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Juan J. Armesto - One of the best experts on this subject based on the ideXlab platform.
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ecological impacts of different harvesting scenarios for temperate evergreen rain forest in southern chile a simulation experiment
Forest Ecology and Management, 2007Co-Authors: Nadja Ruger, Juan J. Armesto, Alvaro G Gutierrez, Daniel W Kissling, Andreas HuthAbstract:Abstract Current forestry practices in Chile largely rely on exotic tree plantations, and limited management experiences are available for the species-rich native evergreen rain forests. Yet, conservationists and forest scientists call for sustainable management of native forests as an alternative to plantations so as to maintain important ecosystem services. We parameterised the process-based forest growth model FORMIND for a Valdivian coastal temperate rain forest in Chiloe Island, Chile, to assess the ecological implications of different logging practices including selective logging and strip-cutting. We tested the model by comparing simulation results with field data from the study site and carried out an extensive sensitivity analysis to explore the impacts of parameter values on model results. Simulated logging practices were compared in regard to expected timber harvest and long-term impacts on forest structure and composition. Results showed that highest harvests could be achieved when strip-cutting was applied, because it promoted the regeneration of the relatively light-demanding and fast-growing Eucryphia cordifolia . However, forest structure and composition were severely altered by this practice. In contrast, selective logging, although providing lower harvests, better conserved old-growth forest structure and composition. Canopy gaps created by selective logging were not large enough to ensure regeneration of E. cordifolia , but favoured the shade-tolerant Laureliopsis philippiana . Overall, the similarity of logged stands to undisturbed forest decreased linearly with increasing harvesting intensity. Management strategies that rely on native species and keep an uneven-aged forest structure ensure the maintenance of native biodiversity, protect ecosystems from exotic species invasions, and promote the conservation of biotic interactions essential for tree reproduction.
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IMPORTANCE OF NATIVE BAMBOO FOR UNDERSTORY BIRDS IN CHILEAN TEMPERATE FORESTS
The Auk, 2004Co-Authors: Sharon Reid, Iván Díaz, Juan J. Armesto, Mary F. WillsonAbstract:Abstract In South American temperate rainforests, five endemic understory birds (four Rhinocryptidae and one Furnariidae) are often associated with the main understory plant, the native bamboo Chusquea valdiviensis (Poaceae: Bambusoideae). We studied the effects of bamboo cover on species abundance and richness of those understory birds and explored the functions of bamboo as food resource and escape cover. In Chiloe Island (42°S), southern Chile, we selected four old-growth forest patches >100 ha and in each patch conducted bird surveys in six plots with >70% understory cover. Three plots were dominated by native bamboo and three plots had a sparse bamboo cover. Bird abundance (point counts) was significantly correlated with both total understory cover and percentage of bamboo cover but was not correlated with other kinds of understory plant cover. Bird species richness was positively correlated with bamboo cover and negatively correlated with other kinds of understory cover but unrelated to total unders...
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coarse woody debris biomass in successional and primary temperate forests in Chiloe island chile
Forest Ecology and Management, 2002Co-Authors: Martin R Carmona, Juan J. Armesto, Juan Carlos Aravena, Cecilia A PerezAbstract:Coarse woody residues (snags and logs) are a massive and functionally important component of high-latitude forest ecosystems, both natural and managed. Decaying logs and snags provide habitat for many organisms and participate in biogeochemical element fluxes within the forest ecosystem. Because of their large mass and slow decay rates, they may also play a significant role in the global carbon cycle. For these reasons, it is important to understand the dynamics of coarse woody debris (CWD) during forest succession. Here, we estimated the biomass of CWD (defined as logs or snags >10 cm stem
William A Overholt - One of the best experts on this subject based on the ideXlab platform.
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Niche overlap and interspecific association between Chilo partellus and Chilo orichalcociliellus on the Kenya coast
Entomologia Experimentalis et Applicata, 1999Co-Authors: V. C. Ofomata, William A Overholt, R. I. Egwuatu, A. Van Huis, A.j. Ngi-songAbstract:Chilo partellus (Swinhoe) and Chilo orichalcociliellus Strand (Lepidoptera: Crambidae) occur sympatrically on the Kenya coast and are injurious to maize and sorghum. Evidence over a period of 30 years indicates that the indigenous stem borer, C. orichalcociliellus, is being gradually displaced by the exotic stem borer, C. partellus. The two species have overlapping niches, but the specific mechanisms driving the displacement are unknown. The distribution and extent of niche overlap and interspecific association between C. partellus and C. orichalcociliellus were investigated in cultivated and wild host plants. No difference in the within-plant distribution of the two borer species in maize and sorghum was found. A niche overlap of 83.7% between C. partellus and C. orichalcociliellus was found. A weak positive association was found between small-, medium-, and large-sized larvae of C. partellus and C. orichalcociliellus. However, as larvae grew, the association decreased with no significant association at the pupal stage. No negative association was found between C. partellus and C. orichalcociliellus, suggesting that the two species do not avoid or directly harm each other. The partial displacement of C. orichalcociliellus may therefore, be attributed to intrinsically superior attributes of C. partellus that indirectly affect the survival of C. orichalcociliellus.
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Diapause Termination of Chilo partellus (Swinhoe) and Chilo orichalcociliellus Strand (Lepidoptera: Pyralidae)
International Journal of Tropical Insect Science, 1999Co-Authors: V. C. Ofomata, William A Overholt, R. I. EgwuatuAbstract:The intensity of diapause of field-collected diapausing larvae of Chilo partellus (Swinhoe) and Chilo orichalcociliellus Strand (Lepidoptera: Pyralidae) was compared in the laboratory at 28 ± 0.5°C under a photoperiod of 12:12 (L:D)h. Chilo partellus terminated diapause faster than C. orichalcociliellus. Mean time to diapause termination was 9.7 days for C. partellus and 14.4 days for C. orichalcociliellus. Male and female C. partellus larvae terminated diapause and adults emerged at the same time, while significant differences were found in diapause termination and in emergence times between male and female C. orichalcociliellus.
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Oviposition, development and searching behaviour of Cotesia flavipes Cameron and Cotesia sesamiae (Cameron) (Hymenoptera: Braconidae) in relation to aestivating and non-aestivatng Chilo spp. (Lepidoptera: Pyralidae) larvae in maize.
African Entomology, 1997Co-Authors: J.c. Mbapila, William A OverholtAbstract:Oviposition, development and searching behavior of Cotesia flavipes Cameron and Cotesia sesamiae (Cameron) on aestivating Chilo spp. and non-aestivating Chilo partellus (Swinhoe) larvae were investigated. Oviposition experiments indicated that parasitoids readily accepted aestivating and non-aestivating larvae for oviposition under laboratory conditions. The development times of C. flavipes from egg to adult emergence in aestivating compared with non-aestivating host larvae were not significantly different. Field-cage studies demonstrated that C. flavipes and C. sesamiae were unable to locate and paraSitize aestivating Chilo spp. larvae in dry maize stems. Parasitization of non-aestivating C. partellus larvae was significantly higher in cages where C. flavipes was released (26.21 %) than in cages where C. sesamiae was released (11.32 %).
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suitability of african gramineous stemborers for development of cotesia flavipes and c sesamiae hymenoptera braconidae
Environmental Entomology, 1995Co-Authors: Adele J Ngisong, William A Overholt, J N AyerteyAbstract:Four cereal stemborers occurring in Kenya, Chilo partellus (Swinhoe), Chilo orichalcociliellus Strand (Lepidoptera:Pyralidae), Busseola fusca (Fuller), and Sesamia calamistis Hampson (Lepidoptera: Noctuidae),were exposed to females of the larval endoparasitoids Cotesia flavipes Cameron and Cotesia sesamiae (Cameron) to assess their acceptability for oviposition and suitability for development of the parasitoids. There was no difference in the acceptability of the 4 hosts exposed to Cotesia flavipes . In contrast, Cotesia sesamiae preferred S. calamistis larvae, followed by the 2 Chilo species; B. fusca larvae were the least attacked by Cotesia sesamiae . The suitability of the 4 hosts also varied with the parasitoid species. Neither parasitoid species developedin B. fusca and egg encapsulation was observed. Both Chilo species and S. calamistis were suitable hosts for the development of Cotesia flavipes . However, higher immature mortality was observed in S. calamistis than in Chilo partellus . There were no differences in the mean number of progeny per female or the sex ratio. The most suitable host for Cotesia sesamiae was S. calamistis , followed by the 2 Chilo species which were equally suitable. When 3rd, 4th, 5th, and 6th instars of Chilo partellus were exposed to Cotesia flavipes females, immature parasitoid mortalitywas highest in 3rd-instar hosts.
Pedro Jara-seguel - One of the best experts on this subject based on the ideXlab platform.
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KARYOTYPE STUDY IN THE SURF CLAM MESODESMA DONACIUM LAMARCK, 1818 (BIVALVIA: VENEROIDA: MESODESMATIDAE) ESTUDIO CARIOTIPICO EN LA MACHA MESODESMA DONACIUM LAMARCK, 1818 (BIVALVIA: VENEROIDA: MESODESMATIDAE)
2008Co-Authors: G Amar, Claudio Palma Rojas, Elisabeth Von Brand, Pedro Jara-seguelAbstract:Mesodesma donacium is a marine clam distributed from Sechura Bay (5°S) in northern Peru to Chiloe Island (43oS) in southern Chile. Due to the commercial importance of this species, their populations have been reduced in the later years. In this work the karyotype morphology of M. donacium is described for the first time, to be additional to taxonomical, ecological, morphological, and reproductive antecedents previously documented for the species. M. donacium shows a diploid karyotype 2n = 38 with one metacentric, fifteen submetacentric and three subtelocentric chromosome pairs. The total haploid set length was 42.4 μm, and the mean chromosome size was 2.2 μm. M. donacium showed similitude in chromosome number with other species of the Veneroida order, but differences were found in morphology and size of the chromosomes. The cytogenetic relationships between M. donacium and other species of Veneroida is also discussed.
Daniel González-acuña - One of the best experts on this subject based on the ideXlab platform.
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Coprologic survey of endoparasites from Darwin’s fox (Pseudalopex fulvipes) in Chiloé, Chile
Archivos de Medicina Veterinaria, 2012Co-Authors: Jaime Jimenez, Héctor Alcaíno, Patricia Vásquez, Stephan M Funk, Cristobal Briceno, Daniel González-acuñaAbstract:A total of 189 faecal samples of the critically endangered Darwin’s fox (Pseudalopex fulvipes [Martin, 1837]), from different areas within Chiloé Island in southern Chile were examined for parasites eggs and oocysts using the sugar flotation technique. The results showed that 21.2% of the samples were positive to either one of nine helminthes and one protozoan. The parasites with the highest prevalence were an ascarid nematode and a Spirometra species of cestode. Other identified endoparasites include Capillaria sp., Toxocara canis, Toxascaris leonina, Filaroides osleri, ancylostomatid nematodes, Trichuris sp., Taenia sp., and Isospora sp. Parasite loads were higher during the winter and in areas having more domestic dogs. All these species and genera are reported for the fist time in the Darwin’s fox.
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Molecular divergence between insular and continental Pudu deer ( Pudu puda ) populations in the Chilean Patagonia
Studies on Neotropical Fauna and Environment, 2011Co-Authors: Marcelo Fuentes-Hurtado, Juan C. Marín, Daniel González-acuña, Claudio Verdugo, Fernando Vidal, Juliana A. ViannaAbstract:Island-continent isolation scenarios have played major roles in the understanding and development of evolutionary theories. During the last glacial maximum (LGM) in southern Chile, ice sheet advances and retreats formed the Patagonian archipelago along the southern Pacific Ocean. Chiloe Island is the largest island from the archipelago isolated from the continent by a narrow and shallow stretch of ocean. Pudu puda is a species endemic to Chile and part of Argentina, distributed along the Valdivian Temperate rainforest. We used mtDNA control region (654 bp) and cytochrome b (734 bp) sequences to understand the consequences in the evolutionary history and population structure of Pudu puda island-continent isolation. Bayesian and Maximum Likelihood phylogenetic analysis revealed two divergent clades corresponding to the continent and Chiloe Island. The Median Joining Network also supports these findings with an isolation of 10 mutational steps between Chiloe and the continent. We also found a significant high genetic structure (phi st = 0.75) and a sequence divergence percentage of 2.3% between the two clades. On the other hand, on the continent we found high haplotype genetic diversity (H = 0.9790 0.0103) but no clear geographical population structure or phylogenetic clades. Our results suggest that the southern Pudu deer populations were isolated since the interglacial period (less than 0.5 million years ago) from the continent leading to two reciprocally monophyletic clades. We propose two subspecies to be considered in the development of future conservation programs for the species.
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Presence of Ixodes neuquenensis Ringuelet, 1947 (Acari: Ixodidae) on the endangered Neotropical marsupial Monito del monte (Dromiciops gliroides Thomas, 1894, Microbiotheria: Microbiotheriidae) at Chiloé Island, Chile
European Journal of Wildlife Research, 2007Co-Authors: Paula Marín-Vial, Juan L. Celis-Diez, Pedro E. Cattan, Daniel González-acuña, Alberto A. GuglielmoneAbstract:The presence of Ixodes neuquenensis (Ringuelet, Notas Mus la Plata 12:207-216, 1947) (Acari: Ixodidae) parasitizing populations of Dromiciops gliroides Thomas, 1894 (Microbiotheria: Microbiotheriidae) at Chiloe Island confirms that this tick species is established in Chile. No preference of the ticks for sex or age of the host was observed.
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First records of Trichodectes canis (Insecta: Phthiraptera: Trichodectidae) from Darwin's fox, Pseudalopex fulvipes (Mammalia: Carnivora: Canidae)
European Journal of Wildlife Research, 2007Co-Authors: Daniel González-acuña, Armando Conrado Cicchino, Stephan M Funk, Cristobal Briceno, Jaime JimenezAbstract:The presence of the dog biting louse, Trichodectes canis (De Geer, 1778; Ischnocera: Trichodectidae), is reported for the first time in the critically endangered Pseudalopex fulvipes (Martin, 1837) in Chiloé Island, south Chile.
Ashley Hink - One of the best experts on this subject based on the ideXlab platform.
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health literacy and child health outcomes a systematic review of the literature
Pediatrics, 2009Co-Authors: Darren A Dewalt, Ashley HinkAbstract:To review the relationship between parent and child lit- eracy and child health outcomes and interventions designed to im- prove child health outcomes for children or parents with low literacy skills. METHODS: We searched Medline and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) for articles published from 1980 through 2008 and included studies that reported original data, mea- sured literacy and 1 health outcome, and assessed the relationship between literacy and health outcomes. Health outcomes included health knowledge, health behaviors, use of health care resources, in- termediate markers of disease status, and measures of morbidity. Two abstractors reviewed each study for inclusion. Included studies were abstracted into evidence tables and were assessed by using an 11-item quality scale. RESULTS: We reviewed 4182 new titles and abstracts published since 2003. Fifty-eight articles were retained for full review, and 13 met the inclusion criteria. Eleven articles from the systematic review from 1980 to 2003 met the inclusion criteria, giving us a total of 24 articles. Chil- dren with low literacy generally had worse health behaviors. Parents with low literacy had less health knowledge and had behaviors that were less advantageous for their children's health compared with par- ents with higher literacy. Children whose parents had low literacy often had worse health outcomes, but we found mixed results for the relationship of literacy to the use of health care services. Interventions found that improving written materials can increase health knowl- edge, and combining good written materials with brief counseling can improve behaviors including adherence. The average quality of the studies was fair to good. CONCLUSIONS: Child and parent literacy seems associated with im- portant health outcomes. Future research can help us understand under what circumstances this relationship is causal, how literacy and health outcomes are related in noncausal pathways, the relative im- portance of parent and child literacy, and what interventions effec- tively reduce health literacy-related disparities. Pediatrics 2009;124: S265-S274
