International Journal of Ecology The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. Changes in Allometric Attributes and Biomass of Forests and Woodlands across an Altitudinal and Rainfall Gradient: What Are the Implications of Increasing Seasonality due to Anthropogenic Climate Change? Tue, 28 Apr 2015 11:51:56 +0000 Canonical correspondence analysis and linear regressions were used to relate height, diameter, and dispersion measurements of 36,380 stems from 197 species recorded in 2,341 plots against both climatic and landscape variables. Above ground biomass increased in wetter and cooler locations that ameliorate the seasonal rainfall deficits. Taller and greater diameter trees with lower wood densities occur at higher altitudes. Differences between locations are based on a change in the composition of species rather than a change in the allometric properties within a species. The results support the hydraulic limitation and species packing hypotheses. These interrelationships may be affected by the interactions of fire frequency and drought which are a common feature of much of the study area. Under current climate change scenarios it is likely that there will be a reduction in above ground biomass, the number of stems per hectare, average height, average diameter, and basal area due to increasing seasonality of rainfall, temperatures, and the intensity and frequency of fires. The largest of trees are likely to be removed early due to their inability to cope with increased drought stress. The results suggest a marked reduction in carbon storage will occur across the study region in eastern Australia. John T. Hunter Copyright © 2015 John T. Hunter. All rights reserved. Seasonality of Climate Drives the Number of Tree Hollows in Eastern Australia: Implications of a Changing Climate Wed, 08 Apr 2015 13:38:22 +0000 Tree hollow number is investigated across an altitudinal and climatic gradient in eastern Australia. The relationship between seasonal climate and local site factors to hollow number at a regional scale was investigated. Moisture retention, rainfall, and solar radiation during the summer period were the highest contributing factors to hollow number in the model presented. The relationship of hollow number with the significant variables was unimodal in nature with either extreme causing a decline within the region. The results indicate that increased seasonality of rainfall, solar radiation, and temperatures as predicted by anthropogenic climate change will cause a shift in the optimal location for hollow number. Change in tree hollows is reliant on taxonomic replacement through dispersal and establishment and subsequently time to allow individuals to mature. The reduction in this resource stimulated by changes in seasonality predicted within the ensuing decades is likely to cause a loss of hollows across the landscape with the resource not being replaced for hundreds of years. The number of hollows within a landscape may drastically reduce due to climate change alone irrespective of tree clearing rates. John T. Hunter Copyright © 2015 John T. Hunter. All rights reserved. Modeling Aquatic Macroinvertebrate Richness Using Landscape Attributes Mon, 26 Jan 2015 06:53:47 +0000 We used a rapid, repeatable, and inexpensive geographic information system (GIS) approach to predict aquatic macroinvertebrate family richness using the landscape attributes stream gradient, riparian forest cover, and water quality. Stream segments in the Allegheny River basin were classified into eight habitat classes using these three landscape attributes. Biological databases linking macroinvertebrate families with habitat classes were developed using life habits, feeding guilds, and water quality preferences and tolerances for each family. The biological databases provided a link between fauna and habitat enabling estimation of family composition in each habitat class and hence richness predictions for each stream segment. No difference was detected between field collected and modeled predictions of macroinvertebrate families in a paired t-test. Further, predicted stream gradient, riparian forest cover, and total phosphorus, total nitrogen, and suspended sediment classifications matched observed classifications much more often than by chance alone. High gradient streams with forested riparian zones and good water quality were predicted to have the greatest macroinvertebrate family richness and changes in water quality were predicted to have the greatest impact on richness. Our findings indicate that our model can provide meaningful landscape scale macroinvertebrate family richness predictions from widely available data for use in focusing conservation planning efforts. Marcia S. Meixler and Mark B. Bain Copyright © 2015 Marcia S. Meixler and Mark B. Bain. All rights reserved. Potential Effects of the Loss of Native Grasses on Grassland Invertebrate Diversity in Southeastern Australia Mon, 01 Dec 2014 07:42:30 +0000 Reduction in area of the southeastern temperate grasslands of Australia since European settlement has been accompanied by degradation of remaining remnants by various factors, including the replacement of native plant species by introduced ones. There are suggestions that these replacements have had deleterious effects on the invertebrate grassland community, but there is little evidence to support these suggestions. In the eastern Adelaide Hills of South Australia, four grassland invertebrate sampling areas, in close proximity, were chosen to be as similar as possible except for the visible amount of native grass they contained. Sample areas were surveyed in four periods (summer, winter, spring, and a repeat summer) using pitfall traps and sweep-netting. A vegetation cover survey was conducted in spring. Morphospecies richness and Fisher’s alpha were compared and showed significant differences between sample areas, mainly in the summer periods. Regression analyses between morphospecies richness and various features of the groundcover/surface showed a strong positive and logical association between native grass cover and morphospecies richness. Two other associations with richness were less strong and lacked a logical explanation. If the suggested direct effect of native grass cover on invertebrate diversity is true, it has serious implications for the conservation of invertebrate biodiversity. Roger Edgcumbe Clay Copyright © 2014 Roger Edgcumbe Clay. All rights reserved. Edge Effects and the Population Structure of Humboldt Bay, California, Eelgrass (Zostera marina L.) Sun, 23 Nov 2014 08:19:26 +0000 The physical structure of a habitat (e.g., fragmentation) may affect the distribution of genetic diversity within a population, and genetic diversity may alter ecological function. This study investigates the population genetics of Humboldt Bay, California, eelgrass in light of the habitat’s fragmented physical structure. Historical and ongoing dredging operations in the bay maintain channels between fragmented tidal mudflats that are inhabited by eelgrass. A sample of 469 individuals, from 11 discrete fragments, was genotyped using microsatellite analysis. Ramets were collected at multiple points located at the edge and in the interior of each fragment. The sampling scheme was designed to detect evidence of population structure within and between fragments, as well as between edge and interior bed positions. Genetic diversity is not shown to differ among fragments and is not consistent with widespread clonality. Heterozygosity levels indicate that Hardy-Weinberg equilibrium predominates across loci in most instances. Comparisons of edge and interior bed positions also reveal similarities between positions for the metrics described above. Results suggest efficient gene flow between fragments and between bed positions. Such findings, which indicate the unstructured nature of the population, can guide resource managers in making evolutionarily informed conservation decisions by discouraging assumptions of low genetic diversity and insignificant sexual reproduction. Joshua S. Neely Copyright © 2014 Joshua S. Neely. All rights reserved. Litter Fall and Its Decomposition in Sapium sebiferum Roxb.: An Invasive Tree Species in Western Himalaya Thu, 13 Nov 2014 00:00:00 +0000 Recognizing that high litter fall and its rapid decomposition are key traits of invasive species, litter fall and its decay in Sapium sebiferum Roxb. were studied in Palampur. For this, litter traps of dimension 50 × 50 × 50 cm3 were placed in under-canopy and canopy gap of the species. Litter fall was monitored monthly and segregated into different components. For litter decay studies, litter bags of dimension 25 × 20 cm2 with a mesh size 2 mm were used and the same were analyzed on a fortnightly basis. Litter fall in both under-canopy and canopy gap was highest in November (1.16 Mg ha−1 y−1 in under-canopy and 0.38 Mg ha−1 y−1 in canopy gap) and lowest during March. Litter production in under-canopy and canopy gap was 4.04 Mg ha−1 y−1 and 1.87 Mg ha−1 y−1, respectively. These values are comparable to sal forest (1.7 t C ha−1 y−1), chir pine-mixed forest (2.1 t C ha−1 y−1), and mixed oak-conifer forest (2.8 t C ha−1 y−1) of the Western Himalaya. The decay rate, 0.46% day−1 in under-canopy and 0.48% day−1 in canopy gap, was also fast. Owing to this the species may be able to modify the habitats to its advantage, as has been reported elsewhere. Vikrant Jaryan, Sanjay Kr. Uniyal, R. C. Gupta, and R. D. Singh Copyright © 2014 Vikrant Jaryan et al. All rights reserved. Distribution and Conservation of Davilla (Dilleniaceae) in Brazilian Atlantic Forest Using Ecological Niche Modeling Wed, 12 Nov 2014 12:34:53 +0000 We have modeled the ecological niche for 12 plant species belonging to the genus Davilla (Dilleniaceae) which occur in the Atlantic Forest of Brazil. This group includes endemic species lianas threatened by extinction and is therefore a useful indicator for forest areas requiring conservation. The aims are to compare the distribution and richness of species within the protected areas, assessing the degree of protection and gap analysis of reserves for this group. We used the Maxent algorithm with environmental and occurrence data, and produced geographic distribution maps. The results show that high species richness occurs in forest and coastal forest of Espírito Santo to Bahia states. The endemic species comprise D. flexuosa, D. macrocarpa, D. flexuosa, D. grandifolia, and D. sessilifolia. In the Atlantic Forest of southeastern Brazil, the following endemic species occur: D. tintinnabulata and D. glaziovii, with this latter species being included in the “red list” due habitat loss and predatory extractivism. The indicators of species richness in the coastal region of Bahia correspond with floristic inventories that point to this area having a high biodiversity. Although this region has several protected areas, there are gaps in reserves, which, combined with anthropogenic threats and fragmentation, have caused several problems for biodiversity. Ismael Martins Pereira, Vera Lúcia Gomes-Klein, and Milton Groppo Copyright © 2014 Ismael Martins Pereira et al. All rights reserved. Assessment of the Bioavailability of Cu, Pb, and Zn through Petunia axillaris in Contaminated Soils Mon, 25 Aug 2014 09:45:18 +0000 Heavy metals are potentially toxic to human life and the environment. Metal toxicity depends on chemical associations in soils. For this reason, determining the chemical form of a metal in soils is important to evaluate its mobility and the potential accumulation. The aim of this examination is to evaluate the accumulation potential of Petunia x hybrida as a flower crop for three metals, namely, copper (Cu), lead (Pb), and nickel (Ni). Trace metals (Zn, Cu, and Pb) in the soils were partitioned by a sequential extraction procedure into H2O extractable (F1), 1 M CH3COONa extractable (F2). Chemical fractionation showed that F1 and F2 fraction of the metals were near 1% and residue was the dominant form for Zn, Cu, and Pb in all samples. Using fluorescence method allowed us to estimate condition of the plants by adding metals. As result of plant and soil analysis, we can conclude that Petunia has Cu, Zn, and Ni tolerance and accumulation. Therefore, Petunia has the potential to serve as a model species for developing herbaceous, ornamental plants for phytoremediation. Lydia Bondareva, Roman Teisserenc, Nina Pakharkova, Alexander Shubin, Théo Le Dantec, Leïla Renon, and Ivan Svoboda Copyright © 2014 Lydia Bondareva et al. All rights reserved. Responses of Soil Organic Carbon to Long-Term Understory Removal in Subtropical Cinnamomum camphora Stands Thu, 03 Jul 2014 06:43:38 +0000 We conducted a study on a 48-year-old Cinnamomum camphora plantation in the subtropics of China, by removing understory gradually and then comparing this treatment with a control (undisturbed). This study analyzed the content and storage soil organic carbon (SOC) in a soil depth of 0–60 cm. The results showed that SOC content was lower in understory removal (UR) treatment, with a decrease range from 5% to 34%, and a decline of 10.16 g·kg−1 and 8.58 g·kg−1 was noticed in 0–10 cm and 10–20 cm layers, respectively, with significant differences (). Carbon storage was reduced in UR, ranging from 2% to 43%, with a particular drastic decline of 15.39 t·hm−2 and 11.58 t·hm−2 in 0–10 cm () and 10–20 cm () layers, respectively. Content of SOC had an extremely significant () correlation with soil nutrients in the two stands, and the correlation coefficients of CK were higher than those of UR. Our data showed that the presence of understory favored the accumulation of soil organic carbon to a large extent. Therefore, long-term practice of understory removal weakens the function of forest ecosystem as a carbon sink. Yacong Wu, Zhengcai Li, Caifang Cheng, and Rongjie Liu Copyright © 2014 Yacong Wu et al. All rights reserved. Are Commonly Measured Functional Traits Involved in Tropical Tree Responses to Climate? Wed, 25 Jun 2014 11:11:01 +0000 Climate models predict significant rainfall reduction in Amazonia, reducing water availability for trees. We present how functional traits modulate the tree growth response to climate. We used data from 3 years of bimestrial growth measurements for 204 trees of 53 species in the forest of Paracou, French Guiana. We integrated climate variables from an eddy covariance tower and functional trait values describing life history, leaf, and stem economics. Our results indicated that the measured functional traits are to some extent linked to the response of trees to climate but they are poor predictors of the tree climate-induced growth variation. Tree growth was affected by water availability for most of the species with different species growth strategies in drought conditions. These strategies were linked to some functional traits, especially maximum height and wood density. These results suggest that (i) trees seem adapted to the dry season at Paracou but they show different growth responses to drought, (ii) drought response is linked to growth strategy and is partly explained by functional traits, and (iii) the limited part of the variation of tree growth explained by functional traits may be a strong limiting factor for the prediction of tree growth response to climate. Fabien Wagner, Vivien Rossi, Christopher Baraloto, Damien Bonal, Clément Stahl, and Bruno Hérault Copyright © 2014 Fabien Wagner et al. All rights reserved. Location and Roles of Deep Pools in Likangala River during 2012 Recession Period of Lake Chilwa Basin Tue, 03 Jun 2014 12:32:53 +0000 The ecological study focusing on Likangala River was conducted during the recent (2012) Lake Chilwa recession and aimed at identifying the important pools and the impact of indigenous ecological knowledge on the use and management of the aquatic biodiversity in the pools. An extensive georeferencing of the pools, field observations, and measurement of the pool depths was conducted to locate and map the deep pools along the river. Garmin Etrex Venture HC, GPS, and georeferencing were used to obtain the points and locate the place. Oral interviews with local leaders were conducted to understand the use and management of the pools by communities. The study showed that Likangala River has 17 pools with depths ranging from 1.85 m to 3.6 m. The pools act as habitats and feeding and spawning ground for various aquatic biodiversity. The study further found that some important deep pools have apparently become shallower during the past few years due to increased silt deposition from the upper part of the catchment. The study shows that deep pools are very important during Lake Chilwa recession and recommends the participatory fisheries management as the best way of sustaining the aquatic biodiversity and endangered species in Lake Chilwa basin. Rodgers Makwinja, Mphatso Chapotera, Patrick Likongwe, John Banda, and Asaf Chijere Copyright © 2014 Rodgers Makwinja et al. All rights reserved. Stabilizing Effect of Prey Refuge and Predator’s Interference on the Dynamics of Prey with Delayed Growth and Generalist Predator with Delayed Gestation Wed, 30 Apr 2014 07:24:42 +0000 In the present paper, I study a prey-predator model with multiple time delays where the predator population is regarded as generalist. For this regard, I consider a Holling-Tanner prey-predator system where a constant time delay is incorporated in the logistic growth of the prey to represent a delayed density dependent feedback mechanism and the second time delay is considered to account for the length of the gestation period of the predator. Predator’s interference in predator-prey relationship provides better descriptions of predator's feeding over a range of prey-predator abundances, so the predator's functional response here is considered to be Type II ratio-dependent. In accordance with previous studies, it is observed that delay destabilizes the system, in general, and stability loss occurs via Hopf bifurcation. There exist critical values of delay parameters below which the coexistence equilibrium is stable and above which it is unstable. Hopf bifurcation occurs when delay parameters cross their critical values. When delay parameters are large enough than their critical values, the system exhibits chaotic behavior and this abnormal behavior may be controlled by refuge. Numerical computation is also performed to validate different theoretical results. Lyapunov exponent, recurrence plot, and power spectral density confirm the chaotic dynamical behaviors. Debaldev Jana Copyright © 2014 Debaldev Jana. All rights reserved. A Comparison of Three Dry Matter Forage Production Methods Used in South Africa Sun, 27 Apr 2014 13:59:38 +0000 A common method for determining forage production of rangelands is by clipping and weighing forage from quadrats with predetermined areas. This technique is however time consuming. Other techniques which require less time and labour include amongst others using the disk pasture meter or phytomass derived from the vegetation classification program PHYTOTAB, in conjunction with the Plant Number Scale, which is used to determine vegetation canopy cover. The phytomass determined using PHYTOTAB/Plant Number Scale and the disk pasture meter was compared to the phytomass obtained from the actual clipping and weighing of forage. Tests showed that there were indeed statistically significant differences between the mean phytomass values of the three techniques. Considerable variation was shown in the results of the disk pasture meter readings compared to the other two techniques. The phytomass values obtained using the disk pasture meter were significantly higher than the phytomass determined using both the PHYTOTAB/Plant Number Scale and the clipping and weighing techniques. Results further indicated a significant similarity in the phytomass determined using the PHYTOTAB/Plant Number Scale and the clipping and weighing technique. The results of this pilot study need further investigation. A. J. Joubert and W. J. Myburgh Copyright © 2014 A. J. Joubert and W. J. Myburgh. All rights reserved. Semideciduous Seasonal Forest Production of Leaves and Deciduousness in Function of the Water Balance, LAI, and NDVI Mon, 31 Mar 2014 00:00:00 +0000 This study investigated the relationship between leaf production, litterfall, water balance, Leaf Area Index (LAI), and Normalized Difference Vegetation Index (NDVI) in semideciduous forests. The goal was to model this phenomenon to obtain the estimates of this component as an additional compartment of the ecosystem carbon sink. The tests were conducted in eight semideciduous forest fragments. Twenty-four permanent plots were monitored monthly and LAI measurements and weighing of litterfall deposited in nets were conducted for a period of thirteen months. In this period, Landsat 5 and IRS satellite images were obtained and processed for generation of NDVI. The water balance was calculated for each day. The relationship among the variables “leaf dry weight,” “LAI,” “NDVI,” and “water balance” was verified and a regression model was built and evaluated. The deciduous phenomenon can be explained by hydric balance, and LAI and NDVI are ancillary variables. The tendency of the variables in the period of 13 months was explained by quadratic functions. The varied behavior among the monitoring sites helped to know differences in the deposition of leaves. This study showed that only the leaf component of the litterfall of a semideciduous forest in tropical climate can capture 4 to 8 Mgha−1yr−1 of CO2 and this amount can be estimated using climate, biophysics, and vegetation index variables. Thomaz Correa e Castro da Costa, João Herbert Moreira Viana, and Juliana Leite Ribeiro Copyright © 2014 Thomaz Correa e Castro da Costa et al. All rights reserved. Potential Propagation by Seed and Cuttings of the Azorean Native Calluna vulgaris (L.) Hull Tue, 25 Mar 2014 08:00:40 +0000 This work investigates the potential propagation by seed and cuttings of the Azorean native Calluna vulgaris (L.) Hull. for landscape conservation. With that purpose we have performed several germination and cuttings trials, using plant material from wild populations of this species. In the germination trials, we tested the effects of photoperiod length (8 and 16 h), temperature (10, 15, 20, and 20–10°C), seed age (6, 108, and 270 days), temperature of seed storage (4°C and room temperature), and seed surface sterilization on the germination characteristics. In the cuttings trials, we tested the effects of stem cutting type, cultural conditions, cuttings’ harvest month, and rooting substrates on the rooting percentages. The best percentages of germination, 93 and 90%, were obtained with fresh seeds and surface sterilized and sown under an 8 h photoperiod and with temperatures of 10°C or 15°C, respectively; germination after seed storage during 270 days is significantly superior (71%) when seeds are stored at 4°C. The best percentages of rooting were achieved for straight (96%) or heel cuttings (90%) harvested in March, planted on soil from natural stands of C. vulgaris and Erica azorica Hochst., outdoors in half shade, and partially covered with transparent polyethylene film. Maria João Pereira, Helena Fagundo, Tiago Menezes, and João Couto Copyright © 2014 Maria João Pereira et al. All rights reserved. Venus Flytrap Seedlings Show Growth-Related Prey Size Specificity Tue, 18 Mar 2014 09:10:20 +0000 Venus flytrap (Dionaea muscipula) has had a conservation status of vulnerable since the 1970s. Little research has focussed on the ecology and even less has examined its juvenile stages. For the first time, reliance on invertebrate prey for growth was assessed in seedling Venus flytrap by systematic elimination of invertebrates from the growing environment. Prey were experimentally removed from a subset of Venus flytrap seedlings within a laboratory environment. The amount of growth was measured by measuring trap midrib length as a function of overall growth as well as prey spectrum. There was significantly lower growth in prey-eliminated plants than those utilising prey. This finding, although initially unsurprising, is actually contrary to the consensus that seedlings (traps < 5 mm) do not catch prey. Furthermore, flytrap was shown to have prey specificity at its different growth stages; the dominant prey size for seedlings did not trigger mature traps. Seedlings are capturing and utilising prey for nutrients to increase their overall trap size. These novel findings show Venus flytrap to have a much more complex evolutionary ecology than previously thought. Christopher R. Hatcher and Adam G. Hart Copyright © 2014 Christopher R. Hatcher and Adam G. Hart. All rights reserved. Understanding the Terrestrial Carbon Cycle: An Ecohydrological Perspective Tue, 04 Mar 2014 12:03:10 +0000 The terrestrial carbon (C) cycle has a great role in influencing the climate with complex interactions that are spatially and temporally variable and scale-related. Hence, it is essential that we fully understand the scale-specific complexities of the terrestrial C-cycle towards (1) strategic design of monitoring and experimental initiatives and (2) also developing conceptualizations for modeling purposes. These complexities arise due to the nonlinear interactions of various components that govern the fluxes of mass and energy across the soil-plant-atmospheric continuum. Considering the critical role played by hydrological processes in governing the biogeochemical and plant physiological processes, a coupled representation of these three components (collectively referred to as ecohydrological approach) is critical to explain the complexity in the terrestrial C-cycling processes. In this regard, we synthesize the research works conducted in this broad area and bring them to a common platform with an ecohydrological spirit. This could aid in the development of novel concepts of nonlinear ecohydrological interactions and thereby help reduce the current uncertainties in the terrestrial C-cycling process. The usefulness of spatially explicit and process-based ecohydrological models that have tight coupling between hydrological, ecophysiological, and biogeochemical processes is also discussed. Ajit Govind and Jyothi Kumari Copyright © 2014 Ajit Govind and Jyothi Kumari. All rights reserved. Adaptation of Australia’s Marine Ecosystems to Climate Change: Using Science to Inform Conservation Management Tue, 25 Feb 2014 08:28:25 +0000 The challenges that climate change poses for marine ecosystems are already manifesting in impacts at the species, population, and community levels in Australia, particularly in Tasmania and tropical northern Australia. Many species and habitats are already under threat as a result of human activities, and the additional pressure from climate change significantly increases the challenge for marine conservation and management. Climate change impacts are expected to magnify as sea surface temperatures, ocean chemistry, ocean circulation, sea level, rainfall, and storm patterns continue to change this century. In particular, keystone species that form the foundation of marine habitats, such as coral reefs, kelp beds, and temperate rocky reefs, are projected to pass thresholds with subsequent implications for communities and ecosystems. This review synthesises recent science in this field: the observed impacts and responses of marine ecosystems to climate change, ecological thresholds of change, and strategies for marine conservation to promote adaptation. Increasing observations of climate-related impacts on Australia’s marine ecosystems—both temperate and tropical—are making adaptive management more important than ever before. Our increased understanding of the impacts and responses of marine ecosystems to climate change provides a focus for “no-regrets” adaptations that can be implemented now and refined as knowledge improves. Johanna E. Johnson and Neil J. Holbrook Copyright © 2014 Johanna E. Johnson and Neil J. Holbrook. All rights reserved. Impact of Environmental Changes on Migratory Bird Survival Wed, 19 Feb 2014 00:00:00 +0000 We present a mathematical model that studies and simulates the interconnection between energetic and ecological aspects of bird migration. By comparing model predictions with experimental data, we show that it can be used to assess the impact of changing environmental conditions in breeding, wintering, and stop-over sites on migratory success. We relate in particular to the European white stork (Ciconia ciconia) and its Eastern migration route and discuss questions concerning the timing, stopover, and feeding behavior en route. Opinions concerning the importance of resource availability and resource quality en route are divided. Whereas some studies have shown that storks gain weight in the wintering site, but almost do not feed en route, others stress the importance of the quality of stop-over locations. We address these questions and simulate the development of stork populations for changing environmental conditions. We demonstrate that resource availability and competition for breeding sites are crucial factors determining the timing of spring migration and the length of stop-over periods. Analyzing the robustness of migration strategies with respect to changing environmental conditions, we show that birds will shorten their stay in stop-over places of poor resource availability rather than prolonging it in the attempt to gain time for accumulating fat reserves. Sabine Stöcker-Segre and Daniel Weihs Copyright © 2014 Sabine Stöcker-Segre and Daniel Weihs. All rights reserved. Biological Monitoring Using Macroinvertebrates as Bioindicators of Water Quality of Maroaga Stream in the Maroaga Cave System, Presidente Figueiredo, Amazon, Brazil Mon, 17 Feb 2014 12:52:12 +0000 Aquatic environments are being modified by anthropogenic activities regarding their biological, physical, and chemical conditions; even pristine aquatic ecosystems can be threatened. This study focused on the biological monitoring of Maroaga Stream—a first order stream located in an Environmental Protection Area in the Amazon using the Biological Monitoring Working Party (BMWP) Score System. The BMWP Score System revealed that the Maroaga Stream was a Class I stream (score of 138 points), indicating clean or not significantly altered water quality. The results suggest the adequate environmental conditions and ecological responses of the Maroaga Stream. Christiane Brito Uherek and Fernando Bernardo Pinto Gouveia Copyright © 2014 Christiane Brito Uherek and Fernando Bernardo Pinto Gouveia. All rights reserved. Conservation Concern for the Deteriorating Geographical Range of the Grey Parrot in Cameroon Sun, 16 Feb 2014 14:37:58 +0000 The need for information on Grey Parrot distribution and vegetation associations for informed management and policy decisions was the basis for this study. A nationwide survey of the Grey Parrot population and habitat status was carried out, using questionnaire and point count methods. From the results, the extent of the contemporary range of the parrots was restricted to Southern Cameroon, which harbours the rainforest. Regional parrot population means ranged from 3,487 parrots in the Littoral to 1,351,275 parrots in the East Regions. The extent of the contemporary range as a percentage of the whole country was 25.4% and as a percentage of the regions with rainforest was 44.5%. The historic range of the bird has been reduced by over 55.5%. Estimated percentage of forest lost per region ranged from 20.4% in the Centre to 57.1% in the East and South Regions. At a global level, Cameroon contributed 9% to the total extent of the range of the Grey Parrot in Africa. The range is increasingly fragmented, contracted, and lost through land-based socioeconomic activities. These degradation pressures on the range called for urgent conservation considerations for long-term survival of the parrot species and its associated biodiversity in Cameroon. Simon A. Tamungang, Robert A. Cheke, Gilbert Z. Mofor, Richard N. Tamungang, and Fritz T. Oben Copyright © 2014 Simon A. Tamungang et al. All rights reserved. Ecological Importance of Insects in Selenium Biogenic Cycling Thu, 06 Feb 2014 00:00:00 +0000 Selenium is an essential trace element for animal and human beings. Despite the importance of insects in most ecosystems and their significant contribution to the biological cycling of trace elements due to high abundance, population productivity, and diverse ecosystem functions, surprisingly little information is available on selenium bioaccumulation by these arthropods. This review considers selenium essentiality and toxicity to insects as well as insects’ contribution to selenium trophic transfer through the food chains. Data on Se accumulation by insects of the Dniester River Valley with no anthropogenic Se loading reveal typically low Se content in necrophagous insects compared to predators and herbivores and seasonal variations in Se accumulation. Nadezhda Golubkina, Sergey Sheshnitsan, and Marina Kapitalchuk Copyright © 2014 Nadezhda Golubkina et al. All rights reserved. Macroinvertebrate Richness Importance in Coastal Tropical Streams of Esmeraldas (Ecuador) and Its Use and Implications in Environmental Management Procedures Tue, 14 Jan 2014 09:13:31 +0000 This study was aimed at determining the performance of some indices and community attributes frequently used to assess river quality and test the role of macroinvertebrate taxa richness as element of bioindication in several coastal tropical streams of western Esmeraldas (Ecuador). In addition, a macroinvertebrate taxon list of this region was provided for the first time. Thirteen sampled points distributed across nine streams were selected for this study and nineteen parameters and attributes of bioindication were tested. The differences between nonimpact and impact places were evaluated mainly using one-way analysis of variance. Jackknife 2 and Clench were used to estimate the regional richness and the quality of the inventory, respectively. Seventy taxa (principally genus and family) of the main groups of macroinvertebrates were collected. Measured richness and family richness were the best metric followed by Biological Monitoring Working Party/Colombia (BMWP/Col), Odonata richness, Shannon-Weiner, and EPT richness (Ephemeroptera + Plecoptera + Trichoptera) indices. Only a slight right trend (Ephemeroptera, Trichoptera, and Chironomidae attributes) or incorrect performances (Average Score Per Taxon (ASPT) and % EPT) were showed by frequently used metrics. Finally, several recommendations were made about taxonomic level used, the ranks of quality of taxa richness, and the effort-results relationship in the field of bioindication. Carlos Martínez-Sanz, Sara María Puente-García, Eduardo Rodolfo Rebolledo, and Pedro Jiménez-Prado Copyright © 2014 Carlos Martínez-Sanz et al. All rights reserved. Diversity-Productivity Relationship in the Northeastern Tamaulipan Thornscrub Forest of Mexico Sun, 05 Jan 2014 12:21:19 +0000 This research examines the diversity-productivity relationship in a semiarid scrubland, initially under late successional conditions and subsequently under early successional conditions created by experimental clearing, to explore the roles that productivity and stochastic mortality play in species exclusion in this environment. A total of fifteen plots were studied by measuring environmental conditions and biomass components of shrubs and seedlings. These stands were distributed along a productivity gradient across five different landforms. A hypothesis about the stochastic self-thinning mortality model along the gradient was evaluated with the diversity-productivity-environment data. The diversity-productivity relationship was linear and reversed between the early and late succession stages. The hypothesis of stochastic mortality of species exclusion was rejected in the early stages of succession and partially accepted in the mature stage of succession. Species exclusion was negatively related to productivity gradients, suggesting that strong interspecific competition occurs in high productivity plots and that a larger number of species can survive in higher abiotic stress landscapes. Further research is needed to understand the temporal and spatial variations of the ecological interactions that shape this plant community. Jose Navar, F. de Jesus Rodriguez-Flores, Pedro A. Dominguez-Calleros, and Gustavo Perez-Verdin Copyright © 2014 Jose Navar et al. All rights reserved. Influence of Plant Diversity on the Numerical Response of Eriopis connexa (Coleoptera: Coccinellidae) to Changes in Cereal Aphid Density in Wheat Crops Thu, 26 Dec 2013 11:26:50 +0000 Cereal aphids cause economic injury to wheat crops. In Argentina, Eriopis connexa is an indigenous ladybird. In the present study, the numerical response of E. connexa to changes in aphid density on wheat crops with high and low plant diversity was investigated. The study was carried out in Balcarce, Buenos Aires, Argentina, from September to December 2007 and 2008, on two wheat crops with either a higher plant diversity (HPD) with refuge strips or a lower plant diversity (LPD) without refuge strips. Crops were sampled every week and the abundance of aphids and E. connexa was recorded. The dominant aphid species were Schizaphis graminum, Metopolophium dirhodum, and Sitobion avenae. Eriopis connexa showed a linear increase in the numerical response to an increase in aphid density, which varied in space and time. The abundance of E. connexa increased in relation to the crop development and aphid population and was higher in the HPD than in the LPD system. This predator increased its reproductive numerical response only in 2008, with a significant liner response in the HPD system. This suggests that the potential of E. connexa as a predator of cereal aphids also increases directly in proportion to landscape vegetal diversity. María C. Tulli, Dora M. Carmona, and Ana M. Vincini Copyright © 2013 María C. Tulli et al. All rights reserved. Analysis of Temporal and Spatial Changes in the Vegetation Density of Similipal Biosphere Reserve in Odisha (India) Using Multitemporal Satellite Imagery Tue, 24 Dec 2013 18:20:19 +0000 National parks and protected areas require periodic monitoring because of changing land cover types and variability of landscape contexts within and adjacent to their boundaries. In this study, remote sensing and GIS techniques were used to analyse the changes in the vegetation density particularly in the zones of higher anthropogenic pressure in the Similipal Biosphere Reserve (SBR) of Odisha (India), using Landsat imagery from 1975 to 2005. A technique for the detection of postclassification changes was followed and the change in vegetation density as expressed by normalized difference vegetation index was computed. Results indicate that high dense forest in the core zone has been conserved and the highest reforestation has also occurred in this zone of SBR. The results also reveal that anthropological interventions are more in the less dense forest areas and along the roads, whereas high dense forest areas have remained undisturbed and rejuvenated. This study provides baseline data demonstrating alteration in land cover over the past three decades and also serves as a foundation for monitoring future changes in the national parks and protected areas. Anima Biswal, A. Jeyaram, Sumit Mukherjee, and Umesh Kumar Copyright © 2013 Anima Biswal et al. All rights reserved. Forest Fragments Surrounded by Sugar Cane Are More Inhospitable to Terrestrial Amphibian Abundance Than Fragments Surrounded by Pasture Sat, 14 Dec 2013 10:51:15 +0000 In recent years, there has been increasing interest in matrix-type influence on forest fragments. Terrestrial amphibians are good bioindicators for this kind of research because of low vagility and high philopatry. This study compared richness, abundance, and species composition of terrestrial amphibians through pitfall traps in two sets of semideciduous seasonal forest fragments in southeastern Brazil, according to the predominant surrounding matrix (sugar cane and pasture). There were no differences in richness, but fragments surrounded by sugar cane had the lowest abundance of amphibians, whereas fragments surrounded by pastures had greater abundance. The most abundant species, Rhinella ornata, showed no biometric differences between fragment groups but like many other amphibians sampled showed very low numbers of individuals in fragments dominated by sugar cane fields. Our data indicate that the sugar cane matrix negatively influences the community of amphibians present in fragments surrounded by this type of land use. Paula Eveline Ribeiro D’Anunciação, Marcela Fernandes Vilela Silva, Lucas Ferrante, Diego Santana Assis, Thamires Casagrande, Andréa Zalmora Garcia Coelho, Bárbara Christina Silva Amâncio, Túlio Ribeiral Pereira, and Vinícius Xavier da Silva Copyright © 2013 Paula Eveline Ribeiro D’Anunciação et al. All rights reserved. Winter Latitudinal Population Age-Structure of a Migratory Seagull (Larus fuscus) Differs between Its Two Major Migratory Flyways Sun, 08 Dec 2013 11:26:08 +0000 The migration is energy-demanding and is expected to greatly affect the distribution of individuals over the species range and condition the choice of migratory routes. We investigated the wintering distributions and migratory flyways use of geographically contiguous populations of Lesser Black-backed Gulls (Larus fuscus) and difference in population winter age structure between migratory flyways. Recoveries of metal ringed pulli from Denmark, Sweden, and Finland were used. The results showed that contiguous populations can have distinct wintering distribution patterns and migratory flyways. More importantly, we found that depending on the place of origin, the population winter distribution may or may not show a latitudinal cline in the age structure. The population migrating via the eastern Atlantic flyway (western flyway) showed a winter age-related latitudinal cline, with adults staying at more northern latitudes than immatures. In contrast, no such pattern was found in the population migrating along the Mediterranean/Black sea flyway (eastern flyway). Interestingly, immatures within the eastern population showed a more dispersed pattern of migratory bearings. Overall, our results enhance the importance of the migration flyway in shaping the age structure of populations in the winter quarters and how it may influence the effect of other factors like sexual maturation. Paulo A. M. Marques and Paulo E. Jorge Copyright © 2013 Paulo A. M. Marques and Paulo E. Jorge. All rights reserved. Ecological Restoration and Reforestation of Fragmented Forests in Kianjavato, Madagascar Thu, 05 Dec 2013 14:18:12 +0000 A reforestation effort in Kianjavato Commune in southeast Madagascar is presented that combines native diversity with rapidly growing introduced and native pioneer trees. This work utilizes a three-tiered corridor design that capitalizes on the region’s mountainous terrain. The process of seed selection, transplantation, and survival rate of seedlings over a 16 month period is reported. The uppermost 50% of each mountain is planted with 38 woody species and most closely approximates native forest. This tier was divided into two categories, pioneer and secondary species. Most of the pioneer species were not native; however, results showed that four fast-growing, environmentally-tolerant native species could be suitable alternatives: Streblus mauritianus, Syzygium bernieri, Treculia madagascariensis and Uapaca thouarsii. More than 70,000 seeds of secondary species were extracted from fecal samples from wild, free-ranging black and white ruffed lemurs; the majority of which germinated significantly better after gut passage. The most effective pretreatment that enhanced germination was to scarify unwashed seeds. Commercially valuable trees, belonging to the community members, were grown on the lower half of each mountain. Lastly, the various contributions of the community are described along with agroforestry development plans designed to reduce pressure on forest resources and generate supplemental income. Christophe Manjaribe, Cynthia L. Frasier, Bakolimalala Rakouth, and Edward E. Louis Jr. Copyright © 2013 Christophe Manjaribe et al. All rights reserved. Induced Bacteriovory in a Declining Culture of the Mixotrophic Dinoflagellate Prorocentrum minimum (Pavillard) Schiller Tue, 03 Dec 2013 12:07:19 +0000 Bacteriovory was reported previously in the dinoflagellate, Prorocentrum minimum, but it was unclear if this is constitutive or induced under certain conditions. We tested the hypothesis that phosphate deficiency, or cessation of autotrophic growth for other reasons, would induce bacteriovory in a culture of P. minimum that is harmful to shellfish. Phosphate-starved cells did not ingest fluorescently labeled bacteria and died. In stationary-phase, full-enrichment cultures, more than half of viable P. minimum cells showed declines in chlorophyll that was coincident with incorporation of fluorescently labeled bacteria. Declining populations of P. minimum increase in toxicity to suspension-feeding shellfish; this suggests a possible association between bacteriovory and toxicity. Gary H. Wikfors and Emilie Fernandez Copyright © 2013 Gary H. Wikfors and Emilie Fernandez. All rights reserved.