Fern Communities Research Articles

Fern ecological implications from the Lower Jurassic in Western Hubei, China

The Lower Jurassic Hsiangchi Formation in western Hubei, China is well known for its abundant and diverse fossil ferns, including Marattiaceae, Osmundaceae, Matoniaceae, Dipteridaceae and Dicksoniaceae. Through recent collections and investigation of the fossil plants in this area, an autochthonous/hypoautochthonous fern community has been recognised from the upper part of the Hsiangchi Formation in Zigui, Hubei. This community is dominated by the matoniaceous ferns of the genus Phlebopteris; Dipteridaceous ferns mainly characterised by Dictyophyllum rank second in abundance. Marattiaceae ( Marattia) and Osmundaceae ( Todites and Cladophlebis) are often dispersed spatially among the dominant ferns, whereas the small and slender herbaceous Dicksoniaceae, characterised by Coniopteris, are sparsely distributed within the community. This fern community colonised the fluviatile peat-forming environment and indicates a tropical to subtropical climate with warm and humid conditions, which is favourable for the peat accumulation. It is also a representative fern community recognised from the Southern Floristic Province in China during late Early Jurassic period.

Assessing New Zealand fern diversity from spatial predictions of species assemblages

The utility of explicit spatial predictions for biodiversity assessment is investigated with New Zealand fern flora. Distributions of 43 species were modelled from climatic and landform variables and predicted across New Zealand using generalised additive models (GAM). An original package of functions called generalised regression analysis and spatial prediction (GRASP) was developed to perform the analyses. On average, for the 43 models, the contributions of environmental variables indicate that mean annual temperature is the most important factor at this broad regional scale. Both annual solar radiation and its seasonality had higher correlations than temperature seasonality. Measures of water availability such as ratio of rainfall to potential evapotranspiration, air saturation deficit and soil water deficit presented significant contributions. Lithology was a better predictor than slope and drainage. These results are similar to those obtained from analyses of the distributions of New Zealand tree species and are consistent with the hypothesis that both tree and fern diversity are highest on sites conducive to high productivity. In order to identify hotspots of fern diversity, spatial predictions of individual species were summed up. The resulting map gave a very similar result to the direct prediction of their corresponding richness (number of species by plot out of 43 spp.). As a consequence, and where individual species models were not all available, the number of species within different species assemblages was directly modelled. Predicted richness hotspots of total species (out of 122 spp.), selected species (out of 43 and 21 spp.) and common species (out of 23 spp.) present very similar spatial patterns and are highly correlated. Richness of uncommon species (out of 39 spp.) was also accurately predicted, but presented a different spatial pattern. The number of rare species (out of 60 spp.) was not correctly modelled. Even though the lack of data for rare species clearly limits the application of this approach, fern community composition of more common species can be partially reconstructed from individual species predictions. This case study offers therefore a consistent approach not only for biodiversity hotspots identification, but also for setting targets to biodiversity assessment and restoration programs.

A palynological record of a secondary succession after fire in the Gran Sabana, Venezuela

Fire has been considered one of the most important factors in the expansion of savannas in the Gran Sabana region. In Urué, an important fire event that occurred before 1.6 kyr BP led to the replacement of ‘primary’ forests by savannas and morichales (monospecific communities of the palm Mauritia). In the present work, the secondary succession after fire is reconstructed by palynological analysis of a previously dated clay core, and the results are compared with those from studies based on present-day ecosystems. Charcoal analysis is used to infer fire incidence and surface samples are used as modern analogues. The secondary succession is subdivided into seven seral stages: open secondary forests, helechal or dense fern community, transitional savanna, wet savanna with morichales, treeless savanna, wet savanna with morichales, and treeless savanna. Fires were common at the beginning, but climate constituted the main successional control from the transitional savanna stage onwards. The process is characterised by a continuous impoverishment of taxa, but there was a steady increase in Mauritia, due to its ability to colonise new habitats created by disturbances. The conclusions of this palynological reconstruction show good correspondence with present-day studies on fire ecology. Copyright © 1999 John Wiley & Sons, Ltd.

Abundance of Viable Hay-Scented Fern Spores Germinated from Hardwood Forest Soils at Various Distances from a Source

Abundance of Viable Hay-Scented Fern Spores Germinated from Hardwood Forest Soils at Various Distances from a Source

Species Composition and Structure of Epiphytic Fern Community on Oil Palm Trunks in Malay Archipelago.

Fern species composition and fern community were observed at oil palm plantation and adjacent natural forest near Kuala Lumpur in Malaysia, with respect to tree size and structure. Sixteen fern species were found on oil palm trunks. Six species of Nephrolepis biserrata, Davalia denticulata, Vittaria ensiformis,Asplenium nidus,A. glaucophyllum andA. longissimum are common on various sizes of oil palms (1-8.5m height). Early invasion of fern community on oil palm trunks is conducted by N. biserratas and D. denticulata. Microhabitat of N. biserrata seems to be a sunny site while that of V. ensiformis a shade site on oil palm trunk. Fern species composition and frequency change during oil palm development and with different height. A. nidus sometimes (19% of tall and 3% of all trees) occurs in natural forest; and invades on oil palms exceeding 4m height. A. nidus seem to be a micro-ecosystem for some insects. Such vertical vegetation cover by epiphytic ferns on tree trunk seems to contribute a high phytodiversity at narrow site and insect biodiversity as well as canopy in tropical rain forest.

Some vicariating plant communities in Brazil, Malaysia and Singapore

Dune communities with dominant Ipomoea pes-caprae (coastal strand vegetation) and communities with dominant Gleicheiniaceae (fern communities of forest borderlines) were distinguished and comparatively studied in Brazil, Malaysia and Singapore, and compared with similar stands around the world. A total of 71 vegetation releves was collected. In coastal dune vegetation, the new associations Ipomoeo pediscaprae-Sporoboletum virginicae was distinguished for Brazil, and the vicariant Wedelio biflorae-Ipomoeetum pedis-caprae is described from Malaysia and Singapore. The vegetation of forest borderlines is characterized in Brazil by the new association Lycopodio cernuui-Gleicheinietum bifidae, which was subdivided in two subassociations (droseretosum capillaris and typicum). A physiognomically similar community was detected and described in Malaysia and Singapore as the new association Lycopodio cernuui-Dicranopteridetum curranii with two subassociations (typicum and dicranopteridetosum linearis).

Observed Use of Forage and Plant Communities by Black-Tailed Deer

During 1964, 6,746 observations were made of known numbers of black-tailed deer (Odocoileus hemionus columbianus) within an enclosure on the Cedar Creek watershed within the Tillamook Burn, Oregon. These observations provide a basis of insight into the deer's use of vegetation within the enclosure. The interpretation centers around feeding and bedding behavior in relation to forage availability and plant communities. Indices of preference by deer for plant communities showed a spatial and seasonal nonrandom distribution of deer. Red huckleberry (Vaccinium parvifolium) was the principal browse plant; vine maple (Acer circinatum) and red alder (Alnus rubra) were unimportant as browse. Browsing of Douglas fir (Pseudotsuga menziesii) began with the first snow. Sightings of deer in the vine maple (Acer circinatum/Polystichum munitum) community were high every month. Deer presence in the huckleberry (Vaccinium parvifolium/Gaultheria shallon) community increased in late winter, peaked in May, and declined the rest of the year. In the big-leafed maple (Acer macrophyllum/Symphoricarpos mollis) community, deer sightings increased in late winter, declined in March and April, increased during the summer, and peaked in October. Relatively few deer were observed in the bracken fern (Pteridium aquilinum/Lotus crassifolius) and thimbleberry (Rubus parviflorus/Trientalis latifolia) communities. Occurrence of deer in the alder (Alnus rubra/Rubus parviflorus) community was highest in spring and fall. This study relates direct observations on feeding and bedding behavior of blacktailed deer to measured environment within an enclosure on the Cedar Creek watershed within the Tillamook Burn, Oregon. Interpretation of the data seeks insight into the deer's use of vegetation. Previous studies on the Burn were not based on direct observations of deer (Einarsen 1946, Chatelain 1947, Lightfoot and Hines 1960, and Crouch 1966). Acknowledgment is made to Dr. Thomas G. Scott, Department of Fisheries and Wildlife, Oregon State University; to Dr. Arthur W. Bailey, Weed Science and Crop Ecology, University of Alberta; and to William W. Hines, Division of Wildlife Research, Oregon State Game Commission, for critical reading of the manuscript. THE STUDY ENCLOSURE The study enclosure is in the Coast Range Mountains of northwestern Oregon, approximately 18 miles inland from Tillamook, on the Cedar Creek watershed in that portion of Tillamook County known as the Tillamook Burn. The elevation within the enclosure ranges from 800 to about 2,000 ft, measured from mean sea level. The enclosure is west of the summit, and it receives a mean annual precipitation of 130 inches, based on a 25-year average at Glenora 3 miles east of the study area (U. S. Weather Bureau 1936). Maritime influences result in cool, wet winters with prolonged snow cover sufficient to restrict deer travel at elevations above 2,000 ft. The summers are usually dry and hot, but small, permanent streams occur in the study

A Fern Community in Pennsylvania

A Fern Community in Pennsylvania

Some Noteworthy Fern Communities of Arkansas

American Ferns (2). 1. The region around Hot Springs National Park, Garland County, is particularly rich in ferns. Dr. F. J. Scully, 1937, (1), presented a list of 18 ferns which he had found in that vicinity and in 1939 (3) published in mimeographed form a bulletin of the ferns of that region as Number 5 of the local Natural History Journal in which he lists 26 different species and varieties. This is a very nice and reasonably complete list of the ferns of that region. To it may be added five other names. Adiantum capillus-veneris L. has been found in one of the caves near Hot Springs by Mr. E. J. Palmer. Athyrium asplenioides f. subtripinnatum Butters has been found with the typical form of the species in various situations in and near the region. Dr. Scully lists Cystopteris fragilis var. protrusa Weatherby, but does not mention the typical form of the species. Collections of the latter have been made in nearby Magnet Cove, and in all probability it could be found at various other stations.