Spectrophotometric color measurement for early detection and monitoring of greening on granite buildings

This paper addresses the detection and monitoring of the development of epilithic phototrophic biofilms on the granite façade of an institutional building in Santiago de Compostela (NW Spain), and reports a case study of preventive conservation. The results provide a basis for establishing criteria for the early detection of phototrophic colonization (greening) and for monitoring its development on granite buildings by the use of color changes recorded with a portable spectrophotometer and represented in the CIELAB color space. The results show that parameter b* (associated with changes of yellowness-blueness) provides the earliest indication of colonization and varies most over time, so that it is most important in determining the total color change. The limit of perception of the greening on a granite surface was also established in a psycho-physical experiment, as Δb*: +0.59 CIELAB units that correspond, in the present study, to 6.3 μg of biomass dry weight cm^?2 and (8.43 ± 0.24) × 10^?3 μg of extracted chlorophyll a cm^?2.     

Some Analyses and Recommendations on Diet Formulation for Conservation Breeding of the Galapagos Rice Rat of Isla Santiago, Nesoryzomys swarthi

Nesoryzomys swarthi, the most endangered of the three surviving, endemic Galapagos “rice rats,” was only discovered in the early 20th Century and was considered extinct until its rediscovery in 1997 at a north‐central coastal location on Isla Santiago. Potential threats to the entire genus include invasive rodent species, feral cats, new diseases, and climate change. These threats have been the basis for conservation breeding recommendations (as yet unmet) by several observers during the last several decades. This paper considers likely dietary requirements of N. swarthi in light of recent studies on the ecology of this species plus new data on the nutrient composition of Opuntia galapageia (a “resource refuge” for this species) and circulating vitamin values of animals sampled on Isla Santiago. It is concluded that, despite some unusually high mineral values for O. galapageia, a diet for N. swarthi under human care should be the same as it is for most other rodents, noting some caution in regard to possible needs for mineral and/or protein adjustment. Zoo Biol. 31:498–505, 2012. © 2012 Wiley Periodicals, Inc.     

Arbuscular mycorrhizas in coastal sand dunes of the Paraguaná Peninsula, Venezuela

Arbuscular mycorrhizal colonization was measured in the most abundant plant species of the Paraguaná Peninsula, northwestern Venezuela. These plant species included: Acacia tortuosa, Argusia gnaphalodes, Croton punctatus, Croton rhamnifolius, Egletes prostrata, Melochia tomentosa, Panicum vaginatum, Scaevola plumieri, Sporobolus virginicus, Suriana maritima, Leptothrium rigidum, and Fimbristylis cymosa. Mycorrhizal colonization was assessed using the Trouvelot et al. (1986) method that allows for simultaneous evaluation of frequency of colonization (%F), intensity of colonization (%M), and the proportion of arbuscules (%A) and vesicles (%V) present in the roots. Average frequency of colonization was 69%. The highest frequency of colonization was around 92% in C. rhamnifolius and A. tortuosa; in the other species, it varied from 49 to 86%. L. rigidum and F. cymosa were considered nonmycorrhizal because its colonization was very scarce and at all times appeared without arbuscules. Average intensity of colonization was 7%. The highest intensity of colonization was 18% in C. rhamnifolius. In the other species, it varied from 3 to 15%. Paspalum vaginatum, A. gnaphalodes, M. tomentosa, and S. maritima had their fungal structures tightly packed in modified little ovoid roots. In general, frequency of AM colonization was high and similar to those reported for other tropical ecosystems, whereas the intensity of AM colonization was low and similar to values obtained in analogous studies in disturbed ecosystems.     

Growth and survival of peritrich ciliates in an urban stream

Summary A computerized system was devised to trace the attachment, growth and disappearance of peritrich ciliates in an urban river. By tracing the development of each Carchesium polypinum colony in the river, it was possible to estimate the actual growth rate of this species without considering the effect of immigration. The survival and colonization rates of the colonies and individuals of solitary species could also be estimated. C. polypinum showed high growth rates (r=1.370 day^-1, doubling time 12.14 h). The number of daily colonizers also increased at a high rate, and the combination of growth and colonization caused very high population increase rates at the area level. Because of its low survivorship, the rate of Vorticella microstoma increase was much lower than previously reported. The survival of solitary species and small colonies was lower than with large colonies, and fewer new colonizers survived with the development of the attached microbial community.     

Intraspecific interference among larvae in a semivoltine dragonfly population

Summary This study focuses on ways that the size distribution of individuals influences the types and intensities of competitive interactions within a population of aquatic arthropod predators. Three field experiments and one laboratory experiment were designed to test for feeding interference, interference mortality, and dispersal effects within and between larval size classes of the primarily semivoltine dragonfly Tetragoneuria cynosura in Bays Mountain Lake. One field experiment documented the temporal pattern of colonization of large-mesh cylinders by the small, first-year-class larvae during a 30-day period; the results are consistent with passive (density-independent) colonization. A second field experiment examined the effect of large, second-year-class larvae at densities of 1 or 3 per cylinder (14 or 42 m^-2) on colonization by small larvae; this colonization was inhibited at the high density of large larvae. In the laboratory experiment, when larvae of the two size-classes were together in the same aquarium, small larvae moved around less than when by themselves (dispersal inhibition). Thus the inhibition of colonization observed in the field may result from interference mortality, rather than from a flight response to the presence of larger conspecifics.To evaluate this interpretation, the third field experiment measured the in-situ functional response of large larvae to each other and to their small conspecific prey. Results suggest a type 1 (linear) functional response, with feeding inteference among large larvae. Moreover, the interference mortality inflicted by larger larvae on smaller conspecifics was apparently more intense on larger individuals within the small size-class. Taken together, the three field experiments and a statistical power analysis show how colonization and interference interact to determine the local density of small larvae, and why such interference effects are difficult to detect experimentally in the field.     

Fission and fusion in island taxa – serendipity,or something to be expected?

A well‐used metaphor for oceanic islands is that they act as ‘natural laboratories’ for the study of evolution. But how can islands or archipelagos be considered analogues of laboratories for understanding the evolutionary process itself? It is not necessarily the case that just because two or more related species occur on an island or archipelago, somehow, this can help us understand more about their evolutionary history. But in some cases, it can. In this issue of Molecular Ecology, Garrick et al. ( 2014 ) use population‐level sampling within closely related taxa of Galapagos giant tortoises to reveal a complex demographic history of the species Chelonoidis becki – a species endemic to Isabela Island, and geographically restricted to Wolf Volcano. Using microsatellite genotyping and mitochondrial DNA sequencing, they provide a strong case for C. becki being derived from C. darwini from the neighbouring island of Santiago. But the interest here is that colonization did not happen only once. Garrick et al. ( 2014 ) reveal C. becki to be the product of a double colonization event, and their data reveal these two founding lineages to be now fusing back into one. Their results are compelling and add to a limited literature describing the evolutionary consequences of double colonization events. Here, we look at the broader implications of the findings of Garrick et al. ( 2014 ) and suggest genomic admixture among multiple founding populations may be a characteristic feature within insular taxa.     

Microhabitat Preference of Egernia napoleonis in Undisturbed Jarrah Forest,and Availability and Introduction of Microhabitats to Encourage Colonization of Restored Forest

An animal's microhabitat requirements can impact its ability to colonize restored areas, particularly species requiring slow developing microhabitats, such as logs and woody debris piles. Introduction of these microhabitats may be required to facilitate colonization by some species. Restored bauxite mine‐pits in the Jarrah (Eucalyptus marginata) forest of south‐western Australia contain introduced log piles at densities of 1 ha^?1. However, these have not facilitated colonization by Napoleon's skink (Egernia napoleonis), which rely on logs for habitat and are largely absent from restored sites. We radio‐tracked 12 skinks in unmined forest to determine their microhabitat preferences and examined differences in vegetation structure, and microhabitat and food availability, between restored and unmined forests to identify reasons for their absence. Restored and unmined forests differed in canopy, mid‐ and understory cover and ground substrates, which were all potential barriers to colonization. Food availability was similar between restored and unmined forest, thus not a barrier to colonization. Skinks primarily utilized long logs, large woody debris piles, and large trees; microhabitats that were scarce or absent in restored sites and, therefore, potential barriers to colonization. Using this information, we introduced small woody debris piles into restored sites in close proximity to unmined areas containing skinks to facilitate skink colonization. This showed early signs of success and suggested that the lack of logs and woody debris were barriers to colonization. However, further monitoring is required to accurately determine the long‐term value of woody debris piles in facilitating skink colonization.     

Aggressiveness of Hedera helix L. growing on monuments: Evaluation in Roman archaeological sites and guidelines for a general methodological approach

Ivy (Hedera helix L.) growing on monuments is a common issue in the study of nature’s relationship with artefacts in the Euro-Mediterranean area. This is due to its pervasiveness and its double role as protective and as deteriogen. We studied the effect of ivy colonization within the archaeological site of Villa of Massentius. We applied a quantitative method derived from monument mapping method by Fitzner, to evaluate deterioration due to ivy colonization on vertical surfaces. Instead, the capping ivy effects was investigated through a multi-parameter evaluation. We recognized three different damage categories: the superficial loss of surface (W), ivy residues on wall after the removal event (I), and the loss of compact stone fragments (P/O). Mean W corresponded to 58% and P/O to 14%. The total damage rate was positively correlated to the amount of ivy cover and to favourable shady conditions. For the capping ivy, we calculated an average loss of 4.34 cm³/m² and a high level of soil deposit, which led to a secondary ivy colonization process. This paper proposes a contribution to the identification and quantification of ivy deteriogen activity. The application of the proposed method also provides a useful tool for planning restoration activity.     

Dispersion and Ecological Impact of the Invasive Freshwater Bivalve Limnoperna fortunei in the Río de la Plata Watershed and Beyond

Limnoperna fortunei is a freshwater bivalve that invaded South America through Río de la Plata estuary in 1989 and has since become a major macrofouling pest. Along the Paraná-Paraguay waterway, which hosts intense boat traffic, L. fortunei has moved upstream at an average rate of of 250 km per year. In contrast, along the Uruguay river, where boat traffic is restricted to the lowermost 200 km section, upstream colonization is almost 10-times slower. This suggests that attachment to vessels is by far the most important dispersion mechanism. It is suggested that the Amazon, Orinoco and Magdalena basins are under high risk of invasion by this mussel, especially through their estuarine gateways. All South American basins host innumerable water bodies with favorable conditions for L. fortunei’s colonization. Known ecological tolerance limits of the mussel also suggest that it may colonize much of the area from Central America to Canada, including waters that due to their low calcium contents, high temperature and pollution levels, and low oxygen are inadequate for the survival of Dreissena polymorpha. Despite it’s remarkable geographic expansion and its extremely high population densities, L. fortunei’s ecological effects have received very little attention so far. It is suggested that the 2.4-fold increase in Argentine landings of freshwater fish between 1992–1993 and 2000–2001 may be associated with the introduction of this prey species.     

Zum Vorkommen von Tomatenrassen des Pilzes Phytophthora injestans im Gebiet der Deutschen Demokratischen Republik

Occurrence of a new disease, shoot blight was observed afflicting mulberry (Morus spp.) in the southern peninsula of India. The disease initiated as marginal burning or blackening of leaf lamina which later spread across the whole lamina and then to the stems of affected shoots, resulting in the drooping of the entire shoot and complete death of the affected plants. On isolation of the causal organism, a bacterial isolate was found to be associated with the disease symptoms, which was identified as Xanthomonas campestris pv. mori. Scanning electron microscopic (SEM) examination of cross sections of stems revealed the presence of rod-shaped bacteria inside xylem vessels of affected plants. This indicates the vascular translocation and colonization of X. campestris pv. mori which resulted in shoot blight in mulberry.     

Leptospiral agglutinins in the Cayo Santiago macaques

The colony of free-ranging rhesus monkeys (Macaca mulatta) on Cayo Santiago, Puerto Rico, was surveyed for leptospiral agglutinins. Only 5 (3%) of 169 monkeys (25% of the population) were seropositive (titers of ? 1:100). An additional 29 animals (17%) had titers ?1:50. The proportions of seropositive males and females were 22% and 18%, respectively, and twice as many adult as immature animals (32% vs. 15%) were positive. In most seropositive monkeys a single serogroup predominated, Icterohaemorrhagiae being recorded in nearly 60% of these animals. In a follow-up survey conducted a year later, 4% of 158 of the original monkeys were seropositive, with titers of from 1:100 to 1:200. None of 22 Rattus rattus captured on Cayo Santiago had agglutinins to pathogenic serovars. Despite contact with rats and ingestion of stagnant water, the serological evidence, the excellent clinical condition, low mortality, and high reproductive rates of the Cayo Santiago macaques indicate that leptospirosis is not a health problem in this free ranging monkey colony.     

Exploring myrmecophily based on the phylogenetic interrelationships of Falagonia Sharp, 1883 (Coleoptera: Staphylinidae: Aleocharinae) and allied genera

The taxonomy of Lomechusini Fleming has a complex history. Recent studies have shown that this group is polyphyletic; however, little is known about the evolutionary interrelationships among its constituent genera. The goals of the present study are to infer the phylogenetic relationships of Falagonia Sharp and closely related genera; to define the boundaries of those genera based on synapomorphic characters; and to explore the evolution of myrmecophily within the lineage. The phylogenetic analyses are based exclusively on morphological characters of adults. A total of 36 operational taxonomic units were used for the analysis. The best trees were selected based on maximum parsimony and Bayesian inference. During the parsimony reconstruction, different weighting strategies were used to recover the most robust phylogenetic hypothesis. Although minor differences were observed in the results of the different analyses, the topologies were consistent throughout. Several groups of genera proposed by Seevers (1965), such as the ‘Tetradonia’ and ‘Ecitopora’ groups, were not recovered. Thus, these may represent nonmonophyletic groups that were based on nonsynapomorphic diagnostic characters. Our analyses consistently recovered the genera Asheidium Santiago‐Jiménez, Delgadoidium Santiago‐Jiménez, Falagonia, Newtonidium Santiago‐Jiménez, Pseudofalagonia Santiago‐Jiménez, Sharpidium Santiago‐Jiménez, Tetradonia Wasmann and Thayeridium Santiago‐Jiménez, forming a monophyletic group that we have called the ‘Asheidium complex’. Falagonia mexicana Sharp shows seven autapomorphies, none of which were used to establish the genus. Based on the phylogenetic results, myrmecophily has evolved independently at least three times within the lineage. This study, based on morphological characters, is one of the first approaches towards gaining an understanding of the phylogenetic relationships within the polyphyletic tribe Lomechusini.     

Effect of spraying adjuvants with the biocontrol fungus Microsphaeropsis ochracea at different water volumes on the colonization of apple leaves

In a previous study, it was observed that Microsphaeropsis ochracea was less efficacious as a biofungicide for apple scab when applied under field conditions as an unformulated spore suspension with an airblast spray using low water volumes as compared to a ground cover spray using high water volumes. The effect of spore concentration (10⁹ to 10¹² spores ha^?1), water volume (250–1500 L ha^?1), and 20 adjuvants were studied to improve colonization of apple leaves by M. ochracea. Using commercial-type spray equipment, the fungus was applied to excised apple leaves. Higher spores concentrations resulted in greater colonization. Water volume did not have a strong impact on colonization. Only a few adjuvants improved germination (glycerine) and mycelial growth (K-90, Agrimer, Ekol, and Tween 80) in some trials. When tested on apple trees, the adjuvant Assist provided the most consistent improvement in colonization in five out of eight trials. The use of oils, humectants, and surfactants could broaden the opportunities for using this biofungicide.     

Temperature requirements of Alnus pollen in Spain and Italy (1994-1998)

Woody plants in temperate regions, in order to prevent the water in their cells from freezing, interrupt their growth entering into a physiological state called "dormancy". Trees also have a heat requirement that must be fullfilled before actual growth is resumed and pollination occurs. The objective of this study is to ascertain the influence that a climatic parameter such as temperature exerts on Alnus, in order to identify the start of the dormancy period, its duration and the consequent heat requirement that triggers flowering in three European regions located at the same latitude. In this regard, we chose two areas in Spain (Vigo and Santiago de Compostela) and one in Italy (Perugia), since they have different temperature patterns, ranging from mild in the case of Vigo to cold in that of Perugia, including an intermediate temperature pattern (Santiago). Monitoring in the three stations was carried out by means of a 7-day Lanzoni VPPS 2000 pollen trap. Alnus began its pollen season between the second and third week of January in Spain, while in Italy it began during the first week of February. During the four years under study, in order to overcome the dormancy period, Perugia needed an average of 962 chilling hours (CH), Santiago 622 CH, and Vigo had the smallest chilling accumulation with only 460 CH. In the case of heat accumulation, we found that Perugia had the smallest requirement and Vigo the largest, thus Perugia needed an average of 42 (growth degree days) GDD, Santiago around 50 GDD and Vigo 62 GDD.     

Factors determining periphytic algae succession in a tropical hypereutrophic reservoir

The objectives of this study were to evaluate the effect of cyanobacterial blooms on periphyton algal succession and to identify the factors determining community dynamics in a tropical hypereutrophic reservoir. A variety of factors affecting periphytic community structure were identified at two different sites with domestic sewage and spring water inflows and two climatic periods. Microscope glass slides were used to assess periphyton growth. Sampling was carried out at short regular intervals (3–5 days) over 30 days. Climatic periods were limnologically distinct. The rainy period was characterized by an intense cyanobacterial bloom and the dry period by a less intense bloom. Periphyton biomass and growth tended to increase with colonization time during the dry period. Cyanobacteria and Bacillariophyceae were the most representative groups in the rainy period whereas Bacillariophyceae was dominant in the dry period. Community species had successional patterns in both climatic periods. The successional trajectory for sites 1 (domestic sewage) and 2 (spring water) was different in the dry period but similar in the rainy period. We concluded that the community structure over 30 days of colonization under hypereutrophic conditions was primarily determined by seasonal scale (bloom intensity), followed by successional scale (autogenic), and, finally, by the local scale (spring water and sewage inflow). Positive periphyton biological response (higher biomass and algal growth, dominance of diatoms, Cyanobacteria reduction) during small variations of bloom intensity may indicate rapid re-establishment of the community during recovery of the ecosystem.     

Reduction of Overall Helicobacter pylori Colonization Levels in the Stomach of Mongolian Gerbil by Lactobacillus johnsonii La1 (LC1) and Its in Vitro Activities against H. pylori Motility and Adherence

The effects of Lactobacillus johnsonii La1 (LC1) on Helicobacter pylori colonization in the stomach were investigated. H. pylori colonization and gastritis in LC1-inoculated Mongolian gerbils were significantly less intense than those in the control animals. LC1 culture supernatant (>10-kDa fraction) inhibited H. pylori motility and induced bacterial aggregation in human gastric epithelial cells, suggesting the potential of clinical use of LC1 product.     

Under pressure from above: Overgrazing decreases mycorrhizal colonization of both preferred and unpreferred grasses in the Patagonian steppe

Arbuscular mycorrhizal fungi (AMF) are related to plant community dynamics and ecosystem functioning. Overgrazing can negatively affect plant performance, and consequently unbalance the association with AMF. We studied the grazing effect on AMF colonization for preferred (Bromus pictus and Poa ligularis) and unpreferred grasses (Pappostipa speciosa and Pappostipa humilis) by sheep in the Patagonian steppe. For each species, AMF colonization in ungrazed, moderate and intense grazing sites was quantified. In ungrazed areas, B. pictus showed the highest extent of AMF colonization. Mycorrhizal colonization was higher during the active season, and largely reduced by intense grazing conditions. The decrease of AMF colonization was maximal for the most preferred species, but also significant for the unpreferred species. Our results suggest that overgrazing could reduce mycorrhizal benefits for the plant by reduction of AMF colonization, which can be a good indicator of ecosystem functioning, eventually revealing an increasing degree of environmental degradation.     

Sulfide Production from Cysteine by Desulfovibrio desulfuricans

Two rumen nitrate-reducing isolates of Desulfovibrio desulfuricans were found to hydrolyze cysteine with the production of sulfide and pyruvate. When cultured on agar medium containing yeast extract with nitrate as the primary electron acceptor and ferrous chloride as the indicator, blackening of colonies occurred. The blackening of colonies appeared sooner and was more intense when either cysteine or sulfate was added to the culture medium with nitrate present.     

Performance of vesicular-arbuscular mycorrhizae in saline-alkali soil in relation to various amendments

The present study shows that vesicular-arbuscular mycorrhizal colonization in plants grown in saline-alkali soil is host dependent and it is significantly affected by various amendments given to reclaim such soils. Maximum reduction in vesicular-arbuscular mycorrhizal colonization was observed in the plants raised in saline-alkali soil amended with gypsum and maximum colonization was observed after plant-growth promoting rhizobacterium or farm yard manure amendments. Plants possessing high level of vesicular-arbuscular mycorrhizal colonization (50–70%) included Acacia nilotica, Albizia lebbeck and Dalbergia sissoo. Casuarina equisetifolia possessed moderate level of vesicular-arbuscular mycorrhizae colonization (30–50%) and Azadirachta indica possessed low level of colonization (20–40%).     

栎方翅网蝽Corythucha arcuata(Say)在中国的潜在适生区预测

【目的】栎方翅网蝽是栎树上的一种重要害虫,自21世纪入侵意大利以来,迅速在欧洲地区暴发成灾。本文旨在探明栎方翅网蝽入侵中国的风险性。【方法】利用MaxEnt生态位模型预测栎方翅网蝽在中国的潜在适生区,分析栎方翅网蝽入侵、定殖和扩散的可能性。【结果】栎方翅网蝽入侵中国并在中国黄河长江中下游平原定殖和扩散的风险性极高,高度适生区包括重庆市、安徽省、湖北省、河南省、浙江省、湖南省、贵州省和四川省。通过分析环境因子重要性表明,最冷季度平均温度是影响栎方翅网蝽适应区的最关键环境变量;年平均温度、等温性和最干季度平均温度是影响栎方翅网蝽适应区分布的主要环境因素。【结论】栎方翅网蝽在我国定殖扩散风险高,建议植物检疫部门加强栎方翅网蝽的监控,并将栎方翅网蝽列入中华人民共和国进境植物检疫性有害生物名录。