Relations between forest management,stand structure and productivity across different types of Central European forests

In the past 30 years, many stand structural attributes (SSAs) have been suggested and structural indices have been developed to describe the complex structure of forests. Most studies, however, have explored the potential and limits of structural measures to quantify forest structures by applying multiple measures to one stand or few measures to several stands. However, the interdependencies of multiple structural attributes across many stands of different forest management types and developmental stages have not yet been explored. Using 20 structural attributes and 124 completely inventoried 1 ha sized stands we tested to what extent structural characteristics reflect different stand types and management intensities, and how these characteristics change over time. We found that single SSAs do not show the clear gradients that they were intended to reflect, suggesting that stand structure should be described by multiple structural attributes, and that these should represent different structural aspects (including vertical, and horizontal heterogeneity, density, and diversity). A principal component analysis showed that combining several SSAs, allowed us to distinguish between stand types. The structure of mature stands remained rather constant over the observed period of about 6 years, while that of young stands changed more rapidly due to ingrowth and mortality. The older the stands, the less the large trees contributed to stand growth relative to their size. We conclude that multiple stand structural attributes are needed to characterise stand types, management effects and to explain stand productivity.     

Conserving global biological diversity by encouraging alternative development paths: can development coexist with diversity?

The conservation of biological diversity concerns the management of the development process, not only at the national but also at the global level. Individual countries have made their development choices independently but relatedly, too often following the precise form of the choices of other countries preceding them in the development process. Development via imitation is pursuing the form, rather than the substance of a successful development strategy. Countries should instead be developing upon a base of assets that provides them with a relatively unique set of goods and services to place upon global markets. When the first countries developed, this criterion indicated that they should convert their countries to new forms of production; when the last countries are developing, relatively unique goods and services flow from their lands as they stand. What is required is the development of global institutions that encourage countries to see that their best development opportunities lie down these alternative development pathways, based upon their already-existing but relatively unique national assets.     

Short‐term response of threatened small macropods and their predators to prescribed burns in subtropical Australia

Fire is an important ecological process that shapes vegetation structure and habitat for faunal assemblages globally. Prescribed burns are increasingly being used in conservation and management to restore fire regimes in fire‐suppressed vegetation communities. Small threatened macropods require structurally complex habitat that allows them to evade detection by predators. Given that fire can alter vegetation structure, it can be viewed as a strong ecological force in shifting the dynamics between predator and prey species. Previous studies in temperate Australia have shown that prescribed burns in the presence of European Red Fox (Vulpes vulpes) and feral Cat (Felis catus) can have negative impacts on small macropods and medium‐sized mammals. Post‐fire response of threatened small macropods and their predators has not been experimentally examined in subtropical Australia despite this region providing refugia for the Long‐nosed Potoroo (Potorous tridactylus) and Red‐legged Pademelon (Thylogale stigmatica). We conducted a before‐after‐control‐impact fire experiment at two paired sites after low–moderate intensity burns typical of cool season prescribed burns. We used camera trapping to investigate changes in activity of threatened small macropods and their predators. We also recorded vegetation change. Despite large reductions in ground and shrub cover, activity of small macropods and the Dingo (Canis dingo) did not change in response to fires. Therefore, the threat of dingo predation appears to have remained unchanged following the fires. Although feral cats and foxes were present, they showed negligible activity across our sites. Our study suggests that small‐scale patchy ecological burns may not lead to increased predation of small macropods in our landscape. We attribute this to sufficient post‐fire refugia and very low densities of foxes.     

Development of a satellite-based hazard rating system for Dendroctonus frontallis (Coleoptera: Scolytidae) in the Ouachita Mountains of Arkansas

The southern pine beetle, Dendroctonus frontalis Zimmermann (Coleoptera: Scolytidae), is the most damaging forest insect pest of pines (Pinus spp.) throughout the southeastern United States. Hazard rating schemes have been developed for D. frontalis, but for these schemes to be accurate and effective, they require extensive on-site measurements of stand attributes such as host density, age, and basal area. We developed a stand hazard-rating scheme for several watersheds in the Ouachita Highlands of Arkansas based upon remotely sensed data and a geographic information system. A hazard model was developed using stand attributes (tree species, stand age and density, pine basal area, and landform information) and was used to establish baseline hazard maps for the watersheds. Landsat 7 ETM+ data were used for developing new hazard maps. Two dates of Landsat imagery were used in the analyses (August 1999 and October 1999). The highest correlations between hazard rating scores and remotely sensed variables from either of the dates included individual Landsat 7 ETM+ bands in the near- and mid-infrared regions as well as variables derived from various bands (i.e., Tasseled cap parameters, principal component parameters, and vegetation indices such as the calculated simple ratio and normalized difference vegetation index). Best subset regression analyses produced models to predict stand hazard to southern pine beetle that consisted of similar variables that resembled but were more detailed than maps produced using inverse distance weighted techniques. Although the models are specific for the study area, with modifications, they should be transferable to geographically similar areas.     

The effects of fire on grassland bird communities of Barberspan,North West Province,South Africa

Considering the frequent nature of fires and resultant drastic change in habitat following fire, research on the effects of fire on birds in the grasslands of South Africa is surprisingly scarce. For at least five months after burns we followed the changes in bird species composition, species richness and densities of two controlled burns and one accidental fire at the Barberspan Nature Reserve in grasslands that had not been burned or grazed in 10 years. Compared with the control areas, species richness and densities increased in the burned areas immediately following the burns, with more species and birds recruited to the burned areas than were lost. Immediate post-burn opportunists tended to be larger species, and the biomass increase mirrored the increases in species richness and densities in burned areas. Avian species richness, densities and biomass tended to return to the initial conditions after a number of months. Although the bird communities from two controlled-burns differed before the burns, they converged to a characteristic immediate post-burn composition. Five months after the burns however, the bird communities reflected a pre-burn composition. Indications were that birds in an area larger than that burned were affected. Mosaic burning, with shifting large and small patches, should be considered on a landscape scale.     

Testing the enemies hypothesis in forest stands: the important role of tree species composition

Numerous studies conducted in agro-ecosystems support the enemies hypothesis, which states that predators and parasites are more efficient in controlling pest densities in polycultures than in monocultures. Few similar studies, however, have been conducted in forest ecosystems, and we do not yet have evidence as to whether the enemies hypothesis holds true in forests. In a 2-year study, we investigated whether the survival of autumnal moth (Epirrita autumnata) larvae and pupae differs between silver birch monocultures and two-species mixtures of birch with black alder, Norway spruce and Scots pine. We placed young larvae on birch saplings and monitored their survival until the end of the larval period, when we checked whether they had been parasitized. After the larvae had pupated, pupal survival was tested in a field trial. In 2002, the larvae disappeared earlier and their overall survival was lower in birch–pine mixtures than in other stand types. In 2003, survival probability was lowest in birch–pine stands only during the first week and there were no differences between stands in overall survival. Larval parasitism was not affected by tree species composition. Pupal weight and pupal survival were likewise not affected by stand type. Among the predators, wood ants were more abundant on birches growing in birch–pine mixtures than in other stand types probably because colonies of myrmecophilic aphids were common on pines. In contrast, spider numbers did not differ between stand types. Ant exclusion by means of a glue ring around the birch trunk increased larval survival, indicating that ants are important predators of the autumnal moth larvae; differences in larval survival between stands are probably due to differential ant predation. Our results provide only partial support for the enemies hypothesis, and suggest that it is both tree species composition and species diversity which affect herbivore survival and predation.     

Variability of the Cytological Parameters of <Emphasis Type="Italic">Pinus sylvestris</Emphasis> L. Seeds from the Unique Hrenovskoy Pine Forest

Hrenovskoy pine forest is a unique island stand at the boundary of the species range of Scots pine Pinus sylvestris L. This object is of exceptional economic value, because it serves as a forest-seed base for the Voronezh oblast and some other regions of Russia; therefore, the stand and seed qualities have to be monitored constantly. The results of the first cytogenetic study of the seed progeny of P. sylvestris from the Morozov Grove, a high-quality stand in a reserved site within the Hrenovskoy pine forest, are reported. The studies have been performed in order to obtain a more correct assessment of seed quality based not only on their germination and energy of germination (traditionally used by forest breeders), but also on their genomic stability. The latter may be estimated by the stability of chromosome number in the somatic cells of seedlings and the regularity of mitotic divisions, because they also characterize the state of the generative system of parental forms and may serve as an integrated estimate of the stand development homeostasis. Therefore, the chromosome number, mitotic and nucleolar activities, and the number and spectrum of pathological mitoses (PMs) have been determined. Seedlings have been obtained from 240 seeds (collected from 12 trees) that resulted from free pollination. The cytological analysis of the rootlets of these seedlings has not detected any deviations from the chromosome number typical of the species P. sylvestris L. (2n = 24). However, considerable variation has been found in each family with respect to the mitotic index (MI) (from 4.2 ± 0.36 to 8.1 ± 0.39%) and the number of PMs (from 0.5 to 2.1%); micronuclei have also been found in each family (from 0.01 to 0.05%). In general, the phenotypic characteristics and the variation pattern of cytological parameters of the progeny of the trees studied in the Hrenovskoy pine forest, together with the high germination rate of seeds (90–98%), indicate that the current state of pines in the Hrenovskoy pine forest can be considered to be satisfactory. However, the presence of micronuclei in all variants and the decrease in MI in some individual plants (which was, on average, 6.1 ± 0.03% in the sample studied, i.e., significantly lower than that of P. sylvestris from the Usmanskii pine forest (7.3 ± 1.2%), where the conditions are optimal for this species) may serve as the bioindicators of the deterioration of both the state of trees themselves and the ecological conditions in the Hrenovskoy pine forest. Therefore, the population structure of this valuable autochtonic stand should be reproduced urgently.__________Translated from Genetika, Vol. 41, No. 6, 2005, pp. 778–783.Original Russian Text Copyright © 2005 by Butorina, Cherkashina, Chernodubov, Avdeeva.     

Alkali burns from wet cement.

When water is added to the dry materials of Portland cement calcium hydroxide is formed; the wet cement is caustic (with a pH as high as 12.9) and can produce third-degree alkali burns after 2 hours of contact. Unlike professional cement workers, amateurs are usually not aware of any danger and may stand or kneel in the cement for long periods. As illustrated in a case report, general physicians may recognize neither the seriousness of the injury in its early stages nor the significance of a history of prolonged contact with wet cement. All people working with cement should be warned about its dangers and advised to immediately wash and dry the skin if contact does occur.     

Mathematical Modelling of Aerosolised Skin Grafts Incorporating Keratinocyte Clonal Subtypes

Severe burns can be very traumatic for the patient, and while burns caused by industrial or domestic accidents are common, there are also increasing numbers of burns associated with terrorism. A novel technique to assist in the healing process is to spray skin cells, keratinocytes, that are cultured from the patient’s own tissue, directly onto the burn site. This process involves taking some undamaged skin from the patient, allowing the skin cells to proliferate rapidly in the laboratory over a period of 5–10 days, harvesting and separating the cells and then spraying them onto the burn. This paper deals with keratinocytes that have been cultured in vitro for a short period of time (early passage cultured cells). The spraying process has yet to be optimised with respect to the seeding density required for fastest re-epithelisation and thus there is a need for this process to be modelled. In this paper, we review some of the skin biology and develop a mathematical model of the growth patterns of cell colonies after they have been applied using a aerosolised technique. The model allows us to predict coverage over time and can be used as a decision support tool for clinicians. PACS: 92B05     

Survival of cultured allografts in patients with burns assessed with probe specific for Y chromosome.

The aim of the study was to determine the fate of cultured skin allografts in patients with burns. In situ DNA hybridisation with a Y probe (pHY 2.1) was used to detect cells carrying the Y chromosome (the probe being visualised by the alkaline phosphatase-antialkaline phosphatase method) in biopsy specimens taken from cultured allografts derived from donors of the opposite sex to the recipients (20 patients with burns). Specimens were taken within a week, between one and three weeks, between four and six weeks, and more than six weeks after grafting. Only two of the 27 biopsy specimens contained cells that were the same sex as the donor; both were taken within a week after grafting. In the 25 other specimens the epithelial cells were the same sex as the recipient. Cultured skin allografts showed no evidence of survival in patients with burns, which suggests that they are probably not suitable for long term management of burns but may be useful as short term biological dressings.     

Variability of the cytological parameters of Pinus sylvestris L. seeds from the unique Hrenovskoy pine forest

Hrenovskoy pine forest is a unique island stand at the boundary of the species range of Scots pine Pinus sylvestris L. This object is of exceptional economic value, because it serves as a forest-seed base for the Voronezh oblast and some other regions of Russia; therefore, the stand and seed qualities have to be monitored constantly. The results of the first cytogenetic study of the seed progeny of P. sylvestris from the Morozov Grove, a high-quality stand in a reserved site within the Hrenovskoy pine forest, are reported. The studies have been performed in order to obtain a more correct assessment of seed quality based not only on their germination and energy of germination (traditionally used by forest breeders), but also on their genomic stability. The latter may be estimated by the stability of chromosome number in the somatic cells of seedlings and the regularity of mitotic divisions, because they also characterize the state of the generative system of parental forms and may serve as an integrated estimate of the stand development homeostasis. Therefore, the chromosome number, mitotic and nucleolar activities, and the number and spectrum of pathological mitoses (PMs) have been determined. Seedlings have been obtained from 240 seeds (collected from 12 trees) that resulted from free pollination. The cytological analysis of the rootlets of these seedlings has not detected any deviations from the chromosome number typical of the species P. sylvestris L. (2n = 24). However, considerable variation has been found in each family with respect to the mitotic index (MI) (from 4.2 +/- 0.36 to 8.1 +/- 0.39%) and the number of PMs (from 0.5 to 2.1%); micronuclei have also been found in each family (from 0.01 to 0.05%). In general, the phenotypic characteristics and the variation pattern of cytological parameters of the progeny of the trees studied in the Hrenovskoy pine forest, together with the high germination rate of seeds (90-98%), indicate that the current state of pines in the Hrenovskoy pine forest can be considered to be satisfactory. However, the presence of micronuclei in all variants and the decrease in MI in some individual plants (which was, on average, 6.1 +/- 0.03% in the sample studied, i.e., significantly lower than that of P. sylvestris from the Usmanskii pine forest (7.3 +/- 1.2%), where the conditions are optimal for this species) may serve as the bioindicators of the deterioration of both the state of trees themselves and the ecological conditions in the Hrenovskoy pine forest. Therefore, the population structure of this valuable autochtonic stand should be reproduced urgently.     

Prolonged Parental Feeding in Tool‐Using New Caledonian Crows

According to life‐history theory, the duration of extended parental feeding is determined by the costs and benefits of maximising reproductive success. Therefore, the length of regular parental provisioning should be correlated with the time required for juveniles to acquire the skills that they need to be independent. The relatively few cases of extremely prolonged parental feeding in both land and sea birds appear to be consistent with this prediction because they are associated with learning‐intensive foraging techniques. New Caledonian crows have the most intricate tool manufacture techniques amongst non‐human animals and juveniles take over 1 yr to reach adult‐like proficiency in their tool skills. We investigated the prediction that this species also should have prolonged parental provisioning. We found that these crows have one of the longest known periods of regular extended parental provisioning in birds. Some parents regularly fed juveniles for up to 10 mo post‐fledging. Humans also stand out amongst primates because of their learning‐intensive foraging strategies and an extended period of juvenile dependence. The independently evolved association between a relatively high level of technological skill in foraging and prolonged juvenile provisioning in both humans and New Caledonian crows raises the possibility that these two characteristics might be causally related.     

Who should Decide for the Unrepresented?

Unrepresented patients lack the capacity to make medical decisions for themselves, have no clear documentation of preferences for medical treatment, and have no surrogate decision maker or obvious candidate for that role. There is no consensus about who should serve as the decision maker for these patients, particularly regarding whether to continue or to limit life‐sustaining treatment. Several authors have argued that ethics committees should play this role rather than the patient's treating physician, a common current default. We argue that concerns about the adequacy of physicians as surrogates are either empirically unfounded or apply equally to ethics committees. We suggest that physicians should be the primary decision maker for the unrepresented because of their fiduciary duties toward their patients. As part of the process of fulfilling these duties, they should seek the advice of third parties such as ethic committees; but final end‐of‐life decision‐making for the unrepresented should rest with the treating physician.     

The outcome is in the assumptions: analyzing the effects on atmospheric CO2 levels of increased use of bioenergy from forest biomass

Recently, several studies have quantified the effects on atmospheric CO₂ concentration of an increased harvest level in forests. Although these studies agreed in their estimates of forest productivity, their conclusions were contradictory. This study tested the effect of four assumptions by which those papers differed. These assumptions regard (1) whether a single or a set of repeated harvests were considered, (2) at what stage in stand growth harvest takes place, (3) how the baseline is constructed, and (4) whether a carbon‐cycle model is applied. A main finding was that current and future increase in the use of bioenergy should be studied considering a series of repeated harvests. Moreover, the time of harvest should be determined based on economical principles, thus taking place before stand growth culminates, which has implications for the design of the baseline scenario. When the most realistic assumptions are used and a carbon‐cycle model is applied, an increased harvest level in forests leads to a permanent increase in atmospheric CO₂ concentration.     

Impact of active soil carbonate and burn size on the capacity of the rockrose Cistus laurifolius to produce Tuber melanosporum carpophores in truffle culture

There are very few studies on Tuber melanosporum associated with Cistus populations. In central Spain, we confirm that C. laurifolius shows carpophore production of Tuber melanosporum. This study demonstrates a correlation between T. melanosporum production and the size of the 41 burns, with burn size explaining 26 % of the variability in carpophore production. However, statistical analysis of the results indicates that average production of 21 burns with Cistus laurifolius is 73 % lower than the production of 20 burns associated with Quercus/Corylus without Cistus laurifolius in this zone, respectively. C. laurifolius develops small burns, which has an impact on their carpophore production, and their soils have 92 % less active carbonate than the burns associated with Quercus/Corylus in this zone, respectively. The low levels of active carbonate allow Cistus laurifolius to grow, but impair Tuber melanosporum production. We thus provide a mechanism, based on the inability of Cistus laurifolius to grow in highly carbonated soils, which contradicts the well-known fact that C. laurifolius might act as a transmitter of Tuber melanosporum mycorrhizae. These results indicate that this rockrose can not be considered a useful species for truffle culture. We thus recommend that particular attention should be given to the concentration of active carbonate present in the soil in future studies on the relationship between Cistus species and truffles.     

The Morning after the Night Before

Benefits to females of short-term mating have recently been identified, and it has been suggested that women have evolved adaptations for this strategy. One piece of evidence supporting such a female adaptation would be that women find the experience of a one-night stand as affectively positive as men. Individuals (N = 1,743) who had experienced a one-night stand were asked to rate aspects of their “morning after” feelings (six positive and six negative). Women were significantly more negative and less positive than men. Although women did not especially view these relationships as a prelude to long-term relationships, they felt greater regret than men about having been “used.” Extra-pair copulations were rated more negatively, but not less positively, than singles’ experiences. There was no interaction between gender and mated status on positivity or negativity. Although, in terms of subsequent affective response, women do not seem well adapted to casual sexual encounters, it may be important to distinguish impelling sexual motivation preceding intercourse from later evaluations of the event. Menstrual cycle changes may also be important in altering the strength and target of sexual motivation.     

青藏高原东部采伐迹地早期人工重建序列梯度上植物多样性的变化

 采伐是青藏高原东部亚高山森林过去经营管理中最常见的实践。采伐的一个重要后果就是林地生物多样性的衰退和损失。目前虽然对采伐环境退化与迹地人工林恢复重建开展过许多研究,但对采伐迹地以及人工重建过程中的生物多样性变化研究很少。人工重建时间序列上的植物组成变化还不清楚,也没有人去检测人工林早期发展阶段间多样性的差异。作者选择大渡河上游亚高山针叶林序列采伐迹地,调查了采伐后8个人工造林时间序列梯度（1年、2年、5年、7年、10年、15年、19年和30年）和相邻的原始林内的物种组成和丰富度,比较分析了序列梯度上的植物     

Microsatellite analysis of seed dispersal and parentage of saplings in bur oak, Quercus macrocarpa

Microsatellite analysis was used to examine parentage and spatial distributions of 62 adult bur oaks Quercus macrocarpa, and 100 saplings in a single stand. Using genotypes scored by PCR products at four microsatellite loci, we determined that 94 saplings matched at least one parent in the stand. Saplings often occur as dense clusters of half-sibs around the presumed maternal parent, and only four adults were seed parents to a large proportion of the saplings sampled. A stump apparently was the seed parent of the largest cluster of half-sibs, which occupied a sizeable light gap opened up by the death of their maternal tree. Approximately half of the saplings appeared to have grown from seeds that had not been removed after falling from the tree, and half from seeds that were dispersed beyond the crown of their maternal parent. Long-distance seed dispersal may be more common than has been previously reported. Extremely high levels of long-distance pollination were indicated, and pollen donors within the stand were generally distributed randomly around maternal trees. More than half of the saplings had paternal parents outside of the stand. This study demonstrates the utility of microsatellite analysis for studying mating systems, seed dispersal and seedling establishment in natural plant populations.     

Subalpine vegetation pattern three decades after stand‐replacing fire: effects of landscape context and topography on plant community composition,tree regeneration,and diversity

Objective: Our purpose was to characterize vegetation compositional patterns, tree regeneration, and plant diversity, and their relationships to landscape context, topography, and light availability across the margins of four stand‐replacing subalpine burns. Location: Four 1977 to 1978 burns east of the Continental Divide in Colorado: the Ouzel burn, a burn near Kenosha Pass, the Badger Mountain burn, and the Maes Creek burn. Methods: Vegetation and environmental factors were sampled in 200 0.01‐ha plots on transects crossing burn edges, and stratified by elevation. We utilized dissimilarity indices, mixed‐effects models, and randomization tests to assess relationships between vegetation and environment. Results: Three decades after wildfire, plant communities exhibited pronounced compositional shifts across burn edges. Tree regeneration decreased with increasing elevation and distance into burn interiors; concomitant increases in forbs and graminoids were linked to greater light availability. Richness was roughly doubled in high‐severity burn interiors due to the persistence of a suite of native species occurring primarily in this habitat. Richness rose with distance into burns, but declined with increasing elevation. Only three of 188 plant species were non‐native; these were widespread, naturalized species that comprised <1% total cover. Conclusions: These subalpine wildfires generated considerable, persistent increases in plant species richness at local and landscape scales, and a diversity of plant communities. The findings suggest that fire suppression in such systems must lead to reduced diversity. Concerns about post‐fire invasion by exotic plants appear unwarranted in high‐elevation wilderness settings.