THE ECOLOGY OF THE MACROFUNGI AT THE LANPHERE-CHRISTENSEN DUNES PRESERVE, ARCATA, CALIFORNIA by Sue Sweet Van Hook A Thesis Presented to The Faculty of Humboldt State University In Partial Fulfillment of the Requirements for the Degree Master of Arts December, 1985 THE ECOLOGY OF THE MACROFUNGI AT THE LANPHERE-CHRISTENSEN DUNES PRESERVE ARCATA, CALIFORNIA by Sue Sweet Van Hook We certify that we have read this study and that it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a thesis for the degree of Master of Arts. Major Professor V 1 Y Approved by the Graduate Dean Acknowledgements I wish to thank Dr. David L. Largent, my major professor and mentor, for years of excellent guidance and encouragement in the field of mycology; the members of my graduate committee, Drs. Dennis Anderson, Francis Meredith, and Richard Hurley, for their critical review of the thesis; mycologists, Dr. Orson K. Miller, Dr. Joseph F. Ammirati, and Dr. Harry D. Theirs, for their verification of species identifications; Hortense M. Lanphere for the background material on the fungi at the preserve and for her supportive correspondence; Marjorie Moore for data entry and graphics; The Nature Conservancy, for permitting the study at the Lanphere-Cristensen Dunes Preserve; and my family for their labor, love and patience. Table of Contents Page I. Introduction A. Literature review 1 B. Objectives 5 II. The Study Area A. Location 6 B. Geology 6 C. Climate 8 D. Plant Communities 9 III. Methods and Materials A. Areas studied 10 B. Plots within areas 16 C. Measurements of precipitation and air temperatures 17 IV. Results A. Precipitation 25 B. Air temperatures near the ground 27 C. Climatalogical data from Eureka, California 32 D. Fungal Synecology 34 1. Characterization of species 34 2. Seasonal succession 35 3. Seasonal periodicity 41 4. Mid-dates of fruiting 42 5. Average Cluster Size and Cluster Range 61 6. Abundance 61 7. Phanerogam Associates 64 8. Distribution 65 V. Discussion A. Variations in precipitation and temperature 68 B. Clusters, a method for recording sociability 70 C. Synecology of fungal flora 71 1. Characterization of the species 71 2. Seasonal succession 74 3. Seasonal periodicity 83 4. Mid-dates of fruiting 86 5. Abundance 90 6. Distribution 91 Table of Contents (continued) Page VI. Conclusion 96 VII. Appendix A 99 VIII. Appendix B 100 IX. Appendix C 103 X. Appendix D 104 XI. Literature Cited 149 I. Introduction Α. Literature review The literature on fungal synecology has been reviewed and critiqued by Hueck (1952), and by Cooke (1953). Both investigators emphasized the difficulties arising from the great variability in earlier synecological methods and the absence of a unified approach to the study of fungal communities. Hueck (1952) attributed the variability in methods to a lack of appropriate techniques for best characterizing a mycoflora and consequently he proposed that a plot should be chosen so that there appears to be both an abundant and an homogeneous flora of fungi as well as a homogeneity of vascular plant vegetation. The plot, whether a series of quadrats or an area of irregular shape, should be delimited in such a way that repeated checks are possible. The plots should be sampled 6-8 times per year for several years until no new species are found. Scales, modified from Braun-Blanquet (1932), Lange (1948), and Haas (1932), should be chosen for recording abundance, sociability, and substrate. The early 1950's was a period of transition in the study of fungal synecology. New methods of sampling were combined with earlier techniques. Questions that arose from sampling fungus populations using this new approach involved: the use of stationary plots versus routes (Parker-Rhoades, 1951; Kalamees, 1968); the sizes and 2 numbers of plots (Parker-Rhoades, 1951; Cooke, 1955; Kalamees, 1968; Richardson, 1970; and Fogel, 1976); the periodicity of sampling (Richardson, 1970); and the description of fungi being sampled (Parker-Rhoades, 1951; Kalamees, 1968; Hering, 1966; Richardson, 1970). The objective of these various mycocoenological methods is to be able to characterize major and minor components of a fungal flora. Hering (1966) labeled those species representing 5 percent of the total biomass or total number as dominants. Richardson (1970) also used the 5 percent of total biomass criterion to determine the major species of a pine plantation in Scotland. Parker-Rhoades (1951) designated species having 4 or more records as "prevalent" species and found that constancy of fruiting was an important criterion in placing a species in the "prevalent" category. It is important to note that comparisons of fungal productivity or occurrence between years within a site, or between similar site types in the same year, are reliable only when both the abundance and sociability of the fungi have been recorded. Kalamees (1968) emphasized the importance of sociability over abundance saying, "It is the only indicator demonstrating, but partly (with the present methods), the connection of fruiting bodies with the respective mycelia, thus giving a certain idea on the distribution of mycelia in the soil." He recognized that in order to determine dominant species, it is necessary to 3 count clusters of fruiting bodies that represent a single mycelium. Since the 1950's, only two studies in fungal synecology have been done in North America. Cooke (1955) studied the relationship of cryptogam to phanerogam communities in eastern Washington and adjacent Idaho and Fogel (1976) studied sporocarp phenology of hypogeous fungi in a Douglas fir stand in western Oregon. Cooke (1955), in describing the characteristics of the fungal flora, was able to make only general statements about constancy, fidelity, vigor, dominance, sociability and phenology. Constancy and species richness increased in the more moist associations. Fidelity to a phanerogam association was greatest among mycorrhizal species. Vigor was difficult to measure, but a loss of vigor was detected in poorer years by the smaller size of sporocarps. Dominance, defined as the volume of space occupied by all sporocarps of the species observed, was not useful for describing competitive significance. Fall and spring fungal floras differed, with only 10 percent of the species occurring in both seasons. Fogel (1976) determined that the minimum area that could be used for sampling was 100 square meters. However, because of the time required to unearth this much area to find the fungi, sporocarp production was estimated from 50 randomly located one-square meter quadrats; sporocarp numbers and biomass were underestimated as a 4 result. Major species were defined as those comprising 5 percent or more of the total dry-weight production. Major species differed in each of the 3 years. The mid-dates of fruiting for each species were determined using Richardson's (1970) formula, "m= Σ dn/Ν"; where d equals the number of days from the starting date times n, the number of sporocarps, all summed, then divided by N, the total number of sporocarps for a species. Sporocarp production increased logarithmically in spring when the mean minimum temperature was between 0° and 6° C and the precipitation was less than 5 cm. In fall, production began when precipitation totaled at least 0.5 cm per month and increased until the mean minimum temperature dropped to 4° C. Mycologists concur that the paucity of synecological studies is due to the inherent difficulties associated with field studies of fungi (Hueck, 1952; Fogel, 1981). Identification of fungal species often involves taxonomic problems which must be overcome before a study of fungal ecology can begin. Also, in theory, sociological studies should be based on the vegetative portion or dominant stage in the fungal life cycle, as they are for vascular plants. However, the inability to quantify microscopic subterranean mycelia has led to a reliance on the reproductive fruiting bodies, whose ephemeral nature and irregular occurrence pose additional difficulties (Hueck, 1952). It is often impractical to carry out long-term 5 studies with weekly sampling, to obtain accurate records of fungal populations (Fogel, 1981). Lastly, fungal synecology requires the development of efficient methods of study different from those established for phanerogams (Hueck, 1952). Β. Objectives The primary objective of this study was to develop a new method of recording sociability of macrofungi. Α second objective was to describe the synecology of the fungal species of a beach pine/dunes system through frequent sampling based on the identification of sporocarps and clusters. Α third objective was to produce a species list of macrofungi for this ecosystem that includes information on growth habit, habitat, ecological function, and distribution for each species. 6 II. The Study Area A. Location The 86 ha Lanphere-Christensen Dunes Preserve of The Nature Conservancy, managed by Humboldt State University, is a sand dune/beach pine system located 6.4 km west of Arcata, California on the Samoa Peninsula (Fig. 1). The preserve is one of four minimally altered habitats supporting native dune plant populations along the California coast (Barbour, 1977). The system is limited to the west by the Pacific Ocean, to the east by pastureland and a tidal slough. The well-defined limits of this ecosystem, in addition to its protected status, make it attractive for studies. The Dunes Preserve is habitat for many interesting and unusual fungi (Smith, 1957; Stuntz, 1962; Largent, Miller, and Ammirati, personal communications). B. Geology The sand dune system extends for 35 km along Humboldt Bay from Table Bluff north to Little River (Fig. 1). The sand dunes are best developed and reach their greatest heights (27 m) and widths (1.2 km) along the Samoa Peninsula where sand accumulates against a forest south of the preserve. The sand consists of fine, light-colored grains of quartz and feldspar averaging .10-.25 mm, and coarse, dark particles of basalt .25-.50 mm in size (Johnson, 1963).