Showing papers in "Ecological Monographs in 1966"

Breeding Ecology of the Yellow-Headed Blackbird

Abstract: AND HATCHING 56 BROODING . 58 NESTING SUCCESS ........ 58 MORTALITY . 60 NESTING GROWTH AND SEX RATIO 61 EXPLOITATION OF FOOD RESOURCES IN THE FEEDING OF NESTLINGS ........ 63 FOOD BROUGHT TO NESTLINGS 63 CHANGES IN FOOD OF NESTLINGS WITH WEATHER. .. 65 DIURNAL CHANGES IN FOOD OF NESTLINGS .... .... 67 FORAGING AREAS OF ADULT YELLOWHEADS ........ 67 RATE OF DELIVERY OF FOOD TO NESTLINGS .... ..... 69 DELIVERY RATE OF FOOD AND FLEDGING SUCCESS .... 71 CARE OF NESTLINGS BY MALES ..... 71

Ecological Observations on a Feral House Mouse Population Declining to Extinction

Abstract: It is clearly an unusual opportunity for an ecologist to be able to observe in detail the extinction of a species over a large area. Quite understandably, ecologists tend to study common species which are not likely to disappear during the time of study. This report documents the events occurring in a population of house mice (Mus musculus), living on 55 acre Brooks Island in San Francisco Bay, as it declined to extinction in a period of little over one year. The study was not initiated with the expectation that the population would become extinct, but rather because the mice occurred on the island in very high densities, and it was hoped that something could be learned about density regulation in this species under these congested, yet completely feral, conditions. Almost exactly coincident with the beginning of my studies on Brooks Island house mice in September of 1958, a few individuals of Microtus californicus were accidentally introduced on to the island from a neighboring islet, and rapidly colonized the entire island. The history of the colonization and exploitation of the island by Microtus is documented in detail in an earlier paper (Lidicker and Anderson 1962). Refer also to that report for a more complete description of the island and its recent history. For our purposes here, it is perhaps sufficient to

Plant Succession and Soil Development on Gravel Outwash of the Muldrow Glacier, Alaska

Abstract: INTRODUCTION . 181 Review of succession studies ........ 181 The Study Area 181 Climate 182 Parent Material 182 Physiography 183 Flora 183 Time 183 METHODS 183 Plant collections and identifications ...... ...... 183 Vegetation analysis 185 Soil Analysis 186 RESULTS 186 Stand descriptions 186 Pioneer stage 186 Meadow stage 187 Early shrub stage 189 Late shrub stage 190 Climax tundra .... 191 DIsCussIoN ....... 192 Vegetation changes 192 Pioneer stage ........ 192 Meadow stage .... 192 Shrub stage . 193 Climax tundra .... 193 General trends 194 Soil Development 194 Texture ........ 194 Organic material 196 Nitrogen ......... 196 Soil reaction 197 Permafrost ......... 197 Wind and snow accumulation 198 SUMMARY ....... 198 LITERATURE CITED ........ 198

Spruce-fir forests of the coast of maine'

Abstract: In the non-montane regions of eastern North America, forests dominated by spruce and fir reach their southern limits on the coasts of Maine and Nova Scotia. The Maine coast is famous for its irregularity and the multitude of islands and peninsulas extending into the cool waters of the Gulf of Maine. Although the coastal region is occupied by forests mostly of mixed character, at exposed shore locations along the entire coast, stands dominated by spruce and fir occur. In eastern Maine, such stands are more common. and extend further inland. The percentage of spruce and fir in these forests appears to be correlated with the intensity of marine influence on the climate of the site. The relationship between the cool maritime climate and the presence of boreal species (e.g. Empetrum nigrum) along the immediate shore has been recognized for some time (Rand & Redfield, 1894; Redfield, 1885, 1886, 1893; Rand, 1900; Hill, 1919; Wherry, 1928). Redfield (1886) noted that the forests of the outer islands in the Mount Desert Island area were dominated by spruce (Picea spp.), balsam fir (Abies balsamea) and paper birch (Betula papyrifera). Hill (1923) described the vegetation of the Penobscot Bay area, claiming that the spruce-fir forests at seaward locations constitute a "physiographic climax, differing from the northern hardwoods-hemlock-spruce-fir climax of the area because of shallow acidic soils and local cool climate. Moore & Taylor (1927), in describing the vegetation of Mount Desert Island, point out that forests dominated by red spruce (Picea rubens) covered a large portion of the island. These forests were thought to be the climax type for most of the island, with a northern hardwoods-spruce climax limited to a few central

The Structure, Function, and Ecological Significance of Root Grafts in Pinus strobus L.

Abstract: B. COMPARATIVE STUDY OF GRAFTED AND NONGRAFTED SUPPRESSED TREES .... ...... 8 Methods and Results .... 8 Bark girdling experiments .... ...... 8 Height and diameter growth ....... . 11 Missing rings 12 Living snags 13 Discussion .. .. .. ... ... ... ... 13 III. ANATOMY OF GRAFTS . .. 15 A. OBSERVATIONS ON THE STRUCTURE OF GRAFTS 15 B. HYPOTHESIS OF GRAFT FORMATION ... . 16 C. IMPLICATIONS OF GRAFT STRUCTURE, FOR WATER TRANSPORT BETWEEN GRAFTED TREES 17