Ecosystem services,sustainability and thermodynamic indicators

It is proposed to calculate the value of ecosystem services by the annual increase of work capacity or eco-exergy. The annual increase of biomass for various ecosystems is known. By multiplication of the biomass increase by the average content of information as Kullbach's measure of information, in the various ecosystems, the eco-exergy or total work capacity is obtained. An economic value can be found by multiplication of the cost of work, which is about 1 EURO-cent per MJ. A comparison of this value with the values found by Costanza et al. (1997) shows that the value based upon the total work capacity is much higher. The ratio between the two economic values have been found for the various ecosystems. It has been found that the ratio is lower the more an ecosystem by a wide range of application possibilities is utilized. The ecosystems have been divided in five classes according to the ratio and thereby in accordance to our utilization of the total work capacity of various ecosystems.     

柞蚕林冠层结构,林内光照分布与叶生物量研究

柞蚕林是以养蚕为目的的萌生栎林,林冠经剪伐而形成不同的冠型结构。本文对3种冠型的叶面积系数,冠层内叶量分布及消光系数等冠层结构特点进行了测定。结果表明,不同冠形的冠层结构特点明显影响林内光照环境及叶生物量。现有的3种冠型中,“阶梯”型结构有较高的叶面积系数和较合理的叶量分布,因而具有较高的叶生物量。“中干”型叶生物量与无干型虽无明显差异,但“中干”型消光系数较低,林内空间较大,林内光照环境比“无干”型结构优越。     

Productivity and mineral cycling in an oak coppice forest 2. Annual net production of the forest

Annual net production was estimated in the secondary coppice forest near Tokyo, which was dominated by a deciduous oak,Quercus serrata Thunb. Lateral growth of stems and old branches was directly estimated by examining the annual rings for 35 shoots in a clear-cut quadrat of 10m×10m. Phytomasses of current organs were also weighed in the quadrat. Preharvest losses of current organs were determined by twelve 0.5 m² litter traps for fine litter and twelve 6 m² quadrats for woody litter. Branch production was also assessed indirectly by use of the stem-branch allometry and death of branches. The results of the indirect method were in sufficient agreement with the result of the direct one. Grazing loss of leaves from the canopy was estimated directly from the loss in leaf area and indirectly from the animal faeces caught by the litter traps. Net production of the canopy trees was 149 kg a⁻¹ year⁻¹, in which leaf production was 36.9 kg. Animals grazed about 14% of the leaf area by the end of the growing season. True consumption of leaves by animals was 7.6% of leaf production or 10% of leaf mass. Production of undergrowth, mainly a dwarf bamboo,Pleioblastus chino Makino, was 28 kg a⁻¹ year⁻¹, being 15% of the total stand production. Productivity of this forest was significantly higher than that of cool-temperate deciduous broadleaf forests.     

Scale and species-environment relationships in a central Himalayan oak forest,Nepal

A quantitative gradient study in a central Himalayan mixed Quercus forest (Q. semecarpifolia and Q. lamellosa) was made to evaluate the relationships between environmental variables and species composition at different scales.The data (91 taxa × 120 sub-plots) were sampled at three sites, where groups of four sub-plots (2.5 m × 2.5 m) were sampled within 10 m × 10 m. The species data were analysed together with the environmental data (elevation, relative radiation (RI) and soil variables) using Correspondence Analysis (CA) and its constrained version (CCA). The environmental variables used in CCA were chosen by forward selection.Elevation was the over-riding complex gradient (2000–3000 m a.s.l.), with loss-on-ignition, total nitrogen, and RI covarying. The most important factors independent of elevation were available phosphorus and tree canopy cover, whereas pH and nitrogen had minor independent influences.The overall species environment correlation was highest for the largest plot size. The species environment correlation increased with spatial extent for the largest plot size. The field-layer and shrub-tree strata did not consistently differ in their concordance between species and environment. The field-layer species had a stronger relationships with the soil variables, which may relate to rapid changes over a short spatial extent both for the field-layer species and for the soil variables.     

柞树林下菌根真菌对碳、氮营养的利用

研究了柞树林下菌根真菌对Ｃ、Ｎ营养的利用状况．结果表明,供试菌种对Ｃ源的利用较为广泛,葡萄糖、果糖为其最适碳源,平均生长量比对照高出４．４倍;供试菌种对有机氮的利用优于无机氮,平均生长量比无机氮源高出１．６倍,硝态无机氮源中平均生长量为对照的２．５倍,对铵态氮的利用较差,平均生长量仅为对照的２．２倍     

The effect of canopy disturbance on species richness in a central Himalayan oak forest

Non-epiphytic species richness was studied in different disturbance classes within a Quercus semecarpifolia forest. Nine disturbance classes were defined according to the degree of biomass removal (lopping) and their spatial mixture. Six of these were observed in the study area. The species were divided into three functional groups: climbers, phanerophytes, and field-layer plants. The primary aim was to test if there is an elevated species richness under an intermediate disturbed canopy for (i) all vascular plants, (ii) lianas, (iii) phanerophytes and (iv) field-layer species. The richness of the different plant groups and all species were fitted against the disturbance gradient by means of Generalized Linear Models (GLM). Other environmental variables such as altitude, potential solar radiation, light intensity, canopy cover and soil parameters were also evaluated as predictors. Disturbance classes, canopy cover and light intensity were combined into a new variable, disturbance-complex, using Principal Component Analyses.Phanerophytes did not respond to any variable. Climbers were mostly related to pH and canopy cover, and were the only group related to altitude, nitrogen and loss-on-ignition. Herbaceous plants and total species richness showed a unimodal response to disturbance classes and the complex disturbance gradient, which supports the intermediate disturbance hypothesis. Relative radiation and slope also supported a unimodal response in herbaceous plants, but disturbance had a significant additional contribution to this pattern. The most significant predictor for these two groups was pH. The responses to organic carbon and phosphorus were not significant for any of the subsets.The results indicate that a small-scale lopping regime will enhance species richness of vascular plants; only a few species in the intermediate disturbed forest are weedy ruderals. In such a situation, the conservation policy may accept small-scale human impact as part of the forest landscape.     

Biomass,production and nutrient distribution of a natural oak forest in central Korea

Biomass, production, and nutrient distribution of a pure Quercus variabilis Bl. stand (stand 1) and two mixed Q. variabilis–Q. mongolica Fisch. stands (stand 2 and 3) were investigated in central Korea. Stand 1 naturally occurred on a site with a southern aspect while stand 2 and stand 3 occurred on sites with a northern aspect. Total (overstory+understory vegetation) biomass (tha^-1) and annual production (tha^–1year^–1) were 137.8 and 11.1 for stand 1, 216.2 and 16.6 for stand 2, and 253.3 and 19.7 for stand 3. Nutrient contents (kgha^–1) in the vegetation were distributed as follows: K, 478–860; N, 471–839; Ca, 428–791; Mg, 72–125; Na, 77–141; and P, 37–71, and were greatest in stand 3 followed by stand 2, and stand 1. Stand density influenced the differences in biomass, annual production and nutrient contents in the vegetation. Forest floor dry mass and N content (kgha^–1) were 13400 and 169 for stand 1, 10400 and 133 for stand 2, and 11200 and 127 for stand 3. Total amounts of N, P and Na in the ecosystem were greatest in the upper 40cm of mineral soil followed by the vegetation and forest floor. However, the vegetation contained a greater amount of K than the mineral soil. It appeared that microenvironments, such as, aspect influenced the distribution of natural oak species within a relatively small area and resulted in differences in biomass, production and nutrient distribution among the stands.     

Generalizations about bacteriology: thermodynamic,open systems,genetic instructions,and evolution

Biological generalizations about bacteriology are discussed to provide a broad perspective of what we know about bacteria. Bacteriology (and possibly all biology) from an overall perspective can be researched and understood as observations and experimentations on mass and energy, which are themselves the products of evolutionary change for about 3.5–3.9 billion years. All organisms have mass, transform, store and use biochemical energy and obey the most fundamental of all laws-the laws of thermodynamics. Bacteria can be viewed as semi-permeable, thermodynamically open systems of mass, controlled by relatively small amounts of genetic instructions with lower entropy than their higher entropy, surrounding environments. Some fundamental properties describing bacterial life are also presented.     

Ecology and late-Quaternary history of the Kurdo-Zagrosian oak forest near Lake Zeribar,western Iran

The ecology and distribution of Quercus aegilops ssp. brantii and the associated Pistacia atlantica var. mutica and P. khinjuk are examined as a basis for explaining the Late Quaternary history of the forest in the Zagros mountains. The three species are tolerant of aridity and low temperatures but sensitive to heavy snowfall. In most of the area, summer rain does not occur. Forest expansion is generally limited by the inability of seedlings to survive the four-month summer drought. Pollen diagrams from Lake Zeribar, Kurdistan show the absence of trees during the last glacial period and the migration of forest into the region between 10 000 and 5 500 B.P. This has been interpreted as indicating aridity during the Pleistocene with gradually increasing precipitation in the late glacial and Holocene. However, the sensitivity of these species to snow and their tolerance of low overall precipitation implicate higher snowfall rather than lower precipitation as the cause of absence during the Pleistocene. The inability of seedlings to survive the present summer-dry conditions suggests that summer rainfall, and not higher total precipitation, was the factor that finally allowed migration. These conclusions are supported by independent evidence of increased winter precipitation during the pleniglacial and a period of summer rainfall but low annual precipitation during forest expansion.     

Influence of cattle grazing on the density of oak seedlings and saplings in a Tabor oak forest in Israel

The effects of cattle grazing on the density of seedlings and saplings in a Tabor oak forest (Quercus ithaburensis subsp. ithaburensis) are investigated. The Tabor oak forest studied is located in a Nature Reserve in the Mediterranean region of Israel. Cattle graze at a stocking density of 0.71 head/ha for 6 months a year. The cattle grazing in the Nature Reserve is a beneficial management measure because it enhances plant species richness and reduces shrub encroachment.The impact of grazing on the densities of seedlings and young saplings was quantified in 46 large sampling plots (333 m² each) distributed over two experimental sites; the first being used as a rangeland for decades while the second is a forest patch totally free from grazing. The density and the height of Tabor oak individuals in each sampling plot were recorded. Four height categories were distinguished with a special focus on young seedlings (<0.15 m), established seedlings and young saplings (0.15 m–1 m).The density of seedlings and young sapling in the grazed Tabor oak forest were, respectively, 61% to 67% lower than in the ungrazed treatment. Implications on the continuity of the entire Tabor oak forest ecosystem are discussed. Three management measures that enable to prevent a decrease in young oak densities are proposed – reduction of stocking rate, deferment of the commencement of grazing, and fencing young seedlings.     

Seed predation by mammals and forest dominance by Quercus oleoides,a tropical lowland oak

Summary Quercus oleoides Cham. and Schlecht is an unusual tree in several respects: it is an oak found in neotropical lowland forests, its distribution is not continuous but ratherdivided into many patches of various sizes, and it is a dominant in all the forests in which it occurs, attaining densities far higher than most species of tropical trees. This density pattern is related to the vulnerability of Q. oleoides acorns to predation by mammals. Observations of agoutis, deer, peccaries, squirrels, pocket mice and other seed consumers in Santa Rosa National Park, Costa Rica, showed that these mammals act only as predators, not dispersers, of Q. oleoides acorns. Experiments which involved placing acorns in deciduous forest where Q. oleoides does not occur, demonstrated that, due to high predation rates, the number of acorns produced by an isolated tree is far too low for adults to replace themselves.In oak forest, on the other hand, where the combined acorn crops of many oaks satiate the seed predators, acorn survivorship until germination is high enough to maintain the population. Furthermore, acorn survivorship in oak forest areas is inversely proportional to the apparent mammal density in those areas. Thus the pattern of forest dominance and patchy distribution is related to positively density-dependent acorn survivorship: where Q. oleoides is the forest dominant, it will survive, but if its density falls to the level typical of tropical trees, it will go locally extinct.     

Water regime of upland oak forests of the south Russian forest steppe

In the southern forest steppe, the upland oak forests on loamy dark grey soils, which have the automorphic mode of water supply, usually endure droughts during the second half of the vegetative season due to the creation and use by biogeocenoses of some moisture reserves into soil and groundwater (GW), which are accessible to deep layers of root systems of trees. Two shallow sandy horizons interlaying moraine loams of the Dnieper glaciation at altitudes of 120 and 143 m above sea level serve as collectors and transporters of GW, the table of which is 10-15 m lower than the surface of the watershed plateaus and terraces. By autumn, trees desiccate subsoil horizons to the capillary fringe of GW. In early spring, the moisture of dried horizons is restored. The reserves of GW permit the upland oak forests to preserve rather high values of predawn leaf water potential such as Ψ _PD ≥ ?0.8 MPa despite the decrease in water potential of soil at a depth of 0-2 m of the soil layer to a value of Ψ _S ≈ ?2.4 MPa.     

Effect of fire intensity on understory composition and diversity in aKalmia-dominated oak forest, New England, USA

This study investigates the understory dynamics of two mixed-oak stands following fire of varying intensity. Composition and diversity of woody and herbaceous species in the understory were measured in two stands 7–8 years after a prescribed burn. On both sites, unburned areas, low-intensity fire areas, and areas where the overstory had been severely damaged were measured. Patterns of species presence and absence following fire were consistent with an initial-floristics model. Most species increased in density and frequency following fire; onlyAralia nudicaulis andQuercus alba showed statistically significant decreases in density. Overall, 29 species increased in density following fire, while 8 declined; 29 species increased in frequency, while 6 declined. However, diversity and equitability measures were depressed on the moderately burned sites, due to rapid regrowth ofKalmia latifolia. Ordination using binary discriminant analysis suggested species responded individualistically to both burning and site variation.     

Biomass and production of a naturally regenerated oak forest in southern Korea

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.     

The regeneration of pioneer tree species under browsing pressure of Sika deer in an evergreen oak forest

The effects of Sika deer (Cervus nippon) browsing on the regeneration of pioneer species were studied in relation to canopy gaps in a warm temperate evergreen oak forest in Kasugayama, Nara City. Four study sites, three in canopy gaps and one under a closed canopy, were selected and each divided into fenced and unfenced plots. Under the closed canopy, seedlings of all the pioneer species died irrespective of browsing pressure. However, in the canopy gap sites, seedlings of the pioneer species could establish and grow well. The seedling survival ratio in the fenced plots in the canopy gaps was >60% 1 year after germination. However, in the unfenced plots, only <20% of the seedlings survived 1 year, with all dying within 3 years after germination. Thus, the regeneration of pioneer trees in this forest was strongly inhibited by deer browsing. Successful regeneration of a pioneer,Zanthoxylum ailanthoides, occurred for several years even after two major wind disturbances during the past 90 years. This may be due to less browsing pressure from the deer.     

Armillaria mellea as a cause of oak decline in Hatam-baigh forest of Iran

A200 ha forest of "Hatam-baig" is located in Ardebil Province on the Northwest of Iran. Oak trees (Quercus macranthera Fisch & Mey) in this forest have been faced with declining and extinction since 1991, that has destructed about one third of the forest trees until now. This disorder was expressed in various symptoms including wilting, defoliation and decline. In order to identify factors causing decline, a study was managed from 1998 to 2001. Samples were taken from roots, trunks, crowns and soil beneath the canopy and were cultured on different culture media subsequently. Armillaria mellea (Vahl) P. Kumm., Phytophthora cryptogea Pethybr. & Laff., Dematophora sp., Pythium aphanidermatum (Edson) Fitzp. and Fusarium spp. were the most common isolated fungi. A. mellea appeared to be the essential causal agent of the decline according to the studies made on oak tress decline around the world and based on brown rot observed beneath mycelial fans in the cross section prepared from the trunk and characteristics of the isolated fungi. The fungus activity had been favored by physiological weakness and stresses in oak rootstocks caused by brown- tail moth (Euproctis chrysorhoea L.) and drought stress in infected trees. The biological species of this fungus was identified as Armillaria mellea, using hybridization tests and application of haploid test strains. The fungi such as Phytophthora sp., Pythium sp., and Dematophora sp. can not be infective in this forest due to being hydrophylous. In the southern part of the forest with remarked steepness, the severity of the decline appears to be more than that in the smoothly northern part. The decline of Q. macranthera is reported as matrix nova. The report of the isolated fungi from this oak species is also universally new.     

Seed dispersal of three sympatric oak species by forest rodents in the Qinling Mountains, Central China

Forest rodents play an essential role as seed dispersal vectors through their caching behaviors. Using seeds of Quercus aliena, Q. glandulifera, and Cyclobalanopsis engleriana (Fagaceae), which are dominant, but poorly studied species, in the Qinling Mountains, Central China, we investigated seed predation and dispersal by forest rodents in 2010 and 2011. There were significant differences in rodent seed-eating and caching strategies among the three tree species. Seeds of Q. aliena and C. engleriana had hard coats, high nutrition contents (e.g., protein, fat, and starch), and long germination schedules (C. engleriana only). They were less frequently eaten in situ, but more likely to be eaten after removal or cached. Seeds of Q. glandulifera had soft coats and low nutrition contents and were more often eaten in situ and less likely to be eaten after removal or cached. Our findings indicated that forest rodents were primarily responsible for seed predation and dispersal of these three tree species in the Qinling Mountains, and seed traits, especially coat hardness, nutrition content, and germination schedule, were important factors influencing rodent eating and caching behaviors. In addition, seed dispersal process of each tree species differed significantly between the 2 years, reflecting the effect of mast seeding on the eating and caching strategies of forest rodents.