Top PDF Effects of timber harvest on structural diversity and species composition in hardwood forests

Effects of timber harvest on structural diversity and species composition in hardwood forests

Effects of timber harvest on structural diversity and species composition in hardwood forests

Abstract. Tavankar F, Bonyad AE. 2015. Effects of timber harvest on structural diversity and species composition in hardwood forests. Biodiversitas 16: 1-9. Forest management leads to changes in structure and species composition of stands. In this research vertical and horizontal structure and species composition were compared in two harvested and protected stands in the Caspian forest of Iran. The results indicated the tree and seedling density, total basal area and stand volume was significantly (P < 0.01) higher in the protected stand. The Fagus orientalis L. had the most density and basal area in the both stands. Species importance value (SIV) of Fagus orientalis in the protected stand (92.5) was higher than in the harvested stand (88.5). While, the SIV of shade-intolerant tree species such as Acer insigne, Acer cappadocicum and Alnus subcordata was higher in the harvested stand. The density of trees and seedling of rare tree species, such as Ulmus glabra, Tilia begonifolia, Zelkova carpinifolia and Fraxinus coriarifolia, was also higher in the protected stand. The Shannon-Wiener diversity index in the protected stand (0.84) was significantly higher (P < 0.01) than in the harvested stand (0.72). The highest diversity value in the harvested stand was observed in DBH of 10-40 cm class, while DBH of 40-70 cm had the highest diversity value in the protected stand.
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Modeling the Effects of Harvest Alternatives on Mitigating Oak Decline in a Central Hardwood Forest Landscape.

Modeling the Effects of Harvest Alternatives on Mitigating Oak Decline in a Central Hardwood Forest Landscape.

Such stand-scale studies provide a scientific basis for applying stand-scale silvicultural treatments to mitigate oak decline, but are insufficient for addressing long-term cumulative management effects at broad spatial and temporal scales. Oak decline is a spatially contiguous landscape process driven by a variety of processes operating from stand to landscape scales [20]. At stand scales, ecological succession and related changes in species composition and stand structure can affect the current and future dynamics of oak decline. At landscape scales, the shifting mosaic of species composition and age cohorts caused by fire, forest harvesting, and environmental heterogeneity (e.g. slope and aspect) can also affect oak decline dynamics. Spetich and He [20] argued that the spatio-temporal patterns of oak decline provided the basis for where, when, how often, and what management alternatives should be used. Moreover, because tree age and species composition considered as predisposing factors in oak decline are temporally dynamic, this requires addressing oak decline over the long term [16]. Although much attention has been paid to maintaining long-term forest productivity and health at large spatial scales, comparatively little attention has been paid to evaluating the effects of forest harvesting on oak decline at landscape scales.
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Dan Xing 1, 2 Zhenhong Wang3 Jiujun Xiao4 Shiyu Han2 Chaobin Luo2 Aimin Zhang2 Lala Song2 Xiubin Gao5

Dan Xing 1, 2 Zhenhong Wang3 Jiujun Xiao4 Shiyu Han2 Chaobin Luo2 Aimin Zhang2 Lala Song2 Xiubin Gao5

ABSTRACT: Arbuscular mycorrhizal fungi (AMF) have been attracted more scientific attentions due to its critical role in enhancement of drought tolerance of plants for growth and vegetation restoration in karst fragile ecosystem. However, scientists know little about the AMF composition and diversity occurring in root systems of mulberry (Morus sp.), and in karst habitats which return land use from mulberry forestry, as well as the effects of soil environment change on the diversity of the AMF communities. To understand: (1) the AMF community composition and diversity at different stage of returning cropland to forest; and (2) the effects of soil environment change on the diversity of the AMF communities, soil and mulberry root samples were collected from Bijie and Libo sites, China, which experienced one and ten years, respectively, after returning croplands to forest. With the high throughput 454-sequencing technology, 8 known genera including 83 virtual species were distinguished and the genera Glomus, Paraglomus, Archaeospora and Diversispora were found to be dominant in soil and root sample. Compared to the samples in Libo, the genera Glomus, Paraglomus, Acaulospora and Claroideoglomus in root samples at Bijie site had a relatively abundance of species indicating that the returning cropland to forest is benefit to the AMF diversity and abundance, which was attribute to the variation of soil physiochemical properties. This conclusion is of great significance for guiding the return of farmland to forests. Key words: mycorrhizal biotechnology, Morus sp., rocky desertification, root, soil properties.
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Composition, diversity and structure of vascular epiphytes in two contrasting Central Amazonian fl oodplain ecosystems

Composition, diversity and structure of vascular epiphytes in two contrasting Central Amazonian fl oodplain ecosystems

Differences in epiphyte diversity may be associated with differences in tree diversity between environments. Epiphytes are dependent on support structure, and they evolved a variety of ways to colonize various tree species and avoid competition. Consequentially, structural host preference of particular epiphytes means that the composition of local tree assemblages can potentially have a strong influence on epiphyte species assemblage composition, (Laube & Zotz 2006; Burns & Zotz 2010). This was shown by Zotz et al. (2014) who investigated canopy of a montane forest in Panama, and found that epiphytes cease to occupy certain habitats not because of climatic adversity, but due to the lack of adequate substrate for colonization. Other supporting evidence comes from observations that epiphyte diversity decreased in areas that suffered a reduction in the tree diversity of primary forest species, and where secondary forests dominated (Bartholott et al. 2001; Wolf 2005).
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Combined effects of landscape composition and heterogeneity on farmland avian diversity

Combined effects of landscape composition and heterogeneity on farmland avian diversity

Meeting conservation objectives without increasing the amount of natural habitats might be achieved through changes in the crops produced, because different crop types have different structural char- acteristics and are associated with distinct agricultural practices that may strongly influence farmland biodiversity (Ribeiro, Santos, Santana, Reino, Beja, et al., 2016; Stoate et al., 2009). In northern Europe, for instance, sowing cereals in spring rather than in autumn increases nest sites for birds (Berg, Wretenberg, Żmihorski, Hiron, & Pärt, 2015; Chamberlain, Fuller, Garthwaite, & Impey, 2001), while producing late- harvested hay rather than early- harvested silage improves forag- ing habitats and increases avian nesting success (Butler, Boccaccio, Gregory, Vorisek, & Norris, 2010). Also, farmland plants, arthropods, and birds are benefited by annual crops and pastures with more hetero- geneous and sparser swards (Wilson, Whittingham, & Bradbury, 2005). The production on former arable land of permanent crops such as olive orchards or energy crops such as willow short rotation coppice may also increase biodiversity, by attracting shrubland and woodland species to farmland (Rey, 2011; Sage, Cunningham, & Boatman, 2006). Despite these potential benefits, however, changing crop types on private land may be difficult, because this is conditional on complex farmers’ deci- sions driven by a combination of agricultural policies, biophysical and socioeconomic constraints, and market demands (Ribeiro et al., 2014).
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Simple does not mean poor: grasslands and forests harbor similar ant species richness and distinct composition in highlands of southern Brazil

Simple does not mean poor: grasslands and forests harbor similar ant species richness and distinct composition in highlands of southern Brazil

Here we assessed the ant community in highlands of the state of Santa Catarina, and showed that grasslands and forests harbor similar richness, yet distinct ant species composition. This work joins recent studies that assessed ant communities in the grassland/mixed forest mosaics of the southern Atlantic forest (Pinheiro et al. 2010, Dröse et al. 2017, Franco & Feitosa 2018). Our results provide insights on the drivers of community organization, and suggest that the combination of relatively high latitude and altitude gives to the ant community some features of temperate habitats, thus distinct from the dense Atlantic Forest and from most Brazilian ecosystems. Such patterns might be context-dependent, and more factors could be involved in the distribution of the biodiversity in this ecosystem, e.g. edge effects (Pinheiro et al. 2010). Nevertheless, we suggest that these grasslands and forests are equally relevant for biodiversity conservation. We call special attention to grasslands, because they are frequently neglected in conservation programs (Overbeck et al. 2015), a conclusion shared by the aforementioned recent studies in the same ecosystem. While grasslands occupy nearly 13.7 million ha in Brazilian territory, less than 0.5% of the ecosystem is within protected areas (Overbeck et al. 2007). As highlighted by some authors, managed grasslands lead to different plant and ant assemblages, and more research is necessary to effectively protect the biodiversity linked with those habitats (Azcárate & Peco 2012). Even though the issues in conservation status of plant species have been raised for over a decade (Overbeck et al. 2007), more recently attention has also been called for arthropod diversity in similar ecosystems around the world (Littlewood et al. 2012).
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Effects of timber harvest on phlebotomine sand flies (Diptera: Psychodidae) in a production forest: abundance of species on tree trunks and prevalence of trypanosomatids

Effects of timber harvest on phlebotomine sand flies (Diptera: Psychodidae) in a production forest: abundance of species on tree trunks and prevalence of trypanosomatids

Although the direct contact between man and phlebotomine foci on the bases of trees is an important source for human infection, the variation of the infec- tion rates of females in time and space has not been sys- tematically studied. The effects of timber harvest on the infection rates of females of those species are unknown. According to Walsh et al. (1993) deforestation results in inevitable effects on vector-borne disease, which in tropical rain forests have rarely been adequately docu- mented. Each environmental change by natural phenom- ena or through human intervention alters the ecological balance and context within which vectors and their para- sites breed develop and transmit diseases (Patz et al. 2000). The present study evaluated the effect of the tim- ber harvest on the abundance of sand flies and their flagel- late infection rates. This study is probably the first to evaluate the logging effects on tree-inhabiting sand fly fauna in Amazonia.
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Composition and diversity of anurans in the Restinga of the Conde municipality, northern coast of the state of Bahia, northeastern Brazil

Composition and diversity of anurans in the Restinga of the Conde municipality, northern coast of the state of Bahia, northeastern Brazil

Abstract: The Conde municipality is located in the northern coast of the state of Bahia (NC), northeastern Brazil, and is part of the Atlantic Tropical domain. The anuran fauna of the northern portion of the NC is still poorly known if compared to the southern portion. The Restinga is one of the predominant environments of the coastal plains of the NC and it is characterized essentially by presenting sandy soil covered by herbaceous and shrubby vegetation. The objective of this study was to determine the anuran species composition and diversity for the Restinga of the Conde municipality. Sampling was carried out at night by active search over four periods of five consecutive days each, two over the ‘main rainy season’ and two in a ‘lesser rainy season’, using 14 sample units (SUs) and five extra sample plots (EPs). We calculated dominance and species diversity using the Berger-Parker and Shannon-Wiener H’ indices, respectively. We used accumulation curves and the Jackknife 1 estimator to estimate anuran species richness, considering only the data obtained from the SUs. We recorded 713 anuran specimens distributed within 33 species, 13 genera and five families (Bufonidae, Craugastoridae, Hylidae, Leptodactylidae and Microhylidae). The Hylidae and Leptodactylidae families had the highest species richness. Considering only the SUs (Jackknife 1 estimator in brackets), we recorded 28 species in the study area (33.9 ± 2.3), 13 in Shrubby Vegetation Zones - SVZ (20.8 ± 2.9) and 25 in Freshwater Wetland Zones - FWZ (28.9 ± 1.9). The abundance and species diversity of the FWZ (n = 638 specimens; H’= 2.4) were higher than those recorded for the SVZ (n = 52 specimens; H’ = 1.9). The SVZ and FWZ showed distinct dominant species, wherein Pristimantis paulodutrai was the dominant species in SVZ and Scinax fuscomarginatus in FWZ. The Restinga of the Conde municipality stands out as the one with the highest anuran species richness already recorded considering only SVZ and FWZ. Moreover, its anuran species composition represented 55% of the anuran species known for the NC and included taxa common to three different morphoclimatic domains (Tropical Atlantic, Cerrado and Caatinga).
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A diverse assemblage of reef corals thriving in a dynamic intertidal reef setting (Bonaparte Archipelago, Kimberley, Australia).

A diverse assemblage of reef corals thriving in a dynamic intertidal reef setting (Bonaparte Archipelago, Kimberley, Australia).

Eight-day average MODIS-derived SST from July 2002 to June 2014 shows that the average SST at North Maret I. ranged from 25.2 to 34.3°C (Table 1). The maximum mean summer SST over this period was 32.2 ± 1.0°C and the minimum mean winter SST was 26.5 ± 1.0°C encompassing a range of 5.7°C. The +1°C bleaching threshold (sensu NOAA Coral Reef Watch methods—see http://coralreefwatch.noaa.gov/satellite/index.php) at North Maret I. is 33.2°C and our data suggest SST remained above this threshold for two 8-day periods in January and February 2013 (Figure E in S1 File). When compared with more typical reef locations (Fig. 7) the mean SST in the vicinity of North Maret I. is significantly higher than Lizard I., Barrow I. and Dent I. but not significantly different from Scott Reef (Table E in S1 File). While Scott Reef has succumbed to bleaching events in the past [43], to date there is no evidence to suggest the intertidal coral communities in the Bona- parte Archipelago have experienced a bleaching event (despite NOAA issuing numerous bleaching alerts e.g Mar-Jun 2013). Even though this region is remote, the Bonaparte Archipelago is intermit- tently visited by scientists (WA Museum, Australian Institute of Marine Science, Department of Fisheries; Cygnet Bay Research Station); tourist vessels and the Australian customs service provide surveillance. While widespread bleaching was been reported across almost 2000 km of Western Australian coastline during the summer of 2010/11 [42] there is no suggestion that the inshore Kimberley reefs have experienced a widespread bleaching event to date.
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Buying Behavior Of Organic Vegetables Product The Effects Of Perceptions Of Quality And Risk

Buying Behavior Of Organic Vegetables Product The Effects Of Perceptions Of Quality And Risk

Quality is defined as the degree of excellence or superiority that an organization’s product possesses (Khan, 2005:28). Consumers judge or perceive the quality of the products and it also called perception of quality, because perception of quality derived from the analysis of consumers on product quality (Sanyal & Datta, 2011:605). Customer perceived value of product quality is a consumer opinion as ability of the product who suitable with expectation of consumer (Terenggana et al., 2013:326). Perception of quality is formed on consumers can be affected by several things including past experience, education, purchasing and consumer community (Yaseen et al., 2011:834), and perception of quality is important in improving the quality of products in the view of consumers (Parrol et al., 2013:603). Since knowledge and consumer needs change time by time, it taken an understanding related consumer perception of quality in evaluated to be known how big influence on purchase intention (Sanyal & Datta, 2011:607). Reviewing consumer behavior in foods, in previous research is often studied through perception of quality (Carrasco et al., 2012:1414). On last studied, perceived quality is the consumer’s judgment about a product’s overall excellence or superiority (Zeithaml, 1988). Meanwhile perceived quality is the judgment a consumer of product which refers to the physical characteristics of the product, and is related more to engineering and food technology (Carrasco et al., 2012). Several things that concern on perception of quality, first are spoke on the advantages related to the assessment of consumer products and the second on the technology applied to products that are both better than similar products. That matter is a critical element for consumer decision making, consequently, consumers will compare the
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Avaliação do impacto no ambiente de compostos hidrossolúveis de Pinus taeda e Araucaria angustifolia (Coniferae) utilizando indicadores biológicos

Avaliação do impacto no ambiente de compostos hidrossolúveis de Pinus taeda e Araucaria angustifolia (Coniferae) utilizando indicadores biológicos

Animals were collected in the summer of 2009/2010 (December, January and February) and winter 2009/2010 (June, July and August); along with macrophytes Callitriche rimosa from their habitat with fish traps. H. castroi, 330 males and 330 females by each season, were collected in São José dos Ausentes Municipality (28°47'00"S – 49°50'53"W; 1200 m a.s.l.), Rio Grande do Sul, Brazil.Animals were transported on cooled water in insulated containers to the Laboratory of Conservation Physiology of PUCRS. Twenty animals of each sex were immediately cryoanesthetized, in order to assess whether there were any differences between the animals collected in the wild (control group) and the animals that received diet ad libitum for 7 days (Diet 7) or 14 days (Diet 14) in cultivation aquariums and the others that received this diet for 7 days and were then exposed to plant material for 7 days.
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Altered community flammability in Florida's Apalachicola ravines and implications for the persistence of the endangered conifer Torreya taxifolia.

Altered community flammability in Florida's Apalachicola ravines and implications for the persistence of the endangered conifer Torreya taxifolia.

The observed magnitude of interspecific differences in flamma- bility suggests that major changes in community flammability have transpired in Florida’s Apalachicola ravines. With the decline of T. taxifolia, a species with very low flammability (Fig. 3, and the relative increases in relatively flammable species, a dramatic shift in community flammability has occurred. Prior to the decline of T. taxifolia, it is likely that T. taxifolia litter dampened the intensity and extent of surface fires that spread from the flammable pine- oak savannas upslope [31]. Extant T. taxifolia contributes little to the litter fuels because it has declined in both abundance and stature, with the average tree height near only 1 m [14, T.S. unpublished manuscript]. As species such as I. opaca, F. grandifolia, and M. grandiflora have replaced forest area formerly occupied by T. taxifolia (Table 3) [19], the flammability and therefore susceptibility of the ravines to fire has increased. The higher flammability of litter of these successor species may promote the spread and increased intensity of fires within the ravines, further suppressing the recovery of T. taxifolia in a negative feedback. Similar fire feedbacks have been found in transitional forests of the tropics [12,13] and savannas in the temperate zone [11] where these feedbacks can act as stabilizing
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Malaria entomological risk factors in relation to land cover in the Lower Caura River Basin, Venezuela

Malaria entomological risk factors in relation to land cover in the Lower Caura River Basin, Venezuela

Vegetation types and land cover - Vegetation analy- sis for the Caura and Erebato basins (M Bevilacqua et al., unpublished observations) identified four types of vegetation within a radius of 5 km around the villages. These types were as follows: forest, vegetation with- out apparent human intervention, a continuous canopy ranging from intermediate to dense coverage (> 70%) and with a mean tree altitude of 18-30 m; late second- ary vegetation, abandoned agricultural area in late suc- cession stage (> 5 years) with trees as the primary life forms and forest as the predominant formation at dif- ferent stages, with coverage of less than 50%, altitude over 5 m, a stratification profile with two-three strata and some wooden emerging elements; early secondary vegetation, abandoned agricultural area characterised by early succession (< 5 years) in which the dominant life forms are grasses, bushes and small trees with altitudes between 3-5 m, medium to scanty coverage and a lack of clear vertical stratification; bare soil-subsistence scale agriculture (conuco), rock, bare soil or very little vegeta- tion coverage and vegetation associated with subsistence agriculture (annual crops, such as cassava, plantains and yam). Table I shows the area in hectares and percentage of coverage for each vegetation type, as well as water bodies (potential larval habitats), which include lagoons, rivers, swamps and streams. Surapire and El Palmar had similar forest coverage (89.60 and 91.97%, respectively), while Jabillal (67.8%) had significantly less forest cover- age (Pearson correlation, p = 0.049), but higher coverage (22.62%) by secondary vegetation and subsistence agri- culture. Intervening forest in Surapire and El Palmar re- sulting in late and early secondary vegetation represented less than 2% of the land cover around these villages.
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Effects of 'target' plant species body size on neighbourhood species richness and composition in old-field vegetation.

Effects of 'target' plant species body size on neighbourhood species richness and composition in old-field vegetation.

Neighbourhoods centred by a large target plant contained fewer neighbour species than associated random neighbourhoods of the same size (Fig. 2); however, this pattern was driven by the four largest individuals in the analysis, including all three samples of a single large species, C. jacea. The size of a target individual did not have a significant effect on the proportion of species reproducing (Fig. 3), or the species-size distribution (Fig. 4), in the local neighbourhood compared with random neighbourhoods. While extremely large target individuals were found to reduce neigh- bourhood plant richness, overall, we found limited support for a general size-advantage, as has been suggested in several simple, short-duration competition experiments [4,11,12]. The growing evidence that such a size-advantage either does not act, or is relatively weak, in natural vegetation signals the limited ability to extrapolate from the results of such competition experiments. The fact that increased body size does not confer a clear advantage emphasizes the need going forward to establish just what conditions favour large plant size, and therefore larger plant species. It remains interesting that many competition experiments have generally supported such an advantage while field studies have generally not. Possible explanations for this disconnect include the general use of biomass based measures of performance [19] which is likely an inadequate measure of fitness [20], the likelihood that smaller species benefit from greater reproductive economy [21,31,50] or are better at occupying resources not captured by large species [32], or that competition in natural communities is predominantly below-ground and size-symmetrical ( [37], but see [15]). Clonal integration does not appear to explain a lack of size-advantage, but warrants further research.
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Filtration of aluminum alloys and its influence on mechanical properties and shape of eutectical silicium

Filtration of aluminum alloys and its influence on mechanical properties and shape of eutectical silicium

Progressive materials with high-speed development in wide range of commercial applications are aluminum alloys Al – Si. Future of their further use is connected with their unique characteristic, resp. advantageous relation between mechanical properties and density. Largest use of these alloys is in the transport industry – automobile and aerial industry. Also often used in engineering industry and special role in army industry. Desirable mechanical properties may be considered one of the main reason for wide spectrum efficiency of aluminum alloys, therefore is very important to understand the factors, which have major impact on this properties. Main goal of this work was to execute group of experiments, to prove impact of filtration elements on morphology of eutectical silicon. Shape, deployment and scale of eutectical silicon are one of the factors, that have
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Comparative Study of Structure Using Composite Members And Conventional Members

Comparative Study of Structure Using Composite Members And Conventional Members

The most important and most frequently encountered combination of construction materials is that of steel and concrete, with applications in multi- storey commercial buildings and factories, as well as in bridges. These materials can be used in mixed structural systems in composite structures where members consisting of steel and concrete act together compositely. Here, in this paper use steel and timber hybrid structure is focused. In conventional practice RCC / structural steel members are used in building structures. But due to Architectural requirement cladding is used in some cases to give aesthetic looks. This increases cost of structure. Hence, if we use composite material then, it saves a lot of material, time and ultimately costing. Benefits of using steel in timber include increase in tensile capacity, seismic performance, and cost savings.
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Effect Of Shape And Plan Configuration On Seismic Response Of Structure

Effect Of Shape And Plan Configuration On Seismic Response Of Structure

frequency of the structure, and its intended use, this method was refined to enable increasingly adequate designs [4]. Buildings have longer periods of vibration and periods of vibration, composed largely of orthogonal, closely spaced modes. Hence, Equivalent static analysis method was adopted in order to design buildings and overcome effect of earthquake on it. In this study I have performed static analysis as per IS 1893-2002. To study the effect of irregular plan and shape configuration I have developed 9 models in STAAD Pro V8i software. Various types of input data to model the all the 9 models were kept same to obtain the predicted behaviour. Various types of data adopted for creating the models are as under,
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Insight into the traditional timber frame walls: Herculaneum evidence versus braced frame structures in Portugal and in Italy

Insight into the traditional timber frame walls: Herculaneum evidence versus braced frame structures in Portugal and in Italy

From the early findings it was clear that the building layout is a result of a post- earthquake reconstruction. Monteix underlines the changes to the original layout through evi- dence of an early Samnite settlement of pre-Roman Age [8,16]. However, the construction solutions were likely selected for the cost-effectiveness, the thinness (possibility to split effi- ciently the interior space), rather than for the seismic resistance of the timber frame system. The internal construction system of the ground floor was probably chosen for the speed of execution and low thickness. In fact, the timber frame walls would have implied the possibility of easy dismantling. In its original conception, the construction system was charac- terized by a timber skeleton filled with heterogeneous components including straw, clay, and fragments of roof tiles. Divided into regular frames of 0.60cmX0.80cm of carbonised wooden components, the framework walls were locked within pillars in brickwork or tuff rocks and brick.
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Factors affecting assemblage attributes of freshwater Oligochaeta in Neotropical shallow floodplain lakes

Factors affecting assemblage attributes of freshwater Oligochaeta in Neotropical shallow floodplain lakes

Oligochaeta species reflect the conditions necessary for their occurrence in certain habitats. When some species found their set of ideal conditions in a same place, it tends to favor co-occurrence of species, which increases the diversity, richness and evenness of the assemblage. From this, it was expected that the availability of various sizes of sediment particles and organic particles would favor the diversity of the Oligochaeta assemblage, similar to found by Fomenko (1972), but this idea was not corroborated by our simple linear regression analysis. Through the contradiction between our data and the literature findings, it can be inferred that the limitations imposed by the limnological variables could mask the effects of sediment heterogeneity.
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Effects of Fishing and Regional Species Pool on the Functional Diversity of Fish Communities

Effects of Fishing and Regional Species Pool on the Functional Diversity of Fish Communities

Although we did not assess the effects of diversity on ecosystem functioning, our results provide stronger evidence for the importance of species richness than many small-scale experimental studies in which the effects of richness are often relatively weak [8–12]. Most small-scale experimental studies have used synthetically assembled communities and it is not clear as to how results from such small-scale manipulative studies may be scaled-up to natural communities. Moreover, empirical studies have been biased towards the study of species at lower trophic levels (e.g. plants and algae) despite the fact that strong interactions may be more common among large animals at higher trophic levels [29]. Vulnerability to extinction is also predicted to increase with both body size and trophic level [4,30–33]. Since richness of large predators is naturally low, a few extinctions may thus result in the loss of the entire top predator trophic level, with disproportionately large effects on ecosystem properties and processes [31,34]. This view is Figure 2. Loss of functional diversity (FD) and regional species richness. Loss of FD is the difference in FD before and after the removal of 1 random species. For each region, the value of FD was calculated as the mean of 100 iterations. See methods for further details.
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