbean island of San Andrés, Colombia. At 82 plots along 20 transects of four distinct mangrove types, samples were obtained of (i) surface sediments for pollen analysis, and (ii) a range of environmental parameters (including inundation levels, salinity and pH). This information was compared to previously sampled mangrove composition and tree basal area. In surface sediment samples 82 pollen taxa were found, from which 19 were present in the vegetation plots. However, because pollen may be transported by wind and/or watercourses, the overall floristic composition of the different forest types may not necessarily be reflected by the pollen spectra. Local vegetation (i.e. mangroves and beach) represented > 90% of the pollen spectra, while the regional one (i.e. hinterland forests) represented < 5% of it. Unlike the four mangrove types that were previously described in the vegetation, the analysis of pollen samples suggested only three distinct types of forest.The groups were characterised based on (i) the dominance of at least one of the true mangrove species from pollen data ordination and the presence of associated species, and (ii) their relationship with environmental parameters. Rhizophora was present in all plot samples, but did not contribute to forest type separation. In fact, just three true mangrove species proved reliable indicators of (i) high salinity and fringe mangroves (i.e. Avicennia), (ii) high pH levels and landward mangroves (i.e. Conocarpus), and (iii) natural or anthropogenic caused disturbance of forest stands (Laguncularia and associated Acrostichum fern). Hence our study confirms that mangrove pollen spectra can be accurately used to describe different mangrove environments for fossil based palaeoecological reconstructions.     

Modern pollen rain in savanna and forest ecosystems of Gabon and Cameroon,Central Atlantic Africa

Eighty modern soil surface and litter samples from southern Cameroon and Gabon, Central Atlantic Africa (5°N–4°S, 10°–15°W), were analysed for pollen content. The samples are distributed among two main vegetation types: savanna (8 samples) and forest (71 samples). The aim of this study is to provide new data on the modern pollen rain in the Guineo-Congolian phytogeographical region, mainly in forest communities (secondary and mature forests on well drained soils, and hygrophilous forests) and to interpret these data using diagrams of pollen percentages and numerical analyses. The savannas are well identified by high frequencies of non-arboreal pollen with as pollen marker the Poaceae, and the forests by high frequencies of arboreal pollen with as important families the Burseraceae, Caesalpiniaceae, Mimosaceae, Euphorbiaceae and Sapindaceae. Within the forest ecosystem, secondary and mature forests on well drained soils can be differentiated on the basis of distinct assemblages of tree pollen taxa such as Zanthoxylum, Phyllanthus, Tetrorchidium, Margaritaria discoidea in secondary forest spectra and abundance of Burseraceae, Caesalpiniaceae, Sapindaceae in mature forest ones. In addition, hygrophilous forests are well identified by the presence of high pollen contributors such as Uapaca, Nauclea, Macaranga and Raphia. This work shows that the major vegetation communities occurring today in Cameroon and Gabon can be well differentiated by their pollen assemblages.     

Secondary pollen types characteristic of Louisiana honeys

Nine secondary pollen types (those comprising 16–45% of the pollen sample) were recovered from 54 honey samples (10 g) collected from the major beekeeping areas of Louisiana. The pollen types in order of decreasing importance are:Berchemia scandens, rattan vine;Rubus spp., blackberry and dewberry;Salix spp., willow;Trifolium repens, white clover;Glycine max, soybean;Parthenocissus quinquefolia, Virginia creeper; Rosaceae, rose family;Cephalanthus occidentalis, buttonbush; andCornus spp., dogwood. The first four secondary types also appeared as dominant pollen (over 45%) in some of the Louisiana honey samples investigated and were previously reported. The remaining five pollen types and the “bee plants” associated with each pollen type are identified and described.     

Stable isotope ratios of carbon and nitrogen in pollen grains in order to characterize plant functional groups and photosynthetic pathway types

Measurements of delta(13)C, delta(15)N and C : N ratios on modern pollen grains from temperate plants, including whole grains as well as extracted sporopollenin, were analysed in order to characterize physiological plant types at the pollen level and to determine the variation of these parameters in modern pollen grains of the same climatic area. Measurements are presented for 95 batches of whole modern pollen from 58 temperate species and on the stable fraction of modern pollen grains, chemically extracted sporopollenin, for two modern species. Fourier transform infrared (FTIR) and cross-polarization and magic-angle spinning (CP/MAS) sporopollenin spectra were conducted in parallel. C(3) and C(4) plants can be separated by delta(13)C measurements based on pollen. Probabilistic assignments to plant functional groups (herbaceous, deciduous woody, evergreen woody) of C(3) plants by the means of a discriminant analysis can be made for C : N ratios and for delta(13)C. The results are related to other studies on sporopollenin in order to use this method in future work on fossil samples. Stable isotope measurements on pollen allow improved pollen diagrams, including forms that cannot be differentiated at species level, increasing the accuracy and resolution of plant physiological type distribution in quaternary and older fossil sediments.     

Palynological richness and evenness: insights from the taxa accumulation curve

Palynology provides the opportunity to make inferences on changes in diversity of terrestrial vegetation over long time scales. The often coarse taxonomic level achievable in pollen analysis, differences in pollen production and dispersal, and the lack of pollen source boundaries hamper the application of diversity indices to palynology. Palynological richness, the number of pollen types at a constant pollen count, is the most robust and widely used diversity indicator for pollen data. However, this index is also influenced by the abundance distribution of pollen types in sediments. In particular, where the index is calculated by rarefaction analysis, information on taxonomic richness at low abundance may be lost. Here we explore information that can be extracted from the accumulation of taxa over consecutive samples. The log-transformed taxa accumulation curve can be broken up into linear sections with different slope and intersect parameters, describing the accumulation of new taxa within the section. The breaking points may indicate changes in the species pool or in the abundance of high versus low pollen producers. Testing this concept on three pollen diagrams from different landscapes, we find that the break points in the taxa accumulation curves provide convenient zones for identifying changes in richness and evenness. The linear regressions over consecutive samples can be used to inter- and extrapolate to low or extremely high pollen counts, indicating evenness and richness in taxonomic composition within these zones. An evenness indicator, based on the rank-order-abundance is used to assist in the evaluation of the results and the interpretation of the fossil records. Two central European pollen diagrams show major changes in the taxa accumulation curves for the Lateglacial period and the time of human induced land-use changes, while they do not indicate strong changes in the species pool with the onset of the Holocene. In contrast, a central Swedish pollen diagram shows comparatively little change, but high richness during the early Holocene forest establishment. Evenness and palynological richness are related for most periods in the three diagrams, however, sections before forest establishment and after forest clearance show high evenness, which is not necessarily accompanied by high palynological richness, encouraging efforts to separate the two.     

Numerical analysis of pollen samples from central Canada: A comparison of methods

The compilation of large and complex sets of modern pollen data has stimulated the use of new methods, including the use of multivariate statistical techniques, for summarizing and presenting these data. This paper compares several of these methods by applying them to Lichti-Federovich and Ritchie's (1968) 131 sediment samples of modern pollen from central Canada. Maps of the major pollen types are presented, and the data are analyzed by canonical variates analysis, principal components analysis, principal coordinates analysis, and minimum-variance cluster analysis.The maps show the geographical distribution of the principal pollen types and reveal that steep gradients in the percentages of eight of the nineteen pollen types used in this study separate the samples in the southwest from the remaining samples. Excluding the southwestern samples, the maps show the frequencies of the other pollen types to be aligned north to south with high values of sedge, birch, and heath pollen in the north, high values of pine in the south, and high values of spruce and alder in between. This same general structure is evident in the results of the four multivariate analyses. The samples are distributed in a closely similar manner along the first two axes derived from canonical varietes analysis, principal components analysis, and principal coordinates analysis. The first axis of each analysis separates the samples in the southwest from the rest of the samples, and the second axis shows these latter samples to be spread fairly evenly along a north—south gradient from the tundra samples to the mixed coniferous—deciduous forest samples. Minimum-variance cluster analysis also shows these divisions by clustering the samples into three major groups: the southwestern samples from the prairie, aspen parkland, and deciduous forest; the northern samples from the tundra and forest—tundra; and the intermediate samples from the mixed forest and closed coniferous forest regions. Further division by the clustering technique yields fourteen groups, and these show the pollen samples to cluster slightly differently from their classification based on their location within the vegetational units. For example, the samples of the forest—tundra and the open coniferous forest are grouped together, but the samples of the upland mixed forest are too heterogeneous in pollen composition to be placed in one group.These results indicate the power of these numerical methods that use prescribed mathematical steps to analyze all samples and major pollen types simultaneously and thereby reveal the basic structure in the data based on numerical criteria alone. These summaries aid an investigator in visualizing the important trends and divisions in a data set and in finding those samples needed for a particular comparison.     

Pollen morphology and taxonomy of the subtribe Diocleinae (Leguminosae: Papilionoideae: Phaseoleae)

The pollen morphology of the thirteen genera currently included in the subtribe Diocleinae is described. Nine pollen types with a number of subtypes are recognized. These are arranged into two main groups. The first comprises the macromorphologically anomalous genera Calopogonium, Herpyza and Pachyrhizus which, although united by some pollen characters, are distinct both from each other and from the rest of the subtribe. The second group, consisting of the remaining genera which can to some extent be distinguished from each other by their pollen morphology, nevertheless appear to make up both macromorphologically and palynologically a more natural Diocleinae. The six pollen types in the second group are further divided into two slightly overlapping subgroups. Luzonia and Macropsychanthus are palynologically somewhat distinct but, together with Dioclea and Canavalia, have generally rather large, oblate pollen grains with a complete or perforate tectum, in contrast with the pollen of the genera Camptosema, Collaea, Cratylia and much of Galactia which is smaller, spheroidal with a reticulate tectum.Dioclea has some species with isopolar pollen and others with heteropolar pollen grains and this more or less correlates with subgeneric divisions within the genus. Galactia from the Caribbean area has similar but much smaller pollen. The taxonomic significance of this parallel between the pollen morphology of Dioclea and Caribbean Galactia is unclear. The pollen of Canavalia appears to show no significant variation.A possible correlation between the pollen subgroups with ecological habitat and pollinators is discussed.     

Floral Preference of Melipona eburnea Friese (Hymenoptera: Apidae) in a Colombian Andean Region

Melipona eburnea Friese is a stingless bee kept in some regions of Colombia, where it is reported to be vulnerable to extinction due to habitat disturbance. To contribute to raising conservation strategies, the aim of this study was to identify the floral preferences of this species using melissopalynological analysis. A total of 31 pollen pot samples and 37 honey samples were taken from March 2009 through March 2010 from four colonies in Fusagasuga, Colombia. We found 92 pollen types: 17 from pollen pot samples, 39 from honey samples (indicating the sources of nectar), and 36 in both types of samples. The most frequent pollen types in the pollen pot samples were Myrcia type (100%), Eucalyptus globulus (96.9%), and Fraxinus uhdei (96.9%). The most frequent pollen types in honey samples were E. globulus (97.4%) and Myrcia type (94.9%). The pollen types corresponded mainly to native plants (68%), trees (44.5%), plants whose sexual system is hermaphroditic (56.5%), and plants with inflorescences (76.2%). The most frequent shapes of the flowers were brush-like (type Myrtaceae) and dish-like (type Asteraceae), and the preferred flower colors were white or cream (52.2%). In general, we found that M. eburnea showed a strong preference for trees of the family Myrtaceae to obtain nectar and pollen, including native and introduced species. Some other families are contributing significantly, such as Melastomataceae for pollen collection and Asteraceae for nectar. These results highlight the key plant species for the diet of M. eburnea.     

Fungi Identify the Geographic Origin of Dust Samples

There is a long history of archaeologists and forensic scientists using pollen found in a dust sample to identify its geographic origin or history. Such palynological approaches have important limitations as they require time-consuming identification of pollen grains, a priori knowledge of plant species distributions, and a sufficient diversity of pollen types to permit spatial or temporal identification. We demonstrate an alternative approach based on DNA sequencing analyses of the fungal diversity found in dust samples. Using nearly 1,000 dust samples collected from across the continental U.S., our analyses identify up to 40,000 fungal taxa from these samples, many of which exhibit a high degree of geographic endemism. We develop a statistical learning algorithm via discriminant analysis that exploits this geographic endemicity in the fungal diversity to correctly identify samples to within a few hundred kilometers of their geographic origin with high probability. In addition, our statistical approach provides a measure of certainty for each prediction, in contrast with current palynology methods that are almost always based on expert opinion and devoid of statistical inference. Fungal taxa found in dust samples can therefore be used to identify the origin of that dust and, more importantly, we can quantify our degree of certainty that a sample originated in a particular place. This work opens up a new approach to forensic biology that could be used by scientists to identify the origin of dust or soil samples found on objects, clothing, or archaeological artifacts.     

Modern pollen studies in the territory of Sagalassos (Southwest Turkey) and their use in the interpretation of a Late Holocene pollen diagram

Modern pollen precipitation studies were carried out on a regional scale in the territory of the classical city of Sagalassos (Southwest Turkey). 57 moss cushions and 7 soil samples from different vegetation types were analysed palynologically. The resulting pollen spectra were grouped into 14 vegetation groups, which were examined using discriminant analysis and principal components analysis. These numerical procedures are applied to display the structure in the data set in a comprehensive way. Some of the modern spectra groups seem to be well-defined, whereas others are difficult to distinguish from each other. After the relationships between the modern pollen spectra had been analysed, the fossil data from a core from the marsh of Gravgaz were added to the data set so that any similarities between fossil and modern spectra could be seen. A joint principal components analysis of the modern and fossil pollen spectra revealed that the pollen spectra from the earliest (ca. 2600-2500 BP; Cal. 830-590 BC till 790-520 BC) and the latest (starting at ca. 1300 BP; Cal. 660-780 AD) pollen assemblage zones have modern counterparts. On the other hand, the pollen spectra from the pollen assemblage zone dominated by Artemisia (ca. 2500-2300 BP; Cal. 790-520 BC till 410-210 BC) and from the pollen assemblage zone that indicated the practice of arboriculture (ca. 2300-1300 BP; Cal. 410-210 BC till 660-780 AD) have no close modern analogues, although individual tabulated pollen percentages revealed some similarities with some modern spectra groups.     

Studies on the peat deposits of the island of Foula,Shetland

Summary

The results of macroscopic and pollen analytical studies on the island of Foula, Shetland, are described and discussed. The tree pollen count never exceeds 11% of the total pollen count in the pollen diagrams. The dominant vegetation of the island during the period which is represented by the peat deposits is shown to have been Ericaceous heath. Macroscopic studies show that although several species of tree did once occur on the island they were never a dominant part of the island's vegetation. It was found impossible to date the peat deposits on the basis of pollen diagrams in view of the extremely low values of the tree pollen curves.     

Comparing pollen spectra from modified Tauber traps and moss samples: examples from a selection of woodlands across Europe

This paper compares pollen spectra derived from modified Tauber traps and moss samples from a selection of woodland types from Bulgaria, the Czech Republic, Georgia, Greece, Poland, Switzerland and Wales. The study examines the representation of individual taxa in the two sampling media and aims to ascertain the duration of pollen deposition captured by a moss. The latter aim was pursued through the calculation of dissimilarity indexes to assess how many years of pollen deposited in a pollen trap yield percentage values that are most similar to those obtained from the moss. The results are broadly scattered; the majority of moss samples being most similar to several years of pollen deposition in the adjacent trap. For a selection of samples, a comparison of the pollen accumulation rate in pollen traps with the pollen concentration in the moss per unit surface indicates that the entrapment and/or preservation of individual pollen types in the moss differ from that in the pollen trap. A comparison of the proportion of different taxa in the moss with the pollen spectrum of 2 years of pollen deposition in the trap also revealed large differences. There is a tendency for bisaccate grains such as Pinus and Picea to have a higher representation in moss than in traps but there is considerable regional variation. The results indicate that pollen proportions from moss samples often represent the pollen deposition of one area over several years. However, bisaccate pollen grains tend to be over-represented in moss samples compared to both pollen traps and, potentially, lake sediments.     

Quantifying ecological change through discriminant analysis: a paleoecological example from the Peruvian Amazon

Question: Can discriminant analysis be used to quantify ecological change? Can fossil pollen data be used as a proxy to quantify moisture availability change through discriminant analysis? Location: Lake Sauce, Amazonian piedmont of Peru. Methods: A linear discriminant function was used to classify taxa found through pollen analysis into wet and dry indicators. The data set was filtered to exclude rare taxa from the analysis. Given that after application of the filter there were more variables (samples) than observations (taxa), the model was “de‐saturated” through simulation of samples based on the existing data set. Results: The inclusion of taxa that have a relative abundance of 1% or more in at least 5% of the samples reduces noise in the data set. Application of discriminant analysis to pollen data gave an error of 18% when classifying taxa by affinity with dry or wet conditions. The inferred moisture availability curve shows consistency with independent proxies from the same core and with identified local and sub‐continental moisture patterns. Conclusions: The method provides a reliable means to reduce a complex paleoecological data set to proportional change in a single pre‐defined variable. The output is a relative scale of change of a defined environmental gradient through time, without reliance on an extensive array of modern analogues. The results appear to provide a comparable quality of information to that of isotopic analysis derived from speleothem or sedimentary records.     

Sexual dimorphism in pollen grain size in cryptically dioecious Thalictrum macrostylum

While several plant species are initially described as androdioecious, upon more thorough investigation, many of these are found to be cryptically dioecious with functionally male flowers and perfect flowers that produce inaperturate pollen or are otherwise functionally female on separate plants. The change in function of pollen produced by perfect flowers opens up the possibility for the evolution of sexual dimorphism in pollen grain size. We found that Thalictrum macrostylum (Ranunculaceae) is cryptically dioecious, and produces apparently inaperturate pollen in perfect flowers. In four field sites throughout North Carolina, inaperturate grains are larger than grains from staminate flowers and also show a greater variance in size. We also found substantial variation in pollen grain size among plants. The sites with lower soil nutrient content also had smaller pollen grains of both types, although local adaptation or genetic drift may also be causing among-site variation.     

Differentiating vegetation types from eastern South American ecosystems based on modern and subfossil pollen samples: evaluating modern analogues

In south and southeast Brazil land use caused profound changes in natural vegetation and consequently the value of the pollen composition in surface samples as modern analogues. In order to test the capability of modern pollen to represent the natural vegetation, three different time slices of pollen assemblages from 27 sites spread over southern and south-eastern Brazil and the Misiones Province in Argentina were collated. Pollen samples from the pre-colonization period, selected from the moment just before abrupt changes evidenced on pollen diagrams caused by the colonization process throughout the last 500 years, were assumed to represent the natural vegetation conditions once the climate remained stable within this period. Thus we used pre-colonization assemblages to compare with modern samples to explore to what extent surface pollen may be biased in representing the natural vegetation types. Furthermore, to compare man made vegetation change to climate driven vegetation change we also compared to these 20 out of 27 samples dated to 3,000 years bp. Guided by ordination and cluster analysis, but using abundance thresholds of indicator taxa we classified the pollen spectra of pre-colonization time into seven groups consistent with the main vegetation types in the area. Ordination analyses capture the differentiation between grassland and forested vegetation and between tropical and subtropical vegetation types. Comparing the pre-colonization with other time slices we observed that based on Poaceae abundance, 70 and 85 % respectively of sites from 3,000 bp and modern assemblages maintained their classification. Based on finer classification criteria these values decreased to 40 and 52 % respectively. Square chord dissimilarity indicates that colonization impact altered the pollen composition as strongly as 3,000 years of climate induced vegetation change. The surface samples still represent important environmental gradients; however, their use as modern analogue requires careful treatment and eventual exclusion of highly impacted sites.     

Palynology and systematics of morinaceae

Pollen grains from all thirteen species of the three genera to be recognised in a forthcoming revision of the Morinaceae, Acanthocalyx, Cryptothladia and Morina, have been investigated by light and scanning electron microscopy. Fresh pollen of M. longifolia has also been studied by light, scanning electron and transmission electron microscopy. Three main pollen types are described and a key provided for their identification. Each pollen type occurs throughout a genus. Further division of two of these pollen types enables groups of species to be recognised. Functional aspects of the pollen are discussed, especially their unique pre-germinative processes. A cladistic analysis of pollen characters provides a hypothesis for their evalution and supports the classification proposed in the recent revision.     

Modern pollen and vegetation relationships in northeastern Patagonia (Golfo San Matías,Río Negro)

The understanding of modern pollen is a critical component of palaeoecological research. The pollen assemblages reflect general patterns in vegetation distribution; however, pollen representation is biased by several factors such as differences in pollen production, dispersal and preservation. Therefore, this relationship cannot be applied directly in pollen records of the past. The aim is to study the relationship between modern pollen and vegetation and to apply this new information on the interpretation of Holocene pollen records. Classification of the vegetation into groups corresponding to different geomorphological units was carried out by cluster analysis. Discriminant analysis was applied on the surface samples to test if different vegetation types could be distinguished by their pollen assemblages. To evaluate the relationship between pollen assemblages and vegetation types, association (A), under-representation (U) and over-representation (O) indexes were calculated for all present taxa in both plant and pollen dataset. The main vegetation types are reflected in pollen assemblages but with greater differences in the proportions of Poaceae, Hyalis argentea, Chenopodiaceae, Asteraceae subf. Asteroideae and Larrea divaricata. Association and representation indexes provided information related to the production rate and pollen dispersal. This study helps to interpret Holocene vegetation and environmental changes from fossil pollen records of the study area.     

The analysis of aquatic vegetation on the Atherton Tableland,north-east Queensland,Australia

The aquatic vegetation of three sites on the Atherton Tableland is described and analysed with the aid of numerical classifications. Despite major physiognomic differences in the vegetation between sites, four floristic groups are recognized which can be related to major habitat types. Water depth and seasonal fluctuations in water level are suggested as the main factors controlling vegetation distributions in the absence of disturbance by biotic agencies. Species characteristic of particular aquatic communities are identified and these could prove useful in the recognition of hydroseral stages in pollen diagrams constructed from these sites and in the determination of past lake levels.     

Dominant Pollen Types Recovered From commercial Louisiana honeys

Microscopical pollen analyses of 54 commercial honey samples collected from the major beekeeping areas of Louisiana during 1967–68 showed six dominant pollen types (a dominant type considered as one contributing over 45% of the total grains counted per sample and denoting a unifloral honey). The dominant pollen types and the “ bee plant ” species associated with each pollen type are identified and described. The pollen types are illustrated with light photomicrographs. The pollen types are in order of importance:Trifolium repens, white clover;Rubus spp., blackberry and/or dewberry;Berchemia scandens, rattan vine;Salix spp., willow; Asteraceae, Sunflower family; and Sapiumsebiferum,Chinese tallow tree. White clover and willow were the largest unifloral honey producers in a region including the floodplain and delta of the Mississippi River, and the floodplain of the Red River (the most productive beekeeping area of Louisiana); blackberry and/or dewberry were most significant in the longleaf pine flat woods and mixed hardwoods in the uplands section on the east side of the Mississippi River; rattan vine was most important in west-central Louisiana in an area consisting originally of pine-oak-hickory uplands and longleaf pine flat woods; white clover appeared most important in the prairie region of southwest Louisiana.     

Do moss samples,pollen traps and modern lake sediments all collect pollen in the same way? A comparison from the forest limit area of northernmost Europe

Moss polsters, pollen traps and lake surface sediment samples are commonly used as climate calibration data or as modern analogues for reconstructing vegetation from fossil profiles, but the differences in pollen content between these media have received little attention. This study aims to analyse how the three media differ in reflecting individual vegetation types and spatial differences in vegetation. 119 modern samples (64 moss polsters, 37 lake surface sediment samples and 18 pollen traps from which a collection was made annually) were taken from northern Fennoscandia and the Kola Peninsula as a broad transect crossing the northernmost forest limits of Betula pubescens ssp. czerepanovii (mountain birch), Pinus sylvestris (Scots pine) and Picea abies (Norway spruce). The pollen assemblages from these samples were compared with the surrounding vegetation visually and via PCA (principle components analysis) and cluster analysis. Both comparisons allow a correct distinction between pollen assemblages of arctic/alpine heath, mountain birch dominated areas, and boreal coniferous forests. The differences between the vegetation zones are stronger than the differences between the sampling media. Nevertheless, lake sediment samples from the mountain birch woodland zone tend to overestimate pine and underestimate birch. Pollen traps are biased towards lower tree pollen percentages and higher values of shrubs, herbs and Cyperaceae. This bias is especially strong in traps that have missing years in the data. Irrespective of the vegetation zone, pollen traps tend to have lower Pinus pollen percentages than in the adjacent moss polsters.