Sapling growth and crown expansion in canopy gaps of Nothofagus pumilio (lenga) forests in Chubut, Patagonia, Argentina

Energy Technology Data Exchange (ETDEWEB)

Lopez Bernal, P. M.; Defosse, G. E.; Quinteros, C. P.; Bava, J. O.

2012-07-01

In the province of Chubut in Patagonia, Argentina, Nothofagus pumilio forests (locally known as lenga), are managed through selective cuts, which imply the opening of canopy gaps. This management scheme is carried out without taking into consideration the changes of sapling requirements through either a cutting cycle or the precipitation gradient in which these forests thrive. To analyze these changes, we inferred the facilitation-competition balance between the canopy and regeneration, studying the effects of precipitation levels, gap size and gap age on saplings growth in height on 45 canopy gaps artificially created between 1960 and 1993. Results showed that during the first 20 years since gap opening, growth of regeneration is determined by light availability in mesic sites and by water availability in xeric sites. However, differences due to precipitation levels gradually decrease over time. Moreover, in the period between 20 and 35 years after gap opening, in both mesic and xeric sites, growth is limited by light availability. This indicates that in xeric sites, sapling growth requirements shift from a water-dependent situation to a light-dependent situation. The average closing rate of gaps due to lateral growth of bordering trees is high enough so that within the proposed gap size range, gap healing can occur before regeneration reaches the upper stratum. Consequently, in mesic sites gap opening can be done by a single operation that generates gaps with diameters of approximately twice the average height of the canopy (D/H). While in xeric environments, lenga seedling establishment and initial growth require the cover of small gaps, but advanced regeneration requires bigger gaps to reach the canopy. For this reason, gaps should be opened in two stages: the first gaps should be opened with a D/H between 0.8 and 1, and after a cutting cycle of 35 years, these openings should be enlarged to a D/H between 1.5 and 2. The close relationship maintained between the

Philodryas chamissonis (Reptilia: Squamata: Colubridae preys on the arboreal marsupial Dromiciops gliroides (Mammalia: Microbiotheria: Microbiotheriidae Philodryas chamissonis (Reptilia: Squamata: Dipsadidae predando o marsupial arborícola Dromiciops gliroides (Mammalia: Microbiotheria: Microbiotheriidae

Directory of Open Access Journals (Sweden)

S. Muñoz-Leal

2013-02-01

Full Text Available Philodryas chamissonis, the Chilean long-tailed snake, is a diurnal predator mainly of Liolaemus lizards, but also of amphibians, birds, rodents and juvenile rabbits. Dromiciops gliroides (Colocolo opossum is an arboreal marsupial endemic of temperate rainforest of southern South America. Little information is available about this marsupial's biology and ecology. Here we report the predation of one Colocolo opossum by an adult female P. chamissonis in a mixed Nothofagus forest, composed mainly by N. dombeyi, N. glauca and N. alpina trees, in the "Huemules de Niblinto" National Reserve, Nevados de Chillán, Chile. Since these two species have different activity and habitat use patterns, we discuss how this encounter may have occurred. Although it could just have been an opportunistic event, this finding provides insights into the different components of food chains in forest ecosystems of Chile.Philodryas chamissonis, cobra de cauda comprida ("Culebra de cola larga", é uma cobra diurna, predadora principalmente de lagartos do gênero Liolaemus, mas também de anfíbios, aves, roedores e coelhos jovens. Dromiciops gliroides (colocolo é um marsupial arborícola endêmico das florestas temperadas do sul da América do Sul. Há pouca informação disponível sobre a biologia e a ecologia deste marsulpial. É reportada, neste estudo, a predação de um colocolo por uma fêmea adulta de P. chamissonis, em uma floresta mista de Nothofagus, composta principalmente por árvores N. dombeyi, N. glauca e N. alpina, na Reserva Nacional de Huemules de Niblinto, Nevados de Chillán, Chile. Uma vez que estas duas espécies possuem diferentes padrões de atividade e de uso de habitat, discute-se como este evento poder ter ocorrido. Embora este possa ter sido apenas um evento oportunístico, o achado fornece novas informações sobre os diferentes componentes da cadeia alimentar nos ecossistemas florestais do Chile.

Transcriptome survey of Patagonian southern beech Nothofagus nervosa (= N. Alpina: assembly, annotation and molecular marker discovery

Directory of Open Access Journals (Sweden)

Torales Susana L

2012-07-01

Full Text Available Abstract Background Nothofagus nervosa is one of the most emblematic native tree species of Patagonian temperate forests. Here, the shotgun RNA-sequencing (RNA-Seq of the transcriptome of N. nervosa, including de novo assembly, functional annotation, and in silico discovery of potential molecular markers to support population and associations genetic studies, are described. Results Pyrosequencing of a young leaf cDNA library generated a total of 111,814 high quality reads, with an average length of 447 bp. De novo assembly using Newbler resulted into 3,005 tentative isotigs (including alternative transcripts. The non-assembled sequences (singletons were clustered with CD-HIT-454 to identify natural and artificial duplicates from pyrosequencing reads, leading to 21,881 unique singletons. 15,497 out of 24,886 non-redundant sequences or unigenes, were successfully annotated against a plant protein database. A substantial number of simple sequence repeat markers (SSRs were discovered in the assembled and annotated sequences. More than 40% of the SSR sequences were inside ORF sequences. To confirm the validity of these predicted markers, a subset of 73 SSRs selected through functional annotation evidences were successfully amplified from six seedlings DNA samples, being 14 polymorphic. Conclusions This paper is the first report that shows a highly precise representation of the mRNAs diversity present in young leaves of a native South American tree, N. nervosa, as well as its in silico deduced putative functionality. The reported Nothofagus transcriptome sequences represent a unique resource for genetic studies and provide a tool to discover genes of interest and genetic markers that will greatly aid questions involving evolution, ecology, and conservation using genetic and genomic approaches in the genus.

Teledetección satelital cuantitativa para estimar el área basal del bosque de Nothofagus pumilio (Nothofagaceae: El rol del índice de área foliar como información auxiliar Quantitative remote sensing to estimate basal area in Nothofagus pumilio (Nothofagaceae forest: The role of leaf area index as ancillary information

Directory of Open Access Journals (Sweden)

GASTÓN M DÍAZ

2011-12-01

Full Text Available Los bosques de lenga (Nothofagus pumilio son el recurso forestal más importante de la región andino patagónica argentina, sin embargo, para implementar planes de manejo en pos de prevenir o revertir su degradación es necesario disponer de mayor información sobre su estructura. Una alternativa para obtener esa información es relacionar datos satelitales con las características del bosque a través de modelos físicos y estadísticos. Pero, ¿cuál es el método más eficaz? El índice de área foliar (IAF se encuentra relacionado con la reflectividad del dosel vegetal a través del modelo de transferencia radiativa PROSAIL, lo que permite desarrollar técnicas de teledetección satelital para estimar el IAF con bases físicas, en vez de con modelos estadísticos. De ese modo se puede aprovechar la relación empírico-biológica existente entre el IAF y la estructura del bosque para estimar el área basal. El objetivo principal fue comparar la exactitud de tres métodos para estimar el área basal de la lenga con datos SPOT-5. Los métodos comparados fueron: estadístico directo (ED, estadístico de dos pasos (E2P y físico-estadístico de dos pasos (FE2P. La exactitud fue evaluada con 24 parcelas no involucradas en el ajuste o calibración de los modelos. No se hallaron diferencias significativas en la exactitud de la alternativa físico-estadística en comparación con las netamente estadísticas. Sin embargo, en base al análisis conjunto de los resultados y lo reportado por otros investigadores, se concluye que la ventaja de utilizar modelos físicos radica en la mayor robustez de la estimación y no en la mayor exactitud.Lenga forests (Nothofagus pumilio are the most important forest resource of the Argentinean Andean Patagonia, however, more information about their structure is needed to implement forest management policies and practices in order to prevent their degradation and revert it. One option to obtain this kind of information

Nicotiana glauca poisoning in ostriches (Struthio camelus)

CSIR Research Space (South Africa)

Botha, CJ

2011-01-01

Full Text Available Putative Nicotiana glauca (wild tobacco) poisoning was diagnosed in a flock of ostriches near Oudtshoorn, South Africa. Post mortem examinations (n = 7) were performed on ostriches (Struthio camelus) that had died. Suspicious leaf remnants (weighing...

Phytochemical Analysis and Free Radical Scavenging Activity of Medicinal Plants Gnidia glauca and Dioscorea bulbifera

Science.gov (United States)

Ghosh, Sougata; Derle, Abhishek; Ahire, Mehul; More, Piyush; Jagtap, Soham; Phadatare, Suvarna D.; Patil, Ajay B.; Jabgunde, Amit M.; Sharma, Geeta K.; Shinde, Vaishali S.; Pardesi, Karishma; Dhavale, Dilip D.; Chopade, Balu A.

2013-01-01

Gnidia glauca and Dioscorea bulbifera are traditional medicinal plants that can be considered as sources of natural antioxidants. Herein we report the phytochemical analysis and free radical scavenging activity of their sequential extracts. Phenolic and flavonoid content were determined. Scavenging activity was checked against pulse radiolysis generated ABTS•+ and OH radical, in addition to DPPH, superoxide and hydroxyl radicals by biochemical methods followed by principal component analysis. G. glauca leaf extracts were rich in phenolic and flavonoid content. Ethyl acetate extract of D. bulbifera bulbs and methanol extract of G. glauca stem exhibited excellent scavenging of pulse radiolysis generated ABTS•+ radical with a second order rate constant of 2.33×106 and 1.72×106, respectively. Similarly, methanol extract of G. glauca flower and ethyl acetate extract of D. bulbifera bulb with second order rate constants of 4.48×106 and 4.46×106 were found to be potent scavengers of pulse radiolysis generated OH radical. G. glauca leaf and stem showed excellent reducing activity and free radical scavenging activity. HPTLC fingerprinting, carried out in mobile phase, chloroform: toluene: ethanol (4: 4: 1, v/v) showed presence of florescent compound at 366 nm as well as UV active compound at 254 nm. GC-TOF-MS analysis revealed the predominance of diphenyl sulfone as major compound in G. glauca. Significant levels of n-hexadecanoic acid and octadecanoic acid were also present. Diosgenin (C27H42O3) and diosgenin (3á,25R) acetate were present as major phytoconstituents in the extracts of D. bulbifera. G. glauca and D. bulbifera contain significant amounts of phytochemicals with antioxidative properties that can be exploited as a potential source for herbal remedy for oxidative stress induced diseases. These results rationalize further investigation in the potential discovery of new natural bioactive principles from these two important medicinal plants. PMID:24367520

Micro-environmental changes induced by shape and size of forest openings: effects on Austrocedrus chilensis and Nothofagus dombeyi seedlings performance in a Pinus contorta plantation of Patagonia, Argentina

Energy Technology Data Exchange (ETDEWEB)

Pafundi, L.; Urretavizcaya, M.F.; Defosse, G.E.

2016-07-01

Aim of the study: to analyze, within a Pinus contorta plantation, the effects of artificially created small rectangular and small medium circular canopy gaps on: i) photosynthetic active radiation (PAR), and soil temperature and moisture, and ii) survival and growth of planted Austrocedrus chilensis and Nothofagus dombeyi seedlings, species which formerly composed the natural forest of the area. Study area: A 2 ha stand of a Pinus contorta stand in Los Alerces National Park, Argentina (42°43’S, 71°43’W, 490 m.a.s.l.). Material and methods: The Pinus contorta stand was 25 yr old, 22 m height and 26 cm DBH, presenting 1000 trees ha-1 of density and 53 m2 ha-1 of basal area. In 2009, rectangular and circular gaps were created within the stand and then seedlings were planted. During two growing seasons (2010-2011 and 2011-2012), PAR, soil temperature and moisture were measured in gaps and understory (control), and seedling survival and growth in gaps. Main results: During both seasons, soil temperature did not differ among gaps and control, whereas PAR and soil moisture were lower in control than in gaps. Seedling survival was high in all gaps regardless of species and season. Seedlings showed higher diameter growth in rectangular than in circular gaps. Research highlights: Austrocedrus chilensis and N. dombeyi seedlings survival is high and their growth slightly affected, when planted in differently-sized canopy gaps within a Pinus contorta plantation in Patagonia. However, other gap sizes and stand densities should be tested before recommending which one shows better results for reconverting monocultures into former native forests. Abbreviations used: PAR (Photosynthetic Active Radiation); DBH (Diameter at Breast Height); INTA (Argentinean Institute of Agricultural Technology); IFONA (Argentinean Forest Institute). (Author)

[Effects of simulating acid rain on photosynthesis and chlorophyll fluorescence parameters of Quercus glauca Quercus glauca].

Science.gov (United States)

Wang, Sai; Yi, Li-Ta; Yu, Shu-Quan; Zhang, Chao; Shi, Jing-Jing

2014-08-01

At three levels of simulated acid rainfall intensities with pH values of 2.5 (severe), 40 (medium) and 5.6 (light) respectively, the responses of chlorophyll fluorescence and photosynthetic parameters of Quercus glauca seedlings were studied in three acid rainfall treatments, i. e. only the aboveground of seedlings exposed to acid rain (T1), both of the seedlings and soil exposed to acid rain (T2), only the soil exposed to acid rain (T3) compared with blank control (CK). Under the severe acid rainfall, T1 significantly inhibited chlorophyll synthesis, and thus reduced the primary photochemical efficiency of PS II ( F(v)/F(m)), potential activity of PS II (F(v)/F(o)) , apparent quantum (Y), net photosynthetic rate (P(n)), and transpiration rate (T(r)), but increased the light compensation point (LCP) and dark respiration rate (R(d)) of Q. glauca seedlings. T2 inhibited, but T3 played a little enhancement on the aforementioned parameters of Q. glauca seedlings. Under the conditions of medium and light acid rainfall intensities, the above parameters in the three treatments were higher than that of CK, except with lower R(d). The chlorophyll fluorescence and photosynthetic parameters showed a similar tendency in the three treatments, i. e. T2>T3 >T1. It indicated that T1 had the strongest inhibition on seedlings in condition of the severe acid rainfall, while T2 had the most dramatic facilitating effect on seedlings under the medium and light acid rainfall. Intensity of acid rainfall had significant influences on SPAD, F(v)/F(m), F(v)/F(o), Y, P(n), T(r), and maximum photosynthetic rate (A(max)), whereas treatments of acid rainfall affected SPAD, F(v)/F(m), Y, P(n), T(r), A(max) and light saturation point (LSP). The interaction of acid rainfall intensities and treatments played significant effects on SPAD, F(v)/F(m), Y, P(n) and A(max).

Seasonal changes in the photosynthetic performance of two evergreen Nothofagus species in south central Chile Cambios estacionales en el desempeño fotosintético de dos especies siempreverdes de Nothofagus en el centro sur de Chile

Directory of Open Access Journals (Sweden)

RAFAEL ZÚÑIGA

2006-12-01

Full Text Available The evergreen Nothofagus dombeyi and Nothofagus nitida are important members of the temperate Chilean rainforest. They seldom grow together in nature. Nothofagus nitida is more susceptible to excess light and drought than N. dombeyi. We postulate that the different properties of the photosynthetic apparatus under common garden conditions of these species could explain their contrasting habitat preferences. The two species growing in a common garden in south central Chile were studied. The optimal photochemical efficiency (Fv/Fm of both species remained within normal values (»0.8 with the exception of a decrease in N. dombeyi at midday in summer, suggesting reversible reduction in photochemical efficiency of photosystem II (PSII. During summer the effective photochemical efficiency (F PSII, photochemical quenching (qP, photosynthesis (Amax, stomatal conductance (gs and transpiration rates (E in N. dombeyi were higher than in N. nitida. The highest increments in photoprotective pigments (zeaxanthin + antheraxanthin and lutein contents between predawn and midday were obtained in summer in N. dombeyi. In N. nitida a nocturnal retention of dissipative pigments, without a decrease in Fv/Fm, was found in winter. The results suggest that N. dombeyi showed a better photosynthetic performance than N. nitida under high light, high temperature, and drier conditions. These data support are consistent with the pioneer character of N. dombeyi and the semi-tolerant shade properties and more restricted distribution of N. nitida. These photosynthetic characteristics, along with their freezing and flooding resistance differences, may result from their habitat separationLas siempreverdes, Nothofagus dombeyi y Nothofagus nitida, representantes importantes de los bosques lluviosos templados de Chile, raramente crecen juntos en forma natural. Nothofagus nitida es más sensible al exceso de luz y déficit de agua que N. dombeyi. Se postula que diferentes propiedades

Use of tree species by White-throated treerunner (Pygarrhichas albogularis King in a secondary native forest of southern Chile

Directory of Open Access Journals (Sweden)

Alberto Gantz

2015-06-01

Full Text Available ABSTRACT In forest ecosystems, numerous species of insectivorous birds use certain tree species as feeding and nesting substrates. Between 2009 and 2010, the use of different floristic components as feeding substrate by the Pygarrhichas albogularis King, 1831 was evaluated in a southern Chilean secondary native forest. From a total of 13 trees and bush species, six tree species were used by P. albogularis as a feeding substrate. Tree use was limited to intermediate heights (11-20 m and, mainly, to the trunk (40% of observations and secondary branches (26%. Pygarrhichas albogularis showed a disproportionated use of N. dombeyi and an important use of trees with a greater age structure (DBH 81-100 cm. Nothofagus dombeyi presented a significantly greater tree bark crevice depth than E. cordifolia. In turn, covariance between crevice depth and invertebrate supply in tree bark was positive and significant. We consider bark depth and invertebrate supply to be the proximate causes explaining P. albogularis disproportionated use of Nothofagus dombeyi.

Detecting Sulfuric and Nitric Acid Rain Stresses on Quercus glauca through Hyperspectral Responses.

Science.gov (United States)

Wang, Shanqian; Zhang, Xiuying; Ma, Yuandan; Li, Xinhui; Cheng, Min; Zhang, Xiaomin; Liu, Lei

2018-03-09

Acid rain, which has become one of the most severe global environmental issues, is detrimental to plant growth. However, effective methods for monitoring plant responses to acid rain stress are currently lacking. The hyperspectral technique provides a cost-effective and nondestructive way to diagnose acid rain stresses. Taking a widely distributed species ( Quercus glauca ) in Southern China as an example, this study aims to monitor the hyperspectral responses of Q. glauca to simulated sulfuric acid rain (SAR) and nitric acid rain (NAR). A total of 15 periods of leaf hyperspectral data under four pH levels of SAR and NAR were obtained during the experiment. The results showed that hyperspectral information could be used to distinguish plant responses under acid rain stress. An index (green peak area index, GPAI) was proposed to indicate acid rain stresses, based on the significantly variations in the region of 500-660 nm. Light acid rain (pH 4.5 SAR and NAR) promoted Q. glauca growth relative to the control groups (pH 5.6 SAR and NAR); moderate acid rain (pH 3.0 SAR) firstly promoted and then inhibited plant growth, while pH 3.0 NAR showed mild inhibitory effects during the experiment; and heavy acid rain (pH 2.0) significantly inhibited plant growth. Compared with NAR, SAR induced more serious damages to Q. glauca . These results could help monitor acid rain stress on plants on a regional scale using remote sensing techniques.

Seed dormancy responses to temperature relate to Nothofagus species distribution and determine temporal patterns of germination across altitudes in Patagonia.

Science.gov (United States)

Arana, María V; Gonzalez-Polo, Marina; Martinez-Meier, Alejandro; Gallo, Leonardo A; Benech-Arnold, Roberto L; Sánchez, Rodolfo A; Batlla, Diego

2016-01-01

Seeds integrate environmental cues that modulate their dormancy and germination. Although many mechanisms have been identified in laboratory experiments, their contribution to germination dynamics in existing communities and their involvement in defining species habitats remain elusive. By coupling mathematical models with ecological data we investigated the contribution of seed temperature responses to the dynamics of germination of three Nothofagus species that are sharply distributed across different altitudes in the Patagonian Andes. Seed responsiveness to temperature of the three Nothofagus species was linked to the thermal characteristics of their preferred ecological niche. In their natural distribution range, there was overlap in the timing of germination of the species, which was restricted to mid-spring. By contrast, outside their species distribution range, germination was temporally uncoupled with altitude. This phenomenon was described mathematically by the interplay between interspecific differences in seed population thermal parameters and the range in soil thermic environments across different altitudes. The observed interspecific variations in seed responsiveness to temperature and its environmental regulation, constitute a major determinant of the dynamics of Nothofagus germination across elevations. This phenomenon likely contributes to the maintenance of patterns of species abundance across altitude by placing germinated seeds in a favorable environment for plant growth. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Performance of the Forest Vegetation Simulator in managed white spruce plantations influenced by eastern spruce budworm in northern Minnesota

Science.gov (United States)

Matthew B. Russell; Anthony W. D' Amato; Michael A. Albers; Christopher W. Woodall; Klaus J. Puettmann; Michael R. Saunders; Curtis L. VanderSchaaf

2015-01-01

Silvicultural strategies such as thinning may minimize productivity losses from a variety of forest disturbances, including forest insects. This study analyzed the 10-year postthinning response of stands and individual trees in thinned white spruce (Picea glauca [Moench] Voss) plantations in northern Minnesota, USA, with light to moderate defoliation...

Structure and resilience of fungal communities in Alaskan boreal forest soils

Science.gov (United States)

D. Lee Taylor; Ian C. Herriott; Kelsie E. Stone; Jack W. McFarland; Michael G. Booth; Mary Beth Leigh

2010-01-01

This paper outlines molecular analyses of soil fungi within the Bonanza Creek Long Term Ecological Research program. We examined community structure in three studies in mixed upland, black spruce (Picea mariana (Mill.) BSP), and white spruce (Picea glauca (Moench) Voss) forests and examined taxa involved in cellulose...

Intraspecific trait variation and covariation in a widespread tree species (Nothofagus pumilio) in southern Chile.

Science.gov (United States)

Fajardo, Alex; Piper, Frida I

2011-01-01

• The focus of the trait-based approach to study community ecology has mostly been on trait comparisons at the interspecific level. Here we quantified intraspecific variation and covariation of leaf mass per area (LMA) and wood density (WD) in monospecific forests of the widespread tree species Nothofagus pumilio to determine its magnitude and whether it is related to environmental conditions and ontogeny. We also discuss probable mechanisms controlling the trait variation found. • We collected leaf and stem woody tissues from 30-50 trees of different ages (ontogeny) from each of four populations at differing elevations (i.e. temperatures) and placed at each of three locations differing in soil moisture. • The total variation in LMA (coefficient of variation (CV) = 21.14%) was twice that of WD (CV = 10.52%). The total variation in traits was never less than 23% when compared with interspecific studies. Differences in elevation (temperature) for the most part explained variation in LMA, while differences in soil moisture and ontogeny explained the variation in WD. Traits covaried similarly in the altitudinal gradient only. • Functional traits of N. pumilio exhibited nonnegligible variation; LMA varied for the most part with temperature, while WD mostly varied with moisture and ontogeny. We demonstrate that environmental variation can cause important trait variation without species turnover. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).

Living on the edge: adaptive and plastic responses of the tree Nothofagus pumilio to a long-term transplant experiment predict rear-edge upward expansion.

Science.gov (United States)

Mathiasen, Paula; Premoli, Andrea C

2016-06-01

Current climate change affects the competitive ability and reproductive success of many species, leading to local extinctions, adjustment to novel local conditions by phenotypic plasticity or rapid adaptation, or tracking their optima through range shifts. However, many species have limited ability to expand to suitable areas. Altitudinal gradients, with abrupt changes in abiotic conditions over short distances, represent "natural experiments" for the evaluation of ecological and evolutionary responses under scenarios of climate change. Nothofagus pumilio is the tree species which dominates as pure stands the montane forests of Patagonia. We evaluated the adaptive value of variation in quantitative traits of N. pumilio under contrasting conditions of the altitudinal gradient with a long-term reciprocal transplant experimental design. While high-elevation plants show little response in plant, leaf, and phenological traits to the experimental trials, low-elevation ones show greater plasticity in their responses to changing environments, particularly at high elevation. Our results suggest a relatively reduced potential for evolutionary adaptation of high-elevation genotypes, and a greater evolutionary potential of low-elevation ones. Under global warming scenarios of forest upslope migration, high-elevation variants may be outperformed by low-elevation ones during this process, leading to the local extinction and/or replacement of these genotypes. These results challenge previous models and predictions expected under global warming for altitudinal gradients, on which the leading edge is considered to be the upper treeline forests.

Symbiotic and nonsymbiotic hemoglobin genes of Casuarina glauca

DEFF Research Database (Denmark)

Jacobsen-Lyon, K; Jensen, Erik Østergaard; Jørgensen, Jan-Elo

1995-01-01

Casuarina glauca has a gene encoding hemoglobin (cashb-nonsym). This gene is expressed in a number of plant tissues. Casuarina also has a second family of hemoglobin genes (cashb-sym) expressed at a high level in the nodules that Casuarina forms in a nitrogen-fixing symbiosis with the actinomycete...... of the Casuarina gene. The finding that the nonsymbiotic Casuarina gene is also correctly expressed in L. corniculatus suggests to us that a comparable non-symbiotic hemoglobin gene will be found in legume species. Udgivelsesdato: 1995-Feb...

Phytochemical composition and antinociceptive activity of Bauhinia glauca subsp. hupehana in rats.

Science.gov (United States)

Xu, Jinlong; Zhao, Qizhi; Wei, Lei; Yang, Yu; Xu, Rui; Yu, Nengjiang; Zhao, Yimin

2015-01-01

In traditional medicine, Bauhinia glauca subsp. hupehana has long been used as an analgesic agent in China. The aim of this study was to evaluate the antinociceptive activity of the ethanol extract of the aerial parts of B. glauca subsp. hupehana (BHE) in rats and its chemical fingerprint. The antinociceptive activity of BHE was assessed in mice using chemically and heat-induced pain models, such as the acetic acid-induced writhing, hot plate, tail-flick and glutamate tests. Naltrexone hydrochloride, a non-selective opioid receptor antagonist, was utilized to determine the involvement of the opioid system. In addition to this, the involvements of the cGMP and ATP-sensitive K+ channel pathways were also detected using methylene blue and glibenclamide. The oral administration of BHE (at doses of 50, 100 and 200 mg/kg) produced significant and dose-related inhibitions in both the chemically and heat-induced pain models. Interestingly, in the abdominal constriction test, when the dose of BHE was increased to 800 mg/kg (p.o., n = 10), the inhibition rate was 100%. The antinociceptive mechanism may involve the cGMP pathway and ATP sensitive K+ channel pathway. The central antinociceptive effect was not antagonized by naltrexone. One phenolic acid, one lignin and five flavonoids were isolated from BHE. The antinociceptive activity of BHE was most likely due to the presence of the flavonoids. The acute toxicity results showed that BHE was safe at a high dose (2 g/kg, p.o.). The current investigation demonstrates that B. glauca subsp. hupehana is a potential candidate for the development of novel, non-opioid, analgesic phytomedicines.

Mineralización del nitrógeno, carbono y actividad enzimática del suelo en un bosque de Nothofagus obliqua (Mirb Oerst y una plantación de Pinus radiata D. Don. del centro-sur de Chile Nitrogen and carbon mineralization and enzyme activity in soils of Nothofagus obliqua (Mirb Oerst stands and Pinus radiata D. Don plantation in south-central Chile

Directory of Open Access Journals (Sweden)

YESSICA RIVAS

2009-03-01

Full Text Available En Chile, el establecimiento de plantaciones comerciales de rápido crecimiento ha sido sostenido en las últimas décadas mediante la sustitución de bosques nativos y conversión de suelos agrícolas. Pinus radiata D. Don es la principal especie productiva, debido a su crecimiento acelerado y adaptabilidad al clima y los suelos. En el presente estudio se plantea que la actividad biológica del suelo es variable a través del año, en respuesta a variaciones de precipitación, temperatura y contenido de humedad de suelo y que el cambio de uso de suelo desde un bosque templado de Nothofagus obliqua (Mirb Oerst a una plantación con coniferas exóticas, modifica la química del suelo y consecuentemente los procesos de N-min, C-min y la actividad biológica del suelo. Esta hipótesis fue examinada en un bosque de N. obliqua y una plantación de P. radiata del centro-sur de Chile (40°07' S, 72° O. Se evaluó mensualmente la tasa mineralización de nitrógeno (N-min, cabono (C-min y la actividad enzimática potencial del suelo (ureasa, proteasa e hidrólisis de la fluoresceína diacetato entre septiembre 2003 y mayo 2005. Los resultados demuestran que los niveles de las variables de actividad biológica del suelo fueron significativamente diferentes entre las parcelas de bosque y plantación (Lambda de Wilk = 0,022; F 5,80 = 733; P In Chile, commercial forests plantations have increased during the last decades due in part to replacement of native forests and conversion of agricultural soils. Pinus radiata D. Don has been the main tree planted, due to its rapid growth and adaptability. In the present study we proposed that biological activity varies along the year due to changes of precipitation, temperature and soil water content and mainly because the conversion of native forest to exotic P. radiata plantations alters the soil chemistry, N and C mineralization and the potential enzymatic activity in these soils. This hypothesis was examined in a

Patrones de dispersión de semillas y colonización de Misodendrum punctulatum (Misodendraceae en un matorral postfuego de Nothofagus antarctica (Nothofagaceae del noroeste de la Patagonia Misodendrum punctulatum (Misodendraceae seed dispersal and colonization patterns on a Nothofagus antarctica (Nothofagaceae post-fire shrubland from Northwestern Patagonia

Directory of Open Access Journals (Sweden)

NORLAN TERCERO-BUCARDO

2010-01-01

allow understand the patterns of spatial distribution and infection dynamics of Misodendrum punctulatum. In order to plan management strategies, understanding the infection dynamics is useful to perform successfully strategies to the control of hemiparasitic plants in forest to commercial use, and conservation or restoration strategies, e.g. to restorate this hemiparasitic specie in areas recently colonized by N. antárctica. These studied aspects in Misodendrum punctulatum contribute to the knowledge of this ecological interaction, which is frequent in Nothofagus forests from Argentina and Chile.

Single-Step BLUP with Varying Genotyping Effort in Open-Pollinated Picea glauca

Directory of Open Access Journals (Sweden)

Blaise Ratcliffe

2017-03-01

Full Text Available Maximization of genetic gain in forest tree breeding programs is contingent on the accuracy of the predicted breeding values and precision of the estimated genetic parameters. We investigated the effect of the combined use of contemporary pedigree information and genomic relatedness estimates on the accuracy of predicted breeding values and precision of estimated genetic parameters, as well as rankings of selection candidates, using single-step genomic evaluation (HBLUP. In this study, two traits with diverse heritabilities [tree height (HT and wood density (WD] were assessed at various levels of family genotyping efforts (0, 25, 50, 75, and 100% from a population of white spruce (Picea glauca consisting of 1694 trees from 214 open-pollinated families, representing 43 provenances in Québec, Canada. The results revealed that HBLUP bivariate analysis is effective in reducing the known bias in heritability estimates of open-pollinated populations, as it exposes hidden relatedness, potential pedigree errors, and inbreeding. The addition of genomic information in the analysis considerably improved the accuracy in breeding value estimates by accounting for both Mendelian sampling and historical coancestry that were not captured by the contemporary pedigree alone. Increasing family genotyping efforts were associated with continuous improvement in model fit, precision of genetic parameters, and breeding value accuracy. Yet, improvements were observed even at minimal genotyping effort, indicating that even modest genotyping effort is effective in improving genetic evaluation. The combined utilization of both pedigree and genomic information may be a cost-effective approach to increase the accuracy of breeding values in forest tree breeding programs where shallow pedigrees and large testing populations are the norm.

Single-Step BLUP with Varying Genotyping Effort in Open-Pollinated Picea glauca.

Science.gov (United States)

Ratcliffe, Blaise; El-Dien, Omnia Gamal; Cappa, Eduardo P; Porth, Ilga; Klápště, Jaroslav; Chen, Charles; El-Kassaby, Yousry A

2017-03-10

Maximization of genetic gain in forest tree breeding programs is contingent on the accuracy of the predicted breeding values and precision of the estimated genetic parameters. We investigated the effect of the combined use of contemporary pedigree information and genomic relatedness estimates on the accuracy of predicted breeding values and precision of estimated genetic parameters, as well as rankings of selection candidates, using single-step genomic evaluation (HBLUP). In this study, two traits with diverse heritabilities [tree height (HT) and wood density (WD)] were assessed at various levels of family genotyping efforts (0, 25, 50, 75, and 100%) from a population of white spruce ( Picea glauca ) consisting of 1694 trees from 214 open-pollinated families, representing 43 provenances in Québec, Canada. The results revealed that HBLUP bivariate analysis is effective in reducing the known bias in heritability estimates of open-pollinated populations, as it exposes hidden relatedness, potential pedigree errors, and inbreeding. The addition of genomic information in the analysis considerably improved the accuracy in breeding value estimates by accounting for both Mendelian sampling and historical coancestry that were not captured by the contemporary pedigree alone. Increasing family genotyping efforts were associated with continuous improvement in model fit, precision of genetic parameters, and breeding value accuracy. Yet, improvements were observed even at minimal genotyping effort, indicating that even modest genotyping effort is effective in improving genetic evaluation. The combined utilization of both pedigree and genomic information may be a cost-effective approach to increase the accuracy of breeding values in forest tree breeding programs where shallow pedigrees and large testing populations are the norm. Copyright © 2017 Ratcliffe et al.

Overexpression of Laccaria bicolor aquaporin JQ585595 alters root water transport properties in ectomycorrhizal white spruce (Picea glauca) seedlings.

Science.gov (United States)

Xu, Hao; Kemppainen, Minna; El Kayal, Walid; Lee, Seong Hee; Pardo, Alejandro G; Cooke, Janice E K; Zwiazek, Janusz J

2015-01-01

The contribution of hyphae to water transport in ectomycorrhizal (ECM) white spruce (Picea glauca) seedlings was examined by altering expression of a major water-transporting aquaporin in Laccaria bicolor. Picea glauca was inoculated with wild-type (WT), mock transgenic or L. bicolor aquaporin JQ585595-overexpressing (OE) strains and exposed to root temperatures ranging from 5 to 20°C to examine the root water transport properties, physiological responses and plasma membrane intrinsic protein (PIP) expression in colonized plants. Mycorrhization increased shoot water potential, transpiration, net photosynthetic rates, root hydraulic conductivity and root cortical cell hydraulic conductivity in seedlings. At 20°C, OE plants had higher root hydraulic conductivity compared with WT plants and the increases were accompanied by higher expression of P. glauca PIP GQ03401_M18.1 in roots. In contrast to WT L. bicolor, the effects of OE fungi on root and root cortical cell hydraulic conductivities were abolished at 10 and 5°C in the absence of major changes in the examined transcript levels of P. glauca root PIPs. The results provide evidence for the importance of fungal aquaporins in root water transport of mycorrhizal plants. They also demonstrate links between hyphal water transport, root aquaporin expression and root water transport in ECM plants. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

Typha angustifolia L. X T. latifolia L. (T.) (glauca Godr.) in Nederland

NARCIS (Netherlands)

Ooststroom, van S.J.; Reichgelt, Th.J.

1962-01-01

Typha x glauca Godr., the hybrid of T. angustifolia L. and T. latifolia L. was found in the Netherlands for the first time in 1847 and again in 1946, as appears from the collections in the Rijksherbarium, Leiden. Fig. 1 shows the differences found in the female flowers, the pollen, and the

Spatial and seasonal variations of leaf area index (LAI) in subtropical secondary forests related to floristic composition and stand characters

Science.gov (United States)

Zhu, Wenjuan; Xiang, Wenhua; Pan, Qiong; Zeng, Yelin; Ouyang, Shuai; Lei, Pifeng; Deng, Xiangwen; Fang, Xi; Peng, Changhui

2016-07-01

Leaf area index (LAI) is an important parameter related to carbon, water, and energy exchange between canopy and atmosphere and is widely applied in process models that simulate production and hydrological cycles in forest ecosystems. However, fine-scale spatial heterogeneity of LAI and its controlling factors have yet to be fully understood in Chinese subtropical forests. We used hemispherical photography to measure LAI values in three subtropical forests (Pinus massoniana-Lithocarpus glaber coniferous and evergreen broadleaved mixed forests, Choerospondias axillaris deciduous broadleaved forests, and L. glaber-Cyclobalanopsis glauca evergreen broadleaved forests) from April 2014 to January 2015. Spatial heterogeneity of LAI and its controlling factors were analysed using geostatistical methods and the generalised additive models (GAMs) respectively. Our results showed that LAI values differed greatly in the three forests and their seasonal variations were consistent with plant phenology. LAI values exhibited strong spatial autocorrelation for the three forests measured in January and for the L. glaber-C. glauca forest in April, July, and October. Obvious patch distribution pattern of LAI values occurred in three forests during the non-growing period and this pattern gradually dwindled in the growing season. Stem number, crown coverage, proportion of evergreen conifer species on basal area basis, proportion of deciduous species on basal area basis, and forest types affected the spatial variations in LAI values in January, while stem number and proportion of deciduous species on basal area basis affected the spatial variations in LAI values in July. Floristic composition, spatial heterogeneity, and seasonal variations should be considered for sampling strategy in indirect LAI measurement and application of LAI to simulate functional processes in subtropical forests.

Variación estacional y potencial enzimático de microhongos asociados con la descomposición de hojarasca de Nothofagus pumilio Seasonal variation and enzymatic potential of microfungi associated with the decomposition of Nothofagus pumilio leaf litter

Directory of Open Access Journals (Sweden)

EDUARDO VALENZUELA

2001-12-01

Full Text Available Se estudió la variación estacional y el potencial enzimático de microhongos aislados desde el follaje y hojarasca de Nothofagus pumilio sometida a degradación natural durante 1 año. La investigación se realizó en un bosque de N. pumilio ubicado en una microcuenca del Valle de Antillanca, Parque Nacional Puyehue (40° 47' S, 72° 12' O, 1.120 m de altitud. Hojas senescentes colectadas desde árboles de N. pumilio se depositaron en bolsas de malla de nylon ("litter bags" y se sometieron a degradación natural en el piso del bosque durante 1 año (marzo 1997-marzo 1998, realizando muestreos trimestrales. Para el aislamiento de microhongos desde las hojas se utilizó el método de las diluciones, con agar extracto de malta al 2 % como medio de cultivo. Para determinar los potenciales degradativos de los aislamientos, se analizaron in vitro las actividades de amilasa, celulasa, pectinasa, proteasa, lacasa, oxidasa extracelular, peroxidasa, citocromo oxidasa, fosfatasa, esterasa y tirosinasa. Las principales especies aisladas en las hojas senescentes fueron Alternaria alternata, Cladosporium cladosporioides, Epicoccum nigrum, Phialophora grupo hoffmannii y Rhodotorula aurantiaca. Las especies dominantes en la hojarasca fueron Hormonema prunorum, Mortierella ramanniana var. angulispora, Penicillium para-herquei y Trichoderma polysporum. El mayor potencial enzimático lo exhibieron Moniliales y micelios estériles, mientras el menor Sphaeropsidales y levaduras. Las especies más activas fueron Alternaria alternata, Cladosporium cladosporioides, Hormonema prunorum y Phialophora malorum. Las actividades de celulasa y amilasa fueron las más importantes. De las enzimas ligninolíticas, oxidasa extracelular y peroxidasa presentaron los más elevados potenciales enzimáticosThe seasonal variation and enzymatic potential of microfungi isolated from senescent leaves and leaf litter of Nothofagus pumilio was studied. The study was performed in a N

[Effects of simulated acid rain on Quercus glauca seedlings photosynthesis and chlorophyll fluorescence].

Science.gov (United States)

Li, Jia; Jiang, Hong; Yu, Shu-quan; Jiang, Fu-wei; Yin, Xiu-min; Lu, Mei-juan

2009-09-01

Taking the seedlings of Quercus glauca, a dominant evergreen broadleaf tree species in subtropical area, as test materials, this paper studied their photosynthesis, chlorophyll fluorescence, and chlorophyll content under effects of simulated acid rain with pH 2.5, 4.0, and 5.6 (CK). After 2-year acid rain stress, the net photosynthetic rate of Q. glauca increased significantly with decreasing pH of acid rain. The acid rain with pH 2.5 and 4.0 increased the stomatal conductance and transpiration rate, and the effect was more significant under pH 2.5. The intercellular CO2 concentration decreased in the order of pH 2.5 > pH 5.6 > pH 4.0. The maximum photosynthetic rate, light compensation point, light saturation point, and dark respiration rate were significantly higher under pH 2.5 and 4.0 than under pH 5.6, while the apparent quantum yield was not sensitive to acid rain stress. The maximal photochemical efficiency of PS II and the potential activity of PS II under pH 2.5 and 4.0 were significantly higher than those under pH 5.6. The relative chlorophyll content was in the order of pH 2.5 > pH 5.6 > pH 4.0, and there was a significant difference between pH 2.5 and 4.0. All the results suggested that the photosynthesis and chlorophyll fluorescence of Q. glauca increased under the effects of acid rain with pH 2.5 and 4.0, and the acid rain with pH 2.5 had more obvious effects.

Establishment and growth of white spruce on a boreal forest floodplain: interactions between microclimate and mammalian herbivory

Science.gov (United States)

Amy C. Angell; Knut. Kielland

2009-01-01

White spruce (Picea glauca (Moench) Voss) is a dominant species in late-successional ecosystems along the Tanana River, interior Alaska, and the most important commercial timber species in these boreal floodplain forests. Whereas white spruce commonly seed in on young terraces in early primary succession, the species does not become a conspicuous...

Pollination ecology of the invasive tree tobacco Nicotiana glauca: comparisons across native and non-native ranges

Directory of Open Access Journals (Sweden)

Jeff Ollerton

2012-10-01

Full Text Available Interactions with pollinators are thought to play a significant role in determining whether plant species become invasive, and ecologically generalised species are predicted to be more likely to invade than more specialised species. Using published and unpublished data we assessed the floral biology and pollination ecology of the South American native Nicotiana glauca (Solanaceae which has become a significant invasive of semi-arid parts of the world. In regions where specialised bird pollinators are available, for example hummingbirds in California and sunbirds in South Africa and Israel, N. glauca interacts with these local pollinators and sets seed by both out-crossing and selfing. In areas where there are no such birds, such as the Canary Islands and Greece, abundant viable seed is set by selfing, facilitated by the shorter stigma-anther distance compared to plants in native populations. Surprisingly, in these areas without pollinating birds, the considerable nectar resources are only rarely exploited by other flower visitors such as bees or butterflies, either legitimately or by nectar robbing. We conclude that Nicotiana glauca is a successful invasive species outside of its native range, despite its functionally specialised hummingbird pollination system, because it has evolved to become more frequently self pollinating in areas where it is introduced. Its invasion success is not predictable from what is known of its interactions with pollinators in its home range.

Variation in phenology and monoterpene patterns of defoliated and nondefoliated Douglas-fir (Pseudotsuga menziesii var. glauca).

Science.gov (United States)

Rose-Marie Muzika; Judith Engle; Catherine Parks; Boyd. Wickman

1993-01-01

Foliage was collected from paired Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) trees characterized as either "resistant" or "susceptible" western spruce budworm (Choristoneura occidentalis Freeman (Lepidoptera: Tortricidae) attack. Resistant trees produced more...

A Quantitative Index of Forest Structural Sustainability

Directory of Open Access Journals (Sweden)

Jonathan A. Cale

2014-07-01

Full Text Available Forest health is a complex concept including many ecosystem functions, interactions and values. We develop a quantitative system applicable to many forest types to assess tree mortality with respect to stable forest structure and composition. We quantify impacts of observed tree mortality on structure by comparison to baseline mortality, and then develop a system that distinguishes between structurally stable and unstable forests. An empirical multivariate index of structural sustainability and a threshold value (70.6 derived from 22 nontropical tree species’ datasets differentiated structurally sustainable from unsustainable diameter distributions. Twelve of 22 species populations were sustainable with a mean score of 33.2 (median = 27.6. Ten species populations were unsustainable with a mean score of 142.6 (median = 130.1. Among them, Fagus grandifolia, Pinus lambertiana, P. ponderosa, and Nothofagus solandri were attributable to known disturbances; whereas the unsustainability of Abies balsamea, Acer rubrum, Calocedrus decurrens, Picea engelmannii, P. rubens, and Prunus serotina populations were not. This approach provides the ecological framework for rational management decisions using routine inventory data to objectively: determine scope and direction of change in structure and composition, assess excessive or insufficient mortality, compare disturbance impacts in time and space, and prioritize management needs and allocation of scarce resources.

The effect of intermittent dosing of Nicotiana glauca on teratogenesis in goats.

Science.gov (United States)

Welch, K D; Panter, K E; Lee, S T; Gardner, D R

2015-01-01

Sustained inhibition of fetal movement in livestock species, induced by several poisonous plants, can result in numerous skeletal-contracture malformations. Lupines are responsible for a condition in cattle referred to as "crooked calf syndrome" that occurs when pregnant cattle graze teratogenic lupines. Similar malformations are also seen in animals poisoned by Conium maculatum (coniine) and Nicotiana glauca (anabasine). A proposed management strategy to limit these types of birth defects includes utilizing an intermittent grazing schedule to allow short durations of grazing lupine-infested areas interrupted by movement to a lupine-free pasture. The objective of this study was to use a goat model to determine if an intermittent schedule of five continuous days on treatment followed by two days off treatment would be sufficient to decrease, or prevent, the incidence of anabasine-induced malformations. The data from this study suggest that, for N. glauca in goats, the intermittent grazing program of five days exposure with two days of non-exposure is insufficient to prevent significant skeletal malformations from occurring. However, this study did demonstrate an inverse relationship between the amount of serum anabasine in the dam and the extent of fetal movement. Published by Elsevier Ltd.

Integrated analysis of 454 and Illumina transcriptomic sequencing characterizes carbon flux and energy source for fatty acid synthesis in developing Lindera glauca fruits for woody biodiesel.

Science.gov (United States)

Lin, Zixin; An, Jiyong; Wang, Jia; Niu, Jun; Ma, Chao; Wang, Libing; Yuan, Guanshen; Shi, Lingling; Liu, Lili; Zhang, Jinsong; Zhang, Zhixiang; Qi, Ji; Lin, Shanzhi

2017-01-01

Lindera glauca fruit with high quality and quantity of oil has emerged as a novel potential source of biodiesel in China, but the molecular regulatory mechanism of carbon flux and energy source for oil biosynthesis in developing fruits is still unknown. To better develop fruit oils of L. glauca as woody biodiesel, a combination of two different sequencing platforms (454 and Illumina) and qRT-PCR analysis was used to define a minimal reference transcriptome of developing L. glauca fruits, and to construct carbon and energy metabolic model for regulation of carbon partitioning and energy supply for FA biosynthesis and oil accumulation. We first analyzed the dynamic patterns of growth tendency, oil content, FA compositions, biodiesel properties, and the contents of ATP and pyridine nucleotide of L. glauca fruits from seven different developing stages. Comprehensive characterization of transcriptome of the developing L. glauca fruit was performed using a combination of two different next-generation sequencing platforms, of which three representative fruit samples (50, 125, and 150 DAF) and one mixed sample from seven developing stages were selected for Illumina and 454 sequencing, respectively. The unigenes separately obtained from long and short reads (201, and 259, respectively, in total) were reconciled using TGICL software, resulting in a total of 60,031 unigenes (mean length = 1061.95 bp) to describe a transcriptome for developing L. glauca fruits. Notably, 198 genes were annotated for photosynthesis, sucrose cleavage, carbon allocation, metabolite transport, acetyl-CoA formation, oil synthesis, and energy metabolism, among which some specific transporters, transcription factors, and enzymes were identified to be implicated in carbon partitioning and energy source for oil synthesis by an integrated analysis of transcriptomic sequencing and qRT-PCR. Importantly, the carbon and energy metabolic model was well established for oil biosynthesis of developing L

Influencias de las variaciones en el clima y en la concentración de C0(2 sobre el crecimiento de Nothofagus pumilio en la Patagonia Influences of climatic and C0(2 concentration changes on radial growth oí Nothofagus pumilio in Patagonia

Directory of Open Access Journals (Sweden)

ANA M SRUR

2008-06-01

variaciones de la disponibilidad hídrica en sitios mésicos.Influences of climate and C0(2 concentration variations during the last century on radial growth and water-use efficiency oí Nothofagus pumilio were evaluated along an altitudinal gradient in El Chaltén (49°22' S, Santa Cruz, Argentina. We used a combination of dendrochronological and isotopic techniques. Tree growth in the upper treeline shows a positive trend concurrent with increasing regional temperatures. In contrast, due to a gradual increase in water déficits, the rate of radial growth in the xeric forest-steppe ecotone has decreased in the past 100 years. Intermediate-elevation trees from mesic forests show a weak, non-significant negative trend in radial growth during the same interval. 6(13C reflects soil moisture variations with elevation and its differential influence on stomatal conductance and photosynthetic rate processes. In sites with reduced to severe water déficits, the intrinsic water-use efficiency (IWUE appears to be influenced by the amount of water in the soil. However, the relationship between IWUE and climate is more obvious in sites with reduced water stress. In drier sites, the photosynthetic rate is severely limited by water déficits so that the reduction in radial growth is not compensated by the increase in IWUE. In contrast with the traditional assumption in dendrochronology indicating that the strong relationships between radial growth and climate are recorded at the forest ecotones, the variations in 6(13C better reflect water déficits at intermedíate mesic forests.

Seasonal variation and enzymatic potential of microfungi associated with the decomposition of Nothofagus pumilio leaf litter

OpenAIRE

VALENZUELA, EDUARDO; LEIVA, SERGIO; GODOY, ROBERTO

2001-01-01

Se estudió la variación estacional y el potencial enzimático de microhongos aislados desde el follaje y hojarasca de Nothofagus pumilio sometida a degradación natural durante 1 año. La investigación se realizó en un bosque de N. pumilio ubicado en una microcuenca del Valle de Antillanca, Parque Nacional Puyehue (40° 47' S, 72° 12' O, 1.120 m de altitud). Hojas senescentes colectadas desde árboles de N. pumilio se depositaron en bolsas de malla de nylon ("litter bags") y se sometieron a degrad...

Effects on the forest of sulfur dioxide from a sulfur fire near Edson, Alberta

Energy Technology Data Exchange (ETDEWEB)

Hocking, D

1975-01-01

Sulfur was burnt in a sanitary landfill during August 9 and 10, 1974. Resulting sulfur dioxide impinged on the surrounding mixed forest for 29 h. About 4 ha of forest displayed visible injury symptoms of varying intensity soon after. However, only .4 ha remained permanently injured the next season. Here, white spruce (Picea glauca (Moench) Voss) and scattered individuals of balsam poplar (Populus balsamifera L.), alder (Alnus tenuifolia Nutt.), and trembling aspen (Populus tremuloides Michx.) were killed. This report describes the extent of injury, relative sensitivities of affected plant species, and recovery in the spring in 1975.

Variación estacional y potencial enzimático de microhongos asociados con la descomposición de hojarasca de Nothofagus pumilio Seasonal variation and enzymatic potential of microfungi associated with the decomposition of Nothofagus pumilio leaf litter

OpenAIRE

EDUARDO VALENZUELA; SERGIO LEIVA; ROBERTO GODOY

2001-01-01

Se estudió la variación estacional y el potencial enzimático de microhongos aislados desde el follaje y hojarasca de Nothofagus pumilio sometida a degradación natural durante 1 año. La investigación se realizó en un bosque de N. pumilio ubicado en una microcuenca del Valle de Antillanca, Parque Nacional Puyehue (40° 47' S, 72° 12' O, 1.120 m de altitud). Hojas senescentes colectadas desde árboles de N. pumilio se depositaron en bolsas de malla de nylon ("litter bags") y se sometieron a degrad...

Pollinator networks, alien species and the conservation of rare plants: Trinia glauca as a case study

NARCIS (Netherlands)

Carvalheiro, L.G.; Barbosa, E.R.; Memmott, J.

2008-01-01

1. Despite the essential role of pollination in the maintenance of many rare plant species, conservation management plans rarely consider the service of pollination. 2. This study identifies the main pollinators of a rare English plant species, Trinia glauca (Apiaceae), and provides recommendations

Micropropagation of Araucaria excelsa R. Br. var. glauca Carrière from orthotropic stem explants.

Science.gov (United States)

Sarmast, Mostafa Khoshhal; Salehi, Hassan; Khosh-Khui, Morteza

2012-07-01

The objectives of the present work were in vitro propagation of Araucaria excelsa R. Br. var. glauca Carrière (Norfolk Island pine) with focus on the evaluation of the mean number of shoots per explant (MNS/E) and mean length of shoots per explants (MLS/E) produced by different parts of the orthotropic stem of A. excelsa R. Br. var. glauca in response to plant growth regulators. Norfolk Island pine axillary meristems responded very well to the 2-iso-pentenyl adenine (2iP) and thidiazuron (TDZ) levels. Explants taken from stem upper segments in the media containing 2iP had a higher MNS/E (3.47) and MLS/E (6.27 mm) in comparison to those taken from stem lower segments, which were 0.71 and 0.51 mm, respectively. Using 0.045 μM TDZ in the MS medium not only resulted in 4.60 MNS/E with 7.08 mm MLS/E but proliferated shoots showed a good performance as well. Investigating the best position of stem explant on mother plant as well as the best concentrations of growth regulators were performed which were useful for efficient micropropagation of this plant. Thirty three percent of explants were rooted in the MS medium containing 3 % sucrose, supplemented with 7.5 μM of both NAA and IBA for 2 weeks before transferring to a half strength MS medium without any growth regulator. Plantlets obtained were acclimatized and transferred to the greenhouse with less than 20 % mortality. This procedure considered the first successful report for regeneration and acclimatization of A. excelsa R. Br. var. glauca plantlet through main stem explants.

Size and distribution of Pandarus satyrus (Copepoda: Pandaridae on the blue shark Prionace glauca (Carcharhiniformes: Carcharhinidae in Costa Rica

Directory of Open Access Journals (Sweden)

José Rodrigo Rojas M.

2001-03-01

Full Text Available A total of 80 specimens of Pandarus satyrus, a cosmopolitan ectoparasitic copepod, were taken from fishery catches of blue sharks (Prionace glauca in the Eastern Pacific coast of Costa Rica. All specimens were found in the dorsal surface of pectoral fins (8-30 per shark. Longer specimens were most abundant.Un total de 80 especímenes de Pandarus satyrus, un copépodo ectoparásito cosmopolita, fueron tomados de tiburones azules (Prionace glauca capturados en la costa del Pacífico Oriental de Costa Rica. Todos los especímenes fueron encontrados en la superficie dorsal de las aletas pectorales (entre 8 y 30 por tiburón. Los parásitos más grandes son los más abundantes.

Wellington Quaternary palynology

International Nuclear Information System (INIS)

Harris, W.F.; Mildenhall, D.C.

1984-01-01

Pollen samples from a profile at Taita indicate a grassland environment prior to and immediately after the deposition of the Aokautere Ash (Kawakawa Tephra) approximately 21,000 years B.P. This grassland gradually gave way to a Nothofagus menziesii montane forest followed by an abrupt change to a N. ''Fusca'' group dominant forest which continues to the top of the section. The top few centimetres of the profile may have been deposited in post-European time. The abrupt change in the species of beech represents an unconformity of unknown duration. Pollen samples from a number of profiles at Mangaroa (Wallaceville Swamp) indicate a change from a cool environment (Gramineae plus Phyllocladus) through successive phases of Nothofagus menziesii, Podocarpus species, Dacrydium cupressinum to Nothofagus ''fusca'' group close to the present day. These results are presented in an historical context based on notes left by Dr W.F. Harris, supplemented with additional data by the junior author

Decoupling of unpolluted temperate forests from rock nutrient sources revealed by natural 87Sr/86Sr and 84Sr tracer addition

Science.gov (United States)

Kennedy, Martin J.; Hedin, Lars O.; Derry, Louis A.

2002-01-01

An experimental tracer addition of 84Sr to an unpolluted temperate forest site in southern Chile, as well as the natural variation of 87Sr/86Sr within plants and soils, indicates that mechanisms in shallow soil organic horizons are of key importance for retaining and recycling atmospheric cation inputs at scales of decades or less. The dominant tree species Nothofagus nitida feeds nearly exclusively (>90%) on cations of atmospheric origin, despite strong variations in tree size and location in the forest landscape. Our results illustrate that (i) unpolluted temperate forests can become nutritionally decoupled from deeper weathering processes, virtually functioning as atmospherically fed ecosystems, and (ii) base cation turnover times are considerably more rapid than previously recognized in the plant available pool of soil. These results challenge the prevalent paradigm that plants largely feed on rock-derived cations and have important implications for understanding sensitivity of forests to air pollution. PMID:12119394

Genetic diversity in populations of Isatis glauca Aucher ex Boiss. ssp. from Central Anatolia in Turkey, as revealed by AFLP analysis.

Science.gov (United States)

Özbek, Özlem; Görgülü, Elçin; Yıldırımlı, Şinasi

2013-12-01

Isatidae L. is a complex and systematically difficult genus in Brassicaceae. The genus displays great morphological polymorphism, which makes the classification of species and subspecies difficult as it is observed in Isatis glauca Aucher ex Boiss. The aim of this study is characterization of the genetic diversity in subspecies of Isatis glauca Aucher ex Boiss. distributed widely in Central Anatolia, in Turkey by using Amplified Fragment Length Polymorphism (AFLP) technique. Eight different Eco RI-Mse I primer combinations produced 805 AFLP loci, 793 (98.5%) of which were polymorphic in 67 accessions representing nine different populations. The data obtained by AFLP was computed with using GDA (Genetic Data Analysis) and STRUCTURE (version 2.3.3) software programs for population genetics. The mean proportion of the polymorphic locus (P), the mean number of alleles (A), the number of unique alleles (U) and the mean value of gene diversity (He) were 0.59, 1.59, 20, and 0.23 respectively. The coancestry coefficient (ϴ) was 0.24. The optimal number of K was identified as seven. The principal component analysis (PCA) explained 85.61% of the total genetic variation. Isatis glauca ssp. populations showed a high level of genetic diversity, and the AFLP analysis revealed that high polymorphism and differentiated subspecies could be used conveniently for population genetic studies. The principal coordinate analysis (PCoA) based on the dissimilarity matrix, the dendrogram drawn with UPGMA method and STRUCTURE cluster analysis distinguished the accessions successfully. The accessions formed distinctive population structures for populations AA, AB, E, K, and S. Populations AG1 and AG2 seemed to have similar genetic content, in addition, in both populations several hybrid individuals were observed. The accessions did not formed distinctive population structures for both populations AI and ANP. Consequently, Ankara province might be the area, where species Isatis glauca Aucher

Estimación del índice de sitio en rodales de Nothofagus dombeyi a través de herramientas de teledetección espacial

Directory of Open Access Journals (Sweden)

C. Esse

2013-12-01

Full Text Available La estimación del índice de sitio y la calidad del sitio constituyen herramientas básicas en la gestión de los ecosistemas forestales y la práctica de la silvicultura. El estudio de la distribución espacial y la dinámica temporal de índice de sitio y la calidad del sitio de los ecosistemas forestales aún carece de los avances tecnológicos. Este estudio propone la integración de las herramientas de teledetección para la estimación de la productividad forestal para áreas remotas. Se evaluó el potencial de aplicación de la metodología en amplias regiones y los bosques con la evaluación de la exactitud. Los resultados muestran que el índice del sitio de los bosques secundarios de Nothofagus dombeyi (Mirb. Oerst., están en correlación lineal con los índices de vegetación normalizada (NDVI, índice de diferencia de vegetación ajustado (TNDVI, banda Infrarroja pura de la imagen y transformación de componentes principales. Este estudio demostró que este enfoque puede ser utilizado en la estimación de la productividad de bosques secundarios en diferentes ecosistemas forestales.

Ecological adaptations in Douglas-fir (Pseudotsuga menziesii var. glauca). IV. Montana and Idaho near the Continental Divide

Science.gov (United States)

Gerald Rehfeldt

1988-01-01

Seventy-seven seedling populations of Douglas-fir (Pseudotsuga menziesii var. glauca) sampled from near the Continental Divide in Idaho and Montana exhibited pronounced genetic differences when compared in three common environments. Differentiation involved several traits that are components of an annual developmental cycle that must be completed within a growing...

Variaciones Intra-Específicas en el crecimiento primario de Nothofagus dombeyi (Nothofagaceae Intra-specific variations in the primary growth of Nothofagus dombeyi (Nothofagaceae

Directory of Open Access Journals (Sweden)

Javier Puntieri

2005-07-01

Full Text Available Se evaluó el patrón de crecimiento bajo condiciones controladas de los ejes foliados de 16 plántulas de Nothofagus dombeyi. Los individuos fueron ubicados en una cámara de crecimiento y se evaluó el crecimiento del tronco en dos eventos de crecimiento sucesivos (julio 2002 - marzo 2004. Se identificaron tres patrones de crecimiento del primer brote medido: (1 crecimiento ininterrumpido por unos 8 meses, (2 crecimiento interrumpido por un período de reposo no menor de 7 semanas, con rebrote posterior y (3 crecimiento ininterrumpido por 6 a 7 meses. En los individuos con los patrones de crecimiento 1 y 2, la tasa máxima de producción de hojas del primer brote producido fue mayor que en los individuos con el tercer patrón de crecimiento. La tasa media de crecimiento fue mayor para los brotes del primer grupo que para los de los otros dos grupos. El segundo de los brotes medidos se alargó en un único pulso y alcanzó menor tamaño que el primero de los brotes. Se discute el posible rol de gradientes ontogenéticos o de variaciones genéticas entre individuos de coihue como explicación de los diferentes patrones de crecimiento registrados.

Ectomycorrhizal fungi enhance nitrogen and phosphorus nutrition of Nothofagus dombeyi under drought conditions by regulating assimilative enzyme activities.

Science.gov (United States)

Alvarez, Maricel; Huygens, Dries; Olivares, Erick; Saavedra, Isabel; Alberdi, Miren; Valenzuela, Eduardo

2009-08-01

Drought stress conditions (DC) reduce plant growth and nutrition, restraining the sustainable reestablishment of Nothofagus dombeyi in temperate south Chilean forest ecosystems. Ectomycorrhizal symbioses have been documented to enhance plant nitrogen (N) and phosphorus (P) uptake under drought, but the regulation of involved assimilative enzymes remains unclear. We studied 1-year-old N. dombeyi (Mirb.) Oerst. plants in association with the ectomycorrhizal fungi Pisolithus tinctorius (Pers.) Coker & Couch. and Descolea antartica Sing. In greenhouse experiments, shoot and root dry weights, mycorrhizal colonization, foliar N and P concentrations, and root enzyme activities [glutamate synthase (glutamine oxoglutarate aminotransferase (GOGAT), EC 1.4.1.13-14), glutamine synthetase (GS, EC 6.3.1.2), glutamate dehydrogenase (GDH, EC 1.4.1.2-4), nitrate reductase (NR, EC 1.6.6.1), and acid phosphomonoesterase (PME, EC 3.1.3.1-2)] were determined as a function of soil-water content. Inoculation of N. dombeyi with P. tinctorius and D. antartica significantly stimulated plant growth and increased plant foliar N and P concentrations, especially under DC. Ectomycorrhizal inoculation increased the activity of all studied enzymes relative to non-mycorrhizal plants under drought. We speculate that GDH is a key enzyme involved in the enhancement of ectomycorrhizal carbon (C) availability by fuelling the tricarboxylic acid (TCA) cycle under conditions of drought-induced carbon deficit. All studied assimilative enzymes of the ectomycorrhizal associations, involved in C, N, and P transfers, are closely interlinked and interdependent. The up-regulation of assimilative enzyme activities by ectomycorrhizal fungal root colonizers acts as a functional mechanism to increase seedling endurance to drought. We insist upon incorporating ectomycorrhizal inoculation in existing Chilean afforestation programs.

Effects of cloning and root-tip size on observations of fungal ITS sequences from Picea glauca roots

Science.gov (United States)

Daniel L. Lindner; Mark T. Banik

2009-01-01

To better understand the effects of cloning on observations of fungal ITS sequences from Picea glauca (white spruce) roots two techniques were compared: (i) direct sequencing of fungal ITS regions from individual root tips without cloning and (ii) cloning and sequencing of fungal ITS regions from individual root tips. Effect of root tip size was...

Potential biotechnological application of mycorrhizas and yeasts associated with Nathofagus nervosa (Rauli)

Energy Technology Data Exchange (ETDEWEB)

Fernandez, N.; Fontenla, S.; Gallo, L.; Marchelli, P.

2009-07-01

Nothofagus nervosa is an ecologically and economically important species of south American temperate forests. In Argentina, it has a reduced natural distribution area due to over exploitation, overgrazing and forest fires. This critical situation led to the implementation of conservation and domestication programs. (Author)

Size and distribution of Pandarus satyrus (Copepoda: Pandaridae) on the blue shark Prionace glauca (Carcharhiniformes: Carcharhinidae) in Costa Rica.

Science.gov (United States)

Rojas, J R; Rodríguez Solano, O; Morales-Ramírez, A

2001-03-01

A total of 80 specimens of Pandarus satyrus, a cosmopolitan ectoparasitic copepod, were taken from fishery catches of blue sharks (Prionace glauca) in the Eastern Pacific coast of Costa Rica. All specimens were found in the dorsal surface of pectoral fins (8-30 per shark). Longer specimens were most abundant.

Modular organization of the white spruce (Picea glauca) transcriptome reveals functional organization and evolutionary signatures.

Science.gov (United States)

Raherison, Elie S M; Giguère, Isabelle; Caron, Sébastien; Lamara, Mebarek; MacKay, John J

2015-07-01

Transcript profiling has shown the molecular bases of several biological processes in plants but few studies have developed an understanding of overall transcriptome variation. We investigated transcriptome structure in white spruce (Picea glauca), aiming to delineate its modular organization and associated functional and evolutionary attributes. Microarray analyses were used to: identify and functionally characterize groups of co-expressed genes; investigate expressional and functional diversity of vascular tissue preferential genes which were conserved among Picea species, and identify expression networks underlying wood formation. We classified 22 857 genes as variable (79%; 22 coexpression groups) or invariant (21%) by profiling across several vegetative tissues. Modular organization and complex transcriptome restructuring among vascular tissue preferential genes was revealed by their assignment to coexpression groups with partially overlapping profiles and partially distinct functions. Integrated analyses of tissue-based and temporally variable profiles identified secondary xylem gene networks, showed their remodelling over a growing season and identified PgNAC-7 (no apical meristerm (NAM), Arabidopsis transcription activation factor (ATAF) and cup-shaped cotyledon (CUC) transcription factor 007 in Picea glauca) as a major hub gene specific to earlywood formation. Reference profiling identified comprehensive, statistically robust coexpressed groups, revealing that modular organization underpins the evolutionary conservation of the transcriptome structure. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Examination as to the classification of representative tree species at Satoyama coppice forest using multiwavelength range data observed from aircraft

International Nuclear Information System (INIS)

Setojima, M.; Imai, Y.; Funahashi, M.; Kawai, M.; Katsuki, T.

2006-01-01

In this study, we examined the possibility of classifying representative tree species at Satoyama coppice forest based on spectral reflectance of the tree species. We used the airborne hyperspectral data observed in exhibition leaf stage at the test forest (about 3.4ha) in Tama Forest Science Garden (Hachioji, Tokyo) , where the forest type similar to that of Satoyama is preserved. The classification accuracy was verified by comparing the results of interpretation of color aerial photographs taken in spring and autumn in chronological order and the field survey. As a result, the 534-556 nm (band 6 and band 7) in the visible range and 739-762 nm (band 15 and band 16), 785nm (band 17) in the near infrared range are effective bands for classification of the species of such trees as Castanopsis sieboldii, Quercus glauca, Zelkova serrata, Quercus serrata, Cryptomeria japonica, and Chamaecyparis obutusa, which are representative trees in Satoyama coppice forest in Tama district

Cestodes of the blue shark, Prionace glauca (Linnaeus 1758), (Carcharhiniformes: Carcharhinidae), off the west coast of Baja California Sur, Mexico.

Science.gov (United States)

Méndez, Oscar; Galván-Magaña, Felipe

2016-03-03

The cestode species recovered from the spiral intestines of 27 blue sharks (Prionace glauca) (Linnaeus, 1758) are reported from the western coast of Baja California Sur (BCS). The sampling was undertaken on a monthly basis from January 2003 to January 2004. The helminthological examination indicated the presence of four species of cestodes: Platybothrium auriculatum Yamaguti, 1952; Prosobothrium japonicum Yamaguti, 1934; Anthobothrium caseyi (Yamaguti, 1934) Ruhnke & Caira, 2009; and Paraorygmatobothrium prionacis (Yamaguti, 1934) Ruhnke, 1994. Of all the 27 sharks examined, 88.8% were infected with at least one cestode species. The most frequent species was P. auriculatum infecting 85% of the spiral intestines examined. In contrast the species with the highest mean intensity was P. prionacis (80.4 200). The species richness of cestodes in P. glauca is very similar in other regions of the world despite its wide distribution; however, this richness is low compared with other species of sharks within the same family. The feeding and host-specific are important factors that influence the parameters of infection of cestodes in this shark. On the west coast of BCS, Prionace glauca feeds mainly on red crab Pleuroncodes planipes Stimpson, 1860; squids Gonatus californiensis Young, 1972, Ancistrocheirus lesueurii (D'Orbigny, 1842), Haliphron atlanticus Steenstrup, 1861, and low proportion of fish teleosts as Merluccius productus (Ayres, 1855), Sardinops sp. Hubbs, 1929 and Scomber japonicus Houttuyn, 1872. We speculate that these prey could be involved as the second intermediate hosts of these cestodes, as in other members of these genera, although the life cycles of none are known.

Habitat conditions and phenological tree traits overrule the influence of tree genotype in the needle mycobiome-Picea glauca system at an arctic treeline ecotone.

Science.gov (United States)

Eusemann, Pascal; Schnittler, Martin; Nilsson, R Henrik; Jumpponen, Ari; Dahl, Mathilde B; Würth, David G; Buras, Allan; Wilmking, Martin; Unterseher, Martin

2016-09-01

Plant-associated mycobiomes in extreme habitats are understudied and poorly understood. We analysed Illumina-generated ITS1 sequences from the needle mycobiome of white spruce (Picea glauca) at the northern treeline in Alaska (USA). Sequences were obtained from the same DNA that was used for tree genotyping. In the present study, fungal metabarcoding and tree microsatellite data were compared for the first time. In general, neighbouring trees shared more fungal taxa with each other than trees growing in further distance. Mycobiomes correlated strongly with phenological host traits and local habitat characteristics contrasting a dense forest stand with an open treeline site. Genetic similarity between trees did not influence fungal composition and no significant correlation existed between needle mycobiome and tree genotype. Our results suggest the pronounced influence of local habitat conditions and phenotypic tree traits on needle-inhabiting fungi. By contrast, the tree genetic identity cannot be benchmarked as a dominant driver for needle-inhabiting mycobiomes, at least not for white spruce in this extreme environment. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Encapsulado de Embriones Somáticos y Embriones Cigóticos para Obtención de Semillas Artificiales de Raulí (Nothofagus alpina (Poepp. & Endl.) Oerst.)

OpenAIRE

Cartes R, Priscila; Castellanos B, Hermes; Ríos L, Darcy; Sáez C, Katia; Spierccolli H, Scarlette; Sánchez O, Manuel

2009-01-01

Somatic and zygotic embryos from mature seeds of rauli-beech, Nothofagus alpina (Poepp. & Endl.) Oerst., were encapsulated in different artificial endosperms in order to generate a cover that fulfills the function of nourishment and protection of the embryos, facilitating their later germination. The content of sodium alginate varied by 4%, 3%, and 2%, as did the immersion time in calcium chloride (CaCl2), which acts as complexing agent. The artificial endosperm components of the Murashige an...

Mercúrio total em músculo de cação Prionace glauca (Linnaeus, 1758 e de espadarte Xiphias gladius Linnaeus, 1758, na costa sul-sudeste do Brasil e suas implicações para a saúde pública Total mercury in muscle of the shark Prionace glauca (Linnaeus, 1758 and swordfish Xiphias gladius Linnaeus, 1758, from the South-Southeast coast of Brazil and the implications for public health

Directory of Open Access Journals (Sweden)

Adriana C. L. Dias

2008-09-01

Full Text Available Foram analisadas as concentrações de mercúrio total (THg em tecido muscular do tubarão azul Prionace glauca e do teleósteo Xiphias gladius, vulgarmente conhecido como espadarte, provenientes das regiões sul e sudeste da costa brasileira, para verificar se estas se encontram dentro dos padrões legais para consumo humano. As amostras foram obtidas utilizando-se o programa REVIZEE, de agosto a setembro de 2001, e por intermédio de uma empresa de pesca em Itajaí, Santa Catarina. Foi analisado um total de 95 espécimes, testando-se as correlações entre THg, comprimento (cm e peso (kg. As concentrações de mercúrio total em todas as amostras variaram de 0,13 a 2,26µgg-1 (peso úmido. A média de mercúrio total em P. glauca foi de 0,76 ± 0,48µgg-1 (p.u., e em X. gladius foi de 0,62 ± 0,31µgg-1 (p.u. com diferença não significativa (teste Mann-Whitney, p Total mercury (THg was analyzed in muscle tissue from the blue shark Prionace glauca and the swordfish Xiphias gladius, obtained from the South and Southeast coast of Brazil, to verify compliance with current limits for human consumption. Samples were obtained through the REVIZEE Program and a commercial fishery in Itajaí, Santa Catarina State. A total of 95 specimens were analyzed (48 X. gladius and 47 P. glauca, and correlations were checked between THg and fish length and weight. THg ranged from 0.13 to 2.26µgg-1 (fresh weight, and there was no significant difference between the means for P. glauca, 0.76 ± 0.48µgg-1 (f.w. and X. gladius, 0.62 ± 0.31 (Mann-Whitney test, p < 0.05. In 16% of samples, THg was above the limits set by the National Health Surveillance Agency (ANVISA, namely 1µgg-1, and 62% exceeded the World Health Organization (WHO limit of 0.5µgg-1. The ingestion of 100g/ day-1 of P. glauca or X. gladius would result in a daily THg intake of more than twice the WHO (1990 suggested limit.

[Phenolic acid derivatives from Bauhinia glauca subsp. pernervosa].

Science.gov (United States)

Zhao, Qiao-Li; Wu, Zeng-Bao; Zheng, Zhi-Hui; Lu, Xin-Hua; Liang, Hong; Cheng, Wei; Zhang, Qing-Ying; Zhao, Yu-Ying

2011-08-01

To study the chemical constituents of Bauhinia glauca subsp. pernervosa, eleven phenolic acids were isolated from a 95% ethanol extract by using a combination of various chromatographic techniques including column chromatography over silica gel, ODS, MCI, Sephadex LH-20, and semi-preparative HPLC. By spectroscopic techniques including 1H NMR, 13C NMR, 2D NMR, and HR-ESI-MS, these compounds were identified as isopropyl O-beta-(6'-O-galloyl)-glucopyranoside (1), ethyl O-beta-(6'-O-galloyl)-glucopyranoside (2), 3, 4, 5-trimethoxyphenyl-(6'-O-galloyl)-O-beta-D-glucopyranoside (3), 3, 4, 5-trimethoxyphenyl-beta-D-glucopyranoside (4), gallic acid (5), methyl gallate (6), ethyl gallate (7), protocatechuic acid (8), 3, 5-dimethoxy-4-hydroxybenzoic acid (9), erigeside C (10) and glucosyringic acid (11). Among them, compound 1 is a new polyhydroxyl compound; compounds 2, 10, and 11 were isolated from the genus Bauhinia for the first time, and the other compounds were isolated from the plant for the first time. Compounds 6 and 8 showed significant protein tyrosine phosphatase1B (PTP1B) inhibitory activity in vitro with the IC50 values of 72.3 and 54.1 micromol x L(-1), respectively.

Knowing and doing: research leading to action in the conservation of forest genetic diversity of Patagonian temperate forests.

Science.gov (United States)

Gallo, Leonardo A; Marchelli, Paula; Chauchard, Luis; Peñalba, Marcelo Gonzalez

2009-08-01

Researchers dealing with conservation subjects usually do not put the results of their work into practice, even when the primary purpose of their research is the preservation of biodiversity. In the South American temperate forests we identified an area with the highest genetic diversity in Argentina of Nothofagus nervosa, one of the most relevant southern beech species. Based on the information of our scientific study and our recommendations, the authorities of Lanin National Park changed the protection status of this area to avoid logging. The new forestry management plans include consideration of "high genetic diversity" in decisions on where logging will be allowed. Results of our initial genetic study induced the analysis of biodiversity at the species and ecosystems levels, which yielded results similar to our genetic studies. A strong connection among researchers and managers from the onset of our study and the awareness of the former about the importance of the implementation of the research work were key to bridging the gap between conservation research and conservation practice.

Complete mitochondrial genome of the blue shark Prionace glauca (Elasmobranchii: Carcharhiniformes).

Science.gov (United States)

Chen, Xiao; Xiang, Dan; Ai, Weiming; Shi, Xiaofang

2015-04-01

In this study, we first presented the complete mitochondrial genome of the blue shark Prionace Glauca, a pelagic and oceanic species. It is 16,705 bp in length and contains 2 rRNA genes, 22 tRNA genes, 13 protein-coding genes and 1 putative control region. The overall base composition is 31.6% A, 24.4% C, 13.1% G and 30.9% T. Overlaps and short inter-genic spaces are located in the genome. The tRNA-Ser2 loses the dihydrouridine arm and cannot be folded into the typical clover-leaf secondary structure. Two start codons (GTG and ATG) with two stop codons (TAG and TAA) or with one incomplete stop codon (T) are found in the 13 protein-coding genes. The control region contains high A + T (69.9%) and low G (12.0%).

THE DYNAMICS OF TOTAL AMYLASE\\'S ACTIVITY IN PANICUM MILIACEUM AND SETARIA GLAUCA DURING THE GERMINATION PERIOD

Directory of Open Access Journals (Sweden)

Elena Ciornea

2006-08-01

Full Text Available : It was studied the dynamics of total amylase\\'s activity in millet (Panicum miliaceum and bristle grass (Setaria glauca during the germination period. The enzymatic activity was determined by the Noelting - Brenfeld method, the results obtained being expressed in M maltose / g. In both millet and bristle grass, it was evidenced that both parameters taken into study (the species and the germination time do influence the enzymatic activity, although to a different extent.

Interspecific transfer of only part of genome by fusion between non-irradiated protoplasts of Nicotiana glauca and X-ray irradiated protoplasts of N. Langsdorffii

International Nuclear Information System (INIS)

Itoh, K.; Futsuhara, Y.

1983-01-01

To transfer only part of genome, X-ray irradiated suspension cell protoplasts of N. langsdorffii were fused with suspension cell protoplasts of N. glauca by polyethylene glycol. Somatic hybrid calli were selected by the growth in the hormone-free medium. Some of somatic hybrid calli from fusion with irradiated protoplasts indicated the loss of small subunit polypeptide of fraction 1 protein which was coded by N. langsdorffii nuclear DNA. Cytological analysis provided an information on significant decrease of chromosomes in somatic hybrid calli from fusion with irradiated protoplasts, compared with the somatic hybrid calli from fusion with non-irradiated protoplasts. In addition, isozyme analysis revealed that somatic hybrid calli from fusion with irradiated protoplasts lost particular bands of N. langsdorffli. These results demonstrate the tranfer of only part of genome from N, langsdorffii to N, glauca by fusion with X-ray irradiated protoplasts

Experimental tolerance to boron of the plant species Nicotiana glauca, Jacaranda mimosifolia, Tecoma stans, Medicago sativa y Spinacea oleracea in Argentina; Tolerancia experimental de las especies vegetales Nicotiana glauca, Jacaranda mimosifolia, Tecoma stans, Medicago sativa y Spinacea oleracea al boro, en Argentina

Energy Technology Data Exchange (ETDEWEB)

Viana, Marta L. de; Albarracin Franco, Silvia [Univ. Nacional de Salta, Inst. de Ecologia y Ambiente Humano, CIUNSa, Buenos Aires No. 177, 4400, Salta (Argentina)], E-mail: mldeviana@arnet.com.ar

2008-09-15

The activity of the borate deposits industries constitutes a point source and diffuse pollution of air, soil and water. Therefore, the study and experimentation on possible ways to offset this impact is a priority. A relatively new technique to decontaminate soils is phytoremediation, which uses plants and associated microorganisms. The first step is to identify tolerant plant species, which is the focus of this work. An experiment was conducted in the laboratory to evaluate the germination, survival and growth of different species in different concentrations of boron. At the beginning and end of the experiment was determined concentration of boron in the substrate for each treatment and for substrates with and without vegetation. Significant differences due to treatment, the species and species-treatment interaction. M. sativa, N. glauca and J. mimosifolia were the species most tolerant to boron. The other species showed a decrease in all variables-response function of the concentration of the contaminant. All had low survival in the highest concentration. The decrease of boron was highest in the treatment of 30 ppm of boron with M. sativa and the lowest was recorded in the treatment of 20 ppm of boron with J. mimosifolia and 30 ppm of boron with T. stans and S. oleracea. It is concluded that N. glauca, M. sativa and J. mimosifolia could be considered as promising remediation. (author) [Spanish] La actividad de las industrias borateras constituye una fuente puntual y difusa de contaminacion del aire, suelo y aguas superficiales y profundas. Por lo tanto, el estudio y experimentacion acerca de las posibles formas de contrarrestar este impacto constituye una prioridad. Una tecnica relativamente nueva para descontaminar suelos es la fitorremediacion, que emplea plantas y microorganismos asociados. El primer paso es detectar las especies vegetales tolerantes, lo que constituye el objetivo de este trabajo. Se realizo un experimento en laboratorio para evaluar la

Climate sensitivity of reproduction in a mast-seeding boreal conifer across its distributional range from lowland to treeline forests.

Science.gov (United States)

Roland, Carl A; Schmidt, Joshua H; Johnstone, Jill F

2014-03-01

Mast-seeding conifers such as Picea glauca exhibit synchronous production of large seed crops over wide areas, suggesting climate factors as possible triggers for episodic high seed production. Rapidly changing climatic conditions may thus alter the tempo and spatial pattern of masting of dominant species with potentially far-reaching ecological consequences. Understanding the future reproductive dynamics of ecosystems including boreal forests, which may be dominated by mast-seeding species, requires identifying the specific cues that drive variation in reproductive output across landscape gradients and among years. Here we used annual data collected at three sites spanning an elevation gradient in interior Alaska, USA between 1986 and 2011 to produce the first quantitative models for climate controls over both seedfall and seed viability in P. glauca, a dominant boreal conifer. We identified positive associations between seedfall and increased summer precipitation and decreased summer warmth in all years except for the year prior to seedfall. Seed viability showed a contrasting response, with positive correlations to summer warmth in all years analyzed except for one, and an especially positive response to warm and wet conditions in the seedfall year. Finally, we found substantial reductions in reproductive potential of P. glauca at high elevation due to significantly reduced seed viability there. Our results indicate that major variation in the reproductive potential of this species may occur in different landscape positions in response to warming, with decreasing reproductive success in areas prone to drought stress contrasted with increasing success in higher elevation areas currently limited by cool summer temperatures.

Interspecific Competition and Trade-offs in Resource Allocation are the Key to Successful Growth of Seedlings of White Spruce (Picea glauca (Moench) Voss) at Subarctic Treelines in Warming Alaska.

Science.gov (United States)

Okano, K.; Bret-Harte, M. S.

2015-12-01

Alpine treelines in Alaska have advanced for the past 50 years in response to the recent climate warming. However, further increases in temperatures may cause treeline species drought stress and increase susceptibility to insect outbreaks and fire. Complex factors such as soil conditions and plant species composition also impact the growth of seedlings, which are essential to sustain boreal forests. Our goals were to assess 1) the current optimal elevation for the treeline species Picea glauca (white spruce) seedlings and how it is altered by climate change, and 2) their growth/survival strategies at each environmental site. We studied the growth response of spruce seedlings along an altitudinal gradient at 6 sites, consisting of tundra, forest, or transitional ecotone in Denali National Park and one forest site in Fairbanks, AK. In May 2012, four-month old seedlings were planted with or without naturally occurring plants to compare the presence or absence of the interspecific interaction. Summer temperatures were increased by one small greenhouse per site. Over 2 growing seasons, growth was measured non-destructively, and then the seedlings were harvested. Relative growth rate (RGR) in height was increased significantly as the altitude was increased. Elevated temperature increased height only in seedlings at a high-altitude forest. Seedlings with neighboring plants had a higher RGR in height than seedlings that had neighbors removed, while significantly wider diameters were measured from the seedlings without neighbors. A weak trend of declining diameter width with increasing altitudes was seen. Seedlings that grew taller did not grow their stems wider, indicating trade-offs in resource allocation. None of the altitudinal sites had a clear advantage for the growth of the seedlings. Habitat microclimate and the interaction with other species could be more important than the altitude or temperatures and hence, key to the survival and growth of spruce seedlings in

MORFOGÉNESIS IN VITRO DE Pseudotsuga menziesii VAR. glauca

Directory of Open Access Journals (Sweden)

María Guadalupe Carrillo-Benítez

2011-01-01

Full Text Available Se evaluó la respuesta morfogénica a partir de embriones cigóticos cultivados in vitro de semilla almacenada (un año de Pseudotsuga menziesii var. glauca recolectada en Tlaxcala. Las semillas fueron desinfestadas con detergente y H2O2 (3 % v/v durante 48 h en agitación a 50 rpm, cultivadas en el medio de Murashige y Skoog (1962 sin reguladores. La germinación ocurrió después de siete días y posteriormente subcultivados a un medio MS con 2,4-D (3 mg·L-1 y BA (1 mg·L-1. Con los callos obtenidos en un medio HS se evaluaron tres concentraciones de ABA para promover formación de estructuras embrionarias, presentándose el mejor tratamiento con concentración de 10.0 mg·L-1 (P<.0001. El mejor desarrollo de plántulas se presentó empleando un medio Murashige y Skoog (1962 con sacarosa al 6 %. Se usaron micorrizas para mejor adaptación de plántulas a suelo. No hubo formación de raíces.

Tolerancia experimental de las especies vegetales Nicotiana glauca, Jacaranda mimosifolia, Tecoma stans, Medicago sativa y Spinacea oleracea al boro, en Argentina

Directory of Open Access Journals (Sweden)

Marta L. de Viana

2008-09-01

Full Text Available La actividad de las industrias borateras constituye una fuente puntual y difusa de contaminación del aire, suelo y aguas superficiales y profundas. Por lo tanto, el estudio y experimentación acerca de las posibles formas de contrarrestar este impacto constituye una prioridad. Una técnica relativamente nueva para descontaminar suelos es la fitorremediación, que emplea plantas y microorganismos asociados. El primer paso es detectar las especies vegetales tolerantes, lo que constituye el objetivo de este trabajo. Se realizó un experimento en laboratorio para evaluar la germinación, la supervivencia y el crecimiento de distintas especies en diferentes concentraciones de boro. Al comienzo y al final del experimento se determinó la concentración de boro en el sustrato para cada tratamiento y para sustratos con y sin vegetación. Se encontraron diferencias significativas debidas al tratamiento, la especie y la interacción especie *tratamiento. M. sativa, N. glauca y J. mimosifolia fueron las especies de mayor tolerancia al boro. Las otras especies presentaron una disminución en todas las variables-respuesta en función de la concentración del contaminante. Todas presentaron una baja supervivencia en la máxima concentración. La disminución de boro fue máxima en el tratamiento de 30 ppm de boro con M. sativa y la menor se registró en los tratamiento de 20 ppm de boro con J. mimosifolia y de 30 ppm de boro con T. stans y S. oleraceae. Se concluye que N. glauca, M. sativa y J. mimosifolia podrían considerarse como prometedoras en remediación.Experimental tolerance to boron of the plant species Nicotiana glauca, Jacaranda mimosifolia, Tecoma stans, Medicago sativa y Spinacea oleracea in Argentina. The activity of boron industries is a punctual and diffuse source of air, soil and water pollution. Therefore, it is a priority to study possible ways of reducing this impact. A relatively new technology for reducing soil pollution is

Micropropagación in vitro de Nothofagus alpina utilizando fitohormonas

Directory of Open Access Journals (Sweden)

Luz García Cruzatty

2015-09-01

Full Text Available Nothofagus alpina es una de las especies forestales más importantes del Sur de Chile y Argentina, países donde se ha empezado con programas de mejoramiento genético. La micropropagación es una técnica muy útil en la clonación de árboles con fines de mejoramiento, por tanto, los objetivos planteados en esta investigación fueron: determinar la mejor concentración de fitohormonas 6-bencilaminopurina (BAP y ácido indol butírico (AIB y, el medio de cultivo idóneo para inducir el enraizamiento de brotes y la brotación de secciones nodales de N. alpina. Se evaluaron los medios de Murashige Skoog (MS y Wood Plant Medium (WPM, con la mitad de los macronutrientes (enraizamiento y los micronutrientes completos (multiplicación, suplementado con peptone (0.1%, sacarosa (2.0%, agar (0.7% y diferentes concentraciones de auxinas. El medio MS suplementado con 2 mg L-1 de AIB resultó mejor para inducir la producción de las raíces, tanto en número como en la longitud de la raíz principal. El mayor porcentaje de enraizamiento se registró en el medio WPM suplementado con 2 mg L-1 AIB. Los tratamientos para inducir multiplicación que incluyeron citoquinina originaron callos y no enraizaron; siendo mayor la presencia de callos en el medio WPM. Se sugiere que la aplicación de citoquininas no es indispensable para la brotación, puesto que en los tratamientos testigos hubo una buena brotación; lo que hace suponer que el material vegetal utilizado tiene suficiente niveles endógenos de esta fitohormona.

Surface-bound phosphatase activity in living hyphae of ectomycorrhizal fungi of Nothofagus obliqua.

Science.gov (United States)

Alvarez, Maricel; Godoy, Roberto; Heyser, Wolfgang; Härtel, Steffen

2004-01-01

We determined the location and the activity of surface-bound phosphomonoesterase (SBP) of five ectomycorrhizal (EM) fungi of Nothofagus oblique. EM fungal mycelium of Paxillus involutus, Austropaxillus boletinoides, Descolea antartica, Cenococcum geophilum and Pisolithus tinctorius was grown in media with varying concentrations of dissolved phosphorus. SBP activity was detected at different pH values (3-7) under each growth regimen. SBP activity was assessed using a colorimetric method based on the hydrolysis of p-nitrophenyl phosphate (pNPP) to p-nitrophenol phosphate (pNP) + P. A new technique involving confocal laser-scanning microscopy (LSM) was used to locate and quantify SBP activity on the hyphal surface. EM fungi showed two fundamentally different patterns of SBP activity in relation to varying environmental conditions (P-concentrations and pH). In the cases of D. antartica, A. boletinoides and C. geophilum, changes in SBP activity were induced primarily by changes in the number of SBP-active centers on the hyphae. In the cases of P. tinctorius and P. involutus, the number of SBP-active centers per μm hyphal length changed much less than the intensity of the SBP-active centers on the hyphae. Our findings not only contribute to the discussion about the role of SBP-active centers in EM fungi but also introduce LSM as a valuable method for studying EM fungi.

Registro de un Monstruo Diprósopo de Tiburón Azul (Prionace glauca) en Chile

OpenAIRE

Hevia-Hormazábal, Valentina; Pastén-Marambio, Víctor; Vega, Alonso

2011-01-01

Un espécimen de siameses de tiburón azul, Prionace glauca, fue recolectado durante actividades de pesca en el norte de Chile. Según una clasificación basada en el grado de duplicación y el sitio de fusión de los gemelos, el espécimen corresponde a un monstruo del tipo diprósopo tetroftalmo. El individuo tiene una duplicación craneofacial parcial con presencia de cuatro globos oculares e igual número de narinas. Las cavidades orales están interconectadas convergiendo en una única faringe. El t...

Morfología y Anatomía del Ápice Caulinar de Nothofagus dombeyi (Nothofagaceae a lo largo de un año Morfology and anatomy of the shoot apex of Nothofagus dombeyi (Nothofagaceae along a year

Directory of Open Access Journals (Sweden)

Soledad García

2006-07-01

Full Text Available En el presente estudio se evaluó la posible variación anual de la morfología y la anatomía del ápice caulinar de coihue, Nothofagus dombeyi (Nothofagaceae. A partir de muestras tomadas a lo largo de un año calendario, se realizaron cortes longitudinales de las yemas terminales con micrótomo de congelación. Independientemente de la época del año, una yema terminal está conformada por un meristema apical y rudimentos de tallo y hojas. Los primordios foliares proximales tienen mayor tamaño y grado de diferenciación que los distales. En la axila de cada estípula se destaca la presencia de coléteres. Cada coléter se comunica vascularmente con la estípula correspondiente. El número de primordios foliares por yema es constante entre abril y octubre y disminuye posteriormente al incrementarse el número de hojas expandidas, aunque sin llegar a cero. Al final de la estación de crecimiento se distinguen yemas de mayor y yemas de menor tamaño; estas últimas se secan y desprenden del tallo antes de la primavera siguiente. Dentro de una yema se evidencian, en un momento dado, distintos grados de diferenciación entre primordios foliares proximales y distales y entre la lámina y las estípulas de los primordios más proximales.The present study evaluates the possible annual variation in the morphology and anatomy of the shoot apex of Nothofagus dombeyi (Nothofagaceae. From samples taken over one year, longitudinal slices of terminal buds were cut with a freezing microtome. Irrespective of the time of the year, a terminal bud consists of an apical meristem and rudiments of stem and leaves. Proximal primordia are larger and have a higher degree of differentiation than distal primordia. Around the axil of each stipule colleters are present. Each colleter is connected with the corresponding stipule through a conducting strand. The number of leaf primordia per bud is constant between April and October and diminishes later on as leaf expansion

Elevated ozone negatively affects photosynthesis of current-year leaves but not previous-year leaves in evergreen Cyclobalanopsis glauca seedlings

International Nuclear Information System (INIS)

Zhang, Weiwei; Feng, Zhaozhong; Wang, Xiaoke; Niu, Junfeng

2014-01-01

To assess the effects of leaf age/layer on the response of photosynthesis to chronic ozone (O 3 ), Cyclobalanopsis glauca seedlings, a dominant evergreen broadleaf tree species in sub-tropical regions, were exposed to either ambient air (AA) or elevated O 3 (AA + 60 ppb O 3 , E-O 3 ) for two growing seasons in open-top chambers. Chlorophyll content, gas exchange and chlorophyll a fluorescence were investigated three times throughout the 2nd year of O 3 exposure. Results indicated that E-O 3 decreased photosynthetic parameters, particularly light-saturated photosynthesis rate, stomatal conductance and effective quantum yield of PSII photochemistry of current-year leaves but not previous-year leaves. Stomatal conductance of plants grown under ambient conditions partially contributed to the different response to E-O 3 between leaf layers. Light radiation or other physiological and biochemical processes closely related to photosynthesis might play important roles. All suggested that leaf ages or layers should be considered when assessing O 3 risk on evergreen woody species. -- Highlights: • Response of evergreen Cyclobalanopsis glauca to O 3 was investigated. • Elevated O 3 significantly reduced photosynthesis of current-year leaves. • Previous-year leaves showed little response to O 3 . • Stomatal conductance contributes to the response difference to O 3 among leaf ages. -- Impacts of elevated O 3 on photosynthesis of evergreen woody species depend on leaf ages

Assessing the impact of plantation forestry on plant biodiversity

Directory of Open Access Journals (Sweden)

Andreas Ch. Braun

2017-04-01

Full Text Available Effects of plantation forestry on biodiversity are controversially discussed in literature. While some authors stress positive effects, others tend to attribute a largely negative influence to plantations. One important factor steering the influence on biodiversity are management practices. A second important factor is the environmental matrix. Chile offers the option to analyse both factors jointly. The coastal range of central Chile has experienced rapid and widespread replacement of native Nothofagus spp. forests in favour of Pinus radiata plantations. Here, native forests remain limited to small patches surrounded by an environmental matrix of plantations. Management is rather intensive and not designed to maintain biodiversity. While in the coastal range of central Chile the transformation from native forests to non-native tree plantations has almost come to an end, spatial extension of P. contorta and P. ponderosa plantations has just recently begun in Chilean Patagonia. While the management is similar to central Chile, plantations rather exist as small patches surrounded by an environmental matrix of native plant formations (e.g. Nothofagus spp. forests and Nothofagus spp. scrublands. In the framework of this work, effects of the two diametric land usages on biodiversity are assessed and compared. Biodiversity is assessed at the α-, β- and γ-scale. At the α-scale, biodiversity impacts are inferred statistically, using one-way ANOVA and Tukey’s PostHoc test. Biodiversity of plants at both sites is significantly reduced in plantations when compared to native forests or scrublands. Plantation forestry lowers α-biodiversity and does not provide additional habitats for specialists. At the β-scale, weak edge effects due to the presence of native forests are observed. In total, plantation forestry tends to promote plant invasions and impairs the survival of endemics. At the γ-scale, plant species communities where predominantly native

Densities of breeding birds and changes in vegetation in an alaskan boreal forest following a massive disturbance by spruce beetles

Science.gov (United States)

Matsuoka, S.M.; Handel, C.M.; Ruthrauff, D.R.

2001-01-01

We examined bird and plant communities among forest stands with different levels of spruce mortality following a large outbreak of spruce beetles (Dendroctonus rufipennis (Kirby)) in the Copper River Basin, Alaska. Spruce beetles avoided stands with black spruce (Picea mariana) and selectively killed larger diameter white spruce (Picea glauca), thereby altering forest structure and increasing the dominance of black spruce in the region. Alders (Alnus sp.) and crowberry (Empetrum nigrum) were more abundant in areas with heavy spruce mortality, possibly a response to the death of overstory spruce. Grasses and herbaceous plants did not proliferate as has been recorded following outbreaks in more coastal Alaskan forests. Two species closely tied to coniferous habitats, the tree-nesting Ruby-crowned Kinglet (Regulus calendula) and the red squirrel (Tamiasciurus hudsonicus), a major nest predator, were less abundant in forest stands with high spruce mortality than in low-mortality stands. Understory-nesting birds as a group were more abundant in forest stands with high levels of spruce mortality, although the response of individual bird species to tree mortality was variable. Birds breeding in stands with high spruce mortality likely benefited reproductively from lower squirrel densities and a greater abundance of shrubs to conceal nests from predators.

Evaluation of the physical, mechanical and biological properties of the combined wood-plastic in Nothofagus Pumilio wood

International Nuclear Information System (INIS)

Benedetto Acuna, Andres

2010-01-01

In this project he studied the physical, mechanical and biological properties of wood-plastic combinations (WPC) in timber Nothofagus pumilio (Lenga) impregnated with the monomer methyl methacrylate (MMA), trying to get a hold and maximum penetration into the wood . It was used for impregnation method fills the cell (Bethell). To achieve the polymerization, the MMA once absorbed by the specimens under study are irradiated with gamma rays at a dose of 25 kGy, ensuring a high percentage of final polymerization, which fluctuated between 55.09% and 84.48%. The tests applied to the specimens were moisture content, dimensional stability, density, compression perpendicular to grain, compression parallel to grain to grain compression 'new' Janka hardness, shear parallel to grain, static bending and termites. In general, except for the static bending test, the WPC had an increase in their property, being the tests of hardness, density and water absorption which achieved higher profits, increasing their properties at 104%, 79% and 75% respectively compared to untreated specimens. From the economic viewpoint, the production of an inch Lenga timber has a cost of $ 19,805, so it may be feasible marketing both domestically and internationally (author)

Encapsulated Somatic Embryos and Zygotic Embryos for Obtaining Artificial Seeds of Rauli-Beech (Nothofagus alpina (Poepp. & Endl. Oerst. Encapsulado de Embriones Somáticos y Embriones Cigóticos para Obtención de Semillas Artificiales de Raulí (Nothofagus alpina (Poepp. & Endl. Oerst.

Directory of Open Access Journals (Sweden)

Priscila Cartes R

2009-03-01

Full Text Available Somatic and zygotic embryos from mature seeds of rauli-beech, Nothofagus alpina (Poepp. & Endl. Oerst., were encapsulated in different artificial endosperms in order to generate a cover that fulfills the function of nourishment and protection of the embryos, facilitating their later germination. The content of sodium alginate varied by 4%, 3%, and 2%, as did the immersion time in calcium chloride (CaCl2, which acts as complexing agent. The artificial endosperm components of the Murashige and Skoog medium (MS were added, supplemented with 0.5 mg L-1 indolacetic acid (IAA, 0.5 mg L-1 naphthaleneacetic acid (NAA, 2 mg L-1 6-benzylaminopurine (BAP and 30 g L-1 sucrose. The germinative behaviors of encapsulated somatic and zygotic embryos were evaluated after 4 wk. Comparing the percentages of germination reached by encapsulated somatic and zygotic embryos it was observed that they had similar germinative behavior according to the type of encapsulation applied. However, zygotic embryos substantially exceeded the germination levels reached by somatic embryos, 100% vs. 45% respectively.Embriones somáticos y cigóticos provenientes de semillas maduras de raulí, Nothofagus alpina (Poepp. & Endl. Oerst., se encapsularon en diferentes endospermas sintéticos con el fin de generar una cubierta que cumpla la función de nutrir y proteger al embrión para facilitar su posterior germinación. Se varió el contenido de alginato de sodio al 4%, 3% y 2% y el tiempo de inmersión en cloruro de calcio (CaCl2, el que actúa como agente acomplejante. Además, a la matriz artificial se adicionaron componentes del medio Murashige y Skoog (MS suplementado con: 0,5 mg L-1 de indolacetic acid (IAA, 0,5 mg L-1 de ácido naftalenacético (NAA, 2 mg L-1 de 6-bencilaminopurina (BAP y 30 gL-1 de sacarosa. Al cabo de 4 semanas el porcentaje de germinación de los embriones somáticos y cigóticos encapsulados tuvieron similar comportamiento germinativo según el tipo de

NUEVA LOCALIDAD GEOGRAFICA PARA BERBERIS NEGERIANA TISCHLER (BERBERIDACEAE) EN LA PROVINCIA DE ARAUCO, REGION DEL BIO-BIO, CHILE

OpenAIRE

Gómez, Persy; Belov, Michail; San Martín, José

2008-01-01

This note reports the finding of a population of Berberis negeriana Tischler (Berberidaceae), in the province of Arauco, Bío-Bío Region (37°42'17" S y 73°19'43" W) in the center south of Chile. The population was found between Nothofagus obliqua and species of the Valdiviano Forest.

Experimental tolerance to boron of the plant species Nicotiana glauca, Jacaranda mimosifolia, Tecoma stans, Medicago sativa y Spinacea oleracea in Argentina

International Nuclear Information System (INIS)

Viana, Marta L. de; Albarracin Franco, Silvia

2008-01-01

The activity of the borate deposits industries constitutes a point source and diffuse pollution of air, soil and water. Therefore, the study and experimentation on possible ways to offset this impact is a priority. A relatively new technique to decontaminate soils is phytoremediation, which uses plants and associated microorganisms. The first step is to identify tolerant plant species, which is the focus of this work. An experiment was conducted in the laboratory to evaluate the germination, survival and growth of different species in different concentrations of boron. At the beginning and end of the experiment was determined concentration of boron in the substrate for each treatment and for substrates with and without vegetation. Significant differences due to treatment, the species and species-treatment interaction. M. sativa, N. glauca and J. mimosifolia were the species most tolerant to boron. The other species showed a decrease in all variables-response function of the concentration of the contaminant. All had low survival in the highest concentration. The decrease of boron was highest in the treatment of 30 ppm of boron with M. sativa and the lowest was recorded in the treatment of 20 ppm of boron with J. mimosifolia and 30 ppm of boron with T. stans and S. oleracea. It is concluded that N. glauca, M. sativa and J. mimosifolia could be considered as promising remediation. (author) [es

The role of Nicotiana gluca Graham (paraguayan herbs) as an adjuvant in immunomodulation of Newcastle disease vaccine for broilers Estudo da ação de Nicotiana glauca Graham (erva paraguaia) como coadjuvante em vacina contra a doença de Newcastle em frangos de corte

OpenAIRE

Fabiane Pereira Gentilini; Telmo Vidor; Rogério Freitag; Marcos Antônio Anciuti; Caren Gularte Quincozes; Marlete Brum Cleff; Geferson Fischer; Carlos Eduardo Nogueira

2008-01-01

The Nicotiana glauca is a native plant species from Argentina, but found all over South América, being used against headaches, rheumatism, injuries, ulcers, and so on. Researchers have considered it as having immunomodulation effect. This study was conducted to investigate the use of a aqueous extract of Nicotiana glauca Graham as an immunomodulator (adjuvant) of a Newcastle disease vaccine.. A total of 56 broilers were distributed into 4 ...

Attraction and antennal response of the common wasp, Vespula vulgaris (L.), to selected synthetic chemicals in New Zealand beech forests.

Science.gov (United States)

El-Sayed, Ashraf M; Manning, Lee-Anne; Unelius, C Rikard; Park, Kye Chung; Stringer, Lloyd D; White, Nicola; Bunn, Barry; Twidle, Andrew; Suckling, David M

2009-09-01

The common wasp, Vespula vulgaris (L.), and the German wasp, Vespula germanica (F.), are significant problems in New Zealand beech forests (Nothofagus spp.), adversely affecting native birds and invertebrate biodiversity. This work was undertaken to develop synthetic attractants for these species to enable more efficient monitoring and management. Seven known wasp attractants (acetic acid, butyl butyrate, isobutanol, heptyl butyrate, octyl butyrate and 2,4-hexadienyl butyrate) were field tested, and only heptyl butyrate and octyl butyrate attracted significantly higher numbers of wasps than a non-baited trap. Accordingly, a series of straight-chain esters from methyl to decyl butyrate were prepared and field tested for attraction of social wasps. Peak biological activity occurred with hexyl butyrate, heptyl butyrate, octyl butyrate and nonyl butyrate. Polyethylene bags emitting approximately 18.4-22.6 mg day(-1) of heptyl butyrate were more attractive than polyethylene bags emitting approximately 14.7-16.8 mg day(-1) of heptyl butyrate in the field. Electroantennogram (EAG) studies indicated that queens and workers of V. vulgaris had olfactory receptor neurons responding to various aliphatic butyrates. These results are the first to be reported on the EAG response and the attraction of social wasps to synthetic chemicals in New Zealand beech forests and will enable monitoring of social wasp activity in beech forests. Copyright 2009 Society of Chemical Industry.

Modeling the distribution of white spruce (Picea glauca) for Alaska with high accuracy: an open access role-model for predicting tree species in last remaining wilderness areas

Science.gov (United States)

Bettina Ohse; Falk Huettmann; Stefanie M. Ickert-Bond; Glenn P. Juday

2009-01-01

Most wilderness areas still lack accurate distribution information on tree species. We met this need with a predictive GIS modeling approach, using freely available digital data and computer programs to efficiently obtain high-quality species distribution maps. Here we present a digital map with the predicted distribution of white spruce (Picea glauca...

Modulation of Fire Regimes by Vegetation and Site Type in Southwestern Patagonia Since 13 ka

Directory of Open Access Journals (Sweden)

Patricio I. Moreno

2018-04-01

Full Text Available The degree to which vegetation and site type have influenced fire regimes through the Holocene has not been investigated in detail in the temperate ecosystems of southern Patagonia. Here we present a first attempt using a paired-basin approach to study the evolution of fire regimes in sectors dominated by humid Nothofagus forests and the xeric Patagonian steppe in the Magallanes region of Chilean Patagonia (51°S. We analyzed sediment cores from two small lakes and a bog located within the same climate zone on opposite sides of the forest-steppe ecotone, ~28 km apart. The position of this biological boundary east of the Andes is controlled by the strength and position of the southern westerly winds, which constitute the sole source of precipitation throughout western Patagonia. Our results indicate that fires have occurred in the study region repeated times over the last ~13,000 years at bi- and tridecadal timescales. Sectors currently dominated by Patagonian steppe feature high frequency and low magnitude of local fires, and vice versa in humid forests. Climate-driven expansion of Nothofagus scrubland/woodland into steppe environments over the last ~4,200 years increased the magnitude and lowered the frequency of fire events, culminating with peak Nothofagus abundance, fire magnitude and frequency during the last millennium. We also detect divergences between lake-based vs. bog-based paleofire histories among paired sites located within the Patagonian steppe, ~12 km apart, which we attribute to local burning of the bog at times of lowered water table. This divergence suggests to us that bog-based vegetation and fire histories exacerbate a local, azonal, signal blurring extra-local or regional regimes, thus accounting for some discrepancies in the Quaternary paleovegetation/paleoclimate literature of southern Patagonia.

Warming and neighbor removal affect white spruce seedling growth differently above and below treeline.

Science.gov (United States)

Okano, Kyoko; Bret-Harte, M Syndonia

2015-01-01

Climate change is expected to be pronounced towards higher latitudes and altitudes. Warming triggers treeline and vegetation shifts, which may aggravate interspecific competition and affect biodiversity. This research tested the effects of a warming climate, habitat type, and neighboring plant competition on the establishment and growth of white spruce (Picea glauca (Moench) Voss) seedlings in a subarctic mountain region. P. glauca seedlings were planted in June 2010 under 4 different treatments (high/control temperatures, with/without competition) in 3 habitats (alpine ridge above treeline/tundra near treeline /forest below treeline habitats). After two growing seasons in 2011, growth, photosynthesis and foliar C and N data were obtained from a total of 156, one-and-a-half year old seedlings that had survived. Elevated temperatures increased growth and photosynthetic rates above and near treeline, but decreased them below treeline. Competition was increased by elevated temperatures in all habitat types. Our results suggest that increasing temperatures will have positive effects on the growth of P. glauca seedlings at the locations where P. glauca is expected to expand its habitat, but increasing temperatures may have negative effects on seedlings growing in mature forests. Due to interspecific competition, possibly belowground competition, the upslope expansion of treelines may not be as fast in the future as it was the last fifty years.

A pollen-based record of late glacial-Holocene climatic variability in the southern lake district, Chile

NARCIS (Netherlands)

Vargas-Ramirez, L.; Roche, E.; Gerrienne, P.; Hooghiemstra, H.

2008-01-01

A pollen record from Puyehue area (40°S; 72°W) in the southern Lake District, Chile, indicates that prior to 13,410 14C yr BP (ca. 16,500-15,200 cal yr BP), cold resistant and hygrophilous vegetation, particularly Nothofagus forest and myricaceous vegetation, covered the area. From ca. 15,000 cal yr

Subantarctic forest ecology : case study of a conifer-broadleaved stand in Patagonia, Argentina

NARCIS (Netherlands)

Dezzotti, A.

2000-01-01

In the temperate rainforests of southern South America, the tree genus Nothofagus (Nothofagaceae) is the dominant in extension and abundance on zonal soils at different latitudes and altitudes, as well as on intrazonal (e.g., wetlands) and azonal soils (e.g., morrenic

Yeast and yeast-like fungi associated with dry indehiscent fruits of Nothofagus nervosa in Patagonia, Argentina.

Science.gov (United States)

Fernández, Natalia V; Mestre, M Cecilia; Marchelli, Paula; Fontenla, Sonia B

2012-04-01

Nothofagus nervosa (Raulí) is a native tree species that yields valuable timber. It was overexploited in the past and is currently included in domestication and conservation programs. Several research programs have focused on the characterization of epiphytic microorganisms because it has been demonstrated that they can affect plant-pathogen interactions and/or promote plant growth. Although the microbial ecology of leaves has been well studied, less is known about microorganisms occurring on seeds and noncommercial fruits. In this work, we analyzed the yeast and yeast-like fungi present on N. nervosa fruits destined for the propagation of this species, as well as the effects of fruit preservation and seed dormancy-breaking processes on fungal diversity. Morphological and molecular methods were used, and differences between fungal communities were analyzed using a similarity index. A total of 171 isolates corresponding to 17 species were recovered, most of which belong to the phylum Ascomycota. The majority of the species develop mycelia, produce pigments and mycosporines, and these adaptation strategies are discussed. It was observed that the preservation process considerably reduced yeast and yeast-like fungal diversity. This is the first study concerning microbial communities associated with this ecologically and economically important species, and the information presented is relevant to domestication programs. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Agrobacterium rhizogenes vs auxinic induction for in vitro rhizogenesis of Prosopis chilensis and Nothofagus alpina.

Science.gov (United States)

Caro, Luis A; Santecchia, Natalia; Marinangeli, Pablo A; Curvetto, Néstor R; Hernández, Luis F

2003-12-01

The induction and improvement of in vitro rhizogenesis of microshoots of Prosopis chilensis (Mol.) Stuntz and Nothofagus alpina (Poep. et Endl. Oerst.) were compared using Agrobacterium rhizogenes (Ar) versus indole-3-butyric acid (IBA) in the culture media. Microshoots of P. chilensis (1-2 cm length), coming from in vitro grown seedlings, were cultivated in a modified Broadleaved Tree Medium (BTMm) containing half salt concentration of macronutrients and 0.05 mg x L(-1) benzilaminopurine (BAP). After 30 days, microshoots with 2-4 leaves were selected and cultured in BTMm-agar in presence or abscense of Ar and in combination with IBA. For N. alpina, the apical shoots with the first 2 true leaves, from 5 weeks old seedlings, were cultured in the abovementioned medium, but with 0.15 mg x L(-1) of BAP. After 2 months, microshoots with 2-3 leaves were selected and cultured in BTMm-agar, supplemented with 5 mg x L(-1) IBA or in liquid BTMm on perlite and, in the presence or absence of A. rhizogenes (Ar) and in combination with 3 mg x L(-1) IBA. Rooting in P. chilensis reached 100.0% when Ar infection was produced in the presence of IBA, increasing both, the number and dry weight of roots. In N. alpina, 90.0% of rooting efficiency was obtained when Ar infection was produced in liquid culture and in the absence of auxin.

Effect of ectomycorrhizal colonization and drought on reactive oxygen species metabolism of Nothofagus dombeyi roots.

Science.gov (United States)

Alvarez, Maricel; Huygens, Dries; Fernandez, Carlos; Gacitúa, Yessy; Olivares, Erick; Saavedra, Isabel; Alberdi, Miren; Valenzuela, Eduardo

2009-08-01

Infection with ectomycorrhizal fungi can increase the ability of plants to resist drought stress through morphophysiological and biochemical mechanisms. However, the metabolism of antioxidative enzyme activities in the ectomycorrhizal symbiosis remains poorly understood. This study investigated biomass production, reactive oxygen metabolism (hydrogen peroxide and malondialdehyde concentration) and antioxidant enzyme activity (superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase) in pure cultures of the ectomycorrhizal fungi Descolea antartica Sing. and Pisolithus tinctorius (Pers.) Coker & Couch, and non-mycorrhizal and mycorrhizal roots of Nothofagus dombeyi (Mirb.) roots under well-watered conditions and drought conditions (DC). The studied ectomycorrhizal fungi regulated their antioxidative enzyme metabolism differentially in response to drought, resulting in cellular damage in D. antartica but not in P. tinctorius. Ectomycorrhizal inoculation and water treatment had a significant effect on all parameters studied, including relative water content of the plant. As such, N. dombeyi plants in symbiosis experienced a lower oxidative stress effect than non-mycorrhizal plants under DC. Additionally, ectomycorrhizal N. dombeyi roots showed a greater antioxidant enzyme activity relative to non-mycorrhizal roots, an effect which was further expressed under DC. The association between the non-specific P. tinctorius and N. dombeyi had a more effective reactive oxygen species (ROS) metabolism than the specific D. antartica-N. dombeyi symbiosis. We conclude that the combination of effective ROS prevention and ROS detoxification by ectomycorrhizal plants resulted in reduced cellular damage and increased plant growth relative to non-mycorrhizal plants under drought.

Identification and characterization of polymorphic microsatellite loci in the blue shark Prionace glauca, and cross-amplification in other shark species.

Science.gov (United States)

Mendonça, F F; Ussami, L H F; Hashimoto, D T; Pereira, L H G; Porto-Foresti, F; Oliveira, C; Gadig, O B F; Foresti, F

2012-06-01

Two to 14 alleles were found to be segregating per locus (mean 5·2), with observed and expected heterozygosities ranging from 0·08 to 0·78 and 0·08 to 0·94, respectively. Cross-amplification of six of these microsatellite loci indicated that they are also polymorphic in three species of Carcharhiniformes and two species of Lamniformes. The newly developed primers reported here constitute a useful tool for genetic population analyses on Prionace glauca and, potentially, other related species. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

Estudio comparativo del crecimiento y la ramificación de brotes anuales en dos especies de Nothofagus (Nothofagaceae y en híbridos inter-específicos Comparative study of annual shoot growth and branching in two species of Nothofagus (Nothofagaceae and inter-specific hybrids

Directory of Open Access Journals (Sweden)

Cristian Torres

2009-12-01

Full Text Available Las ramas principales y secundarias se diferencian en mayor o menor medida según las especies, lo cual puede observarse en base al crecimiento primario de los brotes que las originan. En ejemplares de vivero juveniles-adultos de Nothofagus obliqua, N. nervosa e híbridos entre ambas especies, se compararon la dinámica de alargamiento, el tamaño y la morfología de dos brotes distales de ramas principales: uno que continúa el alargamiento de la rama principal y el otro que inicia una rama secundaria. En N. alpina y en híbridos, los dos brotes más distales se diferencian más que en N. obliqua. A pesar de la homogeneidad ambiental en el vivero y el origen geográfico común para los ejemplares de N. nervosa y los híbridos, hubieron diferencias fenológicas y morfológicas entre estas entidades. La duración y tasa de alargamiento y la longitud final de los brotes fueron altamente variables en cada entidad. Las variaciones entre entidades en la diferenciación de ejes podrían indicar diferencias en sus capacidades de uso del espacio circundante. La diferenciación entre ramas principales y secundarias se iniciaría en el estado de yema. La variación intra-específica fenológica y morfológica es útil para programas de selección artificial de individuos.Main and secondary branches are more or less differentiated according to the species and this could be observed during the primary growth of the shoots that produce them. In young-adult trees of Nothofagus obliqua, N. nervosa and hybrids between them growing in a common garden, growth dynamics, size and morphology were compared between two distal shoots produced by main branches: one of these shoots continued the extension of the main branch whereas the other initiated a secondary branch. The two distal shoots differed from each other more notably in N. nervosa and in the hybrids than in N. obliqua. Despite the environmental homogeneities at the nursery and the common geographic origin of

Investigation of Polarization Phase Difference Related to Forest Fields Characterizations

Science.gov (United States)

Majidi, M.; Maghsoudi, Y.

2013-09-01

The information content of Synthetic Aperture Radar (SAR) data significantly included in the radiometric polarization channels, hence polarimetric SAR data should be analyzed in relation with target structure. The importance of the phase difference between two co-polarized scattered signals due to the possible association between the biophysical parameters and the measured Polarization Phase Difference (PPD) statistics of the backscattered signal recorded components has been recognized in geophysical remote sensing. This paper examines two Radarsat-2 images statistics of the phase difference to describe the feasibility of relationship with the physical properties of scattering targets and tries to understand relevance of PPD statistics with various types of forest fields. As well as variation of incidence angle due to affecting on PPD statistics is investigated. The experimental forest pieces that are used in this research are characterized white pine (Pinus strobus L.), red pine (Pinus resinosa Ait.), jack pine (Pinus banksiana Lamb.), white spruce (Picea glauca (Moench Voss), black spruce (Picea mariana (Mill) B.S.P.), poplar (Populus L.), red oak (Quercus rubra L.) , aspen and ground vegetation. The experimental results show that despite of biophysical parameters have a wide diversity, PPD statistics are almost the same. Forest fields distributions as distributed targets have close to zero means regardless of the incidence angle. Also, The PPD distribution are function of both target and sensor parameters, but for more appropriate examination related to PPD statistics the observations should made in the leaf-off season or in bands with lower frequencies.

INVESTIGATION OF POLARIZATION PHASE DIFFERENCE RELATED TO FOREST FIELDS CHARACTERIZATIONS

Directory of Open Access Journals (Sweden)

M. Majidi

2013-09-01

Full Text Available The information content of Synthetic Aperture Radar (SAR data significantly included in the radiometric polarization channels, hence polarimetric SAR data should be analyzed in relation with target structure. The importance of the phase difference between two co-polarized scattered signals due to the possible association between the biophysical parameters and the measured Polarization Phase Difference (PPD statistics of the backscattered signal recorded components has been recognized in geophysical remote sensing. This paper examines two Radarsat-2 images statistics of the phase difference to describe the feasibility of relationship with the physical properties of scattering targets and tries to understand relevance of PPD statistics with various types of forest fields. As well as variation of incidence angle due to affecting on PPD statistics is investigated. The experimental forest pieces that are used in this research are characterized white pine (Pinus strobus L., red pine (Pinus resinosa Ait., jack pine (Pinus banksiana Lamb., white spruce (Picea glauca (Moench Voss, black spruce (Picea mariana (Mill B.S.P., poplar (Populus L., red oak (Quercus rubra L. , aspen and ground vegetation. The experimental results show that despite of biophysical parameters have a wide diversity, PPD statistics are almost the same. Forest fields distributions as distributed targets have close to zero means regardless of the incidence angle. Also, The PPD distribution are function of both target and sensor parameters, but for more appropriate examination related to PPD statistics the observations should made in the leaf-off season or in bands with lower frequencies.

EFECTO DE LA VEGETACIÓN EN LA INTERCEPCIÓN DE LA PRECIPITACIÓN EN LA PRECORDILLERA DE LA REGIÓN DEL MAULE, CHILE

Directory of Open Access Journals (Sweden)

O. S. Vallejos-Barra

2010-01-01

Full Text Available En este estudio se comparó el comportamiento de un bosque secundario de Roble-Hualo, donde las especies predominantes son Nothofagus obliqua y Nothofagus glauca y una plantación de Pinus radiata D. Don de 12 años de edad, en el proceso precipitación - intercepción. El estudio se desarrolló en la Estación Experimental El Picazo, comuna de San Clemente, Región del Maule, Chile, entre el mes de julio de 2007 a julio de 2008, en dos microcuencas vecinas de dimensiones reducidas con condiciones similares de suelo, exposición y pendiente pero que diferían en la cobertura vegetal. Se caracterizó la vegetación de cada microcuenca y se establecieron indicadores de densidad de parcela. Los indicadores de la cobertura nativa superaron ampliamente a los de las coberturas exóticas. Para registrar la precipitación se instalaron dos pluviógrafos del tipo Hobo en cada microcuenca. Equidistante de ellas se ubicó otro pluviógrafo sin cobertura vegetal. Se registraron 21 tormentas caracterizando temporal y espacialmente el comportamiento de la precipitación abierta y bajo dosel. Los resultados indican que pese a tener diferencias numéricas las coberturas vegetales, éstas no se transforman en diferencias estadísticamente significativas. Además se observó que la intercepción depende en mayor medida de la arquitectura de copa, distribución espacial de los árboles y tipo de hojas, que de la cantidad de árboles por parcela.

Recent drought-induced decline of forests along a water-balance tipping point for ecosystems in western Canada

Science.gov (United States)

Hogg, E. H.; Michaelian, M.

2017-12-01

In western Canada, the forest-prairie boundary corresponds to a hydrologically-defined ecosystem "tipping point" where long-term precipitation is barely sufficient to meet the water use requirements of healthy, closed-canopy forests. In the province of Alberta, the severe subcontinental drought of 2001-2002 heralded the beginning of a 15-year dry period, representing a northward incursion of prairie-like climates into boreal and cordilleran forests. This poses a significant concern for ecosystem functioning of these forests, given GCM projections for continued warming and drying under anthropogenic climate change during this century. Through a multi-scale monitoring approach, we have examined the regional-scale impacts of recent droughts and associated climatic drying on the productivity and health of two important boreal tree species: aspen (Populus tremuloides) and white spruce (Picea glauca). For aspen, the 2016 re-measurement of a regional network of 150 ground plots revealed that tree mortality has escalated, especially in stands exposed to the combined impacts of multi-year drought and insect defoliation. On average, mortality losses exceeded growth gains during 2000-2016 for the 54 aspen plots in Alberta, leading to a net multi-year decline in the aboveground biomass of these stands. For white spruce, tree-ring analysis of 40 stands across Alberta revealed that the prolonged dry period led to a 38% decline in average, tree-level growth in aboveground biomass. In both species, stand age was not a significant factor affecting forest sensitivity to drought and climatic drying, suggesting that these forests are at risk if the trend toward more frequent, severe drought continues in the region.

Investigación sobre manejo forestal a largo plazo en Patagonia Sur -Argentina: Lecciones del pasado, desafíos del presente Long-term forest management research in South Patagonia - Argentina: Lessons from the past, challenges from the present

Directory of Open Access Journals (Sweden)

GUILLERMO J MARTÍNEZ-PASTUR

2010-03-01

ón de tratamientos intermedios, (iii determinar líneas base y definir los impactos de distintos sistemas silvícolas, (iv proponer metodologías de monitoreo de amplio espectro y establecer áreas demostrativas de manejo, y (v proveer áreas y conocimientos para entrenar profesionales en prácticas de manejo forestal y conservación de la biodiversidad. Las parcelas permanentes ya establecidas en los bosques de Nothofagus de Patagonia Sur y las bases de datos obtenidas podrían servir como punto de partida para definir un núcleo regional que pueda participar en el International Long Term Ecological Research para asegurar el uso sustentable de los bosques nativos.Argentina has based its economy in agriculture and cattle production seeing forests as one of the main obstacles for future development. Forest harvesting in South Patagonia has been an activity based on colonization and exploitation of new areas. Harvesting is mainly carried out in old-growth forests without silviculture management after the first cuts. Beyond this mismanagement, scientific research defined the basis to conserve, protect and improve the present forest management for the South Patagonia native forests. The first long-term study permanent plots (1965-1966 monitored only economic and forest structure parameters, and near twenty plots were established in public forested lands of Tierra del Fuego. Most of these plots were destroyed or discontinued due to a lack of land use planning, scarce social interest for long-term researches, absence of commitment of institutions, and few contributions of forest companies. After this, a second group of nine long-term study permanent plots were established in South Patagonia (1993-2004 based in the collaboration between private companies and national research institutions. The objectives included economic as well as ecological parameters. The new plots were established on private lands based on several agreements and joint venture projects between national

Preliminary data on growth and enzymatic abilities of soil fungus Humicolopsis cephalosporioides at different incubation temperatures.

Science.gov (United States)

Elíades, Lorena Alejandra; Cabello, Marta N; Pancotto, Verónica; Moretto, Alicia; Rago, María Melisa; Saparrat, Mario C N

2015-01-01

Nothofagus pumilio (Poepp & Endl.) Krasser, known as "lenga" is the most important timber wood species in southernmost Patagonia (Argentina). Humicolopsis cephalosporioides Cabral & Marchand is a soil fungus associated with Nothofagus pumilio forests, which has outstanding cellulolytic activity. However, there is no information about the ability of this fungus to use organic substrates other than cellulose, and its ability to produce different enzyme systems, as well as its response to temperature. The aim of this study was to examine the role of H. cephalosporioides in degradation processes in N. pumilio forests in detail by evaluating the in vitro ability of four isolates of this fungus to grow and produce different lytic enzyme systems, and their response to incubation temperature. The ability of the fungi to grow and produce enzyme systems was estimated by inoculating them on agar media with specific substrates, and the cultures were incubated at three temperatures. A differential behavior of each strain in levels of growth and enzyme activity was found according to the medium type and/or incubation temperature. A intra-specific variability was found in H. cephalosporioides. Likewise a possible link between the saprotrophic role of this fungus in N. pumilio forests and the degradation of organic matter under stress conditions, such as those from frosty environments, was also discussed. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Ignition probability of fine dead surface fuels of native Patagonian forests or Argentina

Directory of Open Access Journals (Sweden)

Lucas O. Bianchi

2014-04-01

Full Text Available Aim of study: The Canadian Forest Fire Weather Index (FWI is being implemented all over the world. This index is being adapted to the Argentinean ecosystems since the year 2000. With the objective of calibrating the Fine Fuel Moisture Code (FFMC of the FWI system to Patagonian forests, we studied the relationship between ignition probability and fine dead surface fuel moisture content (MC as an indicator of potential fire ignition.Area of study: The study area is located in northwestern Patagonia, Argentina, and comprised two main forest types (cypress and ñire grown under a Mediterranean climate, with a dry summer and precipitations during winter and autumn (~500-800 mm per year.Material and Methods: We conducted lab ignition tests fires to determine the threshold of fine dead fuel ignition at different MC levels. Moisture content of dead fine surface fuels in the field was measured every 10-15 days from November to March for three seasons. We calculated the FFMC during these seasons and correlated it with the measured MC by applying a logistic regression model. We combined the results of the ignition tests and of the regressions to suggest FFMC categories for estimating fire danger in Patagonian forests.Main results: The ignition threshold occurred at MC values of 21.5 and 25.0% for cypress and ñire sites, respectively. The MC measured varied from 7.3 to 129.6%, and the calculated FFMC varied between 13.4 and 92.6. Highly significant regressions resulted when FFMC was related to MC. The ignition threshold corresponded to a FFMC=85. We proposed to divide the FFMC scale in three fire danger categories: Low (FFMC≤85, High (8589.Research highlights: Our results provide a useful tool for predicting fire danger in these ecosystems, and are a contribution to the development of the Argentinean Fire Danger Rating and a reference for similar studies in other countries where the FWI is being implemented

Polychlorinated biphenyls and DDT in swordfish (Xiphias gladius) and blue shark (Prionace glauca) from Brazilian Coast. Preliminary results

Energy Technology Data Exchange (ETDEWEB)

Azevedo e Silva, C E; Azeredo, A; Meire, R; Torres, J P [Laboratorio de Radioisotopos E.P.F., Rio de Janeiro (Brazil). Inst. de Biofisica Carlos Chagas Filho, UFRJ; Brito, Jr, J L; Malm, O [Projeto Mamiferos Aquaticos, Rio de Janeiro (Brazil). Dept. de Oceanografia, UERJ

2004-09-15

There is conclusive evidence showing that, in general, fish in meals human diet contributes with a significant proportion of the total intake of PCBs and others organochlorine compounds, particularly fish with higher fat content. Thus, human exposure to PCBs is predominantly via diet, and especially from fish and seafood products. Comparatively, little is know about organochlorine contaminants in elasmobranch species, although they are also top predators. Characteristically, sharks are live longer, with comparatively slow rates of growth that in conjuction with their high trophic position may contribute to the accumulation of high concentrations of pollutants. Blue shark and swordfish are carnivorous fishes of great economic importance. This study investigate the concentration of polychlorinated biphenyls (PCBs) and DDTs in samples of muscle tissues of blue shark (Prionace glauca) and swordfish (Xiphias gladius) from Brazilian Coast.

Potential therapeutic agents for circulatory diseases from Bauhinia glauca Benth.subsp. pernervosa. (Da Ye Guan Men).

Science.gov (United States)

Tang, Yingzhan; Ling, Junhong; Zhang, Peng; Zhang, Xiangrong; Zhang, Na; Wang, Wenli; Li, Jiayuan; Li, Ning

2015-08-15

Because of platelets as critical factor in the formation of pathogenic thrombi, anti-platelet activities have been selected as therapeutic target for various circulatory diseases. In order to find potential therapeutic agents, bioassay-directed separation of Bauhinia glauca Benth.subsp. pernervosa. (called Da Ye Guan Men as a traditional Chinese medicine) was performed to get 29 main components (compounds 1-29) from the bioactive part of this herbal. It was the first time to focus on the composition with anti-platelet aggregation activities for this traditional Chinese medicine. The constituents, characterized from the effective extract, were established on the basis of extensive spectral data analysis. Then their anti-platelet aggregation effects were evaluated systematically. On the basis of the chemical profile and biological assay, it was suggested that the flavonoid composition (5 and 18) should be responsible for the anti-platelet aggregation of the herbal because of their significant activities. The primary structure and activity relationship was also discussed briefly. Copyright © 2015. Published by Elsevier Ltd.

Are trait-scaling relationships invariant across contrasting elevations in the widely distributed treeline species Nothofagus pumilio?

Science.gov (United States)

Fajardo, Alex

2016-05-01

The study of scaling examines the relative dimensions of diverse organismal traits. Understanding whether global scaling patterns are paralleled within species is key to identify causal factors of universal scaling. I examined whether the foliage-stem (Corner's rules), the leaf size-number, and the leaf mass-leaf area scaling relationships remained invariant and isometric with elevation in a wide-distributed treeline species in the southern Chilean Andes. Mean leaf area, leaf mass, leafing intensity, and twig cross-sectional area were determined for 1-2 twigs of 8-15 Nothofagus pumilio individuals across four elevations (including treeline elevation) and four locations (from central Chile at 36°S to Tierra del Fuego at 54°S). Mixed effects models were fitted to test whether the interaction term between traits and elevation was nonsignificant (invariant). The leaf-twig cross-sectional area and the leaf mass-leaf area scaling relationships were isometric (slope = 1) and remained invariant with elevation, whereas the leaf size-number (i.e., leafing intensity) scaling was allometric (slope ≠ -1) and showed no variation with elevation. Leaf area and leaf number were consistently negatively correlated across elevation. The scaling relationships examined in the current study parallel those seen across species. It is plausible that the explanation of intraspecific scaling relationships, as trait combinations favored by natural selection, is the same as those invoked to explain across species patterns. Thus, it is very likely that the global interspecific Corner's rules and other leaf-leaf scaling relationships emerge as the aggregate of largely parallel intraspecific patterns. © 2016 Botanical Society of America.

Aplicación de relaciones de densidad-diámetro y de área potencial aprovechable en bosques de Nothofagus Dombeyi (mirb.) Oerst, como herramientas de planificación silvícola .

OpenAIRE

Cruz Johnson, Pablo Christian

2013-01-01

Uno de los objetivos de esta tesis de doctorado fue analizar la aplicación de relaciones de densidad ¿ diámetro en bosques de Nothofagus dombeyi (Mirb.) oerst, para la localidad del Río Mirta en la XI Región de Chile, como herramientas de planificación silvícola. El método de análisis consistió en la generación de una muestra de densidad¿diámetro a partir de la que se determinó el índice de densidad máximo (IDmax) a partir del cual se estimaron las máximas densidades que la especie podría alc...

Assessing the interaction between mountain forests and snow avalanches at Nevados de Chillán, Chile and its implications for ecosystem-based disaster risk reduction

Science.gov (United States)

Casteller, Alejandro; Häfelfinger, Thomas; Cortés Donoso, Erika; Podvin, Karen; Kulakowski, Dominik; Bebi, Peter

2018-04-01

Gravitational natural hazards such as snow avalanches, rockfalls, shallow landslides and volcanic activity represent a risk to mountain communities around the world. In particular, where documentary records about these processes are rare, decisions on risk management and land-use planning have to be based on a variety of other sources including vegetation, tree-ring data and natural hazard process models. We used a combination of these methods in order to evaluate dynamics of natural hazards with a focus on snow avalanches at Valle Las Trancas, in the Biobío region in Chile. Along this valley, natural hazards threaten not only the local human population, but also the numerous tourists attracted by outdoor recreational activities. Given the regional scarcity of documentary records, tree-ring methods were applied in order to reconstruct the local history of snow avalanches and debris flow events, which are the most important weather-related processes at respective tracks. A recent version of the model Rapid Mass MovementS (RAMMS), which includes influences of forest structure, was used to calculate different avalanche parameters such as runout distances and maximum pressures, taking into consideration the presence or absence of forest along the tracks as well as different modeled return periods. Our results show that local Nothofagus broadleaf forests contribute to a reduction of avalanche runout distances as well as impact pressure on present infrastructure, thus constituting a valuable ecosystem disaster risk reduction measure that can substitute or complement other traditional measures such as snow sheds.

Similar variation in carbon storage between deciduous and evergreen treeline species across elevational gradients.

Science.gov (United States)

Fajardo, Alex; Piper, Frida I; Hoch, Günter

2013-08-01

The most plausible explanation for treeline formation so far is provided by the growth limitation hypothesis (GLH), which proposes that carbon sinks are more restricted by low temperatures than by carbon sources. Evidence supporting the GLH has been strong in evergreen, but less and weaker in deciduous treeline species. Here a test is made of the GLH in deciduous-evergreen mixed species forests across elevational gradients, with the hypothesis that deciduous treeline species show a different carbon storage trend from that shown by evergreen species across elevations. Tree growth and concentrations of non-structural carbohydrates (NSCs) in foliage, branch sapwood and stem sapwood tissues were measured at four elevations in six deciduous-evergreen treeline ecotones (including treeline) in the southern Andes of Chile (40°S, Nothofagus pumilio and Nothofagus betuloides; 46°S, Nothofagus pumilio and Pinus sylvestris) and in the Swiss Alps (46°N, Larix decidua and Pinus cembra). Tree growth (basal area increment) decreased with elevation for all species. Regardless of foliar habit, NSCs did not deplete across elevations, indicating no shortage of carbon storage in any of the investigated tissues. Rather, NSCs increased significantly with elevation in leaves (P treeline species are sink limited when faced with decreasing temperatures. Despite the overall higher requirements of deciduous tree species for carbon storage, no indication was found of carbon limitation in deciduous species in the alpine treeline ecotone.

Varying boreal forest response to Arctic environmental change at the Firth River, Alaska

International Nuclear Information System (INIS)

Andreu-Hayles, Laia; D'Arrigo, Rosanne; Anchukaitis, Kevin J; Beck, Pieter S A; Goetz, Scott; Frank, David

2011-01-01

The response of boreal forests to anthropogenic climate change remains uncertain, with potentially significant impacts for the global carbon cycle, albedo, canopy evapotranspiration and feedbacks into further climate change. Here, we focus on tree-ring data from the Firth River site at treeline in northeastern Alaska, in a tundra–forest transition region where pronounced warming has already occurred. Both tree-ring width (TRW) and maximum latewood density (MXD) chronologies were developed to identify the nature of tree growth and density responses to climatic and environmental changes in white spruce (Picea glauca), a dominant Arctic treeline species. Good agreement was found between the interannual fluctuations in the TRW chronology and summer temperatures from 1901 to 1950, whereas no significant relationships were found from 1951 to 2001, supporting evidence of significant divergence between TRW and summer temperature in the second half of the 20th century. In contrast to this unstable climatic response in the TRW record, the high frequency July–August temperature signal in the MXD series seems reasonably stable through the 20th century. Wider and denser rings were more frequent during the 20th century, particularly after 1950, than in previous centuries. Finally, comparison between the tree-ring proxies and a satellite-derived vegetation index suggests that TRW and MXD correlate with vegetation productivity at the landscape level at different times of the growing season.

Ecological patterns, distribution and population structure of Prionace glauca (Chondrichthyes: Carcharhinidae) in the tropical-subtropical transition zone of the north-eastern Pacific.

Science.gov (United States)

Vögler, Rodolfo; Beier, Emilio; Ortega-García, Sofía; Santana-Hernández, Heriberto; Valdez-Flores, J Javier

2012-02-01

Regional ecological patterns, distribution and population structure of Prionace glauca were analyzed based on samples collected on-board two long-line fleets operating in oceanic waters (1994-96/2000-02) and in coastal oceanic waters (2003-2009) of the eastern tropical Pacific off México. Generalized additive models were applied to catch per unit of effort data to evaluate the effect of spatial, temporal and environmental factors on the horizontal distribution of the life stages (juvenile, adult) and the sexes at the estimated depth of catch. The presence of breeding areas was explored. The population structure was characterized by the presence of juveniles' aggregations and pregnant females towards coastal waters and the presence of adult males' aggregations towards oceanic waters. The species exhibited horizontal segregation by sex-size and vertical segregation by sex. Distribution of the sex-size groups at oceanic waters was seasonally affected by the latitude; however, at coastal oceanic waters mainly females were influenced by the longitude. Latitudinal changes on the horizontal distribution were coupled to the seasonal forward and backward of water masses through the study area. Adult males showed positive relationship with high temperatures and high-salinities waters (17.0°-20.0 °C; 34.2-34.4) although they were also detected in low-salinities waters. The distribution of juvenile males mainly occurred beyond low temperatures and low-salinities waters (14.0°-15.0 °C; 33.6-34.1), suggesting a wide tolerance of adult males to explore subartic and subtropical waters. At oceanic areas, adult females were aggregated towards latitudes ecological key region to the reproductive cycle of P. glauca. Copyright © 2011 Elsevier Ltd. All rights reserved.

Movements of Blue Sharks (Prionace glauca) across Their Life History

Science.gov (United States)

Vandeperre, Frederic; Aires-da-Silva, Alexandre; Fontes, Jorge; Santos, Marco; Serrão Santos, Ricardo; Afonso, Pedro

2014-01-01

Spatial structuring and segregation by sex and size is considered to be an intrinsic attribute of shark populations. These spatial patterns remain poorly understood, particularly for oceanic species such as blue shark (Prionace glauca), despite its importance for the management and conservation of this highly migratory species. This study presents the results of a long-term electronic tagging experiment to investigate the migratory patterns of blue shark, to elucidate how these patterns change across its life history and to assess the existence of a nursery area in the central North Atlantic. Blue sharks belonging to different life stages (n = 34) were tracked for periods up to 952 days during which they moved extensively (up to an estimated 28.139 km), occupying large parts of the oceanic basin. Notwithstanding a large individual variability, there were pronounced differences in movements and space use across the species' life history. The study provides strong evidence for the existence of a discrete central North Atlantic nursery, where juveniles can reside for up to at least 2 years. In contrast with previously described nurseries of coastal and semi-pelagic sharks, this oceanic nursery is comparatively vast and open suggesting that shelter from predators is not its main function. Subsequently, male and female blue sharks spatially segregate. Females engage in seasonal latitudinal migrations until approaching maturity, when they undergo an ontogenic habitat shift towards tropical latitudes. In contrast, juvenile males generally expanded their range southward and apparently displayed a higher degree of behavioural polymorphism. These results provide important insights into the spatial ecology of pelagic sharks, with implications for the sustainable management of this heavily exploited shark, especially in the central North Atlantic where the presence of a nursery and the seasonal overlap and alternation of different life stages coincides with a high fishing

Interspecific variation in growth responses to tree size, competition and climate of western Canadian boreal mixed forests.

Science.gov (United States)

Jiang, Xinyu; Huang, Jian-Guo; Cheng, Jiong; Dawson, Andria; Stadt, Kenneth J; Comeau, Philip G; Chen, Han Y H

2018-08-01

Tree growth of boreal forest plays an important role on global carbon (C) cycle, while tree growth in the western Canadian boreal mixed forests has been predicted to be negatively affected by regional drought. Individual tree growth can be controlled by many factors, such as competition, climate, tree size and age. However, information about contributions of different factors to tree growth is still limited in this region. In order to address this uncertainty, tree rings of two dominant tree species, trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca (Moench.) Voss), were sampled from boreal mixed forest stands distributed across Alberta, Canada. Tree growth rates over different time intervals (10years interval, 1998-2007; 20years interval, 1988-2007; 30years interval, 1978-2007) were calculated to study the effects of different factors (tree size, competition, climate, and age) on tree growth. Results indicated that tree growth of two species were both primarily affected by competition or tree size, while climatic indices showed less effects on tree growth. Growth of trembling aspen was significantly affected by inter- and intraspecific competition, while growth of white spruce was primarily influenced by tree size, followed by competition. Positive relationship was found between growth of white spruce and competition index of coniferous group, suggesting an intraspecific mutualism mechanism within coniferous group. Our results further suggested that competition driven succession was the primary process of forest composition shift in the western Canadian boreal mixed forest. Although drought stress increased tree mortality, decline of stem density under climate change released competition stress of surviving trees, which in turn sustained growth of surviving trees. Therefore, climatic indices showed fewer effects on growth of dominant tree species compared to other factors in our study. Copyright © 2018 Elsevier B.V. All rights reserved.

Improvement of grafting procedures for the ornmental species: I. Picea pungens Engelm. var. glauca Regel

Directory of Open Access Journals (Sweden)

Ioan Blada

2011-11-01

Full Text Available In order to get ornamental trees for landscaping, Colorado blue spuce (Picea pungens Engelm. var. glauca Regel scions were grafted on Norway spruce (Picea abies (L. Karst. rootstocks.An original double-side-veneer grafting method was applied in five experimental or basic variants. The plastic tapes and the ecological Ceraltin® wax developed by the Research and Development of Bio-stimulators (CCDB BIOS Cluj were tested. In addition, two controls in which the classic raffia and the traditional hot wax and the classic side-veneer-grafting method were used. The obtained results, expressed in percents, were transformed in arcsin square root of percent values, and then a two-way analysis of variance (ANOVA was used. Highly significant (p < 0.001 statistical differences were found between all grafting variants, including controls. The Duncan test proved that original double-side-veneer grafting method and the new developed materials, i.e. plastic tapes and the ecological Ceraltin® wax have contributed in getting a better grafting success compared to the controls.Thus, the double-side-veneer grafting method and the two grafting materials are highly recommended to be used in getting grafted Colorado blue spuce ornamental trees.

Improvement of grafting procedures for the ornamental species: I. Picea pungens Engelm. var. glauca Regel

Directory of Open Access Journals (Sweden)

Ioan Blada

2013-12-01

Full Text Available In order to get ornamental trees for landscaping, Colorado blue spuce (Picea pungens Engelm. var.glauca Regel scions were grafted on Norway spruce (Picea abies (L. Karst. rootstocks. An original double-side-veneer grafting method was applied in five experimental or basic variants. The plastic tapes and the ecological Ceraltin wax developed by the Research and Development of Bio-stimulators (CCDB BIOS Cluj were tested. In addition, two controls in which the classic raffia and the traditional hot wax and the classic side-veneer-grafting method were used. The obtained results, expressed in percents, were transformed in arcsin square root of percent values, and then a two-way analysis of variance (ANOVA was used. Highly significant (p < 0.001 statistical differences were found between all grafting variants, including controls. The Duncan test proved that original double-side-veneer grafting method and the new developed materials, i.e. plastic tapes and the ecological Ceraltin wax have contributed in getting a better grafting success compared to the controls.Thus, the double-side-veneer grafting method and the two grafting materials are highly recommended to be used in getting grafted Colorado blue spuce ornamental trees.

Holocene Dynamics of Temperate Rainforests in West-Central Patagonia

Directory of Open Access Journals (Sweden)

Virginia Iglesias

2018-01-01

Full Text Available Analyses of long-term ecosystem dynamics offer insights into the conditions that have led to stability vs. rapid change in the past and the importance of disturbance in regulating community composition. In this study, we (1 used lithology, pollen, and charcoal data from Mallín Casanova (47°S to reconstruct the wetland, vegetation, and fire history of west-central Patagonia; and (2 compared the records with independent paleoenvironmental and archeological information to assess the effects of past climate and human activity on ecosystem dynamics. Pollen data indicate that Nothofagus-Pilgerodendron forests were established by 9,000 cal yr BP. Although the biodiversity of the understory increased between 8,480 and 5,630 cal yr BP, forests remained relatively unchanged from 9,000 to 2,000 cal yr BP. The charcoal record registers high fire-episode frequency in the early Holocene followed by low biomass burning between 6,500 and 2,000 cal yr BP. Covarying trends in charcoal, bog development, and Neoglacial advances suggest that climate was the primary driver of these changes. After 2,000 cal yr BP, the proxy data indicate (a increased fire-episode frequency; (b centennial-scale shifts in bog and forest composition; (c the emergence of vegetation-fire linkages not recorded in previous times; and (d paludification in the last 500 years possibly associated with forest loss. Our results therefore suggest that Nothofagus-Pilgerodendron dominance was maintained through much of the Holocene despite long-term changes in climate and fire. Unparalleled fluctuations in local ecosystems during the last two millennia were governed by disturbance-vegetation-hydrology feedbacks likely triggered by greater climate variability and deforestation.

Influence of stocking, site quality, stand age, low-severity canopy disturbance, and forest composition on sub-boreal aspen mixedwood carbon stocks

Science.gov (United States)

Reinikainen, Michael; D’Amato, Anthony W.; Bradford, John B.; Fraver, Shawn

2014-01-01

Low-severity canopy disturbance presumably influences forest carbon dynamics during the course of stand development, yet the topic has received relatively little attention. This is surprising because of the frequent occurrence of such events and the potential for both the severity and frequency of disturbances to increase as a result of climate change. We investigated the impacts of low-severity canopy disturbance and average insect defoliation on forest carbon stocks and rates of carbon sequestration in mature aspen mixedwood forests of varying stand age (ranging from 61 to 85 years), overstory composition, stocking level, and site quality. Stocking level and site quality positively affected the average annual aboveground tree carbon increment (CAAI), while stocking level, site quality, and stand age positively affected tree carbon stocks (CTREE) and total ecosystem carbon stocks (CTOTAL). Cumulative canopy disturbance (DIST) was reconstructed using dendroecological methods over a 29-year period. DIST was negatively and significantly related to soil carbon (CSOIL), and it was negatively, albeit marginally, related to CTOTAL. Minima in the annual aboveground carbon increment of trees (CAI) occurred at sites during defoliation of aspen (Populus tremuloides Michx.) by forest tent caterpillar (Malacosoma disstria Hubner), and minima were more extreme at sites dominated by trembling aspen than sites mixed with conifers. At sites defoliated by forest tent caterpillar in the early 2000s, increased sequestration by the softwood component (Abies balsamea (L.) Mill. and Picea glauca (Moench) Voss) compensated for overall decreases in CAI by 17% on average. These results underscore the importance of accounting for low-severity canopy disturbance events when developing regional forest carbon models and argue for the restoration and maintenance of historically important conifer species within aspen mixedwoods to enhance stand-level resilience to disturbance agents and maintain

Nesting ecology of boreal forest birds following a massive outbreak of spruce beetles

Science.gov (United States)

Matsuoka, S.M.; Handel, C.M.

2007-01-01

We studied breeding dark-eyed juncos (Junco hyemalis), yellow-rumped warblers (Dendroica coronata), and spruce-nesting birds from 1997 to 1998 among forests with different levels of spruce (Picea spp.) mortality following an outbreak of spruce beetles (Dendroctonus rufipennis) in Alaska, USA. We identified species using live and beetle-killed spruce for nest sites and monitored nests to determine how the outbreak influenced avian habitat selection and reproduction. We tested predictions that 1) nesting success of ground-nesting juncos would increase with spruce mortality due to proliferation of understory vegetation available to conceal nests from predators, 2) nesting success of canopy-nesting warblers would decrease with spruce mortality due to fewer live spruce in which to conceal nests, and 3) both species would alter nest-site selection in response to disturbance. Juncos did not benefit from changes in understory vegetation; nesting success in highly disturbed stands (46%) was comparable to that in undisturbed habitats throughout their range. In stands with low spruce mortality, nesting success of juncos was low (5%) and corresponded with high densities of red squirrels (Tamiasciurus hudsonicus). Yellow-rumped warblers nested exclusively in spruce, but success did not vary with spruce mortality. As disturbance increased, nesting warblers switched from selecting forest patches with high densities of live white spruce (Picea glauca) to patches with beetle-killed spruce. Warblers also placed nests in large-diameter live or beetle-killed spruce, depending on which was more abundant in the stand, with no differences in nesting success. Five of the 12 other species of spruce-nesting birds also used beetle-killed spruce as nest sites. Because beetle-killed spruce can remain standing for >50 years, even highly disturbed stands provide an important breeding resource for boreal forest birds. We recommend that boreal forest managers preserve uncut blocks of infested

Soil compaction and organic matter affect conifer seedling nonmycorrhizal and ectomycorrhizal root tip abundance and diversity.

Science.gov (United States)

Michael P. Amaranthus; Debbie Page-Dumroese; Al Harvey; Efren Cazares; Larry F. Bednar

1996-01-01

Three levels of organic matter removal (bole only; bole and crowns; and bole, crowns, and forest floor) and three levels of mechanical soil compaction (no compaction, moderate compaction, and severe soil compaction) were studied as they influence Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) and western white...

The role of Nicotiana gluca Graham (paraguayan herbs as an adjuvant in immunomodulation of Newcastle disease vaccine for broilers Estudo da ação de Nicotiana glauca Graham (erva paraguaia como coadjuvante em vacina contra a doença de Newcastle em frangos de corte

Directory of Open Access Journals (Sweden)

Fabiane Pereira Gentilini

2008-07-01

Full Text Available The Nicotiana glauca is a native plant species from Argentina, but found all over South América, being used against headaches, rheumatism, injuries, ulcers, and so on. Researchers have considered it as having immunomodulation effect. This study was conducted to investigate the use of a aqueous extract of Nicotiana glauca Graham as an immunomodulator (adjuvant of a Newcastle disease vaccine.. A total of 56 broilers were distributed into 4 experimental groups. Each one of them received 3 dosages of this vaccine with or without the addition of different concentrations of the extract Using hemmoaglutination inhibition techniques , the results have shown differences (P<0.05 in the third sera collection. An increase in the antibody titer with the inclusion of 5 mg/dosage of the extract (Treatment 3 as compared to 1 mg/dosage (Treatment 2 and 10 mg/dosage of the extract (Treatment 4 was observed, However, birds from Treatment 3 did not differ (P> 0.05 from Treatment 1. These results indicated that further investigations are required, including the use of cytotoxicity tests in vitro, to evaluate the immunomodulation effect of this extract.

KEY WORDS: Immunomodulation effect, Nicotiana glauca Graham, vaccine.

Towards lidar-based mapping of tree age at the Arctic forest tundra ecotone.

Science.gov (United States)

Jensen, J.; Maguire, A.; Oelkers, R.; Andreu-Hayles, L.; Boelman, N.; D'Arrigo, R.; Griffin, K. L.; Jennewein, J. S.; Hiers, E.; Meddens, A. J.; Russell, M.; Vierling, L. A.; Eitel, J.

2017-12-01

Climate change may cause spatial shifts in the forest-tundra ecotone (FTE). To improve our ability to study these spatial shifts, information on tree demography along the FTE is needed. The objective of this study was to assess the suitability of lidar derived tree heights as a surrogate for tree age. We calculated individual tree age from 48 tree cores collected at basal height from white spruce (Picea glauca) within the FTE in northern Alaska. Tree height was obtained from terrestrial lidar scans (= 3 m), yielding strong predictive relationships between height and age (R2 = 0.86, RMSE 12.21 years, and R2 = 0.93, RMSE = 25.16 years, respectively). The slope coefficient for small and large tree models (16.83 and 12.98 years/m, respectively) indicate that small trees grow 1.3 times faster than large trees at these FTE study sites. Although a strong, predictive relationship between age and height is uncommon in light-limited forest environments, our findings suggest that the sparseness of trees within the FTE may explain the strong tree height-age relationships found herein. Further analysis of 36 additional tree cores recently collected within the FTE near Inuvik, Canada will be performed. Our preliminary analysis suggests that lidar derived tree height could be a reliable proxy for tree age at the FTE, thereby establishing a new technique for scaling tree structure and demographics across larger portions of this sensitive ecotone.

Changes in understory species occurrence of a secondary broadleaved forest after mass mortality of oak trees under deer foraging pressure

Directory of Open Access Journals (Sweden)

Hiroki Itô

2016-12-01

Full Text Available The epidemic of mass mortality of oak trees by Japanese oak wilt has affected secondary deciduous broadleaved forests that have been used as coppices in Japan. The dieback of oak trees formed gaps in the crown that would be expected to enhance the regeneration of shade-intolerant pioneer species. However, foraging by sika deer Cervus nippon has also affected forest vegetation, and the compound effects of both on forest regeneration should be considered when they simultaneously occur. A field study was conducted in Kyôto City, Japan to investigate how these compound effects affected the vegetation of the understory layer of these forests. The presence/absence of seedlings and saplings was observed for 200 quadrats sized 5 m ×5 m for each species in 1992, before the mass mortality and deer encroachment, and in 2014 after these effects. A hierarchical Bayesian model was constructed to explain the occurrence, survival, and colonization of each species with their responses to the gaps that were created, expanded, or affected by the mass mortality of Quercus serrata trees. The species that occurred most frequently in 1992, Eurya japonica, Quercus glauca, and Cleyera japonica, also had the highest survival probabilities. Deer-unpalatable species such as Symplocos prunifolia and Triadica sebifera had higher colonization rates in the gaps, while the deer-palatable species Aucuba japonica had the smallest survival probability. The gaps thus promoted the colonization of deer-unpalatable plant species such as Symplocos prunifolia and Triadica sebifera. In the future, such deer-unpalatable species may dominate gaps that were created, expanded, or affected by the mass mortality of oak trees.

Variation in carbohydrate source-sink relations of forest and treeline white spruce in southern, interior and northern Alaska.

Science.gov (United States)

Sveinbjörnsson, Bjartmar; Smith, Matthew; Traustason, Tumi; Ruess, Roger W; Sullivan, Patrick F

2010-08-01

Two opposing hypotheses have been presented to explain reduced tree growth at the treeline, compared with growth in lower elevation or lower latitude forests: the carbon source and sink limitation hypotheses. The former states that treeline trees have an unfavorable carbon balance and cannot support growth of the magnitude observed at lower elevations or latitudes, while the latter argues that treeline trees have an adequate carbon supply, but that cold temperatures directly limit growth. In this study, we examined the relative importance of source and sink limitation in forest and treeline white spruce (Picea glauca) in three mountain ranges from southern to northern Alaska. We related seasonal changes in needle nonstructural carbohydrate (NSC) content with branch extension growth, an approach we argue is more powerful than using needle NSC concentration. Branch extension growth in the southernmost Chugach Mountains was much greater than in the White Mountains and the Brooks Range. Trees in the Chugach Mountains showed a greater seasonal decline in needle NSC content than trees in the other mountain ranges, and the seasonal change in NSC was correlated with site-level branch growth across mountain ranges. There was no evidence of a consistent difference in branch growth between the forest and treeline sites, which differ in elevation by approximately 100 m. Our results point to a continuum between source and sink limitation of growth, with high-elevation trees in northern and interior Alaska showing greater evidence of sink limitation, and those in southern Alaska showing greater potential for source limitation.

Structure and development of old-growth, unmanaged second-growth, and extended rotation Pinus resinosa forests in Minnesota, USA

Science.gov (United States)

Silver, Emily J.; D'Amato, Anthony W.; Fraver, Shawn; Palik, Brian J.; Bradford, John B.

2013-01-01

The structure and developmental dynamics of old-growth forests often serve as important baselines for restoration prescriptions aimed at promoting more complex structural conditions in managed forest landscapes. Nonetheless, long-term information on natural patterns of development is rare for many commercially important and ecologically widespread forest types. Moreover, the effectiveness of approaches recommended for restoring old-growth structural conditions to managed forests, such as the application of extended rotation forestry, has been little studied. This study uses several long-term datasets from old growth, extended rotation, and unmanaged second growth Pinus resinosa (red pine) forests in northern Minnesota, USA, to quantify the range of variation in structural conditions for this forest type and to evaluate the effectiveness of extended rotation forestry at promoting the development of late-successional structural conditions. Long-term tree population data from permanent plots for one of the old-growth stands and the extended rotation stands (87 and 61 years, respectively) also allowed for an examination of the long-term structural dynamics of these systems. Old-growth forests were more structurally complex than unmanaged second-growth and extended rotation red pine stands, due in large part to the significantly higher volumes of coarse woody debris (70.7 vs. 11.5 and 4.7 m3/ha, respectively) and higher snag basal area (6.9 vs. 2.9 and 0.5 m2/ha, respectively). In addition, old-growth forests, although red pine-dominated, contained a greater abundance of other species, including Pinus strobus, Abies balsamea, and Picea glauca relative to the other stand types examined. These differences between stand types largely reflect historic gap-scale disturbances within the old-growth systems and their corresponding structural and compositional legacies. Nonetheless, extended rotation thinning treatments, by accelerating advancement to larger tree diameter

Responses of two températe evergreen Nothofagus species to sudden and gradual waterlogging: relationships with distribution patterns Respuestas de dos especies siempreverdes de Nothofagus al anegamiento gradual y repentino: relaciones con patrones de distribución

Directory of Open Access Journals (Sweden)

FRIDA PIPER

2008-06-01

Full Text Available The effects of gradual waterlogging on trees have been little studied. The températe evergreens Nothofagus nítida and N. dombeyi are differentially distributed on soil moisture gradients, only the former being common on poorly-drained sites. We compared the relative height growth rate (RGR H and foliage loss of seedlings subjected experimentally to normal drainage (soil at field capacity, sudden waterlogging and gradual waterlogging for two months to determine which waterlogging regime more accurately predicts interspecific differences in tolerance, as evident from natural distributions. RGR H was similar between species but differed between treatments (normal watering > gradual waterlogging = sudden waterlogging. Sudden waterlogging caused massive foliage loss in the two species, but gradual waterlogging caused much greater foliage loss in N. dombeyi than in N. nítida, indicating some degree of acclimation by the latter species. Linear regressions indicated that RGR H was negatively affected by foliage loss in both species, without differences between them. Since no difference in RGR H was found between species in the waterlogging treatments, but yet in foliage loss, other mechanisms may be in volved in the short term growth reduction of N. nítida. Effects of waterlogging on long-term performance in the field were evaluated by reciprocal transplants between a poorly-drained site naturally occupied by N. nítida, and a well drained site naturally occupied by N. dombeyi. After two growing seasons, N. dombeyi had significantly lower specific leaf área (SLA and RGR H, at the poorly drained site than at its original site. At the poorly drained site N. nítida achieved 100 % survival, compared with 73.5 % in N. dombeyi. Reduced growth and survival of N. dombeyi associated with the negative effects on carbón gain of extensive foliage loss and reduced SLA may thus exelude it from the wetter sites. We conclude that tolerance may be better

Endogenous Quantification of Abscisic Acid and Indole-3-Acetic Acid in Somatic and Zigotic Embryos of Nothofagus alpina (Poepp. & Endl. Oerst Cuantificación Endógena de Ácido Abscísico y Ácido Indol-3 Acético en Embriones Somáticos y Cigóticos de Nothofagus alpina (Poepp. & Endl. Oerst

Directory of Open Access Journals (Sweden)

Pricila Cartes Riquelme

2011-12-01

Full Text Available Abscisic acid (ABA and indole-3-acetic acid (IAA participate in the propagation of plants by somatic embryogenesis, causing polar structural differentiation of the embryo. The goal of the assay was to compare endogenous levels of ABA and IAA between somatic embryos (SE and zygotic embryos (ZE of Nothofagus alpina (Poepp. & Endl. Oerst. In this study, a somatic embryo maturation assay involving the addition of varying concentrations of exogenous ABA was performed on cotyledonary-stage of N. alpina. Furthermore, the endogenous levels of ABA and IAA were quantified in the immature ZE, the mature ZE, and the embryonic axis of a mature embryo of N. alpina. The current study utilized high performance liquid chromatography (HPLC for quantification. The maturation treatments performed did not present significant differences in the endogenous ABA levels in SE. However, significant differences did exist in levels of ABA and IAA between SE submitted to the different maturation treatments and mature ZE of N. alpina. The application of exogenous ABA to the culture medium increased endogenous ABA levels, therefore, increasing the number of germinated somatic embryos. Thus, the plant conversion process was also successfully completed in somatic embryos of N. alpina.El ácido abscísico (ABA y el ácido indol 3 acético (IAA participan en el proceso de propagación de plantas mediante embriogénesis somática, ya que permiten la diferenciación de la estructura polar del embrión, órganos y regiones meristemáticas de éste. En este estudio se llevó a cabo un ensayo de maduración de embriones somáticos en estado cotiledonar con la adición de diferentes concentraciones de ABA exógeno, además se determinaron niveles endógenos entre ZE inmaduro, ZE maduro, y eje embrionario aislado desde el embrión maduro para luego comparar niveles endógenos de ABA e IAA en embriones somáticos (SE y cigóticos (ZE de raulí, Nothofagus alpina (Poepp. & Endl. Oerst. La

Climatic Sensitivity of a Mixed Forest Association of White Spruce and Trembling Aspen at Their Southern Range Limit

Directory of Open Access Journals (Sweden)

Sophan Chhin

2016-10-01

Full Text Available Climatic sensitivity of white spruce (Picea glauca (Moench Voss was examined growing in association with trembling aspen (Populus tremuloides Michx. at their southern limit of distribution in a transitional ecotone between the southern boreal forest and northern prairie region. The study was carried out in the Spruce Woods Provincial Park (SWPP located in southwestern Manitoba, Canada. The dry regional climate restricted trembling aspen growth during the growing season via moisture deficiency and temperature induced drought stress. Warm, mild winters also negatively affected radial growth of trembling aspen. Growth of white spruce was moderated by conditions within the aspen stands as radial growth patterns showed low variability from year to year, a low common growth signal, and a stronger response to temperature than to precipitation. Nonetheless, the dry regional climate still restricted growth of white spruce during the growing season via temperature induced drought stress. The findings of the study for white spruce support the stress gradient hypothesis in which facilitative interactions between tree species are expected under harsher environmental conditions.

Low Tree-Growth Elasticity of Forest Biomass Indicated by an Individual-Based Model

Directory of Open Access Journals (Sweden)

Robbie A. Hember

2018-01-01

Full Text Available Environmental conditions and silviculture fundamentally alter the metabolism of individual trees and, therefore, need to be studied at that scale. However, changes in forest biomass density (Mg C ha−1 may be decoupled from changes in growth (kg C year−1 when the latter also accelerates the life cycle of trees and strains access to light, nutrients, and water. In this study, we refer to an individual-based model of forest biomass dynamics to constrain the magnitude of system feedbacks associated with ontogeny and competition and estimate the scaling relationship between changes in tree growth and forest biomass density. The model was driven by fitted equations of annual aboveground biomass growth (Gag, probability of recruitment (Pr, and probability of mortality (Pm parameterized against field observations of black spruce (Picea mariana (Mill. BSP, interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn. Franco, and western hemlock (Tsuga heterophylla (Raf. Sarg.. A hypothetical positive step-change in mean tree growth was imposed half way through the simulations and landscape-scale responses were then evaluated by comparing pre- and post-stimulus periods. Imposing a 100% increase in tree growth above calibrated predictions (i.e., contemporary rates only translated into 36% to 41% increases in forest biomass density. This corresponded with a tree-growth elasticity of forest biomass (εG,SB ranging from 0.33 to 0.55. The inelastic nature of stand biomass density was attributed to the dependence of mortality on intensity of competition and tree size, which decreased stand density by 353 to 495 trees ha−1, and decreased biomass residence time by 10 to 23 years. Values of εG,SB depended on the magnitude of the stimulus. For example, a retrospective scenario in which tree growth increased from 50% below contemporary rates up to contemporary rates indicated values of εG,SB ranging from 0.66 to 0.75. We conclude that: (1 effects of

Morphological analysis of the oviduct, oviducal gland and isthmus of the blue shark Prionace glauca (Linnaeus, 1758 (Elasmobranchii: Carcharhiniformes

Directory of Open Access Journals (Sweden)

Bianca S. Rangel

Full Text Available ABSTRACT Oviducal gland present in elasmobranchs is correlated to the organism's reproductive strategy, and its functions are to produce mucus, to form the egg's tertiary envelope and to store sperm. The gland contains four zones: club, papillary,baffle and terminal. The structures of the oviduct, oviducal gland and isthmus of blue shark Prionace glauca were described using macroscopic, light microscopy and scanning electron microscopy techniques. The epithelium of the oviduct and isthmus is folded and is a simple, columnar, ciliated lining epithelium with glandular cells. In the oviducal gland, the lining tissues in the four zones are similar to the oviduct and isthmus lining. The terminal zone shows the presence of sperm in the lumen of the secretory tubules, which remains stored even in the absence of recent copulation. Here, these organs were studied and their connections in an attempt to elucidate the mechanisms of reproduction in the blue shark, showing the three-dimensional aspects, thus adding morphological information important for the understanding of the structure and functioning of these organs of fundamental importance in the life of the majority of elasmobranchs.

ALCALOIDES BISBENCILISOQUINOLINICOS AISLADOS DE LA ESPECIE NATIVA Berberís glauca (HBK Y EVALUACIÓN DE SU ACTIVIDAD ANTIALIMENTARIA

Directory of Open Access Journals (Sweden)

Barbara Moreno Murillo

2010-09-01

Full Text Available Durante el estudio de la potencial actividad tóxica del extracto alcohólico de ios tallos de la especie nativa Berberís glauca (HBK (Berberidaceae. Se realizaron bioensayos con larvas del crustáceo Artemia salina, y de los insectos Musca domestica (Díptera y Spodoptera sunia (Lepidoptera. La fracción alcaloidal soluble en CHCl, obtenida por extracción ácido-base del extracto etanólico mostró notable acción antialimentaria frente a larvas de 3° y 4° estadio de la polilla S. sunia. La separación cromatográfica guiada por bioensayos permitió aislar y purificar de la fracción de mayor actividad varios alcaloides benciltctrahidroisoquinolínicos. Por métodos espectroscópicos se identificaron berbamina, isotalicberina. O- metilisotalicberina y 7- 0-demetilisotalicberina. Este es el primer reporte sobre la presencia de bases diméricas bisbenciltetrahidroisoquinolínicas (bbi en especies de Berberís colombianas. Además se detectó la presencia de una base dimérica novedosa de PM 712 cuya dilucidación estructural no se ha establecido en forma completa.

Sterling C. Robertson Dam and Limestone Lake on the Navasota River, Texas (Leon, Limestone and Robertson Counties).

Science.gov (United States)

1976-04-01

flatsedge (Cyperus s p.) , and Spanish mulberry (Callicarpa americana). Common bottomland forest species included pecan ( Carya illinoensis ), post...ona-wiibT Bull Briar Smilax glauca Cat Greenbriar Salix nigra Black Willow Carya illinoensis Pecan Carya texana Black Hickory Q-erustlefata Post Oak... illinoensis ), post oak (Quercus stellata). hackberry (Ce/is sp.), elm (Ulmus sp.), and holly. Species common in the prairie site included Croton sp., prairie

Vitality structure of the populations of some weed species in crop sowings

Directory of Open Access Journals (Sweden)

E. M. Tikhonova

2010-11-01

Full Text Available Features of development of populations of weed species (Cirsium arvense (L. Scop., Sonchus arvensis L., Melandium album (Mill. Garke, Setaria glauca (L. Beauv., Fallopia convolvulus (L. А. Lоve in most typical crops in the forest-steppe zone of the Sumy region. It was studied the crop sowings (winter wheat, rye, barley, buckwheat, pea which was not subjected to the herbicide treatment.

World without borders-genetic population structure of a highly migratory marine predator, the blue shark (Prionace glauca).

Science.gov (United States)

Veríssimo, Ana; Sampaio, Íris; McDowell, Jan R; Alexandrino, Paulo; Mucientes, Gonzalo; Queiroz, Nuno; da Silva, Charlene; Jones, Catherine S; Noble, Leslie R

2017-07-01

Highly migratory, cosmopolitan oceanic sharks often exhibit complex movement patterns influenced by ontogeny, reproduction, and feeding. These elusive species are particularly challenging to population genetic studies, as representative samples suitable for inferring genetic structure are difficult to obtain. Our study provides insights into the genetic population structure one of the most abundant and wide-ranging oceanic shark species, the blue shark Prionace glauca, by sampling the least mobile component of the populations, i.e., young-of-year and small juveniles (<2 year; N  = 348 individuals), at three reported nursery areas, namely, western Iberia, Azores, and South Africa. Samples were collected in two different time periods (2002-2008 and 2012-2015) and were screened at 12 nuclear microsatellites and at a 899-bp fragment of the mitochondrial control region. Our results show temporally stable genetic homogeneity among the three Atlantic nurseries at both nuclear and mitochondrial markers, suggesting basin-wide panmixia. In addition, comparison of mtDNA CR sequences from Atlantic and Indo-Pacific locations also indicated genetic homogeneity and unrestricted female-mediated gene flow between ocean basins. These results are discussed in light of the species' life history and ecology, but suggest that blue shark populations may be connected by gene flow at the global scale. The implications of the present findings to the management of this important fisheries resource are also discussed.

Clonal variation in gas exchange and freezing tolerance development of interior spruce (Picea glauca (Moench) Voss x P. engelmannii Parry ex Engelm.) during autumn acclimation

Energy Technology Data Exchange (ETDEWEB)

Fan, Shihe; Grossnickle, S.C. [British Columbia Research Corp., Vancouver, BC (Canada). Forest Biotechnology Centre

1999-08-01

Variation in physiological response during autumn acclimation was investigated in somatic seedlings of 10 interior spruce (Picea glauca (Moench) Voss x P. engelmannii Parry ex Engelm.) clones from five full-sib families. Experiments were conducted on 2-yr-old seedlings through simulation in a growth chamber. Throughout the experimental period, gas-exchange parameters (net photosynthesis, stomatal conductance to water vapour and instantaneous water-use efficiency) were measured weekly and freezing tolerance was determined five times. Results showed that as seedlings acclimated to decreasing air temperature and photoperiod, stomatal conductance decreased linearly, photosynthesis was unchanged until air temperature and photoperiod were below 10 deg C and 11 h, respectively, water-use efficiency nearly doubled and freezing tolerance increased in a curvilinear fashion. There was significant between- and within-family clonal variation in all of these physiological parameters. 47 refs, 7 figs

Alcaloides bisbencilisoquinolinicos aislados de la especie nativa berberís glauca (HBK y evaluación de su actividad antialimentaria

Directory of Open Access Journals (Sweden)

Bárbara Moreno-Murillo

2010-07-01

Full Text Available Durante el estudio de la potencial actividad tóxica del extracto alcohólico de ios tallos de la especie nativa Berberís glauca (HBK (Berberidaceae. se realizaron bioensayos con larvas del crustáceo Artemia salina, y de los insectos Musca domestica (Díptera y Spodoptera sunia (Lepidoptera. La fracción alcaloidal soluble en CHCl, obtenida por extracción ácido-base del extracto etanólico mostró notable acción antialimentaria frente a larvas de 3° y 4° estadio de la polilla S. sunia. La separación cromatográfica guiada por bioensayos permitió aislar y purificar de la fracción de mayor actividad varios alcaloides benciltctrahidroisoquinolínicos. Por métodos espectroscópicos se identificaron berbamina, isotalicberina. O- metilisotalicberina y 7- 0-demetilisotalicberina. Este es el primer reporte sobre la presencia de bases diméricas bisbenciltetrahidroisoquinolínicas (bbi en especies de Berberís colombianas. Además se detectó la presencia de una base dimérica novedosa de PM 712 cuya dilucidación estructural no se ha establecido en forma completa.

Imprints of climate signals in a 204 year 18O tree-ring record of Nothofagus pumilio from Perito Moreno Glacier, southern Patagonia (50°S).

Science.gov (United States)

Grießinger, Jussi; Langhamer, Lukas; Schneider, Christoph; Saß, Björn-Lukas; Steger, David; Skvarca, Pedro; Braun, Matthias H.; Meier, Wolfgang J.-H.; Srur, Ana M.; Hochreuther, Philipp

2018-04-01

A 204 year-long record of 18O in tree-ring cellulose of southern beech (Nothofagus pumilio) from a site near Perito Moreno Glacier (50°S) in southern Patagonia was established to assess its potential for a climate reconstruction. The annually resolved oxygen isotope chronology is built out of seven individual tree-ring 18O series with a significant mean inter-series correlation (r = 0.61) and is the first of its kind located in Southern America south of 50°S. Over a common period from 1960 to 2013 of available stationary and high-resolution gridded CRU TS v. 4.01 data, the 18O chronology exhibits a strong sensitivity towards hydroclimatic as well as temperature parameters as revealed by correlation analyses. Among these, positive correlations with maximum temperature in the first part of the summer season (CRU rONDJ = 0.51, pAmerica. The modulation of positive and negative anomalies within this series can be interlinked to changes in moisture source origin as revealed by backward trajectory modeling. Additionally, these anomalies can be directly associated to positive or negative phases of the Antarctic Oscillation Index (AAOI) and therefore the strength of the Westerlies. Aligned by the analysis on the influence of different main weather types on the 18O chronology it is shown that such time-series hold the potential to additionally capture their respective influence and change during the last centuries.

Patterns of cross-continental variation in tree seed mass in the Canadian Boreal Forest.

Directory of Open Access Journals (Sweden)

Jushan Liu

Full Text Available Seed mass is an adaptive trait affecting species distribution, population dynamics and community structure. In widely distributed species, variation in seed mass may reflect both genetic adaptation to local environments and adaptive phenotypic plasticity. Acknowledging the difficulty in separating these two aspects, we examined the causal relationships determining seed mass variation to better understand adaptability and/or plasticity of selected tree species to spatial/climatic variation. A total of 504, 481 and 454 seed collections of black spruce (Picea mariana (Mill. B.S.P., white spruce (Picea glauca (Moench Voss and jack pine (Pinus banksiana Lamb across the Canadian Boreal Forest, respectively, were selected. Correlation analyses were used to determine how seed mass vary with latitude, longitude, and altitude. Structural Equation Modeling was used to examine how geographic and climatic variables influence seed mass. Climatic factors explained a large portion of the variation in seed mass (34, 14 and 29%, for black spruce, white spruce and jack pine, respectively, indicating species-specific adaptation to long term climate conditions. Higher annual mean temperature and winter precipitation caused greater seed mass in black spruce, but annual precipitation was the controlling factor for white spruce. The combination of factors such as growing season temperature and evapotranspiration, temperature seasonality and annual precipitation together determined seed mass of jack pine. Overall, sites with higher winter temperatures were correlated with larger seeds. Thus, long-term climatic conditions, at least in part, determined spatial variation in seed mass. Black spruce and Jack pine, species with relatively more specific habitat requirements and less plasticity, had more variation in seed mass explained by climate than did the more plastic species white spruce. As traits such as seed mass are related to seedling growth and survival, they

Development and microstructure of tooth histotypes in the blue shark, Prionace glauca (Carcharhiniformes: Carcharhinidae) and the great white shark, Carcharodon carcharias (Lamniformes: Lamnidae).

Science.gov (United States)

Moyer, Joshua K; Riccio, Mark L; Bemis, William E

2015-07-01

Elasmobranchs exhibit two distinct arrangements of mineralized tissues in the teeth that are known as orthodont and osteodont histotypes. Traditionally, it has been said that orthodont teeth maintain a pulp cavity throughout tooth development whereas osteodont teeth are filled with osteodentine and lack a pulp cavity when fully developed. We used light microscopy, scanning electron microscopy, and high-resolution micro-computed tomography to compare the structure and development of elasmobranch teeth representing the two histotypes. As an example of the orthodont histotype, we studied teeth of the blue shark, Prionace glauca (Carcharhiniformes: Carcharhinidae). For the osteodont histotype, we studied teeth of the great white shark, Carcharodon carcharias (Lamniformes: Lamnidae). We document similarities and differences in tooth development and the microstructure of tissues in these two species and review the history of definitions and interpretations of elasmobranch tooth histotypes. We discuss a possible correlation between tooth histotype and tooth replacement and review the history of histotype differentiation in sharks. We find that contrary to a long held misconception, there is no orthodentine in the osteodont teeth of C. carcharias. © 2015 Wiley Periodicals, Inc.

Immediate effects of nectar robbing by Palestine sunbirds (Nectarinia osea) on nectar alkaloid concentrations in tree tobacco (Nicotiana glauca).

Science.gov (United States)

Kaczorowski, Rainee L; Koplovich, Avi; Sporer, Frank; Wink, Michael; Markman, Shai

2014-04-01

Plant secondary metabolites (PSMs), such as alkaloids, are often found in many parts of a plant, including flowers, providing protection to the plant from various types of herbivores or microbes. PSMs are also present in the floral nectar of many species, but typically at lower concentrations than in other parts of the plant. Nectar robbers often damage floral tissue to access the nectar. By doing so, these nectar robbers may initiate an increase of PSMs in the floral nectar. It is often assumed that it takes at least a few hours before the plant demonstrates an increase in PSMs. Here, we addressed the question of whether PSMs in the floral tissue are immediately being released into the floral nectar following nectar robbing. To address this research question, we investigated whether there was an immediate effect of nectar robbing by the Palestine Sunbird (Nectarinia osea) on the concentration of nectar alkaloids, nicotine and anabasine, in Tree Tobacco (Nicotiana glauca). We found that the concentration of anabasine, but not nicotine, significantly increased in floral nectar immediately following simulated nectar robbing. These findings suggest that nectar robbers could be ingesting greater amounts of PSMs than they would if they visit flowers legitimately. As a consequence, increased consumption of neurotoxic nectar alkaloids or other PSMs could have negative effects on the nectar robber.

C and N content in density fractions of whole soil and soil size fraction under cacao agroforestry systems and natural forest in Bahia, Brazil.

Science.gov (United States)

Rita, Joice Cleide O; Gama-Rodrigues, Emanuela Forestieri; Gama-Rodrigues, Antonio Carlos; Polidoro, Jose Carlos; Machado, Regina Cele R; Baligar, Virupax C

2011-07-01

Agroforestry systems (AFSs) have an important role in capturing above and below ground soil carbon and play a dominant role in mitigation of atmospheric CO(2). Attempts has been made here to identify soil organic matter fractions in the cacao-AFSs that have different susceptibility to microbial decomposition and further represent the basis of understanding soil C dynamics. The objective of this study was to characterize the organic matter density fractions and soil size fractions in soils of two types of cacao agroforestry systems and to compare with an adjacent natural forest in Bahia, Brazil. The land-use systems studied were: (1) a 30-year-old stand of natural forest with cacao (cacao cabruca), (2) a 30-year-old stand of cacao with Erythrina glauca as shade trees (cacao + erythrina), and (3) an adjacent natural forest without cacao. Soil samples were collected from 0-10 cm depth layer in reddish-yellow Oxisols. Soil samples was separated by wet sieving into five fraction-size classes (>2000 μm, 1000-2000 μm, 250-1000 μm, 53-250 μm, and 2000 μm) mixed with macroaggregates (32-34%), and microaggregates (1-1.3%). Soil organic carbon (SOC) and total N content increased with increasing soil size fraction in all land-use systems. Organic C-to-total N ratio was higher in the macroaggregate than in the microaggregate. In general, in natural forest and cacao cabruca the contribution of C and N in the light and heavy fractions was similar. However, in cacao + erythrina the heavy fraction was the most common and contributed 67% of C and 63% of N. Finding of this study shows that the majority of C and N in all three systems studied are found in macroaggregates, particularly in the 250-1000 μm size aggregate class. The heavy fraction was the most common organic matter fraction in these soils. Thus, in mature cacao AFS on highly weathered soils the main mechanisms of C stabilization could be the physical protection within macroaggregate structures thereby

C and N Content in Density Fractions of Whole Soil and Soil Size Fraction Under Cacao Agroforestry Systems and Natural Forest in Bahia, Brazil

Science.gov (United States)

Rita, Joice Cleide O.; Gama-Rodrigues, Emanuela Forestieri; Gama-Rodrigues, Antonio Carlos; Polidoro, Jose Carlos; Machado, Regina Cele R.; Baligar, Virupax C.

2011-07-01

Agroforestry systems (AFSs) have an important role in capturing above and below ground soil carbon and play a dominant role in mitigation of atmospheric CO2. Attempts has been made here to identify soil organic matter fractions in the cacao-AFSs that have different susceptibility to microbial decomposition and further represent the basis of understanding soil C dynamics. The objective of this study was to characterize the organic matter density fractions and soil size fractions in soils of two types of cacao agroforestry systems and to compare with an adjacent natural forest in Bahia, Brazil. The land-use systems studied were: (1) a 30-year-old stand of natural forest with cacao (cacao cabruca), (2) a 30-year-old stand of cacao with Erythrina glauca as shade trees (cacao + erythrina), and (3) an adjacent natural forest without cacao. Soil samples were collected from 0-10 cm depth layer in reddish-yellow Oxisols. Soil samples was separated by wet sieving into five fraction-size classes (>2000 μm, 1000-2000 μm, 250-1000 μm, 53-250 μm, and cacao AFS soils consisted mainly (65 %) of mega-aggregates (>2000 μm) mixed with macroaggregates (32-34%), and microaggregates (1-1.3%). Soil organic carbon (SOC) and total N content increased with increasing soil size fraction in all land-use systems. Organic C-to-total N ratio was higher in the macroaggregate than in the microaggregate. In general, in natural forest and cacao cabruca the contribution of C and N in the light and heavy fractions was similar. However, in cacao + erythrina the heavy fraction was the most common and contributed 67% of C and 63% of N. Finding of this study shows that the majority of C and N in all three systems studied are found in macroaggregates, particularly in the 250-1000 μm size aggregate class. The heavy fraction was the most common organic matter fraction in these soils. Thus, in mature cacao AFS on highly weathered soils the main mechanisms of C stabilization could be the physical

Effects of Harvesting Systems and Bole Moisture Loss on Weight Scaling of Douglas-Fir Sawlogs (Pseudotsuga Menziesii var. glauca Franco

Directory of Open Access Journals (Sweden)

Jarred D. Saralecos

2014-09-01

Full Text Available Characterizing the moisture loss from felled trees is essential for determining weight-to-volume (W-V relationships in softwood sawlogs. Several factors affect moisture loss, but research to quantify the effects of bole size and harvest method is limited. This study was designed to test whether bole size, harvest method, environmental factors, and the associated changes in stem moisture content of felled Douglas-fir (Pseudotsuga menziesii var. glauca Franco affected the weight-to-volume relationship of sawlogs. Thirty trees in three size classes (12.7–25.4 cm, 25.5–38.1 cm, 38.2–50.8 cm were felled and treated with one of two harvesting processing methods. Moisture content was sampled every two days for four weeks. Results showed 6% greater moisture loss in the crowns of stems that retained limbs after felling compared to stems with limbs removed after harvesting. Additionally, moisture loss rate increased as stem size decreased. The smallest size class lost 58% moisture content compared to 34% in the largest size class throughout the study duration. These stem moisture content changes showed a 17% reduction in average sawlog weight within the largest size class, shifting current W-V relationships from 2.33 tons m−3 to 1.94 tons m−3 during the third seasonal quarter for northern Idaho Douglas-fir and potentially altering relationships year-round.

Mapping Forest Inventory and Analysis forest land use: timberland, reserved forest land, and other forest land

Science.gov (United States)

Mark D. Nelson; John Vissage

2007-01-01

The Forest Inventory and Analysis (FIA) program produces area estimates of forest land use within three subcategories: timberland, reserved forest land, and other forest land. Mapping these subcategories of forest land requires the ability to spatially distinguish productive from unproductive land, and reserved from nonreserved land. FIA field data were spatially...

Testing the importance of plant strategies on facilitation using congeners in a coastal community.

Science.gov (United States)

He, Qiang; Cui, Baoshan; Bertness, Mark D; An, Yuan

2012-09-01

Much is known about how environmental stress mediates the strength of facilitation, but less is known about how different plant traits affect facilitation. We examined interactions between the shrub Tamarix chinensis and two congeneric forbs (Suaeda salsa and S. glauca) on the Chinese coast. Although S. salsa and S. glauca are both annuals, morphologically similar, and have synchronous phenologies, they have contrasting adaptive strategies. S. glauca is salt intolerant but competitively superior, and S. salsa is salt tolerant but competitively inferior. Field surveys showed that S. glauca was associated with T. chinensis canopies while S. salsa was more abundant in open areas. A T. chinensis removal experiment showed that S. glauca cover was lower and soil salinity higher after two years in removal than in control plots. Transplant experiments showed that S. salsa performance under T. chinensis canopies was reduced by competition from S. glauca and T. chinensis, while in open areas S. glauca was not affected by S. salsa competition. Thus, contrasting competitive abilities and stress tolerances of S. glauca and S. salsa underlie their facilitative and competitive interactions with T. chinensis, suggesting that plant strategies are critical to the outcome of species interactions.

Forest resources of the Lincoln National Forest

Science.gov (United States)

John D. Shaw

2006-01-01

The Interior West Forest Inventory and Analysis (IWFIA) program of the USDA Forest Service, Rocky Mountain Research Station, as part of its national Forest Inventory and Analysis (FIA) duties, conducted forest resource inventories of the Southwestern Region (Region 3) National Forests. This report presents highlights of the Lincoln National Forest 1997 inventory...

The taphonomy of a remarkable leaf bed assemblage from the Late Oligocene-Early Miocene Gore Lignite Measures, southern New Zealand

Energy Technology Data Exchange (ETDEWEB)

Ferguson, David K.; Zetter, Reinhard; Vavra, Norbert [Department of Paleontology, University of Vienna, Althanstrasse 14, A-1090 Vienna (Austria); Lee, Daphne E. [Department of Geology, University of Otago, PO Box 56, Dunedin (New Zealand); Bannister, Jennifer M. [Department of Botany, University of Otago, PO Box 56, Dunedin (New Zealand); Jordan, Gregory J. [School of Plant Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001 (Australia); Mildenhall, Dallas C. [GNS Science, PO Box 30-368, Lower Hutt (New Zealand)

2010-08-01

A diverse assemblage of fossil leaves showing cellular detail is reported from the Late Oligocene-Early Miocene Gore Lignite Measures, southern New Zealand. The leaf-remains include at least five conifers, such as the genera Agathis, Dacrycarpus, Phyllocladus and Dacrydium, as well as a number of angiosperms including Gymnostoma, Nothofagus Subgenus Brassospora, Phormium, Proteaceae, Sapindaceae and Ericaceae. A parallel palynological study has identified a number of the same elements. The leaf layers represent litter horizons laid down in pools on the surface of a subtropical ombrotrophic forest mire that formed on an extensive low-lying coastal plain. Highly acidic water ponded in tree-fall depressions prevented microbial decay of the foliage. Taxa represented by both leaves and pollen are considered to have been components of the autochthonous swamp forest. Some other pollen grains are thought to represent local elements, based on the pollination biology of their nearest living relatives. Other taxa whose extant representatives are wind-pollinated may have grown further away. (author)

Forest resources of Mississippi’s national forests, 2006

Science.gov (United States)

Sonja N. Oswalt

2011-01-01

This bulletin describes forest resource characteristics of Mississippi’s national forests, with emphasis on DeSoto National Forest, following the 2006 survey completed by the U.S. Department of Agriculture Forest Service, Forest Inventory and Analysis program. Mississippi’s national forests comprise > 1 million acres of forest land, or about 7 percent of all forest...

An experimental approach to explain the southern Andes elevational treeline.

Science.gov (United States)

Fajardo, Alex; Piper, Frida I

2014-05-01

• The growth limitation hypothesis (GLH) is the most accepted mechanistic explanation for treeline formation, although it is still uncertain whether it applies across taxa. The successful establishment of Pinus contorta--an exotic conifer species in the southern hemisphere--above the Nothofagus treeline in New Zealand may suggest a different mechanism. We tested the GLH in Nothofagus pumilio and Pinus contorta by comparing seedling performance and carbon (C) balance in response to low temperatures.• At a southern Chilean treeline, we grew seedlings of both species 2 m above ground level, to simulate coupling between temperatures at the meristem and in the air (colder), and at ground level, i.e., decoupling air temperature (relatively milder). We recorded soil and air temperatures as well. After 3 yr, we measured seedling survival and biomass (as a surrogate of growth) and determined nonstructural carbohydrates (NSC).• Nothofagus and Pinus did not differ in survival, which, as a whole, was higher at ground level than at the 2-m height. The root-zone temperature for the growing season was 6.6°C. While biomass and NSC decreased significantly for Nothofagus at the 2-m height compared with ground level (C limitation), these trends were not significant for Pinus• The treeline for Nothofagus pumilio is located at an isotherm that fully matches global patterns; however, its physiological responses to low temperatures differed from those of other treeline species. Support for C limitation in N. pumilio but not in P. contorta indicates that the physiological mechanism explaining their survival and growth at treeline may be taxon-dependent. © 2014 Botanical Society of America, Inc.

Forests

Science.gov (United States)

Louis R. Iverson; Mark W. Schwartz

1994-01-01

Originally diminished by development, forests are coming back: forest biomass is accumulating. Forests are repositories for many threatened species. Even with increased standing timber, however, biodiversity is threatened by increased forest fragmentation and by exotic species.

Forest structure in low-diversity tropical forests: a study of Hawaiian wet and dry forests.

Science.gov (United States)

Ostertag, Rebecca; Inman-Narahari, Faith; Cordell, Susan; Giardina, Christian P; Sack, Lawren

2014-01-01

The potential influence of diversity on ecosystem structure and function remains a topic of significant debate, especially for tropical forests where diversity can range widely. We used Center for Tropical Forest Science (CTFS) methodology to establish forest dynamics plots in montane wet forest and lowland dry forest on Hawai'i Island. We compared the species diversity, tree density, basal area, biomass, and size class distributions between the two forest types. We then examined these variables across tropical forests within the CTFS network. Consistent with other island forests, the Hawai'i forests were characterized by low species richness and very high relative dominance. The two Hawai'i forests were floristically distinct, yet similar in species richness (15 vs. 21 species) and stem density (3078 vs. 3486/ha). While these forests were selected for their low invasive species cover relative to surrounding forests, both forests averaged 5->50% invasive species cover; ongoing removal will be necessary to reduce or prevent competitive impacts, especially from woody species. The montane wet forest had much larger trees, resulting in eightfold higher basal area and above-ground biomass. Across the CTFS network, the Hawaiian montane wet forest was similar to other tropical forests with respect to diameter distributions, density, and aboveground biomass, while the Hawai'i lowland dry forest was similar in density to tropical forests with much higher diversity. These findings suggest that forest structural variables can be similar across tropical forests independently of species richness. The inclusion of low-diversity Pacific Island forests in the CTFS network provides an ∼80-fold range in species richness (15-1182 species), six-fold variation in mean annual rainfall (835-5272 mm yr(-1)) and 1.8-fold variation in mean annual temperature (16.0-28.4°C). Thus, the Hawaiian forest plots expand the global forest plot network to enable testing of ecological theory for

Forest structure in low-diversity tropical forests: a study of Hawaiian wet and dry forests.

Directory of Open Access Journals (Sweden)

Rebecca Ostertag

Full Text Available The potential influence of diversity on ecosystem structure and function remains a topic of significant debate, especially for tropical forests where diversity can range widely. We used Center for Tropical Forest Science (CTFS methodology to establish forest dynamics plots in montane wet forest and lowland dry forest on Hawai'i Island. We compared the species diversity, tree density, basal area, biomass, and size class distributions between the two forest types. We then examined these variables across tropical forests within the CTFS network. Consistent with other island forests, the Hawai'i forests were characterized by low species richness and very high relative dominance. The two Hawai'i forests were floristically distinct, yet similar in species richness (15 vs. 21 species and stem density (3078 vs. 3486/ha. While these forests were selected for their low invasive species cover relative to surrounding forests, both forests averaged 5->50% invasive species cover; ongoing removal will be necessary to reduce or prevent competitive impacts, especially from woody species. The montane wet forest had much larger trees, resulting in eightfold higher basal area and above-ground biomass. Across the CTFS network, the Hawaiian montane wet forest was similar to other tropical forests with respect to diameter distributions, density, and aboveground biomass, while the Hawai'i lowland dry forest was similar in density to tropical forests with much higher diversity. These findings suggest that forest structural variables can be similar across tropical forests independently of species richness. The inclusion of low-diversity Pacific Island forests in the CTFS network provides an ∼80-fold range in species richness (15-1182 species, six-fold variation in mean annual rainfall (835-5272 mm yr(-1 and 1.8-fold variation in mean annual temperature (16.0-28.4°C. Thus, the Hawaiian forest plots expand the global forest plot network to enable testing of ecological

Importance of Arboreal Cyanolichen Abundance to Nitrogen Cycling in Sub-Boreal Spruce and Fir Forests of Central British Columbia, Canada

Directory of Open Access Journals (Sweden)

Ania Kobylinski

2015-07-01

Full Text Available The importance of N2-fixing arboreal cyanolichens to the nitrogen (N-balance of sub-boreal interior hybrid spruce (Picea glauca × engelmannii and subalpine fir (Abies lasiocarpa forests was examined at field sites in central BC, Canada. Host trees were accessed by a single-rope climbing technique and foliage as well as arboreal macrolichen functional groups were sampled by branch height in eight random sample trees from each of two high (High Cyano and two low (Low Cyano cyanolichen abundance sites for a total of 32 sample trees. Natural abundances of stable isotopes of N (15N, 14N and carbon (13C, 12C were determined for aggregate host tree and epiphytic lichen samples, as well as representative samples of upper organic and soil horizons (Ae and Bf from beneath host trees. As expected, N2-fixing cyanolichens had 2–6-fold greater N-contents than chlorolichens and a δ15N close to atmospheric N2, while foliage and chlorolichens were more depleted in 15N. By contrast, soils at all trees and sites were 15N-enriched (positive δ15N, with declining (not significant δ15N with increased tree-level cyanolichen abundance. Lichen functional groups and tree foliage fell into three distinct groups with respect to δ13C; the tripartite cyanolichen Lobaria pulmonaria (lightest, host-tree needles (intermediate, and bipartite cyanolichens, hair (Alectoria and Bryoria spp. and chlorolichens (heaviest. Branch height of host trees was an effective predictor of needle δ13C. Our results showed a modest positive correlation between host tree foliage N and cyanolichen abundance, supporting our initial hypothesis that higher cyanolichen abundances would elevate host tree foliar N. Further study is required to determine if high cyanolichen abundance enhances host tree and/or stand-level productivity in sub-boreal forests of central BC, Canada.

Soil fauna and leaf species, but not species diversity, affect initial soil erosion in a subtropical forest plantation

Science.gov (United States)

Seitz, Steffen; Goebes, Philipp; Assmann, Thorsten; Schuldt, Andreas; Scholten, Thomas

2017-04-01

In subtropical parts of China, high rainfall intensities cause continuous soil losses and thereby provoke severe harms to ecosystems. In woodlands, it is not the tree canopy, but mostly an intact forest floor that provides protection from soil erosion. Although the protective role of leaf litter covers against soil losses is known for a long time, little research has been conducted on the processes involved. For instance, the role of different leaf species and leaf species diversity has been widely disregarded. Furthermore, the impact of soil meso- and macrofauna within the litter layer on soil losses remains unclear. To investigate how leaf litter species and diversity as well as soil meso- and macrofauna affect sediment discharge in a subtropical forest ecosystem, a field experiment was carried out in Xingangshan, Jiangxi Province, PR China (BEF China). A full-factorial random design with 96 micro-scale runoff plots and seven domestic leaf species in three diversity levels and a bare ground feature were established. Erosion was initiated with a rainfall simulator. This study confirms that leaf litter cover generally protects forest soils from water erosion (-82 % sediment discharge on leaf covered plots compared to bare plots) and this protection is gradually removed as the litter layer decomposes. Different leaf species showed variable impacts on sediment discharge and thus erosion control. This effect can be related to different leaf habitus, leaf decomposition rates and food preferences of litter decomposing meso- and macrofauna. In our experiment, runoff plots with leaf litter from Machilus thunbergii in monoculture showed the highest sediment discharge (68.0 g m-2), whereas plots with Cyclobalanopsis glauca in monoculture showed the smallest rates (7.9 g m-2). At the same time, neither leaf species diversity, nor functional diversity showed any significant influence, only a negative trend could be observed. Nevertheless, the protective effect of the leaf

Forest ownership dynamics of southern forests

Science.gov (United States)

Brett J. Butler; David N. Wear

2013-01-01

Key FindingsPrivate landowners hold 86 percent of the forest area in the South; two-thirds of this area is owned by families or individuals.Fifty-nine percent of family forest owners own between 1 and 9 acres of forest land, but 60 percent of family-owned forests are in holdings of 100 acres or more.Two-...

Plant Responses to Increased UV-B Radiation: A Research Project

Science.gov (United States)

DAntoni, H. L.; Skiles, J. W.; Armstrong, R.; Coughlan, J.; Daleo, G.; Mayoral, A.; Lawless, James G. (Technical Monitor)

1994-01-01

because there is anecdotal evidence of plant damage on the saguaros that has been linked to increased UV radiation, and (3) the forests of Nothofagus spp. and the steppe of Patagonia where the risk of plant damage at 35S is 5% and increases to as much as 15% at 55S due to increased UV-B radiation. Measurements of UV-B radiation impinging on the surface at 55S largely exceed the predicted UV-B radiation values at 50 latitude and 0% ozone depletion. Preliminary HPLC analyses of UV-B absorbing compounds in Nothofagus antartica, N. pumilio, N. betuloides and Rumex sp. in natural conditions show species-specific patterns. The spectrum of N. antartica grown at 38S differs significantly from that of N. antartica in natural conditions in Ushuaia (55S). These results suggest that the selected main area (Patagonia) is appropriate for assessing the problem and its magnitude and that Nothofagus is appropriate for our study.

Forests

International Nuclear Information System (INIS)

Melin, J.

1997-01-01

Forests have the capacity to trap and retain radionuclides for a substantial period of time. The dynamic behaviour of nutrients, pollution and radionuclides in forests is complex. The rotation period of a forest stand in the Nordic countries is about 100 years, whilst the time for decomposition of organic material in a forest environment can be several hundred years. This means that any countermeasure applied in the forest environment must have an effect for several decades, or be reapplied continuously for long periods of time. To mitigate the detrimental effect of a contaminated forest environment on man, and to minimise the economic loss in trade of contaminated forest products, it is necessary to understand the mechanisms of transfer of radionuclides through the forest environment. It must also be stressed that any countermeasure applied in the forest environment must be evaluated with respect to long, as well as short term, negative effects, before any decision about remedial action is taken. Of the radionuclides studied in forests in the past, radiocaesium has been the main contributor to dose to man. In this document, only radiocaesium will be discussed since data on the impact of other radionuclides on man are too scarce for a proper evaluation. (EG)

Forests and Forest Cover - MDC_NaturalForestCommunity

Data.gov (United States)

NSGIC Local Govt | GIS Inventory — A point feature class of NFCs - Natural Forest Communities. Natural Forest Community shall mean all stands of trees (including their associated understory) which...

LA GEOPEDOLOGIA COMO BASE PARA ZONIFICAR LA APTITUD FORESTAL EN UNA CUENCA DEL NOROESTE DE LA PATAGONIA ARGENTINA

Directory of Open Access Journals (Sweden)

Maria Cristina Frugoni

2016-12-01

Full Text Available Geopedology at a semi-detailed scale (1:50.000 was carried out in Buta Mallín catchment which includes an area of 21.065ha, in the northwest of Neuquén province, Argentine Patagonia. Geopedology provides a spatial dimension of soil-landscape relations, which are displayed in a map and its legend, showing the geoforms (contours and their soils (content, based on the premise that soil is landscape as well as profile. According to this approach three landscapes were recognized: glacial modeled mountains, plateau and valley. The relief consists mainly of steep to very steep slopes, and valley bottoms with poorly drained soils. Lithology (parent material corresponds to holocene volcanic ash in the western sector of the study area, while the eastern sector is dominated by tuff. Twenty terrain forms and their soils were identified. With this basic information, attribute tables were constructed considering landscape and soil properties. Regarding soils, physical fertility properties were considered, since these are the most correlated ones with Pinus ponderosa (pino ponderosa growth, the main species used in afforestation in Patagonia. Those tables were included and analized with a GIS (Geographic Information System to obtain a forest suitability map. The study area shows four forest suitability classes. Suitable: 37ha; moderately suitable: 4.512ha; marginally suitable: 6.072ha; not suitable: 10.444ha. The main limitations of the area are the very steep slopes, height and the areas dominated by rock outcrops and detrital covers. Nothofagus antarctica (ñire shrubs cover part of the suitable areas; because of conservation criteria of these natural communities, these lands were considered not suitable. On the other side, there are more than 4.000 ha of moderately suitable lands, which can be considered for a more detailed study. Transhumant cattle raising is the main land use system in this catchment, which is an ancient culture of the Northern Neuquian

Combating Forest Corruption: the Forest Integrity Network

NARCIS (Netherlands)

Gupta, A.; Siebert, U.

2004-01-01

This article describes the strategies and activities of the Forest Integrity Network. One of the most important underlying causes of forest degradation is corruption and related illegal logging. The Forest Integrity Network is a timely new initiative to combat forest corruption. Its approach is to

A comparison of genomic selection models across time in interior spruce (Picea engelmannii × glauca) using unordered SNP imputation methods.

Science.gov (United States)

Ratcliffe, B; El-Dien, O G; Klápště, J; Porth, I; Chen, C; Jaquish, B; El-Kassaby, Y A

2015-12-01

Genomic selection (GS) potentially offers an unparalleled advantage over traditional pedigree-based selection (TS) methods by reducing the time commitment required to carry out a single cycle of tree improvement. This quality is particularly appealing to tree breeders, where lengthy improvement cycles are the norm. We explored the prospect of implementing GS for interior spruce (Picea engelmannii × glauca) utilizing a genotyped population of 769 trees belonging to 25 open-pollinated families. A series of repeated tree height measurements through ages 3-40 years permitted the testing of GS methods temporally. The genotyping-by-sequencing (GBS) platform was used for single nucleotide polymorphism (SNP) discovery in conjunction with three unordered imputation methods applied to a data set with 60% missing information. Further, three diverse GS models were evaluated based on predictive accuracy (PA), and their marker effects. Moderate levels of PA (0.31-0.55) were observed and were of sufficient capacity to deliver improved selection response over TS. Additionally, PA varied substantially through time accordingly with spatial competition among trees. As expected, temporal PA was well correlated with age-age genetic correlation (r=0.99), and decreased substantially with increasing difference in age between the training and validation populations (0.04-0.47). Moreover, our imputation comparisons indicate that k-nearest neighbor and singular value decomposition yielded a greater number of SNPs and gave higher predictive accuracies than imputing with the mean. Furthermore, the ridge regression (rrBLUP) and BayesCπ (BCπ) models both yielded equal, and better PA than the generalized ridge regression heteroscedastic effect model for the traits evaluated.

Forest resources of the Nez Perce National Forest

Science.gov (United States)

Michele Disney

2010-01-01

As part of a National Forest System cooperative inventory, the Interior West Forest Inventory and Analysis (IWFIA) Program of the USDA Forest Service conducted a forest resource inventory on the Nez Perce National Forest using a nationally standardized mapped-plot design (for more details see the section "Inventory methods"). This report presents highlights...

Hyphomycetes isolados da água e do solo da Reserva Florestal de Dois Irmãos, Recife, PE, Brasil Hyphomycetes from water and soil at the Dois Irmãos Forest Reserve, Recife, Pernambuco State, Brazil

Directory of Open Access Journals (Sweden)

Marilene da Silva Cavalcanti

2007-12-01

Full Text Available (Hyphomycetes isolados da água e do solo, da Reserva Florestal de Dois Irmãos, Recife, PE, Brasil. Visando ampliar o conhecimento sobre a diversidade de fungos em ambientes aquáticos, coletas da água e do solo das margens dos açudes do Vale do Prata e do Meio foram efetuadas na Reserva Florestal de Dois Irmãos, Recife, Estado de Pernambuco. Dentre outras, foram isoladas cinco espécies pouco comuns de Hyphomycetes. As amostras de água foram coletadas abaixo da lâmina d'água e as de solo nas margens dos referidos açudes. As amostras de solo foram submetidas a diluições até 1:10000 e 1 mL de cada suspensão foi plaqueado no meio de Martin acrescido de cloranfenicol (50 mg/L. Alíquotas (1 mL das amostras de água foram semeadas no mesmo meio. As placas foram deixadas em temperatura ambiente (27 ºC±2, durante 3-4 dias, para o desenvolvimento de colônias e posterior isolamento dos fungos. Dentre as espécies identificadas Curvularia tuberculata Jain, Dendrosporium lobatum Plakidas & Edgerton ex Crane, Dichotomophthoropsis nymphaearum (Rand M. B. Ellis, Phaeoisaria glauca (Ellis & Everh. Hoog & Papendorf e Trichurus spiralis Hasselbring são destacadas porque haviam sido pouco referidas e não descritas anteriormente no Brasil.(Hyphomycetes from water and soil at the Dois Irmãos Forest Reserve, Recife, Pernambuco State, Brazil. To increase our knowledge regarding fungal diversity in aquatic environments, water and soil were collected at the edge of two dams (Açude do Vale do Prata and Açude do Meio at the Dois Irmãos Forest Reserve, Recife, Pernambuco state. Five uncommon species of Hyphomycetes were found, among others. Water samples were collected below the water surface and soil samples from the shores of these dams. Soil samples were diluted to 1:10000, and 1 mL of each suspension was plated in Martin's medium with 50 mg/L chloranphenicol. Water samples (1 mL were plated in the same medium. The plates were left at room

Variation in Wood Quality in White Spruce (Picea Glauca (Moench Voss. Part I. Defining the Juvenile–Mature Wood Transition Based on Tracheid Length

Directory of Open Access Journals (Sweden)

Cyriac Serge Mvolo

2015-01-01

Full Text Available Estimations of transition age (TA and juvenile wood proportion (JWP are important for wood industries due to their impact on end-product quality. However, the relationships between analytical determination of TA based on tracheid length (TL and recognized thresholds for adequate end products have not yet been established. In this study, we used three different statistical models to estimate TA in white spruce (Picea glauca (Moench Voss based on TL radial variation. We compared the results with technological maturity. A two-millimeter threshold, previously suggested for good paper tear strength, was used. Tracheid length increased from pith to bark and from breast height to upper height. Juvenile wood (JW was conical with the three models. At breast height, TA ranged from 11 to 27 years and JWP ranged from 15.3% to 47.5% across the three models. The linear mixed model produced more conservative estimates than the maximum-quadratic-linear (M_Q_L model. Both the linear mixed model and the M_Q_L model produced more conservative TA estimates than the piecewise model. TA estimates by the MIXED model, and to a lesser extent by the M_Q_L model, were equivalent to those for real mature wood, whereas TA estimates by the piecewise model were considerably lower, falling into the transition wood area.

Forest rights

DEFF Research Database (Denmark)

Balooni, Kulbhushan; Lund, Jens Friis

2014-01-01

One of the proposed strategies for implementation of reducing emissions from deforestation and forest degradation plus (REDD+) is to incentivize conservation of forests managed by communities under decentralized forest management. Yet, we argue that this is a challenging road to REDD+ because...... conservation of forests under existing decentralized management arrangements toward a push for extending the coverage of forests under decentralized management, making forest rights the hard currency of REDD+....

Forest structure in low diversity tropical forests: a study of Hawaiian wet and dry forests

Science.gov (United States)

R. Ostertag; F. Inman-Narahari; S. Cordell; C.P. Giardina; L. Sack

2014-01-01

The potential influence of diversity on ecosystem structure and function remains a topic of significant debate, especially for tropical forests where diversity can range widely. We used Center for Tropical Forest Science (CTFS) methodology to establish forest dynamics plots in montane wet forest and lowland dry forest on Hawai‘i Island. We compared the species...

Does participatory forest management promote sustainable forest utilisation in Tanzania?

DEFF Research Database (Denmark)

Treue, Thorsten; Ngaga, Y.M.; Meilby, Henrik

2014-01-01

Over the past 20 years, Participatory Forest Management (PFM) has become a dominant forest management strategy in Tanzania, covering more than 4.1 million hectares. Sustainable forest use and supply of wood products to local people are major aims of PFM. This paper assesses the sustainability...... of forest utilisation under PFM, using estimates of forest condition and extraction rates based on forest inventories and 480 household surveys from 12 forests; seven under Community Based Forest Management (CBFM), three under Joint Forest Management (JFM) and two under government management (non......-PFM). Extraction of products is intense in forests close to Dar es Salaam, regardless of management regime. Further from Dar es Salaam, harvesting levels in forests under PFM are, with one prominent exception, broadly sustainable. Using GIS data from 116 wards, it is shown that half of the PFM forests in Tanzania...

Urban Forests

Science.gov (United States)

David Nowak

2016-01-01

Urban forests (and trees) constitute the second forest resource considered in this report. We specifically emphasize the fact that agricultural and urban forests exist on a continuum defined by their relationship (and interrelationship) with a given landscape. These two forest types generally serve different purposes, however. Whereas agricultural forests are...

Phylobetadiversity among forest types in the Brazilian Atlantic Forest complex.

Science.gov (United States)

Duarte, Leandro Da Silva; Bergamin, Rodrigo Scarton; Marcilio-Silva, Vinícius; Seger, Guilherme Dubal Dos Santos; Marques, Márcia Cristina Mendes

2014-01-01

Phylobetadiversity is defined as the phylogenetic resemblance between communities or biomes. Analyzing phylobetadiversity patterns among different vegetation physiognomies within a single biome is crucial to understand the historical affinities between them. Based on the widely accepted idea that different forest physiognomies within the Southern Brazilian Atlantic Forest constitute different facies of a single biome, we hypothesize that more recent phylogenetic nodes should drive phylobetadiversity gradients between the different forest types within the Atlantic Forest, as the phylogenetic divergence among those forest types is biogeographically recent. We compiled information from 206 checklists describing the occurrence of shrub/tree species across three different forest physiognomies within the Southern Brazilian Atlantic Forest (Dense, Mixed and Seasonal forests). We analyzed intra-site phylogenetic structure (phylogenetic diversity, net relatedness index and nearest taxon index) and phylobetadiversity between plots located at different forest types, using five different methods differing in sensitivity to either basal or terminal nodes (phylogenetic fuzzy weighting, COMDIST, COMDISTNT, UniFrac and Rao's H). Mixed forests showed higher phylogenetic diversity and overdispersion than the other forest types. Furthermore, all forest types differed from each other in relation phylobetadiversity patterns, particularly when phylobetadiversity methods more sensitive to terminal nodes were employed. Mixed forests tended to show higher phylogenetic differentiation to Dense and Seasonal forests than these latter from each other. The higher phylogenetic diversity and phylobetadiversity levels found in Mixed forests when compared to the others likely result from the biogeographical origin of several taxa occurring in these forests. On one hand, Mixed forests shelter several temperate taxa, like the conifers Araucaria and Podocarpus. On the other hand, tropical groups, like

First quantification of subtidal community structure at Tristan da Cunha Islands in the remote South Atlantic: from kelp forests to the deep sea.

Science.gov (United States)

Caselle, Jennifer E; Hamilton, Scott L; Davis, Kathryn; Thompson, Christopher D H; Turchik, Alan; Jenkinson, Ryan; Simpson, Doug; Sala, Enric

2018-01-01

Tristan da Cunha Islands, an archipelago of four rocky volcanic islands situated in the South Atlantic Ocean and part of the United Kingdom Overseas Territories (UKOTs), present a rare example of a relatively unimpacted temperate marine ecosystem. We conducted the first quantitative surveys of nearshore kelp forests, offshore pelagic waters and deep sea habitats. Kelp forests had very low biodiversity and species richness, but high biomass and abundance of those species present. Spatial variation in assemblage structure for both nearshore fish and invertebrates/algae was greatest between the three northern islands and the southern island of Gough, where sea temperatures were on average 3-4o colder. Despite a lobster fishery that provides the bulk of the income to the Tristan islands, lobster abundance and biomass are comparable to or greater than many Marine Protected Areas in other parts of the world. Pelagic camera surveys documented a rich biodiversity offshore, including large numbers of juvenile blue sharks, Prionace glauca. Species richness and abundance in the deep sea is positively related to hard rocky substrate and biogenic habitats such as sea pens, crinoids, whip corals, and gorgonians were present at 40% of the deep camera deployments. We observed distinct differences in the deep fish community above and below ~750 m depth. Concurrent oceanographic sampling showed a discontinuity in temperature and salinity at this depth. While currently healthy, Tristan's marine ecosystem is not without potential threats: shipping traffic leading to wrecks and species introductions, pressure to increase fishing effort beyond sustainable levels and the impacts of climate change all could potentially increase in the coming years. The United Kingdom has committed to protection of marine environments across the UKOTs, including Tristan da Cunha and these results can be used to inform future management decisions as well as provide a baseline against which future monitoring

A degradation debt? Large-scale shifts in community composition and loss of biomass in a tropical forest fragment after 40 years of isolation.

Science.gov (United States)

Zahawi, Rakan A; Oviedo-Brenes, Federico; Peterson, Chris J

2017-01-01

Habitat loss and fragmentation are among the biggest threats to tropical biodiversity and associated ecosystem services. We examined forest dynamics in a mid-elevation 365-ha fragment in southern Costa Rica. The fragment was isolated in the mid-1970s and belongs to the Las Cruces Biological Station. A 2.25-ha permanent plot was established in the center of the old-growth forest (>400 m to nearest edge boundary) and all plants >5 cm DBH were censused, mapped, and identified to species in two surveys taken ~5-6 years apart (>3,000 stems/survey). Although the reserve maintains high species richness (>200 spp.), with many rare species represented by only one individual, we document a strong shift in composition with a two-fold increase in the number of soft-wooded pioneer individuals. The dominant late-successional understory tree species, Chrysochlamys glauca (Clusiaceae), and most species in the Lauraceae, declined dramatically. Turnover was high: 22.9% of stems in the first survey were lost, and 27.8% of stems in the second survey represented new recruits. Mean tree diameter decreased significantly and there was a 10% decrease in overall biomass. Such alteration has been documented previously but only in smaller fragments or within ~100 m of an edge boundary. Further penetration into this fragment was perhaps driven by a progressive invasion of disturbance-adapted species into the fragment's core over time; the loss of once-dominant late successional species could be a contributing factor. The pattern found is of particular concern given that such fragments represent a substantial portion of today's remaining tropical habitat; further studies in similar-sized fragments that have been isolated for similar prolonged periods are called for.

A degradation debt? Large-scale shifts in community composition and loss of biomass in a tropical forest fragment after 40 years of isolation.

Directory of Open Access Journals (Sweden)

Rakan A Zahawi

Full Text Available Habitat loss and fragmentation are among the biggest threats to tropical biodiversity and associated ecosystem services. We examined forest dynamics in a mid-elevation 365-ha fragment in southern Costa Rica. The fragment was isolated in the mid-1970s and belongs to the Las Cruces Biological Station. A 2.25-ha permanent plot was established in the center of the old-growth forest (>400 m to nearest edge boundary and all plants >5 cm DBH were censused, mapped, and identified to species in two surveys taken ~5-6 years apart (>3,000 stems/survey. Although the reserve maintains high species richness (>200 spp., with many rare species represented by only one individual, we document a strong shift in composition with a two-fold increase in the number of soft-wooded pioneer individuals. The dominant late-successional understory tree species, Chrysochlamys glauca (Clusiaceae, and most species in the Lauraceae, declined dramatically. Turnover was high: 22.9% of stems in the first survey were lost, and 27.8% of stems in the second survey represented new recruits. Mean tree diameter decreased significantly and there was a 10% decrease in overall biomass. Such alteration has been documented previously but only in smaller fragments or within ~100 m of an edge boundary. Further penetration into this fragment was perhaps driven by a progressive invasion of disturbance-adapted species into the fragment's core over time; the loss of once-dominant late successional species could be a contributing factor. The pattern found is of particular concern given that such fragments represent a substantial portion of today's remaining tropical habitat; further studies in similar-sized fragments that have been isolated for similar prolonged periods are called for.

First quantification of subtidal community structure at Tristan da Cunha Islands in the remote South Atlantic: from kelp forests to the deep sea

Science.gov (United States)

Hamilton, Scott L.; Davis, Kathryn; Thompson, Christopher D. H.; Turchik, Alan; Jenkinson, Ryan; Simpson, Doug; Sala, Enric

2018-01-01

Tristan da Cunha Islands, an archipelago of four rocky volcanic islands situated in the South Atlantic Ocean and part of the United Kingdom Overseas Territories (UKOTs), present a rare example of a relatively unimpacted temperate marine ecosystem. We conducted the first quantitative surveys of nearshore kelp forests, offshore pelagic waters and deep sea habitats. Kelp forests had very low biodiversity and species richness, but high biomass and abundance of those species present. Spatial variation in assemblage structure for both nearshore fish and invertebrates/algae was greatest between the three northern islands and the southern island of Gough, where sea temperatures were on average 3-4o colder. Despite a lobster fishery that provides the bulk of the income to the Tristan islands, lobster abundance and biomass are comparable to or greater than many Marine Protected Areas in other parts of the world. Pelagic camera surveys documented a rich biodiversity offshore, including large numbers of juvenile blue sharks, Prionace glauca. Species richness and abundance in the deep sea is positively related to hard rocky substrate and biogenic habitats such as sea pens, crinoids, whip corals, and gorgonians were present at 40% of the deep camera deployments. We observed distinct differences in the deep fish community above and below ~750 m depth. Concurrent oceanographic sampling showed a discontinuity in temperature and salinity at this depth. While currently healthy, Tristan’s marine ecosystem is not without potential threats: shipping traffic leading to wrecks and species introductions, pressure to increase fishing effort beyond sustainable levels and the impacts of climate change all could potentially increase in the coming years. The United Kingdom has committed to protection of marine environments across the UKOTs, including Tristan da Cunha and these results can be used to inform future management decisions as well as provide a baseline against which future

Forest tenure and sustainable forest management

Science.gov (United States)

J.P. Siry; K. McGinley; F.W. Cubbage; P. Bettinger

2015-01-01

We reviewed the principles and key literature related to forest tenure and sustainable forest management, and then examined the status of sustainable forestry and land ownership at the aggregate national level for major forested countries. The institutional design principles suggested by Ostrom are well accepted for applications to public, communal, and private lands....

Estimating forest conversion rates with annual forest inventory data

Science.gov (United States)

Paul C. Van Deusen; Francis A. Roesch

2009-01-01

The rate of land-use conversion from forest to nonforest or natural forest to forest plantation is of interest for forest certification purposes and also as part of the process of assessing forest sustainability. Conversion rates can be estimated from remeasured inventory plots in general, but the emphasis here is on annual inventory data. A new estimator is proposed...

Polyphenolic enriched extract of Cassia glauca Lamk, improves streptozotocin-induced type-1 diabetes linked with partial insulin resistance in rats.

Science.gov (United States)

Veerapur, V P; Pratap, V; Thippeswamy, B S; Marietta, P; Bansal, Punit; Kulkarni, P V; Kulkarni, V H

2017-02-23

Traditionally Cassia glauca (CG) has been used to treat diabetes. The study was undertaken to evaluate anti-diabetic and antioxidant activity of polyphenolic enriched extract of CG in standardized streptozotocin (STZ)-induced diabetic rats. The effect of ethanol (CGE) and water (CGW) extracts of CG (200 and 400mg/kg) treatment were evaluated in STZ (50mg/kg, iv) induced diabetic rats. On 10 th day, oral glucose tolerance test and degree of insulin resistance was calculated. On 13 th day, insulin tolerance test was performed to know the peripheral utilization of glucose. On 15 th day, blood glucose, lipid profiles and endogenous antioxidant levels were estimated. In addition, the effects on oral glucose/sucrose tolerance test in normal rats. Further, HPLC fingerprinting profile of CGE and simultaneous quantification of biomarkers were carried out. Supplementation with CGE and CGW significantly reduced STZ-induced deleterious effects and improved glucose tolerance, and insulin tolerance. In addition, supplementation also decreased oxidative stress by improving endogenous antioxidant levels. Furthermore, administration significantly improves sucrose tolerance suggesting that extract possess inhibition of α-glucosidase enzyme. Further, HPLC studies revealed that CGE contains three bioactive polyphenolic compounds viz., rutin (0.10±0.01mg/g), luteolin-7-glucoside (0.06±0.01mg/g) and isorhoifolin (0.7±0.05mg/g). Observed beneficial outcome of CG might be attributed to the presence of polyphenolic compounds and mediated by interacting with multiple targets of diabetes and oxidative stress. Taken together, this study provided the scientific evidence for the traditional use of CG. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Forest Classification Based on Forest texture in Northwest Yunnan Province

Science.gov (United States)

Wang, Jinliang; Gao, Yan; Wang, Xiaohua; Fu, Lei

2014-03-01

Forest texture is an intrinsic characteristic and an important visual feature of a forest ecological system. Full utilization of forest texture will be a great help in increasing the accuracy of forest classification based on remote sensed data. Taking Shangri-La as a study area, forest classification has been based on the texture. The results show that: (1) From the texture abundance, texture boundary, entropy as well as visual interpretation, the combination of Grayscale-gradient co-occurrence matrix and wavelet transformation is much better than either one of both ways of forest texture information extraction; (2) During the forest texture information extraction, the size of the texture-suitable window determined by the semi-variogram method depends on the forest type (evergreen broadleaf forest is 3×3, deciduous broadleaf forest is 5×5, etc.). (3)While classifying forest based on forest texture information, the texture factor assembly differs among forests: Variance Heterogeneity and Correlation should be selected when the window is between 3×3 and 5×5 Mean, Correlation, and Entropy should be used when the window in the range of 7×7 to 19×19 and Correlation, Second Moment, and Variance should be used when the range is larger than 21×21.

Forest Classification Based on Forest texture in Northwest Yunnan Province

International Nuclear Information System (INIS)

Wang, Jinliang; Gao, Yan; Fu, Lei; Wang, Xiaohua

2014-01-01

Forest texture is an intrinsic characteristic and an important visual feature of a forest ecological system. Full utilization of forest texture will be a great help in increasing the accuracy of forest classification based on remote sensed data. Taking Shangri-La as a study area, forest classification has been based on the texture. The results show that: (1) From the texture abundance, texture boundary, entropy as well as visual interpretation, the combination of Grayscale-gradient co-occurrence matrix and wavelet transformation is much better than either one of both ways of forest texture information extraction; (2) During the forest texture information extraction, the size of the texture-suitable window determined by the semi-variogram method depends on the forest type (evergreen broadleaf forest is 3×3, deciduous broadleaf forest is 5×5, etc.). (3)While classifying forest based on forest texture information, the texture factor assembly differs among forests: Variance Heterogeneity and Correlation should be selected when the window is between 3×3 and 5×5; Mean, Correlation, and Entropy should be used when the window in the range of 7×7 to 19×19; and Correlation, Second Moment, and Variance should be used when the range is larger than 21×21

Simulation of Forest Cover Dynamics for Eastern Eurasian Boreal Forests

Science.gov (United States)

Shugart, H. H.; Yan, X.; Zhang, N.; Isaev, A. S.; Shuman, J. K.

2006-12-01

We are developing and testing a boreal zone forest dynamics model capable of simulating the forest cover dynamics of the Eurasian boreal forest, a major biospheric ecosystem with potentially large roles in the planetary carbon cycle and in the feedback between terrestrial surface and the atmosphere. In appreciating the role of this region in the coupling between atmosphere and terrestrial surface, on must understand the interactions between CO2 source/sink relationships (associated with growing or clearing forests) and the albedo effects (from changes in terrestrial surface cover). There is some evidence that in the Eurasian Boreal zone, the Carbon budget effects from forest change may oppose the albedo changes. This creates complex feedbacks between surface and atmosphere and motivates the need for a forest dynamics model that simultaneous represents forest vegetation and carbon storage and release. A forest dynamics model applied to Eastern Eurasia, FAREAST, has been tested using three types of information: 1. Direct species composition comparisons between simulated and observed mature forests at the same locations; 2. Forest type comparisons between simulated and observed forests along altitudinal gradients of several different mountains; 3. Comparison with forest stands in different succession stages of simulated forests. Model comparisons with independent data indicate the FAREAST model is capable of representing many of the broad features of the forests of Northeastern China. After model validation in the Northeast China region, model applications were developed for the forests of the Russian Far East. Continental-scale forest cover can be simulated to a relatively realistic degree using a forest gap model with standard representations of individual-plant processes. It appears that such a model, validated relatively locally in this case, in Northeastern China, can then be applied over a much larger region and under conditions of climatic change.

European mixed forests

DEFF Research Database (Denmark)

Bravo-Oviedo, Andres; Pretzsch, Hans; Ammer, Christian

2014-01-01

Aim of study: We aim at (i) developing a reference definition of mixed forests in order to harmonize comparative research in mixed forests and (ii) review the research perspectives in mixed forests. Area of study: The definition is developed in Europe but can be tested worldwide. Material...... and Methods: Review of existent definitions of mixed forests based and literature review encompassing dynamics, management and economic valuation of mixed forests. Main results: A mixed forest is defined as a forest unit, excluding linear formations, where at least two tree species coexist at any...... density in mixed forests, (iii) conversion of monocultures to mixed-species forest and (iv) economic valuation of ecosystem services provided by mixed forests. Research highlights: The definition is considered a high-level one which encompasses previous attempts to define mixed forests. Current fields...

Forest crimes as a threat to sustainable forest management

Directory of Open Access Journals (Sweden)

S. Özden

2016-08-01

Full Text Available From ancient times to the present day, forest public relations has been an issue on the agenda. This relationship’s purpose was initially needed for shelter and nutrition; however today this process has changed with urbanization, overpopulation and understanding the new functions of forests. When land ownership became a tool of production, offenses occurred in order to convert forestlands to agricultural lands. So the vast majority of the world’s forests have been lost for this reason. Today, deforestation is occurring in tropical countries that are expecting to gain agricultural area. The purpose of this study is to investigate the relationship between urbanization and the qualitative and quantitative characteristics of forest crimes, which are a major obstacle for sustainable forestry. Although forests cover about 27 % of Turkey’s territory, the forests are losing viability; the status of wood raw material per unit area and the total area of the country in the ratio of productive forests are becoming critical in Turkey. Turkey’s rugged terrain and factors such as human interventions, fires, deforestation for agriculture, illegal cuttings, or improper grazing reduce existing forests or cause deterioration of their structure. In the past, deforestation, as a result of human interventions in Turkey, was done by forest villagers who live in rural areas. The forest crimes depend on various socio-economic reasons and have many adverse effects on the sustainability of forest and forest existence. In developed countries, illegal interventions such as opening, grazing, cutting, occupation, use, settlement, or hunting crimes have been largely eliminated because of the absence of cadastral problems, the existence of more responsive people to protect the environment and forests and a rural population, which has a higher standard of living. In the last 20 years, there has been both a dramatic decrease in the population living in rural areas and a

Magellanic Woodpeckers in three national parks of central-southern Chile: habitat effects and population variation over the last two decades

Directory of Open Access Journals (Sweden)

Pablo M. Vergara

2017-12-01

Full Text Available A major challenge for protected areas is providing wildlife with enough suitable habitat to cope with stochastic environment and increased pressure from the surrounding landscapes. In this study, we addressed changes in local populations of Magellanic Woodpeckers (Campephilus magellanicus occupying three national parks of central-southern Chile. We compared the breeding and postbreeding abundance of woodpeckers during the 1990s with the present (2016 abundance (n = 4 years, and assessed the extent to which abundance was explained by forest type and quality of foraging habitat (as quantified through the plant senescence reflectance index; PSRI. Results show a distinctive temporal variation in woodpecker abundance at each park, with local populations of Magellanic Woodpeckers declining by 42.2% in Conguillío National Park, but increasing by 34.3% in Nahuelbuta National Park. Woodpeckers responded to forest conditions within each park such that their abundance increased with high quality of foraging habitat, i.e., large PSRI values, and the presence of old-growth Monkey puzzle (Araucaria araucana - Nothofagus pumilio mixed forest. Anecdotal evidence suggests that populations of woodpeckers in Conguillío National Park might have responded negatively to large-scale disturbances from recent forest fires affecting part of the forest area within park. Because stochastic events seemed to strongly mediate population changes, our findings suggest that regional conservation of Magellanic Woodpeckers requires expanding the current conservation area network in central-southern Chile.

Modelling mixed forest growth : a review of models for forest management

NARCIS (Netherlands)

Porte, A.; Bartelink, H.H.

2002-01-01

Most forests today are multi-specific and heterogeneous forests (`mixed forests'). However, forest modelling has been focusing on mono-specific stands for a long time, only recently have models been developed for mixed forests. Previous reviews of mixed forest modelling were restricted to certain

Forest Stakeholder Participation in Improving Game Habitat in Swedish Forests

Directory of Open Access Journals (Sweden)

Eugene E. Ezebilo

2012-07-01

Full Text Available Although in Sweden the simultaneous use of forests for timber production and game hunting are both of socioeconomic importance it often leads to conflicting interests. This study examines forest stakeholder participation in improving game habitat to increase hunting opportunities as well as redistribute game activities in forests to help reduce browsing damage in valuable forest stands. The data for the study were collected from a nationwide survey that involved randomly selected hunters and forest owners in Sweden. An ordered logit model was used to account for possible factors influencing the respondents’ participation in improving game habitat. The results showed that on average, forest owning hunters were more involved in improving game habitat than non-hunting forest owners. The involvement of non-forest owning hunters was intermediate between the former two groups. The respondents’ participation in improving game habitat were mainly influenced by factors such as the quantity of game meat obtained, stakeholder group, forests on hunting grounds, the extent of risk posed by game browsing damage to the economy of forest owners, importance of bagging game during hunting, and number of hunting days. The findings will help in designing a more sustainable forest management strategy that integrates timber production and game hunting in forests.

Effects of Deforestation and Forest Degradation on Forest Carbon Stocks in Collaborative Forests, Nepal

Directory of Open Access Journals (Sweden)

Ram Asheshwar MANDAL

2012-12-01

Full Text Available There are some key drivers that favor deforestation and forest degradation. Consequently, levels of carbon stock are affected in different parts of same forest types. But the problem lies in exploring the extent of the effects on level of carbon stocking. This paper highlights the variations in levels of carbon stocks in three different collaborative forests of same forest type i.e. tropical sal (Shorea robusta forest in Mahottari district of the central Terai in Nepal. Three collaborative forests namely Gadhanta-Bardibas Collaborative Forest (CFM, Tuteshwarnath CFM and Banke- Maraha CFM were selected for research site. Interview and workshops were organized with the key informants that include staffs, members and representatives of CFMs to collect the socio-economic data and stratified random sampling was applied to collect the bio-physical data to calculate the carbon stocks. Analysis was carried out using statistical tools. It was found five major drivers namely grazing, fire, logging, growth of invasive species and encroachment. It was found highest carbon 269.36 ton per ha in Gadhanta- Bardibash CFM. The findings showed that the levels of carbon stocks in the three studied CFMs are different depending on how the drivers of deforestation and forest degradation influence over them.

Forest soils

Science.gov (United States)

Charles H. (Hobie) Perry; Michael C. Amacher

2009-01-01

Productive soils are the foundation of sustainable forests throughout the United States. Forest soils are generally subjected to fewer disturbances than agricultural soils, particularly those that are tilled, so forest soils tend to have better preserved A-horizons than agricultural soils. Another major contrast between forest and agricultural soils is the addition of...

Forest Management

Science.gov (United States)

S. Hummel; K. L. O' Hara

2008-01-01

Global variation in forests and in human cultures means that a single method for managing forests is not possible. However, forest management everywhere shares some common principles because it is rooted in physical and biological sciences like chemistry and genetics. Ecological forest management is an approach that combines an understanding of universal processes with...

Forest hydrology

Science.gov (United States)

Ge Sun; Devendra Amatya; Steve McNulty

2016-01-01

Forest hydrology studies the distribution, storage, movement, and quality of water and the hydrological processes in forest-dominated ecosystems. Forest hydrological science is regarded as the foundation of modern integrated water¬shed management. This chapter provides an overview of the history of forest hydrology and basic principles of this unique branch of...

Texas' forests, 2008

Science.gov (United States)

James W. Bentley; Consuelo Brandeis; Jason A. Cooper; Christopher M. Oswalt; Sonja N. Oswalt; KaDonna Randolph

2014-01-01

This bulletin describes forest resources of the State of Texas at the time of the 2008 forest inventory. This bulletin addresses forest area, volume, growth, removals, mortality, forest health, timber product output, and the economy of the forest sector.

Illinois' Forests 2005

Science.gov (United States)

Susan J. Crocker; Gary J. Brand; Brett J. Butler; David E. Haugen; Dick C. Little; Dacia M. Meneguzzo; Charles H. Perry; Ronald J. Piva; Barry T. Wilson; Christopher W. Woodall

2009-01-01

The first full, annualized inventory of Illinois' forests reports more than 4.5 million acres of forest land with an average of 459 trees per acre. Forest land is dominated by oak/hickory forest types, which occupy 65 percent of total forest land area. Seventy-two percent of forest land consists of sawtimber, 20 percent contains poletimber, and 8 percent contains...

Minnesota's Forests 2008

Science.gov (United States)

Patrick D. Miles; David Heinzen; Manfred E. Mielke; Christopher W. Woodall; Brett J. Butler; Ron J. Piva; Dacia M. Meneguzzo; Charles H. Perry; Dale D. Gormanson; Charles J. Barnett

2011-01-01

The second full annual inventory of Minnesota's forests reports 17 million acres of forest land with an average volume of more than 1,000 cubic feet per acre. Forest land is dominated by the aspen forest type, which occupies nearly 30 percent of the total forest land area. Twenty-eight percent of forest land consists of sawtimber, 35 percent poletimber, 35 percent...

A tale of two "forests": random forest machine learning AIDS tropical forest carbon mapping.

Science.gov (United States)

Mascaro, Joseph; Asner, Gregory P; Knapp, David E; Kennedy-Bowdoin, Ty; Martin, Roberta E; Anderson, Christopher; Higgins, Mark; Chadwick, K Dana

2014-01-01

Accurate and spatially-explicit maps of tropical forest carbon stocks are needed to implement carbon offset mechanisms such as REDD+ (Reduced Deforestation and Degradation Plus). The Random Forest machine learning algorithm may aid carbon mapping applications using remotely-sensed data. However, Random Forest has never been compared to traditional and potentially more reliable techniques such as regionally stratified sampling and upscaling, and it has rarely been employed with spatial data. Here, we evaluated the performance of Random Forest in upscaling airborne LiDAR (Light Detection and Ranging)-based carbon estimates compared to the stratification approach over a 16-million hectare focal area of the Western Amazon. We considered two runs of Random Forest, both with and without spatial contextual modeling by including--in the latter case--x, and y position directly in the model. In each case, we set aside 8 million hectares (i.e., half of the focal area) for validation; this rigorous test of Random Forest went above and beyond the internal validation normally compiled by the algorithm (i.e., called "out-of-bag"), which proved insufficient for this spatial application. In this heterogeneous region of Northern Peru, the model with spatial context was the best preforming run of Random Forest, and explained 59% of LiDAR-based carbon estimates within the validation area, compared to 37% for stratification or 43% by Random Forest without spatial context. With the 60% improvement in explained variation, RMSE against validation LiDAR samples improved from 33 to 26 Mg C ha(-1) when using Random Forest with spatial context. Our results suggest that spatial context should be considered when using Random Forest, and that doing so may result in substantially improved carbon stock modeling for purposes of climate change mitigation.

A tale of two "forests": random forest machine learning AIDS tropical forest carbon mapping.

Directory of Open Access Journals (Sweden)

Joseph Mascaro

Full Text Available Accurate and spatially-explicit maps of tropical forest carbon stocks are needed to implement carbon offset mechanisms such as REDD+ (Reduced Deforestation and Degradation Plus. The Random Forest machine learning algorithm may aid carbon mapping applications using remotely-sensed data. However, Random Forest has never been compared to traditional and potentially more reliable techniques such as regionally stratified sampling and upscaling, and it has rarely been employed with spatial data. Here, we evaluated the performance of Random Forest in upscaling airborne LiDAR (Light Detection and Ranging-based carbon estimates compared to the stratification approach over a 16-million hectare focal area of the Western Amazon. We considered two runs of Random Forest, both with and without spatial contextual modeling by including--in the latter case--x, and y position directly in the model. In each case, we set aside 8 million hectares (i.e., half of the focal area for validation; this rigorous test of Random Forest went above and beyond the internal validation normally compiled by the algorithm (i.e., called "out-of-bag", which proved insufficient for this spatial application. In this heterogeneous region of Northern Peru, the model with spatial context was the best preforming run of Random Forest, and explained 59% of LiDAR-based carbon estimates within the validation area, compared to 37% for stratification or 43% by Random Forest without spatial context. With the 60% improvement in explained variation, RMSE against validation LiDAR samples improved from 33 to 26 Mg C ha(-1 when using Random Forest with spatial context. Our results suggest that spatial context should be considered when using Random Forest, and that doing so may result in substantially improved carbon stock modeling for purposes of climate change mitigation.

Forest and water relationships: hydrologic implications of forestation campaigns in China

Science.gov (United States)

Ge Sun; Guoyi Zhou; Zhiqiang Zhang; Xiaohua Wei; Steven G. McNulty; James Vose

2005-01-01

Reforestation and afforestation (referred to forestation thereafter) campaigns in the past two decades have resulted in great increases in both forest land area and forest ecosystem productivity in China. Although the ecological benefits of forests are well accepted, the hydrologic consequences of man-made forests by forestation are unclear. Debate and confusion on the...

Potential of the Russian forests and forest industries

Energy Technology Data Exchange (ETDEWEB)

Anttonen, T.; Petrov, A.P. [eds.

1997-12-31

The publication contains the proceedings of the seminar `Potential of the Russian Forests and Forest Industries` held in Moscow, May 14-16, 1997. The seminar was one step along the road to spread knowledge and become acquainted with forestry and forest industries in northern Europe and Russia. The seminar proceedings contain a lot of fresh information concerning forestry and forest industries in Russia. Both have undergone many changes and reforms during the last few years

Ecological consequences of forest elephant declines for Afrotropical forests.

Science.gov (United States)

Poulsen, John R; Rosin, Cooper; Meier, Amelia; Mills, Emily; Nuñez, Chase L; Koerner, Sally E; Blanchard, Emily; Callejas, Jennifer; Moore, Sarah; Sowers, Mark

2017-10-27

Poaching is rapidly extirpating African forest elephants (Loxodonta cyclotis) from most of their historical range, leaving vast areas of elephant-free tropical forest. Elephants are ecological engineers that create and maintain forest habitat; thus, their loss will have large consequences for the composition and structure of Afrotropical forests. Through a comprehensive literature review, we evaluated the roles of forest elephants in seed dispersal, nutrient recycling, and herbivory and physical damage to predict the cascading ecological effects of their population declines. Loss of seed dispersal by elephants will favor tree species dispersed abiotically and by smaller dispersal agents, and tree species composition will depend on the downstream effects of changes in elephant nutrient cycling and browsing. Loss of trampling and herbivory of seedlings and saplings will result in high tree density with release from browsing pressures. Diminished seed dispersal by elephants and high stem density are likely to reduce the recruitment of large trees and thus increase homogeneity of forest structure and decrease carbon stocks. The loss of ecological services by forest elephants likely means Central African forests will be more like Neotropical forests, from which megafauna were extirpated thousands of years ago. Without intervention, as much as 96% of Central African forests will have modified species composition and structure as elephants are compressed into remaining protected areas. Stopping elephant poaching is an urgent first step to mitigating these effects, but long-term conservation will require land-use planning that incorporates elephant habitat into forested landscapes that are being rapidly transformed by industrial agriculture and logging. © 2017 Society for Conservation Biology.

Indiana's Forests 2008

Science.gov (United States)

Christopher W. Woodall; Mark N. Webb; Barry T. Wilson; Jeff Settle; Ron J. Piva; Charles H. Perry; Dacia M. Meneguzzo; Susan J. Crocker; Brett J. Butler; Mark Hansen; Mark Hatfield; Gary Brand; Charles. Barnett

2011-01-01

The second full annual inventory of Indiana's forests reports more than 4.75 million acres of forest land with an average volume of more than 2,000 cubic feet per acre. Forest land is dominated by the white oak/red oak/hickory forest type, which occupies nearly a third of the total forest land area. Seventy-six percent of forest land consists of sawtimber, 16...

Mixed-Forest Species Establishment in a Monodominant Forest in Central Africa: Implications for Tropical Forest Invasibility

Science.gov (United States)

Peh, Kelvin S.-H.; Sonké, Bonaventure; Séné, Olivier; Djuikouo, Marie-Noël K.; Nguembou, Charlemagne K.; Taedoumg, Hermann; Begne, Serge K.; Lewis, Simon L.

2014-01-01

Background Traits of non-dominant mixed-forest tree species and their synergies for successful co-occurrence in monodominant Gilbertiodendron dewevrei forest have not yet been investigated. Here we compared the tree species diversity of the monodominant forest with its adjacent mixed forest and then determined which fitness proxies and life history traits of the mixed-forest tree species were most associated with successful co-existence in the monodominant forest. Methodology/Principal Findings We sampled all trees (diameter in breast height [dbh]≥10 cm) within 6×1 ha topographically homogenous areas of intact central African forest in SE Cameroon, three independent patches of G. dewevrei-dominated forest and three adjacent areas (450–800 m apart). Monodominant G. dewevrei forest had lower sample-controlled species richness, species density and population density than its adjacent mixed forest in terms of stems with dbh≥10 cm. Analysis of a suite of population-level characteristics, such as relative abundance and geographical distribution, and traits such as wood density, height, diameter at breast height, fruit/seed dispersal mechanism and light requirement–revealed after controlling for phylogeny, species that co-occur with G. dewevrei tend to have higher abundance in adjacent mixed forest, higher wood density and a lower light requirement. Conclusions/Significance Our results suggest that certain traits (wood density and light requirement) and population-level characteristics (relative abundance) may increase the invasibility of a tree species into a tropical closed-canopy system. Such knowledge may assist in the pre-emptive identification of invasive tree species. PMID:24844914

Mixed-forest species establishment in a monodominant forest in central Africa: implications for tropical forest invasibility.

Directory of Open Access Journals (Sweden)

Kelvin S-H Peh

Full Text Available BACKGROUND: Traits of non-dominant mixed-forest tree species and their synergies for successful co-occurrence in monodominant Gilbertiodendron dewevrei forest have not yet been investigated. Here we compared the tree species diversity of the monodominant forest with its adjacent mixed forest and then determined which fitness proxies and life history traits of the mixed-forest tree species were most associated with successful co-existence in the monodominant forest. METHODOLOGY/PRINCIPAL FINDINGS: We sampled all trees (diameter in breast height [dbh]≥10 cm within 6×1 ha topographically homogenous areas of intact central African forest in SE Cameroon, three independent patches of G. dewevrei-dominated forest and three adjacent areas (450-800 m apart. Monodominant G. dewevrei forest had lower sample-controlled species richness, species density and population density than its adjacent mixed forest in terms of stems with dbh≥10 cm. Analysis of a suite of population-level characteristics, such as relative abundance and geographical distribution, and traits such as wood density, height, diameter at breast height, fruit/seed dispersal mechanism and light requirement-revealed after controlling for phylogeny, species that co-occur with G. dewevrei tend to have higher abundance in adjacent mixed forest, higher wood density and a lower light requirement. CONCLUSIONS/SIGNIFICANCE: Our results suggest that certain traits (wood density and light requirement and population-level characteristics (relative abundance may increase the invasibility of a tree species into a tropical closed-canopy system. Such knowledge may assist in the pre-emptive identification of invasive tree species.

Forest owners' perceptions of ecotourism: Integrating community values and forest conservation.

Science.gov (United States)

Rodríguez-Piñeros, Sandra; Mayett-Moreno, Yesica

2015-03-01

The use of forest land for ecotourism has been well accepted due to its ability to provide income to local people and to conserve the forest. Preparing the forest with infrastructure to attract and educate visitors has been reported of importance. This study applied Q methodology in a small rural community of the State of Puebla, Mexico, to reveal forest owners' perceptions to build infrastructure in their forest as part of their ecotourism project. It also discloses forest owners' underlying motives to use their forest for ecotourism. Ecotourism is perceived as a complementary activity to farming that would allow women to be involved in community development. Low impact infrastructure is desired due to forest owners' perception to preserve the forest for the overall community well-being.

Forest inventory: role in accountability for sustainable forest management

Science.gov (United States)

Lloyd C. Irland

2007-01-01

Forest inventory can play several roles in accountability for sustainable forest management. A first dimension is accountability for national performance. The new field of Criteria and Indicators is an expression of this need. A more familiar role for the U.S. Department of Agriculture Forest Service Forest Inventory and Analysis (FIA) program is for assessment and...

Tropical Forest Gain and Interactions amongst Agents of Forest Change

Directory of Open Access Journals (Sweden)

Sean Sloan

2016-02-01

Full Text Available The tropical deforestation literature advocates multi-agent enquiry in recognition that key dynamics arise from inter-agent interactions. Studies of tropical forest-cover gain have lagged in this respect. This article explores the roles and key aspects of interactions shaping natural forest regeneration and active reforestation in Eastern Panama since 1990. It employs household surveys of agricultural landholders, interviews with community forest-restoration organisations, archival analysis of plantation reforestation interests, satellite image analysis of forest-cover change, and the consideration of State reforestation policies. Forest-cover gain reflected a convergence of interests and land-use trends amongst agents. Low social and economic costs of sustained interaction and organisation enabled extensive forest-cover gain, but low transaction costs did not. Corporate plantation reforestation rose to the fore of regional forest-cover gain via opportunistic land sales by ranchers and economic subsidies indicative of a State preference for autonomous, self-organising forest-cover gain. This reforestation follows a recent history of neoliberal frontier development in which State-backed loggers and ranchers similarly displaced agriculturalists. Community institutions, long neglected by the State, struggled to coordinate landholders and so effected far less forest-cover gain. National and international commitments to tropical forest restoration risk being similarly characterised as ineffective by a predominance of industrial plantation reforestation without greater State support for community forest management.

Forest insect pest management and forest management in China: an overview.

Science.gov (United States)

Ji, Lanzhu; Wang, Zhen; Wang, Xiaowei; An, Linli

2011-12-01

According to the Seventh National Forest Inventory (2004-2008), China's forests cover an area of 195.45 million ha, or 20.36% of the total land area. China has the most rapidly increasing forest resources in the world. However, China is also a country with serious forest pest problems. There are more than 8,000 species of potential forest pests in China, including insects, plant diseases, rodents and lagomorphs, and hazardous plants. Among them, 300 species are considered as economically or ecologically important, and half of these are serious pests, including 86 species of insects. Forest management and utilization have a considerable influence on the stability and sustainability of forest ecosystems. At the national level, forestry policies always play a major role in forest resource management and forest health protection. In this paper, we present a comprehensive overview of both achievements and challenges in forest management and insect pest control in China. First, we summarize the current status of forest resources and their pests in China. Second, we address the theories, policies, practices and major national actions on forestry and forest insect pest management, including the Engineering Pest Management of China, the National Key Forestry Programs, the Classified Forest Management system, and the Collective Forest Tenure Reform. We analyze and discuss three representative plantations-Eucalyptus, poplar and Masson pine plantations-with respect to their insect diversity, pest problems and pest management measures.

Forest Insect Pest Management and Forest Management in China: An Overview

Science.gov (United States)

Ji, Lanzhu; Wang, Zhen; Wang, Xiaowei; An, Linli

2011-12-01

According to the Seventh National Forest Inventory (2004-2008), China's forests cover an area of 195.45 million ha, or 20.36% of the total land area. China has the most rapidly increasing forest resources in the world. However, China is also a country with serious forest pest problems. There are more than 8,000 species of potential forest pests in China, including insects, plant diseases, rodents and lagomorphs, and hazardous plants. Among them, 300 species are considered as economically or ecologically important, and half of these are serious pests, including 86 species of insects. Forest management and utilization have a considerable influence on the stability and sustainability of forest ecosystems. At the national level, forestry policies always play a major role in forest resource management and forest health protection. In this paper, we present a comprehensive overview of both achievements and challenges in forest management and insect pest control in China. First, we summarize the current status of forest resources and their pests in China. Second, we address the theories, policies, practices and major national actions on forestry and forest insect pest management, including the Engineering Pest Management of China, the National Key Forestry Programs, the Classified Forest Management system, and the Collective Forest Tenure Reform. We analyze and discuss three representative plantations— Eucalyptus, poplar and Masson pine plantations—with respect to their insect diversity, pest problems and pest management measures.

Imprints of Climate Signals in a 204 Year δ18O Tree-Ring Record of Nothofagus pumilio From Perito Moreno Glacier, Southern Patagonia (50°S

Directory of Open Access Journals (Sweden)

Jussi Grießinger

2018-04-01

Full Text Available A 204 year-long record of δ18O in tree-ring cellulose of southern beech (Nothofagus pumilio from a site near Perito Moreno Glacier (50°S in Southern Patagonia was established to assess its potential for a climate reconstruction. The annually resolved oxygen isotope chronology is built out of seven individual tree-ring δ18O series with a significant mean inter-series correlation (r = 0.61 and is the first of its kind located in Southern America south of 50°S. Over a common period from 1960 to 2013 of available stationary and high-resolution gridded CRU TS v. 4.01 data, the δ18O chronology exhibits a strong sensitivity toward hydroclimatic as well as temperature parameters as revealed by correlation analyses. Among these, positive correlations with maximum temperature in the first part of the summer season (CRU rONDJ = 0.51, p < 0.01 and negative correlations with precipitation in the latter half of the vegetation period (CRU rONDJ = −0.54, p < 0.01 show the highest sensitivities. A strong supra-regional influence of the Southern Annular Mode (SAM is clearly recorded in this chronology as indicated by significant positive correlations during the vegetation period (rONDJ = 0.62, p < 0.01. This indicates that the presented δ18O-chronology shows great promise to reconstruct the influence and variability of the SAM within the last two centuries in southern South America. The modulation of positive and negative anomalies within this series can be interlinked to changes in moisture source origin as revealed by backward trajectory modeling. Additionally, these anomalies can be directly associated to positive or negative phases of the Antarctic Oscillation Index (AAOI and therefore the strength of the Westerlies. Aligned by the analysis on the influence of different main weather types on the δ18O chronology it is shown that such time-series hold the potential to additionally capture their respective influence and change during the last centuries.

Secondary Forest Age and Tropical Forest Biomass Estimation Using TM

Science.gov (United States)

Nelson, R. F.; Kimes, D. S.; Salas, W. A.; Routhier, M.

1999-01-01

The age of secondary forests in the Amazon will become more critical with respect to the estimation of biomass and carbon budgets as tropical forest conversion continues. Multitemporal Thematic Mapper data were used to develop land cover histories for a 33,000 Square kM area near Ariquemes, Rondonia over a 7 year period from 1989-1995. The age of the secondary forest, a surrogate for the amount of biomass (or carbon) stored above-ground, was found to be unimportant in terms of biomass budget error rates in a forested TM scene which had undergone a 20% conversion to nonforest/agricultural cover types. In such a situation, the 80% of the scene still covered by primary forest accounted for over 98% of the scene biomass. The difference between secondary forest biomass estimates developed with and without age information were inconsequential relative to the estimate of biomass for the entire scene. However, in futuristic scenarios where all of the primary forest has been converted to agriculture and secondary forest (55% and 42% respectively), the ability to age secondary forest becomes critical. Depending on biomass accumulation rate assumptions, scene biomass budget errors on the order of -10% to +30% are likely if the age of the secondary forests are not taken into account. Single-date TM imagery cannot be used to accurately age secondary forests into single-year classes. A neural network utilizing TM band 2 and three TM spectral-texture measures (bands 3 and 5) predicted secondary forest age over a range of 0-7 years with an RMSE of 1.59 years and an R(Squared) (sub actual vs predicted) = 0.37. A proposal is made, based on a literature review, to use satellite imagery to identify general secondary forest age groups which, within group, exhibit relatively constant biomass accumulation rates.

Conservation and divergence of gene expression plasticity following c. 140 million years of evolution in lodgepole pine (Pinus contorta) and interior spruce (Picea glauca×Picea engelmannii).

Science.gov (United States)

Yeaman, Sam; Hodgins, Kathryn A; Suren, Haktan; Nurkowski, Kristin A; Rieseberg, Loren H; Holliday, Jason A; Aitken, Sally N

2014-07-01

Species respond to environmental stress through a combination of genetic adaptation and phenotypic plasticity, both of which may be important for survival in the face of climatic change. By characterizing the molecular basis of plastic responses and comparing patterns among species, it is possible to identify how such traits evolve. Here, we used de novo transcriptome assembly and RNAseq to explore how patterns of gene expression differ in response to temperature, moisture, and light regime treatments in lodgepole pine (Pinus contorta) and interior spruce (a natural hybrid population of Picea glauca and Picea engelmannii). We found wide evidence for an effect of treatment on expression within each species, with 6413 and 11,658 differentially expressed genes identified in spruce and pine, respectively. Comparing patterns of expression among these species, we found that 74% of all orthologs with differential expression had a pattern that was conserved in both species, despite 140 million yr of evolution. We also found that the specific treatments driving expression patterns differed between genes with conserved versus diverged patterns of expression. We conclude that natural selection has probably played a role in shaping plastic responses to environment in these species. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

Restoring forest structure and process stabilizes forest carbon in wildfire-prone southwestern ponderosa pine forests.

Science.gov (United States)

Hurteau, Matthew D; Liang, Shuang; Martin, Katherine L; North, Malcolm P; Koch, George W; Hungate, Bruce A

2016-03-01

Changing climate and a legacy of fire-exclusion have increased the probability of high-severity wildfire, leading to an increased risk of forest carbon loss in ponderosa pine forests in the southwestern USA. Efforts to reduce high-severity fire risk through forest thinning and prescribed burning require both the removal and emission of carbon from these forests, and any potential carbon benefits from treatment may depend on the occurrence of wildfire. We sought to determine how forest treatments alter the effects of stochastic wildfire events on the forest carbon balance. We modeled three treatments (control, thin-only, and thin and burn) with and without the occurrence of wildfire. We evaluated how two different probabilities of wildfire occurrence, 1% and 2% per year, might alter the carbon balance of treatments. In the absence of wildfire, we found that thinning and burning treatments initially reduced total ecosystem carbon (TEC) and increased net ecosystem carbon balance (NECB). In the presence of wildfire, the thin and burn treatment TEC surpassed that of the control in year 40 at 2%/yr wildfire probability, and in year 51 at 1%/yr wildfire probability. NECB in the presence of wildfire showed a similar response to the no-wildfire scenarios: both thin-only and thin and burn treatments increased the C sink. Treatments increased TEC by reducing both mean wildfire severity and its variability. While the carbon balance of treatments may differ in more productive forest types, the carbon balance benefits from restoring forest structure and fire in southwestern ponderosa pine forests are clear.

Tenure and forest income

DEFF Research Database (Denmark)

Jagger, Pamela; Luckert, Martin K.; Duchelle, Amy E.

2014-01-01

We explore the relationship between tenure and forest income in 271 villages throughout the tropics. We find that state-owned forests generate more forest income than private and community-owned forests both per household and per hectare. We explore whether forest income varies according...... to the extent of rule enforcement, and congruence (i.e., overlap of user rights between owners and users). We find negative associations between enforcement and smallholder forest income for state-owned and community forests, and positive associations for privately owned forests. Where user rights are limited...... to formal owners we find negative associations for state-owned forests. Overlapping user rights are positively associated with forest income for community forests. Our findings suggest that policy reforms emphasizing enforcement and reducing overlapping claims to forest resources should consider possible...

Forest Loss in Protected Areas and Intact Forest Landscapes: A Global Analysis.

Science.gov (United States)

Heino, Matias; Kummu, Matti; Makkonen, Marika; Mulligan, Mark; Verburg, Peter H; Jalava, Mika; Räsänen, Timo A

2015-01-01

In spite of the high importance of forests, global forest loss has remained alarmingly high during the last decades. Forest loss at a global scale has been unveiled with increasingly finer spatial resolution, but the forest extent and loss in protected areas (PAs) and in large intact forest landscapes (IFLs) have not so far been systematically assessed. Moreover, the impact of protection on preserving the IFLs is not well understood. In this study we conducted a consistent assessment of the global forest loss in PAs and IFLs over the period 2000-2012. We used recently published global remote sensing based spatial forest cover change data, being a uniform and consistent dataset over space and time, together with global datasets on PAs' and IFLs' locations. Our analyses revealed that on a global scale 3% of the protected forest, 2.5% of the intact forest, and 1.5% of the protected intact forest were lost during the study period. These forest loss rates are relatively high compared to global total forest loss of 5% for the same time period. The variation in forest losses and in protection effect was large among geographical regions and countries. In some regions the loss in protected forests exceeded 5% (e.g. in Australia and Oceania, and North America) and the relative forest loss was higher inside protected areas than outside those areas (e.g. in Mongolia and parts of Africa, Central Asia, and Europe). At the same time, protection was found to prevent forest loss in several countries (e.g. in South America and Southeast Asia). Globally, high area-weighted forest loss rates of protected and intact forests were associated with high gross domestic product and in the case of protected forests also with high proportions of agricultural land. Our findings reinforce the need for improved understanding of the reasons for the high forest losses in PAs and IFLs and strategies to prevent further losses.

Illinois' Forests 2010

Science.gov (United States)

Susan J. Crocker; Mark D. Nelson; Charles J. Barnett; Brett J. Butler; Grant M. Domke; Mark H. Hansen; Mark A. Hatfield; Tonya W. Lister; Dacia M. Meneguzzo; Ronald J. Piva; Barry T. Wilson; Christopher W. Woodall

2013-01-01

The second full annual inventory of Illinois' forests, completed in 2010, reports more than 4.8 million acres of forest land and 97 tree species. Forest land is dominated by oak/hickory and elm/ash/cottonwood forest-type groups, which occupy 93 percent of total forest land area. The volume of growing stock on timberland totals 7.2 billion cubic feet. The average...

Nebraska's Forests 2010

Science.gov (United States)

Dacia M Meneguzzo; Susan J. Crocker; Mark D. Nelson; Charles J. Barnett; Brett J. Butler; Grant M. Domke; Mark H. Hansen; Mark A. Hatfield; Greg C. Liknes; Andrew J. Lister; Tonya W. Lister; Ronald J. Piva; Barry T. (Ty) Wilson; Christopher W. Woodall

2012-01-01

The second full annual inventory of Nebraska's forests reports more than 1.5 million acres of forest land and 39 tree species. Forest land is dominated by the elm/ash/cottonwood and oak/hickory forest types, which occupy nearly half of the total forest land area. The volume of growing stock on timberland currently totals 1.1 billion cubic feet. The average annual...

Forest report 2016

International Nuclear Information System (INIS)

2016-01-01

This forest condition report of Hesse (Germany) includes the following topics: forest condition survey for all tree species, forest in the in the Rhine-Main area, weather and climate, soil water balance and drought stress, insects and fungi, Forestry Environment Monitoring, infiltrated substances, main results of Forest soil survey in Hesse (BZE II), the substrate group red sandstone, heavy metal contamination of forests.

Michigan's Forests 2009

Science.gov (United States)

Scott A. Pugh; Lawrence D. Pedersen; Douglas C. Heym; Ronald J. Piva; Christopher W. Woodall; Charles J. Barnett; Cassandra M. Kurtz; W. Keith. Moser

2012-01-01

The seventh inventory of Michigan's forests, completed in 2009, describes more than 19.9 million acres of forest land. The data in this report are based on visits to 7,516 forested plots from 2005 to 2009. Timberland accounts for 97 percent of this forest land, and 62 percent is privately owned. The sugar maple/beech/yellow birch forest type accounts for 18...

Michigan's forests 2004

Science.gov (United States)

Scott A. Pugh; Mark H. Hansen; Lawrence D. Pedersen; Douglas C. Heym; Brett J. Butler; Susan J. Crocker; Dacia Meneguzzo; Charles H. Perry; David E. Haugen; Christopher Woodall; Ed Jepsen

2009-01-01

The first annual inventory of Michigan's forests, completed in 2004, covers more than 19.3 million acres of forest land. The data in this report are based on visits to 10,355 forested plots from 2000 to 2004. In addition to detailed information on forest attributes, this report includes data on forest health, biomass, land-use change, and timber-product outputs....

Size of forest holdings and family forests: implications for forest management in South Carolina.

Science.gov (United States)

Brian Williams; Thomas Straka; Richard Harper

2012-01-01

There are about 11.3 million private forest owners in the United States; of those, 10.4 million are family forest owners who control 62% of the nation's private timberland. South Carolina has about 262,000 family forest owners who control almost two-thirds of the state's private timberland (Butler, 2008). In the recent past, these ownerships were generally...

Analysis of Expectations of Forest Products Industry from Forest Industry Engineering Education

OpenAIRE

GEDİK, Tarık; ÇİL, Muhammet; SEVİM KORKUT, Derya; CEMİL AKYÜZ, Kadri; KOŞAR, Gökşen; BEKAR, İlter

2016-01-01

Forest industry engineers, representing the qualified labor within the forest products industry, choose their field of study either deliberately or by chance. This study explores the main skill sets of forest industry engineers required by forest products industry. As representatives of forest industry owner of forest products companies were surveyed about their views on the qualifications a forest industry engineer must have.This study covered total 7111 companies registered to TOBB as a for...

Net aboveground biomass declines of four major forest types with forest ageing and climate change in western Canada's boreal forests.

Science.gov (United States)

Chen, Han Y H; Luo, Yong

2015-10-01

Biomass change of the world's forests is critical to the global carbon cycle. Despite storing nearly half of global forest carbon, the boreal biome of diverse forest types and ages is a poorly understood component of the carbon cycle. Using data from 871 permanent plots in the western boreal forest of Canada, we examined net annual aboveground biomass change (ΔAGB) of four major forest types between 1958 and 2011. We found that ΔAGB was higher for deciduous broadleaf (DEC) (1.44 Mg ha(-1)  year(-1) , 95% Bayesian confidence interval (CI), 1.22-1.68) and early-successional coniferous forests (ESC) (1.42, CI, 1.30-1.56) than mixed forests (MIX) (0.80, CI, 0.50-1.11) and late-successional coniferous (LSC) forests (0.62, CI, 0.39-0.88). ΔAGB declined with forest age as well as calendar year. After accounting for the effects of forest age, ΔAGB declined by 0.035, 0.021, 0.032 and 0.069 Mg ha(-1)  year(-1) per calendar year in DEC, ESC, MIX and LSC forests, respectively. The ΔAGB declines resulted from increased tree mortality and reduced growth in all forest types except DEC, in which a large biomass loss from mortality was accompanied with a small increase in growth. With every degree of annual temperature increase, ΔAGB decreased by 1.00, 0.20, 0.55 and 1.07 Mg ha(-1)  year(-1) in DEC, ESC, MIX and LSC forests, respectively. With every cm decrease of annual climatic moisture availability, ΔAGB decreased 0.030, 0.045 and 0.17 Mg ha(-1)  year(-1) in ESC, MIX and LSC forests, but changed little in DEC forests. Our results suggest that persistent warming and decreasing water availability have profound negative effects on forest biomass in the boreal forests of western Canada. Furthermore, our results indicate that forest responses to climate change are strongly dependent on forest composition with late-successional coniferous forests being most vulnerable to climate changes in terms of aboveground biomass. © 2015 John Wiley & Sons Ltd.

A model of forest floor carbon mass for United States forest types

Science.gov (United States)

James E. Smith; Linda S. Heath

2002-01-01

Includes a large set of published values of forest floor mass and develop large-scale estimates of carbon mass according to region and forest type. Estimates of average forest floor carbon mass per hectare of forest applied to a 1997 summary forest inventory, sum to 4.5 Gt carbon stored in forests of the 48 contiguous United States.

Forest Grammar(Ⅰ)

Institute of Scientific and Technical Information of China (English)

张松懋

1994-01-01

Forest grammar,a new type of high-dimensional grammar,is proposed in this paper,of which both the left and the right parts of every production are concatenations of tree structures.A classification of forest grammar is studied,especially,a subclass of the forest grammar,i.e.the context-sensitive forest grammar,and one of its subclasses is defined,called the weak precedence forest grammar.

Temporal Forest Change Detection and Forest Health Assessment using Remote Sensing

International Nuclear Information System (INIS)

Ya'acob, Norsuzila; Azize, Aziean Binti Mohd; Mahmon, Nur Anis; Yusof, Azita Laily; Azmi, Nor Farhana; Mustafa, Norfazira

2014-01-01

This paper presents the detection of Angsi and Berembun Reserve Forest change for years 1996 and 2013. Forest is an important part of our ecosystem. The main function is to absorb carbon oxide and produce oxygen in their cycle of photosynthesis to maintain a balance and healthy atmosphere. However, forest changes as time changes. Some changes are necessary as to give way for economic growth. Nevertheless, it is important to monitor forest change so that deforestation and development can be planned and the balance of ecosystem is still preserved. It is important because there are number of unfavorable effects of deforestation that include environmental and economic such as erosion of soil, loss of biodiversity and climate change. The forest change detection can be studied with reference of several satellite images using remote sensing application. Forest change detection is best done with remote sensing due to large and remote study area. The objective of this project is to detect forest change over time and to compare forest health indicated by Normalized Difference Vegetation Index (NDVI) using remote sensing and image processing. The forest under study shows depletion of forest area by 12% and 100% increment of deforestation activities. The NDVI value which is associated with the forest health also shows 13% of reduction

Forest Islands and Castaway Communities: REDD+ and Forest Restoration in Prey Lang Forest

Directory of Open Access Journals (Sweden)

Courtney Work

2017-02-01

Full Text Available Climate Change policies are playing an ever-increasing role in global development strategies and their implementation gives rise to often-unforeseen social conflicts and environmental degradations. A landscape approach to analyzing forest-based Climate Change Mitigation policies (CCM and land grabs in the Prey Lang Forest landscape, Cambodia revealed two Korea-Cambodia partnership projects designed to increase forest cover that are juxtaposed in this paper. Case study data revealed a REDD+ project with little negative impact or social conflict in the project area and an Afforestation/Reforestation (A/R project that created both social and ecological conflicts. The study concludes that forest-based CCM policies can reduce conflict through efforts at minimal transformation of local livelihoods, maximal attention to the tenure rights, responsibilities, and authority of citizens, and by improving, not degrading, the project landscapes. The paper presents the circumstances under which these guidelines are sidestepped by the A/R project, and importantly reveals that dramatic forest and livelihood transformation had already affected the community and environment in the REDD+ project site. There are deep contradictions at the heart of climate change policies toward which attention must be given, lest we leave our future generations with nothing but forest islands and castaway communities.

Non-timber forest products: alternative multiple-uses for sustainable forest management

Science.gov (United States)

James L. Chamberlain; Mary Predny

2003-01-01

Forests of the southern United States are the source of a great diversity of flora, much of which is gathered for non-timber forest products (NTFPs). These products are made from resources that grow under the forest canopy as trees, herbs, shrubs, vines, moss and even lichen. They occur naturally in forests or may be cultivated under the forest canopy or in...

Evaluation of shrub and tree species used for revegetating copper mine wastes in the south-western United States. [Dodonea viscosa (L. ) Jacq. , Baccharis sarothroides Gray, Cerdicium microphyllum Torr. , and Nicotiana glauca Grah

Energy Technology Data Exchange (ETDEWEB)

Norem, M A; Day, A D; Ludeke, K L

1982-12-01

The revegetation work begun in 1970 at Cyprus Pima Mine, an open pit copper mine south-west of Tucson, Arizona, was evaluated to determine the effects of slope aspect and mining waste material on plant survival and growth. Only one shrub, Dodonea viscosa (L.) Jacq. (hopbush), survived on the east slope. Baccharis sarothroides Gray (desert broom) was prolific on the north aspect. Cerdicium microphyllum Torr. (palo verde) survived best on the east slope and Nicotiana glauca Grah. (desert tobacco) survived only on the north slope. The survival of the other tree species was not affected by slope aspect. Slope exposure did not affect tree size, except for Eucalyptus microtheca Muell. (tiny capsule eucalyptus) which grew larger on the north slope. E. rostrata Schlechtend (red gum eucalyptus) grew taller in overburden than in tailing on the east slope. Differences in soil material within each slope exposure did not significantly affect growth of the other tree species. In semi-arid regions, such as south-western Arizona, even slight differences in available moisture may determine the survival of a plant species in the area. (Refs. 11).

Private forest owners of the Central Hardwood Forest

Science.gov (United States)

Thomas W. Birch

1997-01-01

A recently completed survey of woodland owners provides insight into the owners of private forest lands in the Central Hardwood Region. There is increasing parcelization of forested lands and an increase in the numbers of nonindustrial private forest-land owners. Over half of the private owners have harvested timber from their holdings at some time in the past, they...

Effects of national forest-management regimes on unprotected forests of the Himalaya.

Science.gov (United States)

Brandt, Jodi S; Allendorf, Teri; Radeloff, Volker; Brooks, Jeremy

2017-12-01

Globally, deforestation continues, and although protected areas effectively protect forests, the majority of forests are not in protected areas. Thus, how effective are different management regimes to avoid deforestation in non-protected forests? We sought to assess the effectiveness of different national forest-management regimes to safeguard forests outside protected areas. We compared 2000-2014 deforestation rates across the temperate forests of 5 countries in the Himalaya (Bhutan, Nepal, China, India, and Myanmar) of which 13% are protected. We reviewed the literature to characterize forest management regimes in each country and conducted a quasi-experimental analysis to measure differences in deforestation of unprotected forests among countries and states in India. Countries varied in both overarching forest-management goals and specific tenure arrangements and policies for unprotected forests, from policies emphasizing economic development to those focused on forest conservation. Deforestation rates differed up to 1.4% between countries, even after accounting for local determinants of deforestation, such as human population density, market access, and topography. The highest deforestation rates were associated with forest policies aimed at maximizing profits and unstable tenure regimes. Deforestation in national forest-management regimes that emphasized conservation and community management were relatively low. In India results were consistent with the national-level results. We interpreted our results in the context of the broader literature on decentralized, community-based natural resource management, and our findings emphasize that the type and quality of community-based forestry programs and the degree to which they are oriented toward sustainable use rather than economic development are important for forest protection. Our cross-national results are consistent with results from site- and regional-scale studies that show forest-management regimes that

78 FR 38287 - Bitterroot National Forest, Darby Ranger District, Como Forest Health Project

Science.gov (United States)

2013-06-26

... DEPARTMENT OF AGRICULTURE Forest Service Bitterroot National Forest, Darby Ranger District, Como Forest Health Project AGENCY: Forest Service. ACTION: Notice; Correction. SUMMARY: The Department of Agriculture (USDA), Forest Service, Bitterroot National Forest, Darby Ranger District published a document in...

Forest Resources

Energy Technology Data Exchange (ETDEWEB)

None

2016-06-01

Forest biomass is an abundant biomass feedstock that complements the conventional forest use of wood for paper and wood materials. It may be utilized for bioenergy production, such as heat and electricity, as well as for biofuels and a variety of bioproducts, such as industrial chemicals, textiles, and other renewable materials. The resources within the 2016 Billion-Ton Report include primary forest resources, which are taken directly from timberland-only forests, removed from the land, and taken to the roadside.

Organization of private forest sector in Timok forest area

Directory of Open Access Journals (Sweden)

Vojislav Milijic

2010-06-01

Full Text Available Today, private forest owners (PFOs in Serbia cooperate in form of private forest owners associations (PFOAs. Currently, there are 20 PFOAs, of which 15 are in Timok region. Initiatives of PFOs from Timok forest area, animated the owners from other parts of the country and led to foundation of Serbian Federation of Forest Owners' Associations. Twelve of PFOAs from Timok forest area are the founders of Serbian private forest owners' umbrella organization. Restructuring of Public Enterprise (PE "Srbijasume", which started in 2001, led to development of private small and medium forest enterprises, engaged as contractors of PE for harvesting, timber transport and construction of forest roads. The objectives of this paper are to elaborate if there are differences between PFOs in Serbia and Timok region and to analyze organization of private forest owners in Timok forest area. In order to reach these objectives, results of PRIFORT project were used. This project focused on four countries of Western Balkans region: Bosnia and Herzegovina, Croatia, Serbia and Macedonia. The aim of this project was to explore precondition for formation of PFOs in this region. Quantitative survey (n = 350 of randomly selected PFOs was conducted in nine municipalities in Serbia, of which two were in Timok region (n = 100. The results show that there are differences between PFOs in Serbia and Timok region in number of PFOs, size of private property and in additional incentives. These results also indicate that economic interest is a motive for establishment of PFOAs and that state support is very important for their development. Since a number of PFOs are entrepreneurs, it can be assumed that, further development of theirs organizations could lead to development of SMEs clusters. 

Impacts of participatory forest management on species composition and forest structure in Ethiopia

DEFF Research Database (Denmark)

Yietagesu, Aklilu Ameha; Meilby, Henrik; Feyisa, Gudina Legese

2016-01-01

The present study assesses the impacts of decentralized forest management on forest conditions in Ethiopian Montane forests. We compared observed densities of different tree species and size categories in forests managed by local forest user groups (FUGs) and the government. We used forest...

Dipterocarpaceae: forest fires and forest recovery

NARCIS (Netherlands)

Priadjati, A.

2002-01-01