Can a death signal half-life be used to sense the distance to a lesion site in axons?

Neuron response to injury depends on the distance to the lesion site, which means that neurons are capable of sensing this distance. Several mechanisms explaining how neurons can do this have been proposed and it is possible that neurons use a combination of several mechanisms to make such measurements. In this paper we investigate the feasibility of the simplest mechanism, which is based on the hypothesis that death signals, produced at the lesion site, propagate toward the neuron soma. The signals are propelled by dynein motors. If signals have a finite half-life, they decay as they propagate. By measuring the concentration of death signals arriving to the soma, neurons should thus be able to determine the distance to the injury site. We develop and solve a transport equation based on the above model. We investigate how a death signal distribution depends on the dynein velocity distribution. We evaluate the efficiency of such a mechanism by investigating the sensitivity of death signal concentration at the soma to the distance to the injury site. By using the hypothesis that system performance is optimized by evolution, we evaluate death signal half-lives that would maximize this sensitivity.     

Can changes in the distributions of resident birds in China over the past 50?years be attributed to climate change?

The distributions of bird species have changed over the past 50 years in China. To evaluate whether the changes can be attributed to the changing climate, we analyzed the distributions of 20 subspecies of resident birds in relation to climate change. Long‐term records of bird distributions, gray relational analysis, fuzzy‐set classification techniques, and attribution methods were used. Among the 20 subspecies of resident birds, the northern limits of over half of the subspecies have shifted northward since the 1960s, and most changes have been related to the thermal index. Driven by climate change over the past 50 years, the suitable range and latitude or longitude of the distribution centers of certain birds have exhibited increased fluctuations. The northern boundaries of over half of the subspecies have shifted northward compared with those in the 1960s. The consistency between the observed and predicted changes in the range limits was quite high for some subspecies. The changes in the northern boundaries or the latitudes of the centers of distribution of nearly half of the subspecies can be attributed to climate change. The results suggest that climate change has affected the distributions of particular birds. The method used to attribute changes in bird distributions to climate change may also be effective for other animals.     

Can we predict carbon stocks in tropical ecosystems from tree diversity? Comparing species and functional diversity in a plantation and a natural forest

? Linking tree diversity to carbon storage can provide further motivation to conserve tropical forests and to design carbon-enriched plantations. Here, we examine the role of tree diversity and functional traits in determining carbon storage in a mixed-species plantation and in a natural tropical forest in Panama. ? We used species richness, functional trait diversity, species dominance and functional trait dominance to predict tree carbon storage across these two forests. Then we compared the species ranking based on wood density, maximum diameter, maximum height, and leaf mass per area (LMA) between sites to reveal how these values changed between different forests. ? Increased species richness, a higher proportion of nitrogen fixers and species with low LMA increased carbon storage in the mixed-species plantation, while a higher proportion of large trees and species with high LMA increased tree carbon storage in the natural forest. Furthermore, we found that tree species varied greatly in their absolute and relative values between study sites. ? Different results in different forests mean that we cannot easily predict carbon storage capacity in natural forests using data from experimental plantations. Managers should be cautious when applying functional traits measured in natural populations in the design of carbon-enriched plantations.     

Can percentage infection and dwarfing be used to differentiate aggressiveness in Plasmopara halstedii?

Aggressiveness was studied in seven Plasmopara halstedii (sunflower downy mildew) parental isolates of races 100, 300, 304, 314, 704, 710 and 714 using five single zoosporangium isolates per parental isolate. Aggressiveness criteria, including percentage infection and dwarfing (reduction of hypocotyl length), were analysed in one sunflower inbred line showing a high level of quantitative resistance. Analysis of five single zoosporangium isolates of each parental isolate showed variability within parental isolate for the two aggressiveness criteria, but not for all parental isolates for percentage infection and vice versa for the reduction of hypocotyl length. Percentage infection showed high values irrespective of the parental isolate used. However, all the parental isolates caused a large reduction in seedling size except for the isolate of race 314. Although percentage infection and reduction of hypocotyl length could be used to differentiate aggressiveness in P. halstedii, it seems that these criteria played a limited role to define P. halstedii isolates according to their aggressiveness.     

Can biotic resistance be utilized to reduce establishment rates of non-indigenous species in constructed waters?

Understanding the mechanisms that facilitate establishment of non-indigenous species is imperative for devising techniques to reduce invasion rates. Passively dispersing non-indigenous organisms, including zooplankton, seemingly invade constructed waters (e.g., ornamental ponds, dams and reservoirs) at faster rates than natural lakes. A common attribute of these invaded water bodies is their relatively young age, leading to the assertion that low biotic resistance may lead to their higher vulnerability. Our aim was to determine if seeding of young water bodies with sediments containing diapausing stages of native zooplankton could accelerate community development, leading to greater biotic resistance to the establishment of new species. Twenty outdoor tanks were filled with water (1,400 L) and nutrients added to attain eutrophic conditions. Ten treatment tanks had sediments added, sourced from local water bodies. In the remaining ten, sediments were autoclaved, and received zooplankton via natural dispersal only. In an initial 12 month monitoring period, species richness increased at a greater rate in the treatment tanks (at 12 months average standing richness per tank = 3.8, accumulated richness = 8.2) than control tanks (2.6 and 5.0, P < 0.05). Treatment tanks developed assemblages with greater proportions of species adapted to pelagic conditions, such as planktonic cladocerans and copepods, while control tanks generally comprised of smaller, littoral dwelling, rotifers. Analysis of similarities indicated community composition differed between the control and treatment groups at 12 months (P < 0.01). Two copepod, four rotifer and one cladoceran species were intentionally added to tanks at 12 months. In the 3 month post-introduction period, five of these species established populations in the control tanks, while only two species established in the treatment tanks. The calanoid copepod Skistodiaptomus pallidus, for example, a non-indigenous species confined to constructed waters in New Zealand, established exclusively in tanks where native calanoid copepod species were absent (primarily control tanks). Our study suggests that biotic resistance could play an important role in reducing the establishment rate of non-indigenous zooplankton. It also provides evidence that seeding constructed water bodies with sediments containing diapausing eggs of native species may provide an effective management tool to reduce establishment rates of non-indigenous zooplankton.     

Can seed characteristics or species distribution be used to predict the stratification requirements of herbs in the Australian Alps?

The germination requirements of 19 herbs in the Australian Alps were investigated to determine which species may be sensitive to predicted climate changes. Seeds were subjected to factorial treatments of cold stratification for 0, 4, 8 and 12 weeks, followed by incubation at constant temperatures of 10, 15, 20 and 25 °C and alternating temperatures of 20/5 and 20/10 °C. Germination responses were used to identify stratification‐dependent species, to classify dormancy and to determine optimum conditions for laboratory germination. Ordinal logistic regression was used to determine whether the duration of stratification required for ≥ 50% germination could be predicted by seed weight, seed length, embryo : seed ratio or species distribution (latitudinal range, altitudinal range and maximum altitude). The Kruskal–Wallis test was used to determine any significant differences in stratification requirement between endospermic and non‐endospermic seeds. Species varied considerably in their response to the treatment combinations, and therefore their dormancy class. No significant predictors of stratification requirement were identified by ordinal logistic regression (P > 0.9); however, there was a significant difference in stratification requirement between endospermic and non‐endospermic seeds (P = 0.003). Species with non‐endospermic seeds did not require any stratification to germinate well over a range of temperatures, and appear most likely to remain stable or expand in range in response to climate warming. Conversely, the need for ≥ 8 weeks of cold stratification was associated with the presence of endosperm and either a restricted distribution or upland ecotypes of widely distributed species. Alpine species with endospermic seed and a restricted distribution are most likely to contract in range under climate change and would be appropriate to prioritize for ex situ conservation. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172 , 187–204.     

Tree distribution pattern and fate of juveniles in a lowland tropical rain forest – implications for regeneration and maintenance of species diversity

Three analyses of species diversity in a lowland dipterocarp forest were conducted to examine whether the nature of forest community dynamics are determined by density-dependent recruitment and mortality of saplings with a data set obtained in a 50 ha plot in Pasoh Forest Reserve. The first analysis examined whether sapling density varied as a function of distance from the nearest conspecific adult. The second analysis assessed the relationship between the spatial distribution patterns of saplings and adult trees. A third analysis examined sapling recruitment and mortality based on data from 2 censuses, taken in 1985 and 1990. Four hundred forty-four species (each with more than 100 individuals) out of the total of 814 species recorded in the plot, were chosen for the analyses. Of these selected species, 56 species showed significant reduction in sapling densities close to the conspecific adults. Within this group, 11 species were in the emergent layer (29.0% of the total species in this layer), 17 were in the canopy layer (10.5%), 18 were in the understory layer (11.3%), and 10 were in treelet and shrub layer (11.8%). In contrast, the sapling densities of 53 species decreased with increasing distance from conspecific adults; 2 of these species were in the emergent layer (5.2% of the total species in this layer), 14 were in the canopy layer (8.6%), 21 were in the understory layer (13.2%), and 16 were in the treelet and shrub layer (18.8%). The saplings of 35 of the 444 total selected species were clumped, while adults were regularly or randomly distributed. Of the remaining species, in 183 species (41.2%), the distributions of both adults and saplings were clumped. Thus, these 2 analyses do not support the prediction that most of the species of lowland tropical forests fail to produce new adults in their vicinity and as a result of this, adult trees are more regularly distributed than their conspecific juveniles (Janzen 1970). In the third analysis, the recruitment of saplings of species in the emergent and canopy layers increased significantly and in proportion with mortality, suggesting that the dominant species suffer higher mortality than do less common species. This trend is not so apparent in the understory, and the treelet and shrub layers. The results imply that a dynamic equilibrium process, which prevents competitive exclusion and maintains space for minor species, may be active among the species in the upper layers (particularly the emergent layer); however, such a dynamic equilibrium condition is not due exclusively to the reduced recruitment of saplings near conspecific adults, and the dynamic equilibrium condition is not prevalent among the lower story species.     

How does variation in total and relative abundance contribute to gradients of species diversity?

Patterns of biodiversity provide insights into the processes that shape biological communities around the world. Variation in species diversity along biogeographical or ecological gradients, such as latitude or precipitation, can be attributed to variation in different components of biodiversity: changes in the total abundance (i.e., more‐individual effects) and changes in the regional species abundance distribution (SAD). Rarefaction curves can provide a tool to partition these sources of variation on diversity, but first must be converted to a common unit of measurement. Here, we partition species diversity gradients into components of the SAD and abundance using the effective number of species (ENS) transformation of the individual‐based rarefaction curve. Because the ENS curve is unconstrained by sample size, it can act as a standardized unit of measurement when comparing effect sizes among different components of biodiversity change. We illustrate the utility of the approach using two data sets spanning latitudinal diversity gradients in trees and marine reef fish and find contrasting results. Whereas the diversity gradient of fish was mostly associated with variation in abundance (86%), the tree diversity gradient was mostly associated with variation in the SAD (59%). These results suggest that local fish diversity may be limited by energy through the more‐individuals effect, while species pool effects are the larger determinant of tree diversity. We suggest that the framework of the ENS‐curve has the potential to quantify the underlying factors influencing most aspects of diversity change.     

Are changes in remotely sensed canopy cover associated to changes in vegetation structure,diversity, and composition in recovered tropical shrublands?

The recovery of vegetation cover is a process that has important implications for the conservation of biodiversity and ecosystem services. Generally, the recovery of vegetation cover is documented over large areas using remote sensing, and it is often assumed that ecosystem properties and processes recover along with remotely sensed canopy cover. Here we analyze and compare the structure, composition, and diversity of trees and shrubs among plots established in a stratified random sampling design over four remotely sensed canopy cover change (CCC) categories defined according to a gradient in the percent of canopy cover. Plots were located in the Lake Cuitzeo basin (Mexico), where canopy recovery associated with agricultural abandonment has occurred in recent decades (1975–2000). We found that diversity measures, basal area, tree and shrub density, ground-truthed canopy cover, and mean plant height increased with increasing CCC category. However, Shannon index (H′) was lower in the CCC category with the most closed canopy cover category than in plots apparently not affected by agriculture. Furthermore, ordination analyses showed that composition of dominant species were not associated with CCC categories. Our results suggest that canopy closure in our study area is not associated with the recovery of species diversity, and does not result in similar species dominance as in sites not affected by agriculture.     

Progressive changes in the structure and dynamics of the phytoplankton community along a pollution gradient in a lowland river — a multivariate approach

The phytoplankton of the River Lujan (Buenos Aires, Argentina) was studied for a period of 18 months, together with physical and chemical variables, in relation to a pollution gradient. 167 taxa were recorded within a seasonal succession characterized by dominance of diatoms with a brief summer green algae facies. A combination of several biotic indices and multivariate analysis was employed to assess the impact of pollution on the phytoplankton community. The biotic indices used were species diversity and richness, algal quotients (green algae/diatom ratio, Centrales/Pennales ratio) and the SD succession rate index. Multivariate procedures included cluster analysis and ordination by PCA of both species and samples, stepwise discriminant analysis and multiple discriminant analysis of variance (MANOVA). Results indicate that community dynamism is attenuated at the more polluted sites, concomitant with an increased predominance of a broad-tolerance algal assemblage, co-dominated by Cyclotella meneghiniana and Nitzschia stagnorum. The changes in the community structure and dynamics described herein involved alterations in the distribution and relative proportions of the algae, rather than modifications in the basic species composition. These changes may not be readily detectable by methods which over-simplify the ecological information, such as systems of indicator species and biotic indices, designed to assess the degree of pollution. The suitability of multivariate analysis and biotic indices in river phytoplankton studies is further discussed.     

Can zebrafish be used as a model to study the neurodevelopmental causes of autism?

The zebrafish has proven to be an excellent model for analyzing issues of vertebrate development. In this review we ask whether the zebrafish is a viable model for analyzing the neurodevelopmental causes of autism. In developing an answer to this question three topics are considered. First, the general attributes of zebrafish as a model are discussed, including low cost maintenance, rapid life cycle and the multitude of techniques available. These techniques include large-scale genetic screens, targeted loss and gain of function methods, and embryological assays. Second, we consider the conservation of zebrafish and mammalian brain development, structure and function. Third, we discuss the impressive use of zebrafish as a model for human disease, and suggest several strategies by which zebrafish could be used to dissect the genetic basis for autism. We conclude that the zebrafish system could be used to make important contributions to understanding autistic disorders.     

Can dual chlorophyll fluorescence excitation be used to assess the variation in the content of UV-absorbing phenolic compounds in leaves of temperate tree species along a light gradient?

The present study assesses light-induced variations in phenolic compounds in leaves of saplings of two co-occurring temperate species (Acer platanoides L., and Fraxinus excelsior L.) along a light gradient using a new non-invasive optical method (Dualex). The Dualex-derived UV absorbance of leaf epidermis (the sum of the adaxial and abaxial faces, AUV) increased significantly with increasing light in both species. AUV values were correlated with absorbance of the leaf extract at 305 nm and 375 nm (A305 and A375) in both species with similar slopes for both species. However, a large difference in intercept was observed between the two species when A305 was regressed against AUV. Similarly, AUV values were well correlated with the amount of phenolics in the leaf extracts assessed by the Folin-Ciocalteu method, but slopes were significantly different for the two species. Thus, the UV-A epidermal transmittance, despite being a reliable indicator of the UV-screening capacity of the leaf epidermis, cannot be used for any quantitative estimate of UV-B screening capacity or of energetic requirement for leaf construction without a species-specific calibration.     

Can macroinvertebrate rapid bioassessment methods be used to assess river health during drought in south eastern Australian streams?

• 1 Despite significant concern about drought impacts in Australia, there have been no broad‐scale studies of drought effects on river health. A severe and prolonged drought has been acting on many streams in south eastern Australia over the past decade. EPA Victoria has undertaken rapid bioassessment (RBA) of over 250 stream reference sites since 1990, providing an opportunity for a before‐after‐control‐impact investigation of drought related changes to macroinvertebrate indices and water quality. This study uses data from 1990 to 2004 to critically evaluate the effectiveness of using RBA methods and indices, which were designed for assessment of human impacts, for monitoring streams during drought.
• 2 Reference stream sites across Victoria (those with minimal anthropogenic disturbances and repeatedly sampled) were classified as being ‘in drought’ or ‘not in drought’ using the Bureau of Meteorology’s rainfall deficiency definition. Four biological indices (SIGNAL, EPT, Family Richness and AUSRIVAS) were calculated for combined autumn and spring samples for edge and riffle habitats for the selected sites.
• 3 General linear models and paired t‐tests were used to detect drought related changes to index and water quality values at state‐wide and bioregional scales. Changes in taxa constancy were examined to determine which taxa were sensitive to or benefited from drought conditions. Frequency of site failure against biological objectives specified in the State Environment Protection Policy (Waters of Victoria) (herein termed ‘SEPP WoV’) before and during drought was also examined to detect changes in a management context.
• 4 Few significant changes in index values were detected for riffle habitat samples. Rates of failure against biological objectives were similar before and during drought for riffle samples. In contrast, edge habitat AUSRIVAS and SIGNAL scores were significantly reduced at the state‐wide scale and most indices showed significant declines in the lower altitude forests, and foothills and coastal plains bioregions.
• 5 Generally, more pollution tolerant, lentic taxa replaced sensitive and flow‐requiring taxa in edge samples during drought. In contrast, there were few reductions in the taxa of riffle samples during drought. However, many pool preferring, but pollution sensitive taxa occurred more frequently in riffle areas. Hence, the riffle community began to resemble that of pools and edges. This was attributed to decreased flow and increased ‘lentic’ habitat opportunities in riffles.
• 6 Detection of a drought effect was confined to the edge habitat and site failure could be assigned to drought and anthropogenic impacts, in conjunction or alone. The riffle sampling protocol was resistant to detection of drought effects as samples were only taken when sufficient water was present within this habitat. Therefore, biological changes at sites not meeting policy objectives for riffle habitats can be attributed to anthropogenic rather than drought impacts.

     

Can stable isotopes be used to infer site fidelity of nekton in open coastal areas?

Stable isotope analysis has been applied to the investigation of movement in several species, including marine animals. However, its application to nekton living in open coastal areas is still very scarce. This study aims to test if stable isotope analysis can be used for this purpose over a much wider spatial scale than previously investigated. Stable isotope analysis was used to 1) investigate isotopic variation in shrimp and fish, in 11 sites, along a 160 km coastal stretch, to 2) determine the site fidelity of the individuals within each species, and to 3) test the relation between the body size of the individuals within each species, at each site and the percentage of isotopic deviants. Site fidelity was the highest for the intertidal fish Gobius paganellus and Coryphoblennius galerita, with 60% and 64% of individuals considered residents, respectively, and lowest for the demersal fish Diplodus vulgaris and Diplodus sargus with 23% and 33% of resident individuals, respectively. The percentage of isotopic deviants was not correlated with length in any species. Site fidelity was considerably higher than that previously found for other open coastal areas and similar to more structured environments, like coastal ponds. It was hypothesized that the complex tri-dimensional structure of the rocky reefs that occur in this area, often encompassing channels and tide pools, offers conditions favourable to high site fidelity. This study shows that stable isotopes can be used to infer nekton movement in wide open coastal areas.     

Can different Catphan phantoms be used in a multi-centre audit of radiotherapy CT image quality?

PurposeTo determine the variation between Catphan image quality CT phantoms, specifically for use in a future multi-centre image quality audit.Method14 Catphan phantoms (models 503, 504 and 604) were scanned on a Canon Aquilion Prime CT scanner using a single scan protocol. Measurements were made of noise in the uniformity section, visibility of low contrast targets and contrast, x-ray attenuation and CT number for 5 materials in the sensitometry section. Scans were also acquired using one phantom and varying reconstruction field of view, image slice thickness, effective tube-current-time product and iterative reconstruction settings to determine how the degree of inter-phantom variability compared with the magnitude of changes from scan parameter alteration.ResultsAcross all phantoms the mean CT value in the uniformity section was 7.0 (SD 0.9) range: 4.9–8.1 HU. For the different materials the CT numbers were air: −1004 ± 5, Polymethylpentene: −190 ± 2, Polystyrene: −42 ± 2, Delrin: 321 ± 5 and Teflon: 898 ± 8 HU. Consistency of low contrast targets through visual scoring was good. Measured contrast was lower (p < 0.001) with more variability for 504 versus 604 models. All phantoms produced identical tube current settings with x-ray tube current modulation, indicating no x-ray attenuation differences. The degree of change in image quality metrics between phantoms was small compared with results when scan parameters were varied.ConclusionCatphan phantoms model 604 showed minimal differences and will be used for multi-centre inter-comparison work, with the consistency between phantoms appropriate for measuring possible variations in image quality.     

Can a finite set of knee extension in supine position be used for a knee functional examination?

The kinematic magnetic resonance imaging technique has been developed to provide a functional examination of the knee. Technical limitations require this examination to be performed in supine position, and the knee motion is represented by an assembly of static positions at different knee angles. However, the main knee function is to support the body weight and perform continuous motion, e.g. parallel squat. Our study quantified the knee kinematics of 20 healthy subjects in different motion conditions (finite and continuous) and in different mechanical conditions (continuous unloaded and continuous loaded). We evaluated the angular and localisation difference of a finite helical axis of the knee motion for parallel squat, continuous knee extension in supine position and the finite set of knee extension in supine position. We found large inter-individual dispersion. The majority of subjects had equivalent knee kinematics between continuous knee extension and the finite set of knee extension in supine position, but not between continuous knee extension in supine position and the parallel squat. Therefore, results from a functional examination of a finite set of knee extensions in supine position do not represent the knee motion in a parallel squat. Our results suggest that functional examination of the knee from magnetic resonance imaging do not necessarily reflect the physiological kinematics of the knee. Further investigation should focus on a new magnetic resonance imaging acquisition protocol that allows image acquisition during weight bearing or includes a special device which reproduces the loaded condition.     

Can Internalism and Externalism be Reconciled in a Biological Epistemology of Language?

This paper is an attempt at exploring the possibility of reconciling the two interpretations of biolinguistics which have been recently projected by Koster (Biolinguistics 3(1):61–92, 2009). The two interpretations—trivial and nontrivial—can be roughly construed as non-internalist and internalist conceptions of biolinguistics respectively. The internalist approach boils down to a conception of language where language as a mental grammar in the form of I-language grows and functions like a biological organ. On the other hand, under such a construal consistent with Koster’s (Biolinguistics 3(1):61-92, 2009), the non-internalist version does not necessarily have to be externalist in nature; rather it is a matter of mutual reinforcement of biology and culture under the rubric of a co-evolutionary dynamics. Here it will be argued that the apparent dichotomy between these two conceptions of biolinguistics can perhaps be resolved if we have a richer synthesis that accounts for both internalism and non-internalism.     

Can eggs in a cavity be a female secondary sexual signal? Male nest visits and modelling of egg visual discrimination in blue tits

Eggshell colouration is thought to function as a female-specific secondary sexual trait. While tests of this idea are rapidly accumulating in cavity-nesting birds, some fundamental underlying assumptions remain rarely investigated: namely, can males see eggshell coloration and perceive colour differences between the eggs of different females? We tested these two key assumptions in a natural population of blue tits (Cyanistes caeruleus). Using transponders, we tracked male nest visits and found that all males visited their nest-boxes while eggs were present and often visually accessible. Interestingly, some males also visited neighbouring nests. We then tested whether birds could detect eggshell coloration using models of avian colour vision; models were performed with and without limitations on visual performance owing to dim light. Both models found that differences in eggshell brightness were often easier to discriminate than differences in colour; there was more contrast in white eggshell background between clutches than within and its contrast against nest background was repeatable within clutches, suggesting these features could act as signals. Yet, the detectability of these contrasts depended entirely on model assumptions of visual limitations. Consequently, we need a better understanding of underlying visual mechanisms in dim-light environments and behavioural discrimination experiments before confirming the signalling potential of eggshell coloration.     

Co-variation and indicators of species diversity: Can richness of forest-dwelling species be predicted in northern boreal forests?

Design and establishment of ecologically good networks of conservation areas often requires quick assessments of their biodiversity. Reliable indicators would be useful when doing such assessments. In order to explore the potential indicators for species richness in boreal forests, we studied (1) the co-variation of species richness and composition of species assemblages among beetles, polypores, birds and vascular plants, (2) the relationships between species richness and four boreal forest site types, (3) the relationship between species richness and forest physical structure and (4) the suitability of potential indicator groups within the four taxa to predict the species richness generally. The data show that there are probably not a single taxonomic or forest structural characteristic to be used as a general biodiversity indicator or surrogate for all the species. The correlations in species richness among the four taxa studied were low. However, group-specific indicators were obvious: forest site type was a good surrogate for vascular plant richness, and quantity and quality of dead wood predicted the species richness of polypores. The results support the view that different indicators shall be used for different forest types and taxonomic groups. These indicators should facilitate relatively rapid methods to assess biodiversity patterns at the forest stand level.