Evergreen Oak Forest Research Articles

Seasonal pattern of total soil respiration in undisturbed and disturbed ecosystems of Central Himalaya

The rates of CO2 efflux were measured by an alkali absorption method (using 20 ml 0.5 N NaOH) from soils in four undisturbed sites [two evergreen oak forests, Quercus floribunda Lindl. (tilonj oak), Quercus leucotrichophora A Camus (banj oak), and two evergreen conifer forests, Cedrus deodara Loud. (deodar forest) and Pinus roxburghii Sarg. (chir pine forest)] and three disturbed sites. The sites were located between elevations of 1850 and 2360 m in the Central Himalaya. The seasonal pattern of soil respiration was similar in all the sites with a maximum during the rainy season, intermediate rates during the summer season and the lowest level of activity in winter. The rate of CO2 efflux was higher in broadleaf than in conifer forests, and it was lowest in the disturbed sites. Among the edaphic conditions, soil moisture, N, organic C, pH, soil porosity, and root biomass positively affected total soil respiration. The proportion of root respiration to total soil respiration was higher in the disturbed sites than the undisturbed sites in winter. Conditions in the winter season were less favourable for microbial respiration than for root respiration.

Role of forest canopies in the collection and neutralization of airborne acid substances

This paper describes the role of the canopy in the collection of airborne acid substances and in the neutralization of the acids by cation exchange processes. Bulk throughfall was collected in three different types of forest in the suburban area of Yokohama. Bulk precipitation was also collected in the open field outside of the forest studied. Samples were analyzed for Ca 2+, Mg 2+, K +, Na +, NH 4 +, H +, Cl −, NO 3 −, SO 4 2, and Al. For almost all components, bulk throughfall exceeded bulk precipitation in elemental flux, owing to interception deposition and canopy leaching. Only the H + flux decreased during passage of precipitation through the canopy. Canopy leaching of Ca 2+, Mg 2+, and K + was determined by assuming that Ca 2+ /Al, Mg 2+ /Al, or K + /Al ratios in interception deposition are equal to the corresponding ratios in bulk precipitation. Total acid deposition to the forest, assumed to be equal to the throughfall fluxes of SO 4 2− and NO 3 −, exceeded the flux of acid substances (H + + NH 4 +) in bulk precipitation by factors of 1.7, 2.0, and 2.5 for Japanese deciduous oak forest, Japanese evergreen oak forest, and Japanese cedar forest, respectively, indicating the importance of interception deposition of acid substances to the canopy. From 49 to 74% of total acid deposition was neutralized at the canopy. A major part of the neutralization was attributable to the cation exchange processes at the canopy surface. Evidently the processes depend on the nature and form of the leaf surface.

Contribution à l’étude des Collemboles des Maures (Var-France)

Inventory of collembolan fauna in some stations of cork oak and evergreen oak forests has been given. Fifty nine species have been recorded, six were new for this area. Some were particularly interesting : Anurophorus massoudi Poinsot endende of Maures mountains and Coloburella zangherii (Denis) known only from Pyrenean mountains, Abruzzes and from Eole island (Italy). These two former species occured in abundant populations and may be considered as the two characteristic species of this area.

The ecology of a Mediterranean tortoise (Testudo hermanni): a declining population

In France, wild tortoises occur at low densities (< 3/ha) in the mixed forest and maquis of the Massif des Maures. In an evergreen oak forest with scattered, traditional cultivations, distinct subpopulations still exist at relatively high density (> 10/ha). The population structure is heavily skewed in favour of old adults and recruitment is low. The population is declining due to habitat loss, both from fire and through the decline in traditional horticultural practices, leading to a reduction in nest site availability. The increase in nest density in the few suitable sites remaining leaves the eggs highly vulnerable to predation and losses of over 90% cannot be sustained. The active season is from March to November, but there is evidence of some activity during the hibernation period. Adult males maintain small, fixed home ranges, while females undertake distinct migrations to and from nesting sites in the spring and can switch to new home ranges. Juveniles are sedentary up to the age of 4 or 5 years, after which they may wander considerable distances in no particular direction, until the onset of sexual maturity. Sex ratio does not differ significantly from parity within any age cohort.

Community dynamics of evergreen broadleaf forests in southwestern Japan

The process and rate of revegetation in gaps in an evergreen oak forest were studied by comparing the species composition, tree density, frequency distribution of tree height, and relation between diameter at breast height and tree height among different aged stands. For estimating stand ages, the ages of gap indicators, such as,Symplocos prunifolia andAcer rufinerve, were very useful. It took about 70 years for gaps to be filled by large fully-grown trees. Since the mean residence time of the forest canopy was 180 years, the trees that attain the forest canopy were expected to be canopy trees for 110 years on the average. Tree densities of all broadleaved evergreens exceptS. prunifolia, were independent of stand age. On the other hand, densities of gap indicators,S. prunifolia andA. rufinerve, decreased as stand age increased. Other deciduous broadleaf and coniferous species were scarce as a whole. According to the frequency distributions of height of live and dead trees in different aged stands, it was suggested that shorter trees were more susceptible to death than taller trees. The self-thinning in revegetation process in gaps approximately followed the 3/2 power law, though the power was larger (−1.32) than expected from the law.

Cycling of soil carbon in a Japanese red pine forest I. Before a clear-felling

Cycling of soil carbon was measured synthetically and quantitatively throughout a year in two Japanese red pine forest stands on mid- and foot-slopes at Mt. Takao, Hiroshima Prefecture, west Japan. There was no distinct difference of soil temperature along the slopes, but the soil water content was higher on the foot-slope than on the midslope. The carbon flow (litterfall, soil respiration, etc.) rates were larger on the foot-slope than on the mid-slope, but there was no significant difference of the accumulation of soil carbon (A0 layer or human in mineral soil) between the areas. The results of the analysis of soil carbon cycling based on a compartment model show that the relative decomposition rate of A0 layer and humaus in mineral soil increased 1.4–1.5 fold from the mid- to the foot-slopes, corresponding to the soil moisture condition. The relative decomposition rate of A0 layer was, however, about one-third of that in a evergreen oak forest. This fact suggests that the great resistance of needle litter to decomposition is one of the main limiting factors of the cycling of soil carbon and prevents the fertilization of mineral soil in the pine forest, which was also proven by the simulation of dynamics of soil carbon cycling.

Community dynamics of evergreen broadleaf forests in southwestern Japan. II. Species composition and density of seeds buried in the soil of a climax evergreen oak forest

The species composition and density of seeds in the soil of a climax evergeen oak forest in the Kasugayama Forest Reserve, Nara, Japan were studied by directly extracting seeds from soil samples and using soil samples in planting boxes as the basis of germination tests.

Community dynamics of evergreen broadleaf forests in southwestern Japan. I. Wind damaged trees and canopy gaps in an evergreen oak forest

The rates of treefall and canopy opening in the evergreen oak forest in southwestern Japan were determined by studying the number and size distribution of overstory trees, wind damaged trees, and canopy gaps in a belt transect in the Kasugayama Forest Reserve in Nara City. Thirty three percent of the overstory trees wereCastanopsis cuspidata. The total area of canopy gaps was about 20% of the total land area in the study area. The ages of the gaps were determined by counting the annual rings of various kinds of trees growing in gaps. By comparing gap ages with meteorological data, it became evident that gap formation was mainly caused by strong typhoons. The mean time interval between strong typhoons visiting the forest reserve, 6.57 years, was determined by applying the MNY method to the meteorological data. The treefall rate and the mean area of canopy openings per year were 0.84 overstory trees/ha·year and 55.6 m2/ha·year, respectively. The mean residence time of the forest canopy was about 180 years.

La vegetation du bassin de l'aude, entre pyrenees et massif central, au tardiglaciaire et au postglaciaire d'apres l'analyse anthracologique

This study presents the first synthesis of the Late and Postglacial vegetation between the Pyrénées and the Massif Central, in the Aude Basin at lower elevation. The results are based upon the identification of more than 2,000 charcoal pieces from prehistoric settlements. Firs and pines ( Pinus sylvestris) persist in the Pyrenean area as far as the Neolithic, contrary to the south of the Massif Central where a Mediterranean influence is recorded. Refuges of vegetation give the best explanation for Late Glacial phytogeography; evidence for these refuges has been found at Belvis. In the Mediterranean area we can describe three vegetation successions during Postglacial time. The early vegetation was dominated by pines and deciduous oaks (Preboreal, Boreal). Later deciduous oak forests with thermophilous plants were growing (Atlantic period). Finally, in the Subboreal and Subatlantic period evergreen oak forests ( Quercus ilex) are extended. The late extension of Quercus ilex (Subatlantic or earlier) is of anthropic origin.

Pestalotia Distincta Refound in Japan

During a survey of the leaf litter fungi of Japanese evergreen oak forests, several collections of a coelomycete on the leaves of Castanopsis cuspidata Schottky caught my attention. Apparently, the is identical to Pestalotia Guba (Guba, 1961). This species was originally collected by Asano in 1922 in Fukuoka, Japan, on the leaves of C. cuspidata. A portion of the specimen was sent to Guba and was treated as a new species of Pestalotia in his monograph (Guba, 1961). The holotype specimen has been preserved in the Herbarium of the New York Botanical Garden and labelled Emil F. Guba, University of Massachusetts, Herbarium Monochaetiarum et Pestalotiarum, Pestalotia Guba, Type specimen, Coll. Asano, etc. The specific epithet distincta might have been given because of its inconspicuous apical cells and the rosettelike arrangement of short setulae near the apex of the conidia. Guba (1961) has mentioned in his book (p. 107) that the fungus is unusual in the absence of conspicuous hyaline apical However, the Latin diagnosis given by him and the original line drawing provided by him which accompanied the type specimen clearly indicate the presence of himispherical, hyaline, apical cells. This discrepancy could have resulted from the examination of the old, dry herbarium material kept for nearly half a century. This might have misled him to conclude that conspicuous apical cells were absent in this species. Fresh collections of P. on the leaves of C. cuspidata were made at Esuzaki, Wakayama, on 18 April, 1969, and later at Miyanoura, Yaku Is., Kagoshima, on 1 June, 1970. Conspicuous, conical, hyaline, apical cells are constantly on the conidia of the collections on C. cuspidata and on the conidia in the cultures made from the recent collections. Setulae, mostly five in number, are short and adorn the basal periphery of the apical cells and very rarely also are on the distal end of the apical cells. They are straight or less curved than those illustrated by Guba. The length of 5-celled conidia of the new collections is somewhat greater than that given by Guba, being 19-28 ,um, and that of the 3-intermediate cells is 15-19 Mm. A full description of P. refound in Japan is given as follows:

VEGETATION ON THE ADRIATIC COAST OF YUGOSLAVIA

The vegetation distribution on the Adrratic coast from Rijeka to Dubrovnik and on the five islands, Krk, Cres, Losinj, Rab and Pag, was studied in relation to the climatic conditions, especially to the local wind, bora. The climax vegetation in this region is the Mediterranean evergreen hard wood forests and deciduous broad leaved forests. The vegetation shows the Mediterranean type on the Adriatic slopes of the Velebit Mts., but, in contrast, the continental type on the inland-facing slopes. The deterioration of vegetation is the most serious on the slopes up to 500 m above the sea level on the coastal region. It looks like a land almost without vegetation. The evergreen oak forests re-main in restricted areas on the Rab island and their degradation types, maquis and garrigue, were found along the coast and on the islands south of Zadar. The poor-vegetation landscape prevails on the windward slopes, but, on the contrary, the forests or the ever-green vegetations on the lee side slopes on the islands.The degree of density of the vegetation was studied for determining quantitatively the effect of the winds in this region. The rough density is found in the coastal and island regions from the north of Senj to the north of Zadar. This region coincides perfectly with the strong bora regions, which was revealed through an intensive investi-gation on the wind-shaped trees. The effect of wind, however, might be in a following way : (i) the original vegetation was destroyed first by human activity, (ii) the strong bora winds hindered the vegetation from restoration, and (iii) overgrazing of goat and sheep and felling of trees for fire-wood intensified the effect of hinderance by the winds.

A Phytosociological Study of an Evergreen Oak Forest in the Vicinity of New Orleans, Louisiana

The evergreen oak forest in the vicinity of New Orleans corresponds to Cover Type No. 78 of the report of the Committee on Types (Hawley, et al, 1932). This type is referred to as the Live Oak Forest in which oak is pure or predominant but with red gum, evergreen magnolia, holly, laurel oak, water oak, and hawthorn as associates. It is said to occur in Southern Louisiana along well-drained borders of tidal marshes and to be climax in the succession. Viosca (1933) states that live oaks, draped with Spanish Moss, are the dominant trees on the coastal ridges, but give way as we proceed inland to a mixed forest consisting chiefly of oak, water oak, red or sweet gum, elm, hackberry and magnolia, often with an undergrowth of dwarf palmetto or switch cane, or both. It is apparent that there is considerable diversity in the composition of the evergreen oak forest and that no single study will suffice to describe this forest adequately.