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In a cloud forest dominated by Quercus costaricensis, the gap size between the crowns was consistent and crowns were asymmetrical, being elongated perpendicular to the prevailing wind direction. A wind storm of 20 m/s removed 1.5% of the leaves, con-sistent with the idea that wind abrasion shapes tree crowns. Natural Sciences and Engineering Research Council/[]/NSERC/Canada UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biología

There is an urgent need in Europe to prepare resources for the arrival of the emerald ash borer, Agrilus planipennis (Buprestidae, Coleoptera) from European Russia, and possibly other invasive jewel beetles. A lightweight, easy to handle, non‐sticky trap could facilitate monitoring and detection to derive information about emerald ash borer and other jewel beetle populations. In two experiments carried out over two consecutive years in an oak forest, a new non‐sticky multi‐funnel trap design with a light‐green (sometimes described as fluorescent yellow) visual cue was developed. Altogether, there were 238 (2018) and 194 (2019) specimens captured often (2018) and eight (2019) Agrilus species, eight of which are oak‐related and one (A. convexicollis) was linked to ash. The new light‐green multi‐funnel trap performed similarly to the sticky design with a similar coloured surface. Our results suggest that the new trap design may be suitable for catching a wide range of buprestid species. It may also have the potential to be further optimized with respect to visual and olfactory cues, which would provide an even more useful tool for monitoring both invasive and indigenous buprestids.

Conspecific negative density dependence (CNDD) is one of the main mechanisms influencing diversity maintenance in tropical forests. Tropical highland forests, in contrast to most lowland forests, are commonly dominated by a few tree species, and testing the importance of density dependence effects on seedling establishment of dominant trees may provide insights on the mechanisms regulating population dynamics and forest composition of tropical highlands. We tested the effect of CNDD regulation on seedling survival and recruitment of Quercus costaricensis, a monodominant oak in the Talamanca highland forests of Costa Rica. We used Ripley's K and generalized linear mixed models to test the effects of conspecific density, distance to the nearest adult, density of Chusquea bamboo shoots, and herbivory on the annual survival probability of 3579 seedlings between 2014 and 2017. We did not find a significant effect of CNDD on seedling survival. However, bamboo density and herbivory both significantly decreased oak seedling survival. All seedlings had signs of herbivory and predator satiation may explain the lack of density dependent regulation in seedlings of this species. We argue that the lack of intraspecific density regulation at the seedling stage may contribute to explain the dominance of Q. costaricensis in the highland forests of Costa Rica. Local seedling dynamics of this endemic oak are instead regulated by herbivory and the density of Chusquea. La denso dependencia negativa específica (DDNE) es uno de los mecanismos que más influyen en el mantenimiento de la diversidad de los bosques tropicales. Los bosques tropicales de tierras altas, en contraste con la mayoría de bosques de tierras bajas, son dominados por unas pocas especies de árboles, y probar la importancia de los efectos denso dependientes en el establecimiento de plántulas de árboles dominantes puede proporcionar información sobre los mecanismos que regulan la dinámica de poblaciones y la composición de estos bosques. Probamos el efecto de la DDNE sobre la supervivencia y el reclutamiento de las plántulas de Quercus costaricensis, un roble monodominante en las tierras altas de Talamanca en Costa Rica. Usamos la K de Ripley y modelos mixtos lineales generalizados para probar los efectos de la densidad conspecífica, la distancia al adulto más cercano, la densidad de bambú de Chusquea y la herbivoría, en la probabilidad de supervivencia anual de 3579 plántulas entre 2014 y 2017. No encontramos que la DDNE tuviera un efecto en la supervivencia de las plántulas, mientras que la densidad del bambú y la herbivoría si disminuyeron significativamente la supervivencia. La falta de DDNE en las plántulas de esta especie podría explicarse por el saciado de los depredadores, ya que todas las plántulas presentaban signos de herbivoría. Argumentamos que la falta de DDNE en la regulación de las plántulas puede contribuir a explicar el predominio de Q. costaricensis en los bosques de tierras altas de Costa Rica. La dinámica local de las plántulas de este roble endémico está regulada por la herbivoría y la densidad de Chusquea. UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biología

Forests exchange CO and O with the atmosphere at similar molar ratios. Correspondingly, the apparent respiratory quotient (CO/O flux ratio, ARQ) is expected to be ≈1 given the stoichiometry o...

Ecological communities are composed of many species and an intricate network of interactions between them. Because of their overall complexity, an intriguing approach to understanding network structure is by breaking it down into the structural roles of its constituent species. The structural role of a species can be directly measured based on how it appears in network motifs – the basic building blocks of complex networks. Here, we study the distribution of species’ roles at three distinct spatio-temporal scales (i.e. species, network, and temporal) in host–parasitoid networks collected across 22 sites over two years within a fragmented landscape of oaks in southern Finland. We found that species’ roles for hosts and parasitoids were heterogeneously distributed across the study system but that roles are strongly conserved over spatial scales. In addition, we found that species’ roles were remarkably consistent between years even in the presence of disturbances (e.g. species turnover). Overall, our results suggest that species’ roles are an intrinsic property of species that may be predictable over spatial and temporal scales.

M. Perez-Suarez, J. T. Arredondo-Moreno,* E. Huber-Sannwald and A. Serna-Perez 1 Division de Ciencias Ambientales, Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la Presa de San Jose #2055 Lomas 4, C.P. 78216, San Luis Potosi, SLP, Mexico 2 Instituto de Ciencias Agropecuarias y Rurales (ICAR), Universidad Autonoma del Estado de Mexico, Instituto Literario No 100, Col. Centro. PO. Box 50000, Toluca, Mexico 3 Campo Experimental Zacatecas, INIFAP, Carretera Zacatecas-Fresnillo, km 24.5. Calera, Zacatecas, CP, 98600, Mexico

We tested the hypothesis that the population density of ambrosia beetles at the stand level influences the spatial distribution of infested trees. We evaluated the spatial distribution of the ambrosia beetle, Platypus koryoensis (Murayama) in three oak forest stands that varied in beetle population density using a multi-year trapping survey. We used these data to inform a clustering analysis based on aggregation indices using the SADIE software. Four important findings emerged: (1) the spatial distribution pattern of P. koryoensis at the stand level changed as the population density of the beetle varied; (2) at low population densities, beetle distribution was contagious at the stand level; (3) as beetle population densities increased, the spatial distribution of infested trees became random, potentially due to beetle avoidance of mass attacked trees; and (4) at high beetle population densities, the spatial distribution of infested trees became contagious, possibly due to temporal changes in location of the attack epicenter within the stand. Our results support the hypothesis that beetle population density has consequences for the spatial distribution of infested trees at the within-stand scale. We conclude that the spatial distribution of infested trees is flexible in response to beetle population density, suggesting that beetle attack behaviors are mediated by one or more density-dependent effects.

Closely related Quercus species generally exhibit low levels of genetic differentiation despite their ecological and morphological differences. However, at a few so-called 'outlier' loci they seem ...

Application of models for estimating rainfall partitioning in deciduous forests may be considered time consuming and laborious given the need for two different parameter sets to describe leafed and leafless periods. This paper reports how rainfall partitioning modelling was done for a downy oak forest plot (Eastern Pyrenees Mountains, NE Spain) using sparse Rutter and Gash interception loss models and their suitability for such studies. Moreover, variability in model sensitivity is evaluated, and an attempt to simplify their application is also presented. The estimation error for interception loss in the leafed period was −26.3% and −4.2% with the Rutter model and the Gash model applied with Penman–Monteith-based evaporation rate, respectively. The estimate for the leafless period was less accurate in both models, suggesting that modelling in the leafless period is more susceptible to error. Nevertheless, with the Gash model, the result was well below the expected measurement error. Models proved to be highly sensitive to change in canopy cover in all periods tested. The Rutter model was especially sensitive to zero plane displacement changes in the leafed period, while the Gash model showed high linear sensitivity to evaporation rate. In addition, a decrease in rainfall rate affects the estimation of interception loss more than an increase in it. Regardless of its high sensitivity to these parameters, the Gash model yielded a good estimate of rainfall partitioning for the total period, when only one set of parameters was used, although event-based error compensation occurred, and some periods were over or underestimated. Copyright © 2011 John Wiley & Sons, Ltd.

In deciduous forests, it is particularly difficult to understand the factors controlling rainfall partitioning because of the seasonal changes of canopy cover. Moreover, under Mediterranean climate conditions, the marked seasonal variability of rainfall produces highly variable event-based interception losses making comparison of throughfall, stemflow and interception loss in each season difficult. Rainfall partitioning in a downy oak forest plot located in the Eastern Pyrenees Mountains (NE Spain) was measured over 3 years to study the differences in throughfall, stemflow and interception loss between the leafed and leafless periods and to find out the role of canopy cover and rainfall type in rainfall partitioning. Results show small differences in rainfall partitioning between the leafed and leafless periods, although different rainfall patterns were observed in the two periods, and there were significant changes in canopy cover. Throughfall and stemflow were slightly higher during the leafless period (about 3.6% and 1.7% higher, respectively), and therefore, interception loss was lower (about 5.4% in this period). On an event basis, the leafless period was characterized by lower absolute and relative interception losses than the leafed period. Rainfall was classified in four types by intensity and duration to study the influence of rainfall type on rainfall partitioning in leafed and leafless seasons separately. Rainfall duration was apparently important for all rainfall partitioning components in the leafless period, when stemflow and throughfall were lower and interception loss was enhanced during short events, whereas in the leafed period, no single dominating factor could be found. Copyright © 2011 John Wiley & Sons, Ltd.

Summary The main objective of this study was to obtain more comprehensive knowledge about the effect of water stress on endophytic fungal communities in asymptomatic and declining cork oak trees. Six asymptomatic and six declining cork oak trees were randomly selected in a natural cork oak forest located in Sardinia, Italy. In February 2003, the soil around three asymptomatic and three declining trees was covered with a circular plastic film to reduce rain water supply with the intention to induce water stress. The remaining six trees served as controls. Predawn xylematic water potential (PWP) was used as water status indicator and measured seasonally. Between July 2003 and June 2004, fungal endophytes were isolated every 2–4 months from twigs, branches and woody tissues. Significant differences in PWP between covered and control trees were detected mainly in autumn. Gas exchange was greatest in asymptomatic control plants. All tissues were colonized by endophytic fungi. Nineteen fungal species were isolated from 1620 plant fragments. Biscogniauxia mediterranea was the most frequently isolated fungus. Its isolation frequency was significantly higher in declining covered trees than in control trees (p

Summary Isolates of Phytophthora cambivora, P. cinnamomi, P. citricola, P. europaea, P. quercetorum and two unidentified species were tested for their pathogenicity to eastern US oak species by root and stem inoculations. Experiments were conducted during two different periods and included 1-, 2- and 20year-old oaks grown under greenhouse and field conditions. Species of Phytophthora were pathogenic in varying degrees to the oak species tested. All species were pathogenic to fine and taproots of at least one oak species. The fine root damage caused by the species of Phytophthora ranged from 9 to 55% when compared to the controls. Roots were more susceptible during the fall inoculation period than the summer. With exception of Phytophthora sp1 and P. quercina-like, all species of Phytophthora were pathogenic to oak stems with P. cinnamomi and P. citricola being the most aggressive. Quercus montana and Q. rubra were the most susceptible oak species to stem inoculation. Lesion sizes were considerably larger when 20-year-old trees were inoculated. Generally, no significant differences in lesion sizes were detected in greenhouse tests when the summer and fall inoculation periods were compared. However, on 2-year-old field-grown seedlings, lesion sizes were considerably smaller or not significantly different from controls during the fall inoculation period, suggesting lower, late season temperatures may restrict lesion development.

Biomass and production of two stands with Quercus variabilis Bl. as the dominant species (stands 1 and 3) and one with Q. mongolica Fisch. as the dominant species (stand 2) were investigated in southern Korea. Stands 1 and 3 naturally occurred on sites with southerly aspects while stand 2 naturally occurred on northerly aspects; stand ages were similar for the three stands (36–38 years old). Total above- and belowground biomass including understory vegetation (Mg ha−1) was 108.4 for stand 1, 115.6 for stand 2, and 132.0 for stand 3, respectively. Understory vegetation constituted 17.4% of the total biomass in stand 1 but only 3.7–4.5% in stand 2 and stand 3. Roots constituted 20.1–24.6% of the biomass of the overstory vegetation. Although stand 3 showed the highest total biomass, net production was highest in stand 2 at 12.6 (Mg ha−1 year−1); net production levels for stands 1 and 3 were 11.7 and 11.1 (Mg ha−1 year−1), respectively. It appeared that the differences in site conditions related to aspect influenced the distribution of naturally regenerated oak species within a relatively small area and resulted in differences in biomass and production among the stands.

Gambel oak (Quercus gambelii) is a valuable tree species for wildlife. In Arizona, USA, it occurs at higher elevations in association with ponderosa pine (Pinus ponderosa). Southwestern myotis (Myotis auriculus) is a bat species that has been anecdotally documented as selecting Gambel oak for maternity roost sites. During summers of 1999 and 2000, we conducted a radiotelemetry study to determine whether lactating, female southwestern myotis selected Gambel oak as maternity roosts within the ponderosa pine–Gambel oak forest in northern Arizona. We located 34 maternity roosts for southwestern myotis in Gambel oak trees (14 females) and 5 roosts in ponderosa pine snags (1 female). Maternity roosts were located in live Gambel oak trees >26-cm diameter at root collar (drc) that contained cavities. We used Akaike's Information Criterion (AIC) to evaluate 4 a priori hypotheses about southwestern Myotis maternity roost selection in northern Arizona. Our top model contained parameters for roost tree heigh...

130 kg of acorns of Common Oak (Quercus robur L.) were distributed on an area of 1.44 ha in an oak forest near Zagreb (Croatia), where acorns were lacking. The influence of this surplus of food on the development of mice and voles was observed from September 1999 till February 2000 on the experimental plot and on an untreated control area before and after offering the acorns. The Redbacked Vole Clethrionomys glareolus was the most abundant and dominant species in both observed areas. After distribution of the acorns, all species of mice, e. g. the Yellownecked Fieldmouse Apodemus flavicollis, the Longtailed Fieldmouse A. sylvaticus, and the Striped Field Mouse A. agrarius, increased up to 4 times in number on the area treated with a surplus of acorns. On the same area, however, all species of voles, e. g. the Redbacked Vole C. glareolus, the Field Vole Microtus agrestis, and the Common Vole M. arvalis, decreased. The numbers of captured and recaptured rodents before and after offering acorns on the treated and the untreated control area were compared by statistical analysis (Chi2-test). The results show how food can influence the competitive relations between mice and voles.

Summary Soil-borne species of Phytophthora were isolated from 19 of 30 examined oak forest areas in Italy. The frequency of isolated Phytophthora spp. (35.2%) was significantly correlated with soil pH and longitude of the sites. Eleven Phytophthora species were detected. Phytophthora cambivora, P. cinnamomi and P. cactorum were recovered from sites in central and southern Italy whereas P. quercina was isolated in the northern and central part of the country. Phytophthora citricola occurred all over Italy. Phytophthora quercina was the only species significantly associated with declining oak trees.

A novel dendroecological procedure was developed to elucidate canopy disturbances spanning a >300-yr period for oak (Quercus) forests of central Pennsylvania. Running comparisons of sequential 10-yr ring-width averages may effectively neutralize both short-term (i.e., drought) and long-term growth trends associated with climate while enhancing detection of abrupt and sustained radial-growth increases characteristic of canopy disturbance. Thinning-response studies revealed the conservative tendencies of overstory oak, with substantial basal area reductions (>1/3) required to attain moderate and consistently detectable growth increases. Based on empirical evidence, a minimum growth-response threshold of 25% was established to depict canopy disturbances. This is in contrast to the 50–100% sustained radial-growth release often used to detect disturbance using understory trees in closed forests. Our default threshold was adjusted higher as necessary for those trees highly correlated to climatic trends (as repr...

Fire is a common but poorly understood disturbance in the forested ecosystems of the Sierra Madre Occidental of Mexico. In this study, fire history, forest structure (density, species composition, regeneration, forest floor fuels, herbaceous cover, and age of pines), and the dendrochronological tree-ring record were measured at two unharvested 70-ha pine-oak sites near Ojito de Camellones, Durango, Mexico. Study sites were matched in slope, aspect, elevation, slope position, and plant composition, but they differed in fire history since 1945 and in forest structure. The long-term mean fire intervals (MFI) for all fires at both sites up to 1945 were similar—4.0 years at Site 1 (1744–1945) and 4.1 years at Site 2 (1815–1945)—but Site 1 burned only three times at the site margins since 1945 while Site 2 had 9 fires that scarred two or more sample trees and 15 total fires since 1945. Density measurements and age and diameter distributions showed that Site 1 was dominated by numerous, younger, smaller trees (mean total basal area of 23.4 m2/ha and 2730 trees/ha), while Site 2 had fewer, older, larger trees (basal area of 37.2 m2/ha, 647 trees/ha). Large, rotten fuel loading and duff depth were also greater at Site 1. Because regeneration averaged 6200 stems/ha at Site 1 and 8730 stems/ha at Site 2 (no significant difference), forest density at Site 2 was not limited by regeneration capability. The distributions of overstory diameter and pine age at both sites indicate that tree establishment occurred in pulses, with the largest cohort of trees establishing at Site 1 following the 1945 fire. The dense regeneration and heavy fuel accumulation at Site 1 are likely to support a switch from the former low-intensity fire regime to a high-intensity, stand-replacing fire across the site when the next suitable combination of ignition and weather occurs. Baseline quantitative information on fire frequency and ecological effects is essential to guide conservation or restoration of Madrean forests and may prove valuable for restoration of related fire-dependent ecosystems that have experienced extended fire exclusion elsewhere in North America.

A phytosociological study of forests on Vosges sandstone in the basins of Pays de Bitche (Bitcherland) resulted in the identification of three plant communities: Luzulo-Quercetum, Leucobryo-Pinetum, and Vaccinio uliginosi-Pinetum. The Luzulo-Quercetum is an association with a typically sub-continental distribution; the two communities with Pinus sylvestris are clearly more continental. The Luzulo-Quercetum oak forest represents a climatic climax and the pine forests are considered edaphic climaxes linked to very dry soils (Leucobryo-Pinetum) or peaty soils (Vaccinio uliginosi-Pinetum). These three associations determine a forest sequence that is typical of sub-continental areas in which Quercus petraea dominates in the climatic climax. In more continental areas, it is gradually replaced by Pinus sylvestris. Thus, the forest sequence in Pays de Bitche represents a remarkable subcontinental link in the transition from Atlantic oak forests to continental pine forests.

This report describes a 2-yr study comparing two sampling systems that are used to measure major ionic constituents in incident precipitation and canopy throughfall: long-term bulk sampling vs. event-based, wet-only sampling. Major deviations in chemical concentrations (SO²⁻₄, NO⁻₃, K⁺, Ca²⁺, and H⁺) were documented between the two sampling systems, deviations that were ion-specific in both incident precipitation and throughfall. Differences in chemical concentrations between the two sampling systems were greater (i) during the growing than during the dormant seasons, and (ii) for incident precipitation (collected in the open) than for throughfall under chestnut oak forest (Quercus prinus L.) canopies. Nutrient-cycling processes in forests may be misinterpreted if flux data are based solely on long-term bulk samplers of incident precipitation and canopy throughfall. For example, comparison of bulk and wet-only throughfall solutions suggests that when bulk samplers collect throughfall under hardwood canopies, the ability of hardwood canopies to increase pH of low pH precipitation may be overestimated. Research sponsored by the Electric Power Res. Inst. (RP-1813-1; RP-1907-1) and by the Office of Health and Environ. Res., U.S. Dep. of Energy, under contract no. DE-AC05-84OR21400 with Martin Marietta Energy Systems, Inc. Partial support for manuscript preparation received from the Integrated Forest Study on Effects of Atmospheric Deposition, coordinated by Oak Ridge Natl. Lab. and sponsored by the Electric Power Res. Inst., and from the School of Natl. Resour., The Univ. of Michigan, and the School of Forestry and Environ. Studies, Duke Univ. Publication no. 2974, Environ. Sci. Div., ORNL.

Allozymic variation in proteins encoded by 25 loci was analyzed electrophoretically in 1982 and 1983 in 356 individual plants from a dense population of wild barley, Hordeum spontaneum, the progenitor of cultivated barley. The test involved six microniches organized in a mosaic pattern in the open Tabor oak forest at Neve Ya'ar, Israel. The microniches were i) sun-soil, ii) sun-rock, iii) shade-soil, iv) shade-rock, and the contact zones: v) soil periphery of the sun-rock microniche, and vi) soil periphery of the shade-rock microniche. Discriminant analysis indicated significant multilocus allozymic differentiation between the microniches. Our results suggest that allozyme polymorphisms in wild barley are at least partly adaptive and differentiate predominately by microniche ecological selection, rather than by stochastic processes and/or neutrality of allozymic variants.

The investigations of the authors were made in the Buda Hills, in a stand of calciphilous oak forest (Orno-Quercetum), a Submediterranean xerothermic forest association frequent in the Transdanubian part of the Hungarian Central Range. Subdividing the 1024 m2 sample plot into 64 portions, the cover values of the dominant- and frequent species were noted; in the same system holes were dug in the ground and 7 physical soil factors studied in all of the soil layers. Considering these factors (together with tree- and shrub cover) as independent ones affecting the species, correlations were calculated between them and the several species. Diverging from preceding studies, not merely first grade (linear) but also quadratic (parabolic), square root, exponential, and logarithmic models were also applied. Some significant correlations may be pointed out among the results. The connection between Vicia sparsiflora and pH is considerable and demonstrable by several methods: related probably to the pH requirement of nitrogen-fixing bacteria symbiotic with the plant. In the case of Lithospermum purpureo-coeruleum, it is not the pH but the nutrient demand wich appears to be the regulating factors: as shown by its close correlation with humus and potassium. On the other hand, the close correlation between Quercus pubescens and humus may result from the inverse relation between humus and soil depth, indicating the significance of topographic effects. Humus plays a role in the appearance of Oryzopsis virescens but also in that of Euphorbia cyparissias; this latter is decisively influenced also by light conditions. Results can, however, be evaluated also methodically. Accordingly, the linear model presents in some cases a good description of the interrelationships, whereas the parabolic approach is better in a great number of other cases; this indicates that in these ones not all regions of the connection is of the same character and that in our ecosystem one has to consider, in several cases, minimum and maximum effects and the subsequent alteration of the direction of relationship. As for the other types of connection, one has to take into account the exponential in some cases. Die Verff. fuhrten ihre Untersuchungen in den Budaer Bergen an einem kalkholden Eichenforst (Orno-Quercetum) durch. Es handelt sich hierbei um eine submediterran-xerotherme Forstgesellschaft, die im transdanubischen Teil des Ungarischen Mittelgebirges haufig ist. Die Untersuchungsflache von 1024 m2 wurde in 64 Parzellen aufgeteilt. Hier wurden die Deckungsgrade der dominanten und haufigen Arten ermittelt. Entsprechend diesem System wurden Bodenprofile ausgehoben und in jedem Horizont 7 physikalische Bodenfaktoren untersucht. Betrachtet man diese Faktoren — zusammen mit der Baum- und Strauchschicht - als unabhangig auf die Arten einwirkend, so lassen sich Korrelationen zwischen ihnen und den verschiedenen Arten ermitteln. Abweichend von bisherigen Studien wurden nicht nur lineare, sondern auch parabolische, exponentiale und logarithmische Modelle angewandt. Aus den Untersuchungsergebnissen konnen einige signifikante Korrelationen herausgestellt, werden. Die Bindung von Vicia sparsiflora an bestimmte pH-Werte ist beachtlich und durch verschiedene Methoden nachweisbar. Wahrscheinlich beruht diese Bindung auf den pH-Wert-Anspruchen der Stickstoffbakterien, die mit dieser Art, in Symbiose leben. Im Beispiel von Lithospermuin purpureo-coeruleum ist offenbar nicht der pH-Wert, sondern der Nahrstoffanspruch als regulierender Faktor anzusehen. Dies wird durch die enge Bindung der Art an Humus und Kalium bestatigt. Andererseits kann die enge Korrelation zwischen Quercus pubescens und dem Humusgehalt auf dem inversen Verha,ltnis zwischen Humus und Bodentiefe beruhen und damit, auf die Bedeutung topographischer Effekte hinweisen. Auch fur das Vorkommen von Oryzopsis virescens und Euphorbiu cyparissins spielt der Humus eine Rolle; letztere wird auserdem entscheidend yon den Lichtverhaltnissen beeinflust. Die Ergebnisse lassen sich andererseits auch methodisch werten. Demgemas liefert das lineare Modell in manchen Fallen ein brauchbares Bild der bestehenden Beziehungen, wahrend in einer grosen Zahl anderer Falle die parabolische Annaherung geeigneter ist. Dies last erkennen. das die Bindung nicht in jedem Bereich gleichen Charakter hat und das in unserem Okosystem von Fall zu Fall Minimum- und Maximumfaktoren und folgende Anderung der Beziehungsrichung zu beachten sind. Bei den ubrigen Typen der Bindung hat man in manchen Fallen das Exponentialmodell in Betracht zu ziehen.

The longer a patient lives, the more predisposed he is to become host to primary malignant neoplasms at various sites. Hence the importance of follow-up clinics in long-term care facilities. Data on multiple malignancies at Oak Forest Hospital are presented. Among 34 such patients (average age, 72 years), 28 had malignant lesions at two primary sites, and 6 at three primary sites.

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