Stages Of Vegetation Succession Research Articles

Physical and chemical dynamics of temporary ponds on a calcareous plateau in Thuringia, Germany

Temporary ponds on calcareous hills surrounding the town of Jena (Thuringia, Germany) were investigated for one year with regard to the dynamics of their physical and chemical characteristics. The present paper concerns selected data from a vertical, diurnal and seasonal sampling program including the major physical and chemical factors. The ponds were also investigated during the dry period in summer, and in winter when they are covered with ice. A description of the emergent vegetation is also given and used for a classification of the ponds. Most of the factors investigated show strong diurnal and seasonal trends and some, — despite all ponds being shallow — were vertically stratified. The measurements emphasize that in small ponds both seasonal and diurnal changes in water-chemistry, as well as changes in vertical gradients, are affected by the vegetation succession stage, and consequently by the temporary character of the ponds. Protection and management of these ponds often involves dredging and therefore the short time response of dredging is discussed.

Diversity of soil macro-invertebrates in grasslands under restoration succession

In grasslands under restoration succession, the effect of nutrient impoverishment on the vegetation has been intensively studied. The invertebrate soil animal community has, however, rarely been studied under such conditions. We hypothesised that a plant community in nutrient-poor grasslands supports fewer macro-invertebrate individuals than richer grasslands. We also hypothesised that the composition of the macro-arthropod community is specific for a certain stage of vegetation succession, i.e. nutrient impoverishment. A detailed sampling programme was carried out in four grasslands under restoration succession. The time since last fertilisation differed for these four grasslands (7, 11, 24 and 29 years). The lowest total number of individuals in different taxonomic groups of macro-invertebrates was found in the most impoverished field in the majority of cases. Analysis of the data set for all specimens identified to order or family level with a canonical correspondence analysis resulted in a pattern not related to successional stage. The same holds when the species composition of the ground beetles was analysed separately. Short-term abiotic factors explained a significant part of the variation in both analyses. With the same multivariate analysis, however, the adult weevils, identified to species level, showed a clear relation with nutrient status of the grasslands.

Habitat Selection and Habitat Use by the Bog Turtle (Clemmys muhlenbergii) in Maryland

Habitat selection of 50 bog turtles (Clemmys muhlenbergii) was studied at two sites in Harford County, Maryland, from April 1996 to August 1997. These sites differ in size, amount of grazing, and stage of vegetative succession. In addition, one of the sites was studied intensively 20 years ago. Turtle movements were monitored using radiotelemetry: Individuals were located twice a week during the active season and once a month during hibernation to assess habitat selection and seasonal changes in habitat use. Vegetative, soil, and water characteristics were recorded in 0.25-m2 quadrats placed at turtle locations and stratified random locations throughout the study areas. Turtles selected sedges and rushes and other low-lying her- baceous plants. They avoided some woody plants (alders, grapes, and berries) and an exotic plant (Japanese honeysuckle, Lonicera japonica) that may gradually eliminate typical wetland vegetation and produce a closed canopy. Management practices, such as moderate animal grazing and winter burns, will help retard plant succession and provide more open habitat. Concern about the long-term persistence of the bog turtle (Clemmys muhlenbergii) has result- ed in federal listing of the bog turtle as a threat- ened species (U.S. Fish and Wildlife Service,

Home Range and Movements of the Bog Turtle (Clemmys muhlenbergii) in Maryland

We studied the home ranges and movements of 50 bog turtles (Clemmys muhlenbergii) at two sites in Harford County, Maryland, from April 1996 to August 1997. These sites differ in size, land use, and stage of vegetative succession. One site (HA406) was intensively studied 17 years ago. Using radiotelemetry, we located turtles two times a week during the active season. The 95% Adaptive Kernel home range esti- mator was used to determine home ranges. Individual turtle home ranges varied from 0.003 ha to 3.12 ha with considerable variation between sites and years. There were no significant differences in home range size or movements between sexes or seasons (mating vs. postmating), although males had larger home ranges during the mating season. Many turtles at site HA406 had home ranges far larger than the average home range reported in the earlier study. An expansion in turtle home ranges may suggest a decrease in site quality resulting from invasion of multiflora rose. Some turtles moved out of their wetlands and across barriers, a finding that demonstrates the importance of appropriate habitat in corridors that connect popu- lations.

Seasonal and successional dietary shifts of two sympatric rodents in coastal heathland: A possible mechanism for coexistence

Abstract Using microscopic analysis of faecal pellets, we compared the seasonal and successional patterns of food resource use of two Australian native rodents, the eastern chestnut mouse (Pseudomys gracilicaudatus) and the swamp rat (Rattus lutreolus) in a coastal heathland at Myall Lakes National Park, New South Wales. Using the Mantel test, the diets of the two mammal species were significantly different in autumn and winter but not in spring and summer. Further, the two species showed differential use of resources at the young and middle‐aged stages of vegetation succession following fire. The mean dietary overlaps for pairs of individuals between the two species were relatively high in all seasons and successional stages, but they were significantly lower than those for pairs of individuals within each species in autumn and winter, and at the young and middle successional stages. Analysis of dietary niche position (γ) and breadth (β) showed lower γ and larger β for P. gracilicaudatus than for R. lutreolus, confirming previous observations that R. lutreolus is more specialized, and less opportunistic in diet than P. gracilicaudatus. Overall, the dietary separations of the two species were less marked in canonical space than they were for specific seasons and successional stages. These results, together with previous studies, indirectly suggest that while these two mammal species may be partitioning diet in autumn and winter in the middle stages, for spring and summer in the old successional stage they might need to partition habitats to facilitate their coexistence. Our results indicate that the local community is more dynamic and complex than previously thought and that other mechanisms of coexistence (e.g. temporal rotation of food resources) may be operating rather than traditional habitat and diet separation.

Competitive effects of Rattus lutreolus presence on food resource use by Pseudomys gracilicaudatus

Abstract We examined faecal samples of the eastern chestnut mouse (Pseudomys gracilicaudatus) that were collected during a removal experiment conducted in a coastal heathland at Myall Lakes National Park to see whether removal of the swamp rat (Rattus lutreolus) had any effects on food resource use by P. gracilicaudatus. The results showed that, at the young successional stage of vegetation (1. 5 years since last fire), the diet of P. gracilicaudatus changed significantly after the number of R. lutreolus was significantly reduced on the experimental sites. Two months after the removal treatment was terminated there were no significant differences between the control and experimental sites. Factor analysis showed that seasonal change was significant for all three food factors on the control sites, whereas on experimental sites the change was significant only for factor 1. At the middle successional stage (3.5 years since last fire), P. gracilicaudatus showed relatively small seasonal changes on both control and experimental sites, and significant differences between the control and experimental sites did not occur until after the removal manipulation was completed, showing a delayed response. Comparisons of the young and the middle successional stages on both control and experimental sites showed that P. gracilicaudatus used proportionally different food when R. lutreolus was present, but consumed similar food when R. lutreolus was removed. These results suggest that R. lutreolus might have restricted the access of P. gracilicaudatus to better microhabitats, and hence to a better food supply. The ecological implication of these results is that the interpretation of observed population and community patterns must take into account the direct effects of species interactions.

Mid-miocene post-disturbance vegetation dynamics and the emergence of cold desert/steppe vegetation in the northern intermountain region

The mesic broad-leaved and coniferous forests of the Middle Miocene of the northern Intermountain region of the United States contrast strongly with the semi-arid shrub/grassland steppe vegetation that comprises the extant vegetation. This contrast is a consequence of the progressive development of a regional rain shadow, beginning in the Late Miocene, coincident with the uplift of the Cascades to the west. It is generally assumed that the emergence of the extant vegetation was a consequence of a combination of in situ evolution of taxa in response to moisture and thermal stress and the immigration of taxa already adapted to such stressful environments. The study of stratigraphically sequential successional vegetation stages in a number of Middle Miocene floras in the northern Great Basin suggest that many elements of the extant vegetation of the region were already present as taxa adapted to the several characteristic environmental conditions of landscapes affected by volcanic disturbance.The Middle Miocene “climax” vegetation of southeastern Oregon and southwestern and southcentral Idaho, documented by paleobotanical and palynological data from floras such as Stinking Water (Oregon), Succor Creek (Oregon-Idaho), and Trapper Creek (Idaho), was a complex mosaic of vegetation types comprised of broad-leaved evergreen, mixed mesophytic, and mixed coniferous forest elements. These floras are preserved in volcaniclastic sediments. Palynological analysis of sequential samples from overlying strata indicate that the bulk of the sedimentary record at each of these sites records vegetation in varying stages of recovery following destruction of forests by local volcanism. The earliest seral stages following such events are characterized by taxa, including Artemisia, Sarcobatus, and other Malvaceae, Chenopodiaceae, Amaranthaceae, Compositae, and Gramineae that represent important components of the extant vegetation of the region.An ash-covered landscape, denuded of forest cover, is a highly stressful environment. Ash forms an edaphically dry and nutrient-poor substrate and such sites would be exposed to a significantly greater range of annual temperatures and much greater exposure than forested sites. Grasses, forbs, and shrubs that evolved in ways that permitted the colonization of such landscapes would be preadapted to the drier and less equable climates that would accompany the development of the Cascadian rain shadow. In addition, such successional areas also supported a mammalian fauna dominated by grazers in contrast to the browsing-dominated fauna of the climax forest mosaic. It would thus appear that the post-disturbance grass/forb/shrub communities provided an evolutionary proving ground for mammalian niches that now dominate the extant cold desert/steppe biome.

The use of a GIS in assessing the impacts of sea level rise on nature conservation along the Dutch coast: 1990–2090

The Dutch coastline is expected to change considerably during the next 100 years. Erosion will prevail, although accretion will occur locally. To establish a new policy for coastal defence management an integrated policy analysis study was performed. Major dune functions (nature conservation, recreation, public drinking water supply, housing and industry) have been inventarized by using a Geographic Information System. This study reports on the part of the analysis which takes nature conservation interests into account. Evaluation of nature interests has been based on the criteria: rarity and diversity of plant species c.q. vegetation types, succession stage, and completeness. This results in a classification of nature into five classes, based on abiotic as well as biotic characteristics of the landscape. Losses of nature interests were studied due to: loss of land because of shoreline retreat, to remodelling of the foredune ridge, and to changes of the dune groundwater level. An evaluation is given of the methods used to assess ecological impacts. Ideas are presented for further research on the prediction of ecological impacts and on coastline management which combines traditional coastal defence with nature conservation.

REMOTE SENSING OF HUMAN MODIFICATIONS IN TAIGA FORESTS

The authors elaborate a methodology for the identification of successional vegetation stages in areas cleared for timber in the northern forests of the USSR and for forecasting possible variants of their evolution. The technique was tested using 1:200,000-scale space imagery, 1:15,000-scale aerial photography, and coordinated ground studies along a 5 X 15 km transect encompassing a variety of climax and successional plant communities in an area of commercial timber operations. Maps of successional communities emerging under different natural conditions within the experiment study area are presented. Translated by Larry Richardson, Glendale, CA 91202 from: L. N. Vasil'yev, ed., Kosmicheskiye metody izucheniya biosfery [Remote Sensing Methods in the Study of the Biosphere]. Moscow: Nauka, 1990, pp. 51–59.

Ökologische Untersuchungen auf einer auf metallhaltigem Boden entwickelten Wiese

AbstractEcological Investigation of a Meadow Developed on a Metal‐Rich SoilThe floristic structure of a meadow over a copper‐rich soil was studied, and four different stages of vegetation succession were described. The following species dominate over the different stages: Minuartia verna, Thymus sibthorpii, Rumex acetosella and Chrysopogon gryllus. Soil analysis showed that the most undeveloped soil of the Minuartia stage exhibits the highest concentration of Cu and of twelve other elements, while the mature soil of the Chrysopogon stage exhibits the highest concentrations of Al, Ca, Na and Ni.An inverse relationship was found between the concentrations of Cu in the soil and the number of species in the forty sampling quadrats. Plant analysis showed that Minuartia verna and Rumex acetosella accumulate more copper in their tissues than the other two dominant species.

Short-term avifaunal turnover in small even-aged forest habitats

Turnover rates of avian communities during three consecutive breeding seasons were compared among six habitats created for ruffed grouse Bonasa umbellus management via forest clearcutting. Habitat size had minimal effect on turnover rates because each habitat selected for study consisted of 3 ha (three 1-ha stands). Degree of isolation of habitats also did not affect turnover of species composition. However, stage of vegetative succession presumably resulted in high turnover rates in the youngest clearcut habitat. Rates declined in clearcut oak habitat compared to clearcut aspen habitat of similar age. In mature aspen habitat on the treated (managed) sector of the study area, rates were affected by proximity to young clearcut habitats. The occasional occurrence of three uncommon species intolerant of forest fragmentation combined with relatively high species richness were factors influencing high turnover rates in habitat on the control (uncut) sector.

Slugs as Generalist Herbivores: Tests of Three Hypotheses on Plant Choices

Three hypotheses explaining plant choices by generalist herbivores were tested by measuring leaf acceptabilities to three slug species, each of which lives in a different successional stage of vegetation. The acceptabilities of 61 plant species were determined in laboratory feeding trials by offering individual slugs leaf discs of a test and a control plant (lettuce) and recording consumption. The plant—defense hypothesis, that plants predictable to herbivores should have greater defense commitments and be less acceptable than unpredictable plants, was contradicted when predictability was judged by successional status. The acceptabilities of climax forest plants and early—successional plants were not significantly different for any of the three slug species. This was also true within woody species and within herbs. However, the plant—defense hypothesis was supported when predictability was measured as seasonal leaf persistence. As seasonal leaf persistence of forest herbs increased, acceptability declined. As alternative explanation based on growth rate is discussed. Alternatively, feeding choices were hypothesized to be determined by adaptations of these generalist herbivores to plants available in their local habitats (the herbivore—adaptation hypothesis). Because slugs are generally restricted to feeding on herbs, woody species were predicted to be less acceptable than herbs and this was strongly supported. Tree leaves were seldom eaten by any of the three slug species. In addition, each slug preferred a few herbaceous species unique to its specific habitat, suggesting local adaptation, but the actual mechanism remains to be determined. If both plants and slugs are coevolving, plant choices would depend upon where we examine the coevolutionary spiral, but they should be unique for each slug species as it coevolves with local plants (the coevolution hypothesis). In these tests, feeding responses of the three slug species were significantly positively correlated and unique responses were not evident. These hypotheses depend upon the probabilities of plant—herbivore encounters, which can be difficult to determine. For these slug species stem heights of only 10 cm acted as effective feeding barriers. Plants were vulnerable during emergence, but they can escape slugs if they emerge early in the spring. Because such subtle factors may determine encounter rates, predictions of feeding choices and plant defenses may be difficult to make. Specific adaptations may not be evident from these tests of general patterns. Field observations suggest that these introduced slug species are exerting significant selective pressure on the morphologies, phenologies, and defenses of native plants.

Characteristics of bird communities on surface mine lands in Pennsylvania

A variety of species was observed as either visitors, permanent, or summer residents on surface mines with different ecological adaptations. Passerine species were the most prevalent of the 25 families represented. Bird communities as well as individual species were correlated with the structure and species of vegetation on the mines. The composition of the bird communities changed in response to successional vegetation stages from grassland to forest communities.

Bird population changes after clearance of deciduous scrub

Clearance of deciduous scrub by cutting in Valdres, South Norway, or by spraying with 2,4,5-T, was followed by a 30% reduction in the number of bird territories in the following spring. The recorded changes were related to differing preferences of the bird species for successional stages of vegetation, i.e. the pioneer species increased while those which prefer old forest were heavily reduced. Four years later the bird population as a whole had increased in the cut area, but not in the sprayed area. The results are discussed in relation to changes in the invertebrate fauna and the vegetation of the habitat. A total of 314 single surveys (1970–73 and 1976) were made in five census plots which covered a total area of 113 ha comprising both clearings and old spruce ( Picea abies) forest. The analysis is based on counts of singing males and estimates of territories held.

Landscape Development, Forest Fires, and Wilderness Management

Landscape Development, Forest Fires, and Wilderness Management

Plant Succession on Dune Sands in Fremont County, Idaho

Active sand dunes in Fremont County, Idaho, move northeastward at an approximate rate of 3 m/year. Sand deposits, continuous in some areas for several kilometers, extend to windward from the dunes in the form of long ridges, parallel to the wind direction. Five successional vegetation stages, distinct as to dominant species, appear on the deposits as belts transverse to the direction of dune movement. Elymus flavascens and Psoralea lanceolata dominate the pioneer stage, which lasts up to about 30 years. The second stage, dominated by Chrysothamnus nauseosus with an understory of the two pioneer species, lasts from 10 to 70 years. Purshia tridentata then replaces much of the C. nauseosus to form a third stage lasting for about 50 to 70 years. Dominant species in the fourth stage are Artemisia tridentata, P. tridentata, and in many areas Prunus virginiana var. demissa. Very little A. tridentata is found after 700 to 900 years of stabilization, and the final and most extensive stage on deep sand is dominated by dense P. tridentata with clumps of P. virginiana var. demissa. Vegetation on old, shallow deposits has characteristics of both that on deep sand and the Artemisia/bunchgrass type on the surrounding native soil. Fields that were plowed and abandoned in the early 1930's now support dense stands of Stipa comata. The presence of dense shrub stands on dunes now topographically sheltered by the wind, but not on migrating dunes, indicates that establishment of a species on sand depends on relative site stability rather than on soil nutrient buildup caused by previous vegetation. Deep sand holds moisture available to plants throughout the dry part of the growing season while the native soil does not, which probably accounts for the greater shrub density and vigor on sand.

Lichens of the Mendenhall Valley, Southeastern Alaska

Ninety-three species are reported from the Mendenhall Valley near Juneau and 35 species from nunataks in the Juneau ice field. The lichens of Alaska still present a challenge because the area is so large and until recently so little had been done with the flora. The present paper reports collections from a limited area in southeastern Alaska. During the summer of 1963, from June to August, I was temporarily employed by the U.S. Forest Service and worked in the Mendenhall Glacier area of the North Tongass National Forest. During that time the Forest Service provided me the 6pportunity to collect in the area. 1 I thank Dr. Aino Henssen who checked many of the determinations, Dr. I. M. Lamb who identified my Stereocaula, Dr. Grace Howard who identified the Ochrolechia, Dr. John W. Thomson for some determinations including those of the crustose lichens from the nunataks, and Drs. Hildur Krog and Teuvo Ahti for several identifications or verifications. 2 Department of Biology, Howard College, Birmingham, Alabama 35209. This content downloaded from 157.55.39.35 on Mon, 29 Aug 2016 06:23:49 UTC All use subject to http://about.jstor.org/terms 222 THE BRYOLOGIST [Volume 68 The Mendenhall Glacier is located about 13 miles northwest of Juneau. The study area included the region from immediately adjacent to the terminus of the glacier outward to sea level. The collection areas more distant from the glacier were outside the boundaries of the National Forest. Physiographically, the area is dominated by the Mendenhall Glacier which extends from the Juneau ice field southward 12 miles, to its terminus in the Mendenhall Valley. The maximum of the present glacier is considered to have been reached about 200 years ago and to have extended about two miles beyond its present terminus. Numerous evidences of recession are present in the valley. Morainal ridges and flats are fairly well covered by successional vegetation stages, depending upon their age. Glacial erratic bouldels are scattered throughout the area. The terminus of the glacier is bounded on the east by Bullard Mountain (4,225 ft) and on the west and northwest by McGinnis Mountain (4,228 ft) and Stroller White Mountain (5,150 ft). South of the glacier, Mendenhall Lake, a meltwater body, covers an area approximately one mile square. An outcropping of a schist bedrock crosses under the lake and is exposed on each side immediately adjacent to the glacier, as well as at one point on the glacial face. This bedrock is the material most recently exposed by the recession of the glacier. From here the valley gradually broadens out toward the southwest to terminate in the Gastineau Channel. Extending northwestward from the main valley is the Montana Creek area which provided muskeg and mature forest collecting sites. Elevation in the region of study varied from about 500 feet to sea level. Most collections were made at about 100 feet (Fig. 1). The climate of the Mendenhall Valley is under the maritime influences which prevail along all of the coastal areas of southeastern Alaska. Thus, the area has abundant precipitation, little sunshine, and generally moderate temperatures. Comparison of weather records from the Juneau airport at the end of the Mendenhall Valley and from the city of Juneau itself indicate that there can be considerable climatic difference in locations only a few miles apart. The average length of the growing season in the city of Juneau is 177 days while at the airport it is 146 days. Total precipitation at the Juneau airport has reached a high of 64.06 inches while at Juneau yearly amounts have reached 119.48 inches. The mean precipitation at the airport over the period 1943-1961 is 54.56 inches. Snowfall is frequently heavy in the Juneau area varying from 32 inches in 1940-41 to a record of 246.3 inches as the annual total for the year 1917-1918 (Anderson 1955; Weather Bureau, U.S. Dept. of Commerce 1961). Four successional stages are evident in the Mendenhall Valley. The natural vegetation is a hemlock-spruce forest with the dominant plants being Tsuga heterophylla and Picea sitchensis. Successional stages leading toward this climax originate with an initial lichen-moss community. As evidenced on the most recently exposed bedrock, This content downloaded from 157.55.39.35 on Mon, 29 Aug 2016 06:23:49 UTC All use subject to http://about.jstor.org/terms 1965] MCCULLOUGH: LICHENS FROM ALASKA 223 I -;??/ \,? ?~p~ a r

Relation of Merriam Kangaroo Rats to Range Vegetation in Southern Arizona

Livestock grazing practices and climatic variations are known to affect the character and abundance of range vegetation. Fluctuations in kinds and numbers of small mammals often accompany these vegetal changes. Certain animal species increase while others decrease as vegetation retrogresses from climax conditions (Phillips, '36). Ground squirrel populations are smaller on ranges protected from livestock grazing (Linsdale, '46). Some animal communities even seem to be dependent upon vegetation remaining at a sub-climax level (Taylor et al., '35). In some instances, small mammal populations are suspected of affecting floristic composition. Arnold ('42) suggests that a range may be held in a lower successional stage of vegetation, once that level is reached, by the presence of small native herbivores alone. Bond ('45) expresses the opinion that recovery of desired range vegetation might be enhanced by the differential feeding pressure of certain rodents. This study concerns the effect of the behavior and abundance of Merriam kangaroo rat (Dipodomys merriami merriami Mearns) upon the character and condition of range vegetation.