Intercropping system of tropical leguminous species and Eucalyptuscamaldulensis, inoculated with rhizobia and/or mycorrhizal fungi in semiarid Brazil

For the purpose of reforestation and wood supply the leguminous tree Anadenanthera peregrina, a native species, was intercropped with Eucalyptus camaldulensis in a degraded semiarid area of Brazil. Single and mixed stands of these species were inoculated with Rhizobium and/or arbuscular mycorrhizal fungi (AMF). The growth of all species in mixed stands did not differ from those cultivated in monoculture and land equivalent ratio (LER) exceeded unity in intercropped plots. Inoculated plants showed greater height and diameter growth and dry matter and nutrient concentration in plants of A. peregrina was higher in inoculated single plots. The distribution, composition and density of AMF species was related to the rhizosphere effect of plant species. The intercropped model where all the plants were inoculated achieved soil AMF diversity patterns similar to those of the preserved area and showed also higher soil organic matter, nutrient content as well as a reduction in soil macroporosity. This model of intercropping may be considered as an efficient system for reforestation under semiarid conditions.     

Mixed-species plantations of Acacia mangium and Eucalyptus grandis in Brazil: 2: Nitrogen accumulation in the stands and biological N2 fixation

The sustainability of plantation forests is closely dependent on soil nitrogen availability in short-rotation forests established on low-fertility soils. Planting an understorey of nitrogen-fixing trees might be an attractive option for maintaining the N fertility of soils. The development of mono-specific stands of Acacia mangium (100A:0E) and Eucalyptus grandis (0A:100E) was compared with mixed-species plantations, where A. mangium was planted in a mixture at a density of 50% of that of E. grandis (50A:100E). N₂ fixation by A. mangium was quantified in 100A:0E and 50A:100E at age 18 and 30 months by the ¹⁵N natural abundance method and in 50A:100E at age 30 months by the ¹⁵N dilution method. The consistency of results obtained by isotopic methods was checked against observations of nodulation, Specific Acetylene Reduction Activity (SARA), as well as the dynamics of N accumulation within both species. The different tree components (leaves, branches, stems, stumps, coarse roots, medium-sized roots and fine roots) were sampled on 5–10 trees per species for each age. Litter fall was assessed up to 30 months after planting and used to estimate fine root mortality. Higher N concentrations in A. mangium tree components than in E. grandis might be a result of N₂ fixation. However, no evidence of N transfer from A. mangium to E. grandis was found. SARA values were not significantly different in 100A:0E and 50A:100E but the biomass of nodules was 20–30 times higher in 100A:0E than in 50A:100E. At age 18 months, higher δ¹⁵N values found in A. mangium tree components than in E. grandis components prevented reliable estimations of the percentage of N derived from atmospheric fixation (%Ndfa). At age 30 months, %Ndfa estimated by natural abundance and by ¹⁵N dilution amounted to 10–20 and 60%, respectively. The amount of N derived from N₂ fixation in the standing biomass was estimated at 62 kg N ha⁻¹ in 100A:0E and 3 kg N ha⁻¹ in 50A:100E by the ¹⁵N natural abundance method, and 16 kg N ha⁻¹ in 50A:100E by the ¹⁵N dilution method. The total amount of atmospheric N₂ fixed since planting (including fine root mortality and litter fall) was estimated at 66 kg N ha⁻¹ in 100A:0E and 7 kg N ha⁻¹ in 50A:100E by the ¹⁵N natural abundance method, and 31 kg N ha⁻¹ in 50A:100E by the ¹⁵N dilution method. The most reliable estimation of N₂ fixation was likely to be achieved using the ¹⁵N dilution method and sampling the whole plant.     

A comparison of two stand table projection methods for young Eucalyptus nitens (Maiden) plantations in Chile

The study compares two methods of stand table projection based on data from young Eucalyptus nitens (Maiden) plantations in Chile. The projected diameter distributions were estimated using the methods proposed by Nepal and Somers (1992) [For. Sci. 38 (1992) 120] and Cao and Baldwin (1999) [For. Sci. 45 (1999) 506]. The evaluation compared the observed and estimated diameter distributions for different projection intervals, using the Kolmogorov–Smirnov test and an error index called ‘relative discrepancy’. The evaluation showed that both methods are suitable for application in the Eucalypt plantations. However, the method proposed by Nepal and Somers proved to be more accurate, especially when the projection period extends over 4 years or more. Expected error and bias for the observed and estimated total and merchantable volumes at stand level were also evaluated. The observed error and bias were relatively low for both methods; however, some differences were detected when the volume distributions were analyzed at diameter class level.     

Effect of Lecanicillium muscarium on Eretmocerus sp. nr. furuhashii (Hymenoptera: Aphelinidae), a parasitoid of Bemisia tabaci (Hemiptera: Aleyrodidae)

Pathogenicity of Lecanicillium muscarium, against Eretmocerus sp. nr. furuhashii (Hymenoptera: Aphelinidae), was investigated under laboratory conditions to determine if the fungal infection of the whitefly host can effect the survival, longevity and fecundity of female parasitoid. The results indicated that the number of parasitized larvae surviving a L. muscarium treatment after 6 days of oviposition decreased with increasing concentrations of L. muscarium and in later stages of development (12 days post oviposition) were not affected by fungal application. There were no significant differences on adult parasitoid survivorship after 7 days among all treatments. Maximum survivorship (73.33%) was observed for control and it was minimum (60%) at 1 × 10⁸ conidia/ml. L. muscarium showed a non significant effect on longevity and next offsprings of female parasitoids. The percentage emergence of parasitoids from the whitefly nymphs produced by the females emerged from treated pupae was almost similar. Maximum emergence (69.77%) was observed at 1 × 10⁶ conidia/ml and it was lowest (61.02%) at conidial concentration of 1 × 10⁸ conidia/ml. Maximum longevity of adult Eretmocerus sp. emerging from whitefly nymphs when treated after 12 days of postoviposition was observed for 1 × 10⁵ conidia/ml having a mean value of 5 days whereas the lowest longevity was 4.9 days observed at 1 × 10⁸ conidia/ml. The results mentioned above indicate that the interaction among biocontrol agents is positive to a greater extent with minimum risk hazards.     

The influence of fire severity,serotiny, and post-fire management on Pinus pinaster Ait. recruitment in three burnt areas in Galicia (NW Spain)

The effect of fire severity and post-fire management on Pinus pinaster recruitment was evaluated in three burnt areas in Galicia (NW Spain) exhibiting different levels of serotiny. Three sites were sampled, each of which had two of the following levels of fire severity: combusted crown, scorched crown and unaffected crown. Viable seed rain was closed related to the canopy cone bank and stand serotiny level. Soil burn severity also favoured seed dispersal. Relative germination success increased with soil burn severity whereas initial and final seedling density depended on both the canopy cone bank and soil burn severity. A positive influence of fire severity on the final/initial seedling density and final density/total seed dispersal ratios was also observed.     

Effects of bark harvest and other human activity on populations of the African cherry (Prunus africana) on Mount Oku, Cameroon

Bark extracts from the African cherry, Prunus africana (Rosaceae), are a popular treatment for enlarged prostates. Harvests of the bark began in Cameroon in the 1970s. Because of concerns regarding the sustainability of the trade, the species is included on the IUCN Red List and in CITES Appendix II. This study followed five P. africana populations in the Kilum-Ijim Forest Preserve on Mount Oku, Cameroon, examining growth, mortality and reproductive parameters, as well as response to harvest and other human activities. During the first part of the study (1998–1999), the forest had limited human activity; by the second part (2007–2008), more activity was apparent, including wildfires, grazing and a forest-wide bark harvest in 2005/2006. Over the study period, population structure differed from a typical J-shaped frequency curve for long-lived species, which may reflect past harvesting. After the 2005/2006 harvest, the population structure had shifted slightly toward the smaller size classes. In addition, the number of surviving trees was reduced in all size classes. About half of the reproductive trees died during the study. Size class was not a significant predictor of death, but the location of the harvest (plot) was. All trees affected by wildfires died, suggesting that the species is not adapted to fire. Trees that were harvested without disrupting the vascular cambium survived better and had minimal loss of crown. Thus, the fate of the trees in a given plot may lie in the care taken by an individual harvester. Average growth (0.34 cm per year) was not significantly different among the size classes. Crown die-back significantly reduced fruit production, obscuring the asynchronous alternating fruiting pattern. Seedling numbers followed a similar alternating pattern, but survival was negligible due to grazing. The combined factors of mortalities of a large percentage of reproductive trees (especially the largest ones), highly reduced fruit production and poor seedling survival offer a bleak prognosis for future regeneration and long-term persistence of the species in this forest. Only after decades of harvest are existing standing crop inventories and scientifically based annual quotas now being determined. It is known that the trees are easily domesticated. Efforts have been intensified to train villagers and community forest managers in vegetative propagation techniques and nursery practices, offering some hope that the species can be successfully managed to provide for sustainable harvests and dependable rural livelihoods.     

Forest management and temporal effects on food abundance for a ground-foraging bird (Catharus guttatus)

While food abundance is known to limit bird populations, few studies have simultaneously examined both temporal and habitat-related variation in food abundance for ground-foraging birds. We surveyed ground-dwelling arthropods throughout the breeding season and in three forest harvest types (clearcut, selection, and shelterwood stands managed for spruce, fir and hemlock) at the Penobscot Experimental Forest (PEF), Bradley, Maine, USA. Pitfall trapping during 2003 and 2004 was used to measure seasonal and habitat-related variation in abundance of ground-dwelling arthropod food items for hermit thrushes. Arthropods were sorted into relevant taxonomic and size class categories based on the known diet of hermit thrushes. Habitat variables included forest management type, stand-level structure and composition of tree species, and microhabitat measures in a 1 m² area around the pitfall traps. We used redundancy analysis to find stand-level and microhabitat measures that best explained variation in arthropod abundance during 2004. The majority of arthropod captures comprised three groups: ants (Formicidae, 44%), ground beetles (Carabidae, 13%), and spiders (Araneae, 11%). There was significant temporal variation in captures for many taxa. Notably, there were as many as six times more Araneae in early compared to late season samples suggesting the importance of Araneae to ground-foraging birds. Carabidae were more abundant in selection versus either shelterwood or clearcut stands on one sample date. Conversely, Formicidae and Curculionidae were more abundant in shelterwood plots on one and three sampling dates, respectively. Overall, our data provided little evidence that forest management type impacts arthropod food abundance, in stands 5–20 years post-harvest. Abundance of Carabidae was positively correlated with the number of softwoods less than 5 cm DBH and the number of hardwoods greater than 10 cm DBH, while abundance of Formicidae and Homopterans was negatively associated with these same measures. Several taxa were negatively associated with percent of the 1 m² around the pitfall that was shaded, including Araneae, Carabidae, Formicidae, and Staphylinidae. These results suggest that less-shaded forest microhabitats are important areas of increased food abundance for ground-foraging birds, regardless of forest management type or tree composition. Consequently, forest managers seeking to maximize food abundance for ground-foraging birds in managed spruce-fir forests should consider retaining some large diameter hardwood trees and use management techniques that reduce forest floor shading.     

Capacity of stem water conductivity for two eucalyptus ( Eucalyptus urophylla ) plantations in South China

The sap flux density (SFD) was used as a measure of water capacity through stems of eucalyptus in this paper. It was found that daily SFD increased with daily vapor pressure deficit (VPD) in nonlinear regression Y=AX ³+BX ²+CX+D (R ²=0.702 1, n=135, p=0.01) at both sites (Hetou and Jijia) in the Leizhou Peninsula, Guangdong Province, China, where Y was daily SFD, X was mean daily VPD, A, B, C, D were constants. But extremely high VPD might limit stem water conductivity. The environmental factors, such as air vapor pressure deficit (VPD), solar radiation (RAD), etc., were the main determinants of SFD for E. urophylla plantations. The upper threshold of diurnal SFD was 51.55–55.65 mL·cm⁻²·h⁻¹ under the selected extremely high environmental conditions.     

Object-based semi-automatic approach for forest structure characterization using lidar data in heterogeneous Pinus sylvestris stands

In this paper, we present a two-stage approach for characterizing the structure of Pinus sylvestris L. stands in forests of central Spain. The first stage was to delimit forest stands using eCognition and a digital canopy height model (DCHM) derived from lidar data. The polygons were then clustered (k-means algorithm) into forest structure types based on the DCHM data within forest stands. Hypsographs of each polygon and field data validated the separability of structure types. In the study area, 112 polygons of Pinus sylvestris were segmented and classified into five forest structure types, ranging from high dense forest canopy (850 trees ha⁻¹ and Loreýs height of 17.4 m) to scarce tree coverage (60 tree ha⁻¹ and Loreýs height of 9.7 m). Our results indicate that the best variables for the definition and characterization of forest structure in these forests are the median and standard deviation (S.D.), both derived from lidar data. In these forest types, lidar median height and standard deviation (S.D.) varied from 15.8 m (S.D. of 5.6 m) to 2.6 m (S.D. of 4.5 m). The present approach could have an operational application in the inventory procedure and forest management plans.     

Nutrient status of managed and natural forest fragments of Fagus sylvatica in southern Europe

Beech forests located in the southwestern limit of Europe have been affected by severe deforestation and long-term fragmentation. Some of these forests have been subjected to partial cutting, whereas others have been maintained with little or no active management. It has previously been shown that past management has led to substantial changes in tree structure, diversity and plant species. These perturbations, through their influence on the litterfall and forest floor, may affect nutrient cycling and the nutritional status of such fragile ecosystems. Mineral nutrition was investigated in 53 forest fragments by analysis of data corresponding to nutrient concentrations in forest floor, mineral soils and foliage. In comparison with other beech forests in Central Europe subjected to higher levels of air pollution, the stands showed fewer incidences of nutrient deficiencies and lower foliar concentrations of S and heavy metals. Partial cuts carried out in recent decades have reduced the forest floor mass proportional to the intensity of the harvesting. The effect was probably due to the lower litter input and the increased decomposition of litter as a consequence of the environmental changes in forest gaps. The partially cut stands displayed higher foliar levels of K and Mg, which could be attributed to the greater release of these elements as a consequence of the increased decomposition of litter. However, past management has brought about lower foliar concentrations of P and N. Both effects were found to be proportional to basal area and the forest floor mass, which suggests that they are related to the intensity of harvesting. Although the causes are uncertain, this negative effect may be due to a reduction in forest floor thickness, which implies the loss of preferred rooting space for trees.     

Coppice forests and genetic diversity: A case study in Quercus pyrenaica Willd. from Central Spain

The amount of standing genetic diversity found in oak coppice forests has been subjected to intense debate amongst forest ecologists and managers. In this study, the level of vegetative propagation and the genetic diversity found in a coppice forest of rebollo oak (Quercus pyrenaica) was examined. The current range of rebollo oak in the Iberian Peninsula reveals its adaptation to sub-Mediterranean mountain ecosystems. High sprouting capability, mainly by root suckers, has favoured traditional exploitation of rebollo oak in coppice forests. Using nine microsatellite loci, we have detected 14 clone assemblies compounded by 2–4 stems (7.9 ± 1.3 ramets per genet, considering stand density) and covering an average surface of 11.4 m² per genet. The levels of genetic diversity and the amount of unique genotypes were high (D = 0.9972, G/N = 0.86) and similar to the clonality levels found in a nearby open oak woodland. Despite numerous clear-cutting rotations, known at least since 1750, and the heavy root sprouting observed after a thinning event, low clonal propagation (∼27%) was detected. This fact pointed towards the long-term persistence of several small clonal assemblies in this coppice. Our findings suggest that intense thinning practices are unadvisable in the conversion of Q. pyrenaica coppice into high forest due to the significant losses of genetic diversity when removing unique genotypes.     

Characterization of a cinnamoyl derivative from broccoli (Brassica oleracea L. var. italica) florets

A new intact glucosinolate Cinnamoyl derivative [6'-O-trans-(4″- hydroxy cinnamoyl)-4-(methylsulphinyl) butyl glucosinolate] (A) has been isolated from Broccoli (Brassica oleracea L. var. italica) florets. The compound was isolated and characterized by LC, MS-ESI, FTIR, ¹H and ¹³C NMR as well as ¹H-¹H COSY, DEPT 135° spectrometric experiments.     

Insecticidal and repellent activities of medicinal plant extracts against the sweet potato whitefly, Bemisia tabaci (Hom.: Aleyrodidae) and its parasitoid Eretmocerusmundus (Hym.: Aphelinidae)

Toxicity and repellent activities of aqueous extracts of nine medicinal plants were evaluated on different life stages of the sweet potato whitefly, Bemisia tabaci. Tomato plants infested with whiteflies were dipped in 10% (wt/wt) of each plant extract for toxicity evaluation. Repellency was evaluated in a choice experiment with detached tomato leaves. All extracts evaluated were relatively ineffective against the adult stage. Extracts of Ruta chalepensis, Peganum harmala and Alkanna strigosa were effective in reducing the numbers of B. tabaci immatures similar to the reduction observed in the imidacloprid treatment. These three extracts were not detrimental B. tabaci parasitoid, Eretmocerus mundus. In addition, the plant extracts Urtica pilulifera and T. capita were repellent to B. tabaci adults. These results indicate that the extracts from the plants R. chalepensis, P. harmala and A. strigosa could act as a potential source for natural product developed for B. tabaci management.     

Potential of the entomopathogenic nematodes Steinernema feltiae , S. weiseri and Heterorhabditis bacteriophora for the biological control of the sugar beet weevil Bothynoderes punctiventris (Coleoptera: Curculionidae)

The sugar beet weevil, Bothynoderes punctiventris Germ. (Coleoptera: Curculionidae), is one of the most damaging pests of sugar beets in Turkey and has been traditionally controlled by application of large amounts of insecticides. The current study used laboratory microcosms to evaluate the possibility of using entomopathogenic nematodes as an alternative control method. The nematodes Steinernema feltiae (strain TUR-S3), Steinernema weiseri (BEY) and Heterorhabditis bacteriophora (TUR-H2) had previously been isolated from Turkey. Nematode-induced mortality generally increased as soil temperature increased from 15 to 25°C but decreased when larvae were located deeper in soil. Heterorhabditis bacteriophora caused the highest larval mortality at 25°C at all depths (5–20 cm). Steinernema feltiae and S. weiseri were more effective than H. bacteriophora at 15°C at all depths. Increasing the application rate of infective nematode dauer juveniles (DJs) affected the number of DJs that penetrated each insect larva and the number of DJs produced per insect. The highest production of DJs per larva occurred at application rates of 50 DJs/larva for S. feltiae and S. weiseri and 100 DJs/larva for H. bacteriophora. Reproduction decreased again at higher application rates. Heterorhabditis bacteriophora had the highest reproductive capability. The results indicate that S. feltiae and S. weiseri might be more effective against this pest early in the growing season when soil temperature is low and that H. bacteriophora might be more effective later in the season when temperature increases.     

Hollows in jarrah (Eucalyptus marginata) and marri (Corymbia calophylla) trees: II. Selecting trees to retain for hollow dependent fauna

From a sample of 665 hollows found in 154 jarrah (Eucalyptus marginata) and 85 marri (Corymbia calophylla), we identified 204 hollows in 84 trees that were potentially suited to one or more of 10 species of hollow using birds and mammals. Occurrence of these hollows increased with tree age, tree size, and species (marri bore more usable hollows than jarrah) and increased amounts of dead wood in tree crowns. Hollow occurrence was most likely in trees with moderately senescent crowns with damage to intermediate sized branches, and the largest hollows were more likely to occur in more highly senescent crowns. Evidence of termite invasion at the tree butt was not related to occurrence of hollows. For all but one of the birds and mammals we considered, dead trees were no more likely than live trees to contain hollows.

Our study indicates that for the purpose of forest management planning, 130 years can be taken as the typical minimum age for the formation of usable hollows in jarrah and marri. The current minimum prescribed diameter for “habitat trees” (trees retained in logged areas to supplement existing hollows), which corresponds to a mean age of 171 years, is thus a realistic minimum size for these retained trees. We recommend raising the prescribed range of crown senescence for retained habitat trees to increase the probability of providing large hollows suited to large species such as red-tailed black cockatoo, and common brushtail possum, and maternal hollows used by smaller species. Retaining the largest trees with appropriate crown attributes will substantially increase the probability that these trees will bear usable hollows.     

Larvicidal activity of Solanum villosum Mill (Solanaceae: Solanales) leaves to Anopheles subpictus Grassi (Diptera: Culicidae) with effect on non-target Chironomus circumdatus Kieffer (Diptera: Chironomidae)

Chloroform-methanol extract of mature leaves from Solanum villosum Mill (Solanaceae: Solanales) was investigated to establish its biocontrol potentiality under laboratory condition against larval forms of Anopheles subpictus Grassi (Diptera: Culicidae), the vector of human malaria. All the graded concentrations (30, 50, 100 and 200 ppm) showed significant (P < 0.05) larval mortality and results of regression equations revealed that the mortality rates were positively correlated with the concentrations of the extract (R ² close to 1). LC₅₀ values for all instars were between 24.20 and 33.73 ppm after 24 h and between 23.47 and 30.63 ppm after 48 h of exposure period. Significant changes in the larval mortality (F < 0.05) was also recorded between instars during single “ANOVA” analysis. This extract also demonstrated no toxicity to larvae of Chironomus circumdatus Kieffer (Diptera: Chironomidae) which were found to be present as most common non-target dipteran insect in the habitats of A. subpictus. Qualitative and chromatographic analysis of the solvent extract revealed the presence of carbohydrates, saponins, terpenoids, volatile oil, steroids, phenols and flavonoids as major bioactive phytochemicals.     

Evaluation of coastal sandy soils and their saline ground waters for afforestation: A case study from India

A study was conducted in coastal Andhra Pradesh to evaluate current practices and suitability of coastal sandy soils for raising tree plantations. Poor soil moisture retention characteristics of these soils make irrigation an essential, but costly silvicultural practice for obtaining desirable establishment and growth. Saline ground water is the only available source of irrigation. Its use seems safe and successful in such soils. The farmers have adopted a specialized manual splashing technique (Doruvu) of seepage pits for irrigating tree plantations in their establishment phase. This technique was observed to be well suited to the sandy soils. Casuarina equisetifolia and Eucalyptus tereticornis were the two most popular species being afforested. E. camaldulensis is also in an introduction phase. Comparison of growth performance and biomass accumulation by C. equisetifolia and E. tereticornis plantations at different growth stages showed the former to be significantly better than the latter. Build up of the soil organic carbon was also found to be markedly more in comparable C. equisetifolia plantations than those of E. tereticornis. Similarly, the blanketing influence of C. equisetifolia plantations was observed to modify soil temperature extremes considerably more than in the case of E. tereticornis. The findings, indicated a vast scope for utilization of coastal sandy soils for afforestation with the successful use of saline ground waters.     

Concentrations and seasonal dynamics of dissolved organic carbon in forest floors of two plantations （Castanopsis kawakamii and Cunninghamia lanceolata） in subtropical China

The concentrations and seasonal dynamics of DOC in forest floors of monoculture plantations ofCastanopsis kawakamii and Chinese fir (Cunninghamia lanceolata) were assessed in Sanming, Fujian, China (26°11′30″N, 117°26′00″E). Forest floor samples were taken in January, April, July and October in 2002 and divided into undecomposed material (horizon Oi), partially decomposed organic material (horizon Oe), and fully decomposed organic material (horizon Oa). Upon collection, DOC concentrations of samples were analyzed by a High Temperature TOC. The results showed that the annual average DOC concentration of Chinese fir (1341.7 mg·kg⁻¹) in the forest floor was higher than that ofCastanopsis kawakamii (1178.9 mg·kg⁻¹). Difference in DOC concentrations was observed among three horizons of the forest floor. DOC concentration of forest floor in the two forests was the highest in horizon Oe. Seasonal trends of DOC concentrations in different horizons of forest floors were similar and the maximal value occurred in autumn (or winter). The concentration and temporal change of DOC in studied forests were probably related to the variation in moisture, temperature, biological activity and quantity of organic matter in the forest floor. Foundation item: This study was supported by the Teaching and Research Award program for MOE P.R.C. (TRAPOYT) Biography: ZHANG Jiang-shan (1946-), male, Researcher in Fujian Normal University, Fuzhou 350007, P.R. China. Responsible editor: Zhu Hong     

Integrating landscape connectivity in broad-scale forest planning through a new graph-based habitat availability methodology: application to capercaillie (Tetrao urogallus) in Catalonia (NE Spain)

The loss of connectivity of forest landscapes is seriously hindering dispersal of many forest-dwelling species, which may be critical for their viability and conservation. In this context, explicitly incorporating connectivity considerations is an important challenge in current forest planning and management, but as yet there is a lack of operative methods for appropriate decision making in this respect. We describe a new methodology based on graph structures and a habitat availability index (integral index of connectivity) that integrates forest attributes (like habitat quality) and network connectivity in a single measure. We apply this methodology to examine the connectivity of the highly fragmented habitat of capercaillie (Tetrao urogallus) in Catalonia (NE Spain), where the threatened status of this forest bird species calls for landscape-level forest planning solutions. We analyse data on the distribution of capercaillie forest habitat at 1 km spatial resolution obtained from the recent Catalan Breeding Bird Atlas. We determine the functionally connected regions existing within its habitat distribution and identify the forest habitat areas that are more important for the maintenance of overall landscape connectivity for this species. Based on these results, we provide recommendations on certain critical public forests where management oriented to the conservation of capercaillie habitat is more necessary. These results highlight the potential and practical interest of the proposed methodology for successfully integrating landscape connectivity in broad scale forest planning.     

Growth and survival of termite-piped Eucalyptus tetrodonta and E. miniata in northern Australia: Implications for harvest of trees for didgeridoos

The most common canopy trees in the savannas of northern Australia, Eucalyptus tetrodonta and E. miniata are also two of the most common species harvested to make didgeridoos, the traditional musical instrument of northern Australian Aboriginal peoples now experiencing high demand from international markets. Most of the trees of the area naturally have hollow cores, or pipes, due to termite activity, but little is known of the relationships of the cores to size of tree, tree growth or survival. In a wooded savanna of northern Australia, 267 individual trees with known growth and survival rates were cored to determine degree of termite-piping. Generalized linear modelling and multi-model inference showed that frequency of piping increased with diameter (dbh) tree for E. tetrodonta, but >85% of E. miniata trees were piped regardless of dbh. Growth (dbh increment) and survival (4-year) were size-dependent. Survival of both species decreased strongly with degree of piping (pipe ratio). For any given diameter, the growth rate of E. miniata trees was independent of pipe ratio, but for E. tetrodonta trees decreased strongly with pipe ratio. From modelled data, a 10-cm tree with pipe ratio of 0.60 was very vulnerable, growing at 0.0 cm year⁻¹ with 46% survival rate, whereas a 40-cm tree, even with large pipe ratios (0.80), grew 0.05 cm year⁻¹ with 98% survival rate. Traditional methods of tree harvesting remove only those smaller hollow trees that are already suffering low growth rates and are likely to die before reaching maturity, whereas current large-scale commercial methods also remove trees with higher growth and survival rates—those trees most likely to contribute to sustainable tree populations. Incorporating traditional selection and harvest methods into current commercial operations would help ensure longevity of this source of livelihood for indigenous peoples of the region.