Open Crown Research Articles

How the Adequate Choice of Plant Species Favors the Restoration Process in Areas Susceptible to Extreme Frost Events.

This work aimed to evaluate the impacts caused by extreme frost events in an ecological restoration area. We grouped the species in three ways: (1) type of trichome coverage; (2) shape of the seedling crown; and (3) functional groups according to the degree of damage caused by frost. The variables of the restored area and species characteristics were selected to be subjected to linear generalization analysis models (GLMs). A total of 104 individuals from seven species were sampled. The most affected species were Guazuma ulmifolia Lam. (98% of leaves affected), followed by Cecropia pachystachia Trécul and Hymenea courbaril L. (both 97%), Inga vera Willd. (84%), and Senegalia polyphylla (DC.) Britton & Rose with 75%. Tapirira guianensis Aubl. was considered an intermediate species, with 62% of the crown affected. Only Solanum granulosoleprosum Dunal was classified as slightly affected, with only 1.5% of leaves affected. With the GLM analysis, it was verified that the interaction between the variables of leaf thickness (Χ² = 37.1, df = 1, p < 0.001), trichome coverage (Χ² = 650.5, df = 2, p < 0.001), and leaf structure culture (Χ² = 54.0, df = 2, p < 0.001) resulted in a model with high predictive power (AIC = 927,244, BIC = 940,735, Χ² = 6947, R² = 0.74, p < 0.001). Frost-affected crown cover was best explained by the interaction between the three functional attributes (74%). We found that there is a tendency for thicker leaves completely covered in trichomes to be less affected by the impact of frost and that the coverage of the affected crown was greatly influenced by the coverage of trichomes. Seedlings with leaves completely covered in trichomes, thicker leaves, and a funneled or more open crown structure are those that are most likely to resist frost events. The success of ecological restoration in areas susceptible to extreme events such as frost can be predicted based on the functional attributes of the chosen species. This can contribute to a better selection of species to be used to restore degraded areas.

Regeneration of Pinus sibirica Du Tour in the Mountain Tundra of the Northern Urals against the Background of Climate Warming

Climate is one of the key drivers of the plant community’s structure and trends. However, the regional vegetation-climate features in the ecotone have not yet been sufficiently studied. The aim of the research is to study features of Pinus sibirica Du Tour germination, survival, and growth in the mountain tundra of the Northern Urals against the background of a changing climate. The following research objectives were set: To determine the abundance and age structure of P. sibirica undergrowth on the mountain tundra plateau, identify the features of P. sibirica growth in the mountain tundra, and examine the correlation between the multi-year air temperature pattern, precipitation, and P. sibirica seedling emergence. A detailed study of the Pinus sibirica natural regeneration in the mountain stony shrub-moss-lichen tundra area at an altitude of 1010–1040 m above sea level on the Tri Bugra mountain massif plateau (59°30′ N, 59°15′ E) in the Northern Urals (Russia) has been conducted. The research involved the period between 1965 and 2017. Woody plant undergrowth was considered in 30 plots, 5 × 5 m in size. The first generations were recorded from 1967–1969. The regeneration has become regular since 1978 and its intensity has been increasing since then. Climate warming is driving these processes. Correlation analysis revealed significant relationships between the number of Pinus sibirica seedlings and the minimum temperature in August and September of the current year, the minimum temperatures in May, June, and November of the previous year, the maximum temperatures in May and August of the current year, and precipitation in March of both the current and previous years. However, the young tree growth rate remains low to date (the height at an age of 45–50 years is approximately 114 ± 8.8 cm). At the same time, its open crowns are rare single lateral shoots. The length of the side shoots exceeds its height by 4–5 times, and the length of the lateral roots exceeds its height by 1.2–1.5 times. This is an indicator of the extreme conditions for this tree species. With the current rates of climate warming and the Pinus sibirica tree growth trends, the revealed relationships allow for the prediction that in 20–25 years, the mountain tundra in the studied Northern Urals plateau could develop underground-closed forest communities with a certain forest relationship. The research results are of theoretical importance for clarifying the forest-tundra ecotone concept. From a practical point of view, the revealed relationship can be used to predict the trend in forest ecosystem formation in the mountain forest-tundra ecotone.

Plant species diversity and crown cover response to vegetation regeneration in community-managed forest in Makawanpur District, Nepal

Abstract. Ghimire P, Lamichhane U. 2020. Plant species diversity and crown cover response to vegetation regeneration in community-managed forest in Makawanpur District, Nepal. Asian J For 5: 36-41. Community forestry is considered as a win-win solution for forest conservation and livelihood provision of forest-based communities. Yet, limited knowledge is available regarding the status of vegetation regeneration in community forests. The study was carried out to assess plant species diversity and crown cover response to regeneration composition in Nawalpur Saraswati (Basamadi) Community Forest of Hetauda Municipality, Makawanpur District, Nepal in November 2020 to December 2020. A stratified random sampling method with a total of 94 sample plots was applied in the study. In total, 44 species belonging to 26 families were recorded in the study site, of which 23 species were represented in tree category, 14 in shrub, and 7 in herb category. Both Shannon-Weiner and Simpson's diversity indices indicated good floral species diversity in the study area. The forest was dominated by Shorea robusta with 396 stem ha-1, followed by Terminalia bellerica 29 stem ha-1, Lagerstroemia parviflora 25 stem ha-1, and Terminalia tomentosa 21 stem ha-1, respectively. Both seedling and sapling were found in good numbers with seedlings 11,583 number ha-1and saplings were 1,896 number ha-1. Both seedling and sapling density was recorded higher in open crown coverage (seedlings=32625 number ha-1; saplings=5033 number ha-1) than in close crown coverage (seedlings=13,708 number ha-1; saplings=2,550 number ha-1). Therefore, the study concluded that crown opening facilitates the growth and development of regeneration density in Shorea robusta and its associated forests. Furthermore, the information generated could be useful to predict future trends in species composition and stand structure in order to optimize the possible forest management strategies.

Estimation of open-pit / underground mining cross-effect in complicated geomechanical conditions

The paper presents the results of prediction model studies of the stress–strain behavior in Gakman field of Yukspor deposit during hybrid open pit/underground mining under conditions of high tectonic stresses. The mountainous relief, rock mass faulting with a series of weak structures, geometry of the ore body, the actual and design parameters of stopes, and mining operation under the uncaved overlying stratum with three-sided support are taken into account. Based on the multivariate threedimensional stress–strain modeling using the finite element method, geomechanical substantiation of simultaneous open-pit and underground mining was carried out. It has been established that the geomechanical determinants in Gakman field are: – gravitational and tectonic stresses with a significant excess of the tectonic component over the gravitational component; – mountainous relief of ground surface with a significant elevation difference in the study area; – location of underground mining under the uncaved overlying stratum with three-sided support; – faulting of rock mass with a series of weak structures (Gakman fault); – formation of the open pit and crown pillar above underground mine; – significant lag of the mining front on the underlying levels of level + 320 m. The dimensions of the cross-effect zone and crown pillar when the underground operations approach the open pit mine are determined.

Canopy position affects photosynthesis and anatomy in mature Eucalyptus trees in elevated CO2.

Leaves are exposed to different light conditions according to their canopy position, resulting in structural and anatomical differences with consequences for carbon uptake. While these structure-function relationships have been thoroughly explored in dense forest canopies, such gradients may be diminished in open canopies, and they are often ignored in ecosystem models. We tested within-canopy differences in photosynthetic properties and structural traits in leaves in a mature Eucalyptus tereticornis canopy exposed to long-term elevated CO2 for up to three years. We explored these traits in relation to anatomical variation and diffusive processes for CO2 (i.e., stomatal conductance, gs and mesophyll conductance, gm) in both upper and lower portions of the canopy receiving ambient and elevated CO2. While shade resulted in 13% lower leaf mass per area ratio (MA) in lower versus upper canopy leaves, there was no relationship between leaf Nmass and canopy gap fraction. Both maximum carboxylation capacity (Vcmax) and maximum electron transport (Jmax) were~18% lower in shaded leaves and were also reduced by ~ 22% with leaf aging. In mature leaves, we found no canopy differences for gm or gs, despite anatomical differences in MA, leaf thickness and mean mesophyll thickness between canopy positions. There was a positive relationship between net photosynthesis and gm or gs in mature leaves. Mesophyll conductance was negatively correlated with mean parenchyma length, suggesting that long palisade cells may contribute to a longer CO2 diffusional pathway and more resistance to CO2 transfer to chloroplasts. Few other relationships between gm and anatomical variables were found in mature leaves, which may be due to the open crown of Eucalyptus. Consideration of shade effects and leaf-age dependent responses to photosynthetic capacity and mesophyll conductance are critical to improve canopy photosynthesis models and will improve understanding of long-term responses to elevated CO2 in tree canopies.

The fluctuation of peatland water table at Tumbang Nusa, Central Kalimantan

Burnt peatland restoration by planting needs stable hydrological condition for the plant’s growth. Water table fluctuation becoming a challenge in the planting effort on degraded peatland. This research aims to determine the water table on degraded peatland and over burnt peat at Tumbang Nusa Forest for Specific Purposes, Pulang Pisau District, Central Kalimantan Province. The data was analyzed to determine the relationship between precipitation characteristics, water table and land elevation. Water table observation was carried out on several fires starting 1997, 2003, 2006 and 2009. We observed 17 points of water table of the total length of 4 km and 250 m distance between points, started from the river edge up to secondary forests. The level of vegetation cover and condition varied from woody plants with low density and open crown up to woody plants with good canopy cover. The result showed that the water table was closely related with the elevation and distance from canal. The fluctuation was closely related with precipitation. Nevertheless, the rainfall did not directly relate but there was a certain interlude period so that the water table was rising or decreasing. This condition shall be considered in the land rehabilitation by planning the right plant in the right time so that the plants can reach optimum growth

The results of computer simulation of the dentinal fluid hydrodynamics in the open crown dentinal tubule

To study the hydrodynamics of the dentinal fluid along the dentinal tubule in the event of its opening as a result of mechanical and acid treatment of the dental crown dentin. Material and methods: A licensed version of the ANSYS / FLOTRAN computer program was used, which is a software tool for solving various problems of hydrodynamics, including laminar and turbulent flow of an incompressible or compressible fluid. The results of computer simulation showed that 1.5 ms after drying of the dentin tubule (length 6 mm) it is refilled with dentin fluid, which then begins to accumulate on the treated surface of the dental hard tissues. Reducing the length of the dentinal tubule as a result of the cavity preparation leads to an increase in the speed and mass of pulp fluid released through it.

First Report of Neofusicoccum parvum Causing Branch Wilt in Phoebe zhennan in Sichuan Province, China

Phoebe zhennan (Hemsl.) Yang is an evergreen broad-leaf, tall, grand tree with an open crown, dense foliage, and sweeping branches, commonly used for shade and landscaping in the urban areas of southern China. This tree is also suitable for hilly and mountainous areas, because it provides a good windbreak, anchors the soil, resists fire, and can also be used to build shelterbelts. A pest census by the Chinese Forestry Service in 2015 to 2017 identified a strain of branch wilt in the P. zhennan trees in Sichuan Province, China. This plant disease has since begun to seriously impact the economic value of P. zhennan, with a general incidence of 30 to 40% and a severe incidence of ≥60% in trees found in the Dujiangyan Park, and then spread to the rest of Sichuan Province with tree transplanting. The disease infects weak main branches, nursery stock, saplings, and even adult trees. The cortex of young P. zhennan branches becomes infected early during the progression. The infected region first exhibits a light chestnut brown color with oval-shaped bright spots that eventually, gradually expand. Once the lesions spread and encircle the branch, the branch wilts, its leaves drop, and it becomes bare. There is no obvious boundary between the infected and healthy parts of the tree, and many small black spots, representing pathogenic pycnidia, are scattered or clustered on the twigs. Severely infected P. zhennan trees possess many brittle, bare branches that tend to fall off in severe weather conditions. A number of infected branches were systematically sampled by cutting the epidermis at the interface of infected and healthy areas in 5 × 5-mm sections, surface sterilized with 3% NaClO and 75% alcohol for 30 s, rinsed three times with sterilized distilled water, and cultured on potato dextrose agar (PDA) (25°C for 4 to 7 days). The fungus formed nearly circular colonies with abundant aerial mycelia and changed from white to greyish black initially and black 3 weeks later. This fungus began to produce pycnidia on PDA medium after 3.5 weeks, and production of conidia was doubled after a 10-min UV irradiation and 3 days more of culture in comparison with culturing the fungus under dark conditions. The pycnidia were mostly spherically shaped, measuring 670 to 910 µm in diameter. The conidia were oval, unicellular with thin walls, measuring 15.2 to 17.2 × 4.6 to 6.4 μm in size. PCR was performed using DNA extracted from the fungal colony using universal primers (ITS1/ITS4), and then a fragment of approximately 572 bp was sequenced. Based on the sequence alignment and phylogenetic analyses in ClustalX and Mega 5.0, this fungus (accession no. MG386181) had the highest homology (99%) with Neofusicoccum parvum (accession no. FJ904915), which was previously found to cause branch and trunk cankers in grapevine, walnut, and peach trees in Sweden, Peru, California (U.S.A.), and Greece (Chen et al. 2014; Cheon et al. 2013; Phillips et al. 2013; Thomidis et al. 2011). To complete Koch’s postulates, N. parvum was cultured to produce microconidia on PDA for 7 days in 25°C. The aqueous conidial suspension was diluted to 1 × 10⁷ spores/ml with sterilized water, and 20 3-year-old potted P. zhennan seedlings were inoculated by scratching the stem epidermis with a piece of sandpaper and applying 100 µl of a microconidial suspension (1 × 10⁷ spores/ml) with a brush to each wounded area, and 20 seedlings inoculated with sterilized distilled water served as controls. The inoculated plants showed the same symptoms as the original diseased plants, and the controls remained asymptomatic 20 day after inoculation. The fungus was reisolated from the symptomatic stems and showed the same morphological characteristics as the isolates used for inoculation, thus confirming Koch’s postulates that N. parvum is the causal agent of branch wilt of P. zhennan. This is the first report of N. parvum causing wilt of P. zhennan trees in Sichuan province, China.

Orzeł Biały z 1 VIII 1919 roku – idealny wzór polskiego orła państwowego czy „heraldyczne nieszczęście”? Uwagi na marginesie inicjatywy obywatelskiej w sprawie przywrócenia „tradycyjnego” herbu Rzeczypospolitej

1 sierpnia 1919 r. Sejm Ustawodawczy przyjął ustawę o polskich godłach państwowych. Posłowie w trakcie obrad parlamentarnych zgłosili szereg wątpliwości w sprawie formy Orła Białego przedłożonego do poselskiej akceptacji. Pomimo zastrzeżeń i wątpliwości Sejm przyjął zgłoszoną regulację. Ustawa z 1919 r. nie zakończyła dyskusji na temat polskich znaków państwowych, a jedynie wprowadziła znak tymczasowy i zapowiedziała jego uszczegółowienie. Godło przyjęte 1 sierpnia 1919 r. było jednym z trzech znaków w grupie ważnych orłów rywalizujących u progu II Niepodległości o miano godła państwowego. Dwa pozostałe godła – orzeł Kazimierza Kierskiego z początku 1917 r. lub nawet z końca 1916 r. i orzeł Bronisława Gembarzewskiego z początku 1917 r. – w różnym czasie pełniły funkcje polskich znaków przedpaństwowych, a nawet funkcje polskich znaków państwowych po 11 listopada 1918 r. Orzeł z sierpnia 1919 r. sylwetą odwoływał się do tradycji polskich znaków państwowych z końca XVIII i XIX w. Wyrażał ciągłość państwa i akcentował przywiązanie twórców godła do tradycji powstania listopadowego i – werbalnie – do herbu ustanowionego przez Sejm i Rząd Narodowy na początku 1831 r. Słuszne założenie o zachowaniu ciągłości z decyzjami władz powstańczych z 1831 r. jednakowoż nie zostało w 1919 r. dobrze zrealizowane. Orzeł z sierpnia 1919 r. był inny od orła z 1831 r., a także został gorzej od niego narysowany. Z tego powodu podjęte zostały prace, które finalnie przynieść miały lepszy wzór godła. Od sierpnia 1919 r. w Ministerstwie Sztuki i Kultury, a następnie w Ministerstwie Wyznań Religijnych i Oświecenia Publicznego przygotowywano nowe wersje godła Rzeczypospolitej. Prace nadzorowane przez aparat państwowourzędniczy II Rzeczypospolitej zmierzały do stworzenia znaku, który stylizacją nawiązywałby do godła z sierpnia 1919 r. Równolegle do prac ministerialnych czołowi graficy ówczesnej Polski opracowywali własne Orły Białe, często wzorując się na orłach jagiellońskich. Na uwagę zasługują prace prof. Zygmunta Kamińskiego i Zofii Trzcińskiej-Kamińskiej. Zaprojektowane przez nich w 1924 i 1925 r. orły zainteresowały rządzących Polską po zamachu majowym z 1926 r. i rządzący ci zlecili w 1927 r., aby prof. Kamiński przygotował wzór nowego herbu Rzeczypospolitej. Orzeł Biały prof. Z. Kamińskiego z 1927 r. formą odbiegał od wzoru z sierpnia 1919 r., a jakością wykonania wyraźnie przewyższał dotychczasowe godło. Kontrowersje wzbudziła zmiana korony na głowie orła. W miejsce korony zamkniętej prof. Kamiński wprowadził koronę otwartą. Dla polityków i dla zwolenników ugrupowań prawicowo-narodowych taka korekta – szczególnie, że nastąpiła po zbrojnym zamachu stanu w maju 1926 r. i bez udziału parlamentu – była nie do zaakceptowania. Dyskusja wywołana zmianą formy korony, czy szerzej – zmianą formy polskiego orła państwowego w 1927 r. trwa do dziś. Heraldycy i politycy spierają się, czy w herbie Rzeczypospolitej powinna być korona otwarta, czy też korona zamknięta, a politycy prawicowo-narodowi podpowiadają, że Rzeczypospolitej należy przywrócić jej tradycyjne godło, a tym tradycyjnym godłem – według polityków prawicowo-narodowych – jest orzeł z sierpnia 1919 r. Odpowiedź na pytanie o właściwą formę polskiego orła państwowego, a także o rodzaj jego korony nie jest łatwa. Źródła (w tym przypadku analizowane były królewskie pieczęcie) sugerują odpowiedź. W długim trwaniu, w okresie przedrozbiorowym polski orzeł ukoronowany był koroną otwartą. Ponadto w 1831 r. Sejm powstańczej Polski i jej rząd zgodnie przyjęli herb z orłem „jagiellońskim” ukoronowanym także koroną otwartą. Korona zamknięta na głowie orła na pieczęciach pojawiła się w okresie panowania Stanisława Augusta Poniatowskiego. Była popularna w przedstawieniach polskiego orła w XIX w. i ta dziewiętnastowieczna tradycja korony zamkniętej wpłynęła na treść dwudziestowiecznej dyskusji o godle Rzeczypospolitej.

Early-stage of invasion by beech bark disease does not necessarily trigger American beech root sucker establishment in hardwood stands

Two concomitant phenomena currently affect the dynamics of sugar maple-American beech (AB) stands in northeastern North America: beech bark disease (BBD), and increased AB understory density. Many studies suggest a causal link between the two phenomena, i.e., BBD favouring beech regeneration. But this link has yet to be experimentally demonstrated. To address the question, we compared regeneration composition between recently BBD-affected and -unaffected stands. A total of 109 stands were sampled; half were affected by BBD. Seedling and sapling density were assessed, together with the origin (seedling or sprout). While BBD affects stands in the eastern part of the study region, AB was observed in the understory across the entire region. No clear difference in AB sprout density between BBD-affected and -unaffected stands was observed while AB seedling density—as well as pooled AB seedling and sprout density were higher in unaffected stands. Findings suggests that BBD, in its early stage, is not a necessary trigger of AB understory establishment. Yet, AB sapling basal area generally was higher in stands affected by BBD, likely indicating a greater rate of AB understory development due to increased light availability beneath a more open crown canopy. That development can lead to AB understory dominance. This distinction—BBD not necessarily triggering AB root sucker establishment but favoring AB advance regeneration development—also questions the generalized perception that dense AB thickets necessarily originate from root suckers.

Global management of a traumatic immature central incisor with an open apex and crown discoloration

Global management of a traumatic immature central incisor with an open apex and crown discoloration

Enhanced Tb(III) luminescence by d10 transition metal coordination

Three new TbIII containing complexes of a novel heptadentate amide open crown ether ligand [Tb4L2(NO3)10(CH3COO)2] (TbL), [ZnTbL(NO3)5]2·3CH3CN·CH3COOCH2CH3·H2O (TbZnL) and [CdTbL(NO3)5]·4CH3CN (TbCdL), L=2,2′-((4-((bis(pyridin-2-ylmethyl)amino)methyl)-1,2-phenylene)bis(oxy))bis(N,N-diisopropylacetamide), were step-by-step prepared and structurally characterized. Photophysical properties of the three emitting TbIII complexes have been investigated in detail. A large increase of the quantum yield and lifetime was observed for TbZnL compared with TbL, whereas a moderate increase of the quantum yield and lifetime was observed for TbCdL.

A tree canopy height delineation method based on Morphological Reconstruction—Open Crown Decomposition

For the purpose of forest management, high resolution LIDAR and optical remote sensing imageries are used for treetop detection, tree crown delineation, and classification. The purpose of this study is to develop a self-adjusted dominant scales calculation method and a new crown horizontal cutting method of tree canopy height model (CHM) to detect and delineate tree crowns from LIDAR, under the hypothesis that a treetop is radiometric or altitudinal maximum and tree crowns consist of multi-scale branches. The major concept of the method is to develop an automatic selecting strategy of feature scale on CHM, and a multi-scale morphological reconstruction–open crown decomposition (MRCD) to get morphological multi-scale features of CHM by: cutting CHM from treetop to the ground; analysing and refining the dominant multiple scales with differential horizontal profiles to get treetops; segmenting LiDAR CHM using watershed a segmentation approach marked with MRCD treetops. This method has solved the problems of false detection of CHM side-surface extracted by the traditional morphological opening canopy segment (MOCS) method. The novel MRCD delineates more accurate and quantitative multi-scale features of CHM, and enables more accurate detection and segmentation of treetops and crown. Besides, the MRCD method can also be extended to high optical remote sensing tree crown extraction. In an experiment on aerial LiDAR CHM of a forest of multi-scale tree crowns, the proposed method yielded high-quality tree crown maps.

Laser-induced breakdown spectroscopy and optical microscopy investigations of crowns on the Pietà from the parish church in Skrzatusz, Poland

Research into two crowns from the Pietà in the parish church in Skrzatusz, Poland, is presented. The aim was to authenticate the individual elements from these crowns and to investigate their composition. Laser-induced breakdown spectroscopy (LIBS), optical microscopy, and multivariate analysis were used. In the first half of the seventeenth century, open crowns were typical for the first Piastowski royal dynasty in Poland. In the following two centuries, specific flower-like bows, decorative finials, and precious stones in settings were added to the crowns. LIBS showed that the crowns were made of very thickly gilded silver. Stratigraphic distributions of alloy elements were determined for all structural components. Some differences between the concentrations of elements in distinct components were confirmed, while optical microscopy demonstrated the small craters caused by the LIBS measurements. Our results confirmed data obtained earlier by art historians, and helped to authenticate the crowns.

A new species of Allagoptera (Arecaceae) from the Cerrado of central Brazil

A new species of Allagoptera from the Cerrado of central Brazil is described. The new species is distinguished by its solitary habit, open crown, and very long inflorescence rachis conspicuously curved at maturity. The new species, A. robusta, is compared morphologically and anatomically with A. campestris and A. leucocalyx.

Can a fast-growing early-successional tree (Ochroma pyramidale, Malvaceae) accelerate forest succession?

Abstract:Species-specific traits of trees affect ecosystem dynamics, defining forest structure and understorey development. Ochroma pyramidale is a fast-growing tree species, with life-history traits that include low wood density, short-lived large leaves and a narrow open thin crown. We evaluated forest succession in O. pyramidale-dominated secondary forests, diverse secondary forests, both 10–15 y since abandonment, and rain forests by comparing height, density and basal area of all trees (&gt; 5 cm dbh). Furthermore, we compared species richness of understorey trees and shrubs, and basal area and density of trees of early- and late-successional species (&lt; 5 cm dbh) between forest types. We found that tree basal area (mean ± SD: 32 ± 0.9 m2 ha−1) and height (12.4 ± 1.8 m) of canopy trees were higher, and density (1450 ± 339 ha−1) lower in O. pyramidale forests than in diverse forests, and more similar to rain forest. Understorey shrub diversity and tree seedling density and diversity were lower in O. pyramidale forests than in diverse forests, but these forest types had a similar density of early- and late-successional trees. Canopy openness (&gt; 15%) and leaf litter (&gt; 10 cm) were both highest in O. pyramidale forests, which positively affected density of understorey trees and shrubs and negatively affected density of late-successional trees. In conclusion, O. pyramidale forests presented structural features similar to those of rain forest, but this constrained the establishment of understorey tree species, especially late-successional species, decreasing successional development.

Cracking in a cementitious backfill and its implications for flow and chemistry

AbstractIn the UK, disposal of packaged intermediate-level radioactive waste may involve waste packages being placed in a geological disposal facility (GDF) and surrounded by a cementitious backfill. Cracking of the backfill could occur due to a number of mechanisms, and this could affect the post-closure performance of the GDF.This work has assessed potential cracking in the backfill during the backfilling and early post-closure period of GDF vaults with an open crown space in a higher strength rock. From the comprehensive range of processes considered, three were identified as potentially causing cracking: (1) during backfilling, plastic settlement under solid horizontal surfaces could result in horizontal gaps beneath waste packages; (2) within days of backfilling, early-age thermal contraction of the backfill could result in primarily vertical cracks; (3) over a number of years, expansion of waste packages could result in large horizontal cracks.A groundwater flow model incorporating a representation of the cracks was used to calculate flows through a backfilled GDF vault, and through the cracks themselves. Including cracks increased the flow rate significantly. A reactive transport model was used to estimate the evolution of the pore water chemistry as groundwater flows through the cracked backfill. Calcite and brucite were predicted to precipitate, with brucite subsequently dissolving. Calcite build-up could seal some cracks.

Giant eucalypts – globally unique fire‐adapted rain‐forest trees?

Tree species exceeding 70m in height are rare globally. Giant gymnosperms are concentrated near the Pacific coast of the USA, while the tallest angiosperms are eucalypts (Eucalyptus spp.) in southern and eastern Australia. Giant eucalypts co-occur with rain-forest trees in eastern Australia, creating unique vegetation communities comprising fire-dependent trees above fire-intolerant rain-forest. However, giant eucalypts can also tower over shrubby understoreys (e.g. in Western Australia). The local abundance of giant eucalypts is controlled by interactions between fire activity and landscape setting. Giant eucalypts have features that increase flammability (e.g. oil-rich foliage and open crowns) relative to other rain-forest trees but it is debatable if these features are adaptations. Probable drivers of eucalypt gigantism are intense intra-specific competition following severe fires, and inter-specific competition among adult trees. However, we suggest that this was made possible by a general capacity of eucalypts for 'hyper-emergence'. We argue that, because giant eucalypts occur in rain-forest climates and share traits with rain-forest pioneers, they should be regarded as long-lived rain-forest pioneers, albeit with a particular dependence on fire for regeneration. These unique ecosystems are of high conservation value, following substantial clearing and logging over 150yr. Contents Summary 1001 I. Introduction 1001 II. Giant eucalypts in a global context 1002 III. Giant eucalypts - taxonomy and distribution 1004 IV. Growth of giant eucalypts 1006 V. Fire and regeneration of giant eucalypts 1008 VI. Are giant eucalypts different from other rain-forest trees? 1009 VII. Conclusions 1010 Acknowledgements 1011 References 1011.

Mapping locations of nesting sites of the Indian house crow in Mombasa

The location of nesting sites of Indian house crows is related with the food availability within an area. Nesting sites are located close to food sources especially areas with poor sanitation. A Google image of the area was zoomed in to visually identify tree clusters and planning of residential areas. Ground observations of the tree clusters identified from the image for nesting and the conditions around them. In the 236 tree clusters identified in the Google image, 167 (71%) were nesting sites as per the ground observation. 69% of the nesting sites were found in areas with poor sanitation. These were areas in unplanned residential areas with poor road network hindering distribution of refuse handling services. The most preferred nesting tree was the mango tree with 1246 nests, observed in 464 trees. Some nests were observed in trees with small and open crowns e.g. pawpaw and Indian tree. House crows put more nests on trees with large crowns. The estimate number of nests in a nesting site may be given by N=2T L+T S. 76% of the model results were close to the actual nest count with a ±3 difference. The municipal council should improve on handling and monitoring of refuse disposal, plant trees that are less conducive for nesting, and regularly prune tall trees with large crowns.

Use of sleeping sites by a titi group (Callicebus coimbrai) in the Brazilian Atlantic Forest

Predation pressure affects most aspects of primate behaviour, and is especially pronounced in the context of the use of sleeping sites, given the vulnerability of the animal at this time. Most small-bodied platyrrhines have highly systematic patterns of sleeping site choice and use. This study analyses the use of sleeping sites by a free-ranging group of titis (Callicebus coimbrai) monitored at a site in Sergipe, Brazil, between July, 2009 and June, 2010. When the subjects approached a sleeping tree their behaviour was typically cautious, including slow and silent movement, early retirement (20-162min before sunset on 52 dry afternoons), and sleeping in a tight huddle with their tails entwined. Despite this behaviour, which has an obvious anti-predator function, the group slept in only three different trees during the course of the study, and returned to the same tree used on the previous night on a quarter of evenings (n=56). This was despite the availability within the group's home range of a large number of trees with similar structural characteristics (i.e. tall, open crown in the upper canopy). Surprisingly, the three trees were all members of the same species, Licania littoralis (Chrysobalanaceae). The choice of this species, which was not an important source of dietary resources, and the repeated use of a small number of sites, did not seem to be related to factors such as ranging or foraging patterns, but may have a been a response to the specific threat from capuchins, Cebus xanthosternos.