2002.  R.E. Peachey, A. Moldenke, R.D. William, R. Berry, E. Ingham, Eric Groth.  Effect of cover crops and tillage system on symphylan (Symphlya: Scutigerella immaculata, Newport) and Pergamasus quisquiliarum Canestrini (Acari: Mesostigmata) populations, and other soil organisms in agricultural soils.

ABSTRACT: The garden symphylan (Scutigerella immaculata: Newport) is a common myriapod soil pest of vegetable crops in the Pacific Northwest and other regions of the US. Symphylans consume germinating seeds, plant roots, and above-ground plant parts in contact with the soil. Factors regulating symphylan populations in agricultural soil systems are poorly understood, particularly the effects of farming practices such as cover cropping and reduced-tillage. 
    Cover crops were planted in the fall of 1994 through 1996 and either incorporated into the soil in the spring with tillage or killed with glyphosate and the residue left on the soil surface. Fewer symphylans were recovered with Berlese funnels from soil under cereal cover crops than soil in mustard cover crops, regardless of tillage system. Fewer symphylans were recovered from soil under the spring oat cover crop than soil under the barley cover crop. Eliminating spring tillage may have increased symphylan populations but the effect of reduced tillage on symphylan populations was less important than cover cropping.
    Predaceous mites were more abundant in soil under large amounts of cover crop residue but these predators were not correlated with lower populations of symphylans. Spring tillage dramatically reduced populations of Pergamasus quisquiliarum, a known predator of symphylans. Cover crops increased both the ratio of predaceous mites to symphylans and the total population of potential prey, thereby reducing the capacity of predaceous mites to regulate symphylan populations.

1999. Moldenke, A.R., M. Pajutee, and E. Ingham. The functional role of forest soil arthropods: the soil is a living place. p. 7-22. IN: Proceedings of the California Forest Soils Council Conference on forest Soils Biology and Forest Management, Feb. 23-24, 1996; ed. R.F. Powers, D.L. Hauxwell, G.M. Nakamura. Gen. Tech. Rept. PSW-GTR-178. US Dept.Agric. Forest Service, Pacific Southwest Research Station. 113 pp.

ABSTRACT: Plant growth is dependent upon the activity of numerous types of organisms within the environment. The recycling of nutrients in forest floor litter involves the interaction of a vast diversity of bacteria, fungi, protozoa and invertebrates. Arthropods are integral to the initial shredding of the litter, which exposes the encapsulated nutrients to microbial digestion. Hundreds of California species either feed directly upon the e decomposer fungi, or predate the fungivorous taxa. Fungivory insures that a succession of microbial taxa with differential enzymatic capabilities processes soil resources. The final step of recycling, the entry of soil nutrients back into a root, is largely the result of invertebrates feeding upon microbes which have immobilized nutrients within the rhizosphere. Forest management practices can significantly alter soil foodwebs, which may in turn have significant effects on long-term soil productivity. Because arthropods facilitate a number of different processes, assays of soil arthropod abundance and community composition may prove to be a useful management tool.

1996. Moldenke, A.R., and W.G. Thies. Effect of chloropicrin application to control laminated root-rot on soil arthropods one year after application: research design and seasonal dynamics of control populations. Environ. Entom. 25:925-932.

ABSTRACT: A methodology using soil arthropods as a nontarget assay of chloropicrin fumigation against Phellinus root rot is described. Significant differences in seasonal abundances in control plot populations occurred for each of the 6 most common trophic guilds. Population densities were highest for springtails (Collembola) and oribatid mites (Cryptostigmata) during the late summer dry season; densities were highest in early spring for worms (Oligochaeta), mesostigmatid mites, and fungivorous macroarthropods. Biomass was highest for worms and mesostigmatid mites in spring, but fungivorous macroarthropods peaked in late summer. Springtails and oribatids were equivalent throughout the year measured as biomass; population peaks in dry summer are composed primarily of immatures. Nearly all individual species of springtails and oribatid mites had population densities that differed significantly by season; individual springtail abundances fluctuated with greater amplitudes than those of oribatids. Both springtails and oribatid mites increased significantly in population density and biomass from the 1st yr to the 2nd yr postharvest. Experiments using soil arthropods as bioindicators in forest soils beneath clearcuttings should be monitored throughout the year to avoid confusing treatment effects with normal life history cycles.

1996. Moldenke, A.R., and W.G. Thies. Effects of four nontreatment variables on soil arthropods one year after application of chloropicrin to control laminated root rot. For. Sci. (in press).

ABSTRACT: The effects of harvest, slash-burning, distance from stump and presence of Phellinus weirii (Murr.) Gilb. on the abundance of soil arthropod species and feeding guild composition were quantified in a Northwest conifer forest. Harvest (removal of canopy, compaction of soil, sudden litter addition) had the greatest effect on arthropod density and community composition. Harvested and nonharvested controls were significantly different (p < 0.05) in population densities of nearly all individual species and all summed guilds as well. Lumbricid and enchytraeid worms and endeostigmatid mites were more abundant in clearcuts; all other groups (particularly fungivorous springtails and oribatid mites) predominated in mature forest. Likewise, slash burning altered the population density of nearly every species, facilitating herbivorous macroarthropods while inhibiting predaceous mites and fungivorous macroarthropods; 60% of the affected species showed declines under burned conditions. Distance from tree stump ranked third in importance, altering densities of 50% of the common species and four guilds. Most species decreased with increasing distance from the stump, 11% increased with increasing distance and 15% were more abundant at an intermediate distance. Phellinus weirii infection of stumps affected only 12 arthropod taxa. Ordination analysis revealed the primary role of harvesting and secondary role of burning in structuring species diversity within the two most abundant guilds (fungivorous springtails and oribatid mites).

1996. Moldenke, A.R., and W.G. Thies. Effect on soil arthropods one year after application of chloropicrin to control laminated root-rot.  III. Treatment effects on nontarget soil invertebrates. Can. J. For. Res. 26:120-127.

ABSTRACT: Soil arthropods were observed as nontarget bioindicators of chloropicrin fumigation used to control Phellinus in Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) forests of Washington. Three dosages were investigated: 100% and 20% labeled dosages and a 0% control. Area-wide random samples from treated regions revealed few statistically significant (ANOVA, p < 0.05) shifts in abundance of functional guilds (one of eight). Treatment responses were shown by 23 species, a similar number decreased or increased along with increasing dosage. Stump- centered samples (0.5-2.0 m from trunk; "worst case scenarios") revealed significant changes (p < 0.05) in 6 of 8 functional guilds o soil arthropods; most guilds were more abundant in the control and least abundant under 20% labeled dosage. Many common fungivorous oribatid mite species (20 of 63) showed significant stump-centered responses but most springtails (Collembola; 13 of 15) did not. Ordination analyses of random samples showed no area-wide effect of treatment dosage, whereas stump-centered samples revealed that the species compositions of treated versus nontreated communities of predaceous mites, oribatid mites and endeostigmatid mites were distinct.

1995. Ingham, E.R and A.R. Moldenke. Microflora and microfauna on stems and trunks: diversity, food webs, and effects on plants. pp. 241-256. IN: B. Gartner,(ed.) Plant Stems: Physiology and Functional Morphology. Academic Press, New York.

CONCLUSIONS: Plants have always existed with bacteria, fungi, protozoa and nematodes on their surfaces. A small amount of information is available on the density and diversity of organisms inhabiting plant surfaces, but little is known about how they influence plant growth. Although number and species composition differ in the phyllosphere as compared to the rhizosphere, similar interactions occur in both places. The following summary statements can be made.  1. The rhizosphere and phyllosphere food webs consist of communities of bacteria, fungi, protozoa, nematodes, microarthropods, and insects driven by plant exudates and detrital material.  2. Food web structure and function are strongly influenced by colonization processes, moisture and temperature regimes, and exudate production by the plant.  3. Interactions between saprophytes and their predators alter the form of nitrogen and other nutrients in stem flow. Plants can absorb these nutrients through above-ground surfaces, or after incorporation into the soil. How important the processes of phyllosphere immobilization and mineralization may be to plant growth is unknown.  4. The food web of organisms on the surfaces of plants provides protection against pathogens and parasites. The mechanisms preventing pathogen attack include competition for nutrients and competition for space on the surface of the plant.  5. Predators on the surface of plants protect plants from pathogen attack, once established bark or leaf-surface organisms compete with other colonizing organisms, often preventing establishment of pathogens on the surface of the plant. Predatory arthropods and perhaps nematodes remove potential invaders from the bark surface.  6. If the phyllosphere defense and the physical barrier of the plant surface are overcome, plants typically respond to pathogen attack by producing thicker bark, structurally denser wood, or higher levels of toxic compounds in the wood, often resulting in mechanically stronger or more resistant wood products.  Management of plant-surface microbial communities could be used to improve wood quality, but use of these interactions requires a better understanding of the physiology, ecological niche, and competitive interactions of both the surface-dwelling organisms and their host plants.

1995. Torgersen, C.E., J.A. Jones, A.R. Moldenke, and M. LeMaster. The spatial heterogeneity of soil invertebrates and edaphic properties in an old growth forest stand in western Oregon. pp. 225-236 In: HP Collins, GP Robertson & MJ Klug (eds.), The significance and regulation of Soil Biodiversity, Kluwer Acad. Publ., Amsterdam.

ABSTRACT: Geostatistical tools, the semi-variogram and correlogram, were used to compare spatial heterogeneity and patterns of soil microarthropods, O-horizon depth, moisture content, temperature and pH in two contrasting forest stands near the HJ Andrews Experimental forest, Oregon for June of 1992 and 1993. Two adjacent research plots were sampled: one plot consisted of a heterogeneous mix of age classes with a high density of oldgrowth Douglas-fir; the other plot was dominated by a homogeneous post-fire stand of Douglas-fir regrowth with a low density of oldgrowth trees. Spatial analysis revealed distinguishable differences between oldgrowth and regrowth forest and between sampled years. In the hot dry spring of 1992, short range variability and patches (0-5 m), especially in pH, moisture, O-horizon depth, and faunal census, were more pronounced in the homogeneous regrowth plot, whereas long range patterns (17 to 22 m) were more pronounced in the heterogeneous oldgrowth plot. In the cold wet spring of 1993 both oldgrowth and regrowth forest plots had only short range variation.

1994. Moldenke, A.R. Arthropods. pp. 517-542. In: Methods of Soil Analysis: Microbiological and Biochemical Properties, SSSA Book Series, no. 5. Madison, WI.

1994. Moldenke, A.R., N. Baumeister, E. Estrada-Venegas, and J. Wernz. Linkages between soil biodiversity and above- ground plant performance. Trans. 15th World Cong. Soil Sci., Vol 4a (III): 186-204, Acapulco.

ABSTRACT: Soil invertebrates engineer the soil environment itself, and determine the structure and abundance of soil microbial populations. A community of diverse species of mycorrhizae of differing structural types allow plant roots to compete effectively for mineralized nutrients and prevent natural ecosystems from losing water soluble ions. Soil invertebrates, in turn, catalyze microbial exoenzymatic nutrient mobilization and increase the rate of plant growth, both by grazing upon bacteria and fungi and by continual predation upon grazer populations. Reductionistic approaches to biodiversity reveal the roles of keystone species; species which perform critical functions that can't be subsumed by other taxa if they are lost. Holistic approaches to biodiversity emphasize the uniqueness of each species and emphasize that management excels if a suite of similar species is present to maximize an ecological process through time or over space. The surprising identities of keystone species and the need to manage for enhanced soil biodiversity and increased complexity of food webs is a challenge being explored by sustainable agricultural systems. Increased biologic awareness among soil scientists will facilitate interdisciplinary solutions.

1992. Schowalter, T.D., B.A. Caldwell, A.R. Moldenke et al. Decomposition of fallen trees: effects of initial conditions and heterotroph colonization rates. pp. 373-383. In: Tropical ecosystems: Ecology and Management (KP & JS Singh, eds.) Wiley Eastern Publ., New Delhi.

ABSTRACT: Decomposition of an experimental cohort of conifer boles in a temperate rain forest was studied during the first two years after cutting. The decomposing bole was viewed as a successional ecosystem with measurable inputs, outputs, internal cycling processes, and controlling factors. Inputs included nitrogen fixation, interception of canopy throughfall, and immigration of xylophages (insects) and decomposers (fungi and bacteria), all small relative to nutrient pools in boles. Different xylophage functional groups colonized different tree species and inoculated galleries with different decomposer assemblages. Outputs included fragmentation via gallery excavation by insects (<1% per year), respiration (1% per year), and leaching (0.02% per year). Bole chemistry, temperature and moisture influenced colonization and biodegredation by xylophages and decomposers. These results from the initial stages of bole decomposition provide new information on processes contributing to decomposition of fallen trees. Our study challenges the assumptions of chronosequence studies (the traditional approach to studying long-term successional processes) that initial conditions and heterotroph colonization patterns (especially lag times) do not influence decomposition rates.

1992. Moldenke, A.R. Response of soil invertebrates to management practices in ponderosa pine plantations: herbicide, insecticide and fertilizer. Symposium volume, Eureka CA meeting Nov. 1991. US Dept Agriculture, Forest Service, Southwest region.

ABSTRACT: Soil arthropod species richness, density, biomass and species composition was analyzed in three ponderosa pine plantations in northern California to assess the non-target effects of fertilizer, herbicide (glyphosate) and insecticide (orthene). The soil arthropod fauna was very similar between the sites encompassing an altitudinal difference of 730 m (arthropod abundance was correlated with plant productivity, not altitude). Plantation soils were less dense and less rich in arthropods than surrounding stands of mature forest; composition by functional guild and nearly all individual species was unaltered between mature forest and plantation. Within plantation soils, fertilizer and insecticide have positive effects and herbicide a negative effect on arthropod density, diversity and biomass; all of these effects are primarily quantitative, without significant differential effects on individual species or functional components of the soil ecosystem.

1992. McIver, J.D., G.L. Parsons, and A.R. Moldenke. Litter spider succession after clearcutting in a western coniferous forest. Canad. J. For. Res. 22: 964-982.

ABSTRACT: The litter spiders of a coniferous forest in western Oregon were trapped in pitfalls to study the effects of, and recovery after, clearcutting. Traps were placed in oldgrowth sites (150-450 years) and in clearcuts of three different ages (4-7, 16-19, and 22-31 years); each age class was represented by sites that differed along a gradient of moisture availability. A total of 8905 individuals were collected over the 2 year study period, comprising 93 species, 54 genera, and 15 families. Visual pursuit hunting spiders dominated clearcuts, while "sit-and-wait" microweb and trapdoor spiders dominated mature forests. Most of the common forest species were reestablished in the wettest sites by 30 years after clearcutting; species composition in dry 30-year-old clearcuts more closely resembled the fauna of shrubby wet 16-year-old clearcuts. Microenvironmental conditions and the availability and species composition of prey are the most likely factors behind variation in spider species composition among sites. Prey and microenvironment are in turn largely influenced by canopy closure and litter depth. The use of litter spiders as bioindicators of litter habitat quality and forest recovery is discussed.

1991. Shaw, C.H., H. Lundkvist, A.R. Moldenke, and J.R. Boyle. The relationships of soil fauna to long-term forest productivity in temperate and boreal ecosystems: processes and research strategies. pp. 39-77 In: WJ Dyck and CA Mees (eds.) Long-term field trials to assess environmental impacts of harvesting. Forest Research Inst., Rotorua, N.Z. FRI Bulletin no. 161.

ABSTRACT: Forest management and use can affect soil fauna and alter the ecosystem characteristics and processes that they mediate. In this paper the distribution of soil fauna is described and the mechanisms through which they may regulate nutrient cycling and soil water dynamics are reviewed. Results from studies that evaluated the impact of forest management practices on soil fauna are summarized, and, finally, some future research directions are suggested. Although generalization is difficult, distribution patterns of soil fauna emerged across forest types, humus forms, and latitudinal gradients. Nutrient cycling is regulated by soil fauna through indirect means such as microbial grazing, predation on microbivores, modification of habitats and substrates through faeces production, transport of soil components across boundaries, and spread of microbial inoculum. Soil fauna have the potential to influence soil water dynamics by altering soil porosity and pore size distribution which can affect soil physical properties. Studies on the effects of harvesting, burning, and nitrogen fertilization on soil fauna have produced variable results suggesting that effects of forest disturbances will depend on site-specific pre-disturbance ecosystem processes and the nature of the disturbance. A four-step strategy for research relating soil fauna to long-term productivity is proposed. Focus is placed on knowledge gaps identified in the review. Potential research topics include: 1) collect descriptive information on forest soil fauna in North America where data are relatively sparse; 2) role of macrofauna in regulating fungal biomass and activity; 3) regulation of the balance between fungivores and bacterivores by soil fauna predators; 4) transport roles of micro- through macro-fauna that affect the proximities of substrates and microorganisms; 5) potential influences of fauna on soil water dynamics in forest ecosystems; 6) role of fauna in the special habitats of coarse woody debris and the rhizosphere; 7) links between soil fauna, the development of forest humus forms, and forest productivity; 8) the relationship between soil fauna faeces and forest productivity; 9) the potential for using the humus form as the link to facilitate scaling of results from process larval studies up to the level of the forest stand, where measurements of forest productivity and management decisions are made; 10) an understanding of climate-induced synchronies between plant phenologies and activities of soil fauna that may help us understand and predict impacts of manipulations. These ideas should be applied to the longer-term "phenologies" of forest stand succession and timing silvicultural activities to minimize disruptions of desirable synchronies between above- and below-ground parts of forest ecosystems. For all investigations involving questions related to long-term productivity, interdisciplinary teams of researchers and managers should establish replicate sites for modal forest types and cooperate on baseline studies. Within this framework, an essential research goal should be to contribute an understanding of the relationship between soil biological agents and processes, the humus form, and forest productivity.

1991.   Bioresponse of nontarget organisms resulting from use of chloropicrin to control laminated root rot in a northwestern conifer forest: installation of study. pp. 81- 84. In: Pesticides in Natural Ecosystems: How Can Their Effects Be Monitored? Environ. Protect. Agcy. Rept 910/9-91- 011 (Thies, W.G., M.A. Castellano, E.R. Ingham, D.L. Luoma & A.R. Moldenke).   

1991.   Bioresponse of nontarget organisms resulting from use of chloropicrin to control laminated root rot in a northwestern conifer forest: evaluation of bioresponses. pp. 85-90. In: Pesticides in Natural Ecosystems: How Can Their Effects Be Monitored? Environ. Protect. Agcy. Rept 910/9-91- 011 (Ingham, E.G., M.A. Castellano, E.R. Ingham, D.L. Luoma, A.R. Moldenke & W.G. Thies).

1991.   Invertebrates of the H.J. Andrews Experimental Forest: western Cascade Region, Oregon. V: An annotated list of insects and other arthropods. USDA Forest Service, PNW Forest and Range Expt Sta., General Technical Report PNW- GTR-290. (Parsons, G.L., G. Cassis, A.R. Moldenke, J.D. Lattin, et al.).

1991.   Computer-driven image-based soil fauna taxonomy. Agric. Ecos. Env. 34:177-185. (Moldenke, A.R., C. Shaw & J.R. Boyle).

ABSTRACT: The study of soil ecology has long been hampered by the diversity of species and functional groups of soil fauna. Many of these taxa are poorly studied and integrated taxonomic references are unavailable on a regional basis.  We used Hypercard, a hypermedia program for the Macintosh computer, to develop COMTESA (computer taxonomy and ecology of soil animals). COMTESA is an image-based, taxonomic key for soil fauna, which also acts as a data base to store ecological information about the organisms. Multi- level linking within COMTESA allows the user to peruse the module in a non-linear fashion, so that learning can proceed at an individualized pace that is driven by curiosity. Its basic design can be useful to all levels of users from novice to experienced soil zoologist.  COMTESA is conceptually divided into two parts designed to deal with different scales of resolution. Part I distinguishes 150 different functional/taxonomic groups, has an ecological emphasis and should be useful throughout North America. Part II consists of modules that provide identification to the generic and species level and are specific to region/site/ecosystem.  Within the community of individuals involved in soil ecology research the demand is high for those with skills in identification of soil fauna. Since few individuals are knowledgeable in this area, the burden for identification of specimens falls either on inadequately trained ecologists or upon the limited resource of taxonomic specialists. COMTESA can offer a partial solution to this problem of "communication". Taxonomists can use COMTESA to produce user-friendly regional keys that can be rapidly updated and quickly distributed to users at low cost. Ecologists would have better resolution in their results, and by high-grading their samples could provide material more likely of interest to the taxonomists. Successful integration would generate broader interest and support for the multidisciplinary basic research that needs to be done. A simplified version could be introduced to science classes in the secondary education system, to expose a new generation of potential taxonomists and soil ecologists to the world of soil biology.

1990.   Dispersal characteristics of old-growth soil arthropods: the potential for loss of diversity and biological function. Northwest Env. J. 6:408-409. (Moldenke, A.R. & J.D. Lattin).

1990.   Arthropods: the invisible diversity. Northwest Env. J. 6:404-405. (Asquith, A., J.D. Lattin & A.R. Moldenke).

1990.   Moss lacebugs in northwest conifer forests: adaptation to long-term stability. Northwest Env. J. 6:406- 407. (J.D. Lattin & A.R. Moldenke).

1990.   Density and diversity of soil arthropods as "biological probes" of complex soil phenomena. Northwest Env. J. 6:409-410. (Moldenke, A.R. & J.D. Lattin).

1990.   Litter spiders as bio-indicators of recovery after clear-cutting in a western coniferous forest. Northwest Env. J. 6:410-412. (McIver, J.D., A.R. Moldenke & G.L. Parsons).

1990.   One hundred twenty thousand little legs. Wings (1990) 11-14.

1988.   Interactions between soil animals and ectomy- corrhizal fungal mats. IN: C.A. Edwards (ed.), Proceedings of Workshop on interactions between soil-inhabiting invertebrates and microorganisms in relation to plant growth. Ohio State University, Columbus.  (Cromack K, Fichter BL, Moldenke AR, Entry JA, Ingham ER).

ABSTRACT: Estimates of microbial biomass were made for ectomycorrhizal fungal mats colonizing mineral soil in a 50- 75-year-old Douglas-fir stand in western Oregon. The ectomy- corrhizal fungal mats are from the basidiomycete, Hysterangium setchellii. Numbers and biomass of soil animals including microarthropods and nematodes were estimated for both fungal mat and non-mat areas. The mats generally showed a significantly greater microbial biomass and also greater numbers of soil microarthropods. Protozoans were also sampled and exhibited greater abundance in fungal mats for amoebae and ciliates, but not flagellates. We hypothesize that these mats represent a larger and more active microbial biomass, available as a soil-animal food resource. Fungal mats had greater concentrations of soil C and soil N, and soil respiration and enzyme activity rates were significantly greater in mat than non-mat soil.

1988.   Invertebrates of the HJ Andrews Experimental Forest, western Cascade Mountains, Oregon: IV. The oribatid mites (Acari:  Cryptostigmata). USDA Forest Service, Pacific Northwest Research Station, General Technical Report PNW- GTR-217, 112 pp. (A.R. Moldenke & B.L. Fichter).

ABSTRACT: A fully illustrated key is presented for identifying genera of oribatid mites known from or suspected of occurring in the Pacific Northwest. The manual included an introduction detailing sampling methodology; an illustrated glossary of all terminology used; two color plates of all taxa from the HJ Andrews Experimental Forest; a diagnostic key to the 16 major groups of adult oribatids; illustrations to aid in quick recognition of the 16 adult groups; keys to all adult genera; and a diagrammatic key to the major types of immature oribatid mites with local species illustrated. The text on adults is broken into 16 sections, each structured around a key to the genera within each major type of oribatid mite; the text associated with the keys describes each species from the Andrews Forest, its microhabitat preference, pattern of abundance, and seasonal phenology. A total of 246 scanning electron micrographs (with pointers indicating characters useful for identification) are provided to help in identifying species.