Woodland Improvement and Crop Trees in Iowa, 2005

Vigorous and Healthy woodlands in Iowa have the unique distinction of being able to provide a wealth of benefits for the landowner and residents of the state. Benefits from a healthy forest include timber and wood resources, watershed protection, fragile site protection, wildlife and bird habitat, aesthetics and beauty, and recreational opportunities.

Descrição da larva de Popanomyia femoralis Kertész, 1909 e do pupário de Engicerus major Lindner, 1964 (Diptera, Stratiomyidae)

The larva of Popanomyia femoralis and puparium of Engicerus major are described. The larvae were collected under the bark of fallen trees in an area near the tropical rain forest at Ilha da Marambaia (23º 04'15''S-43º53'59''W-sea level) and Cabo Frio (22º52'46''S-42º01'07''W-4 m), State of Rio de Janeiro, Brazil. Biological notes are presented. The larva of Popanomyia femoralis and puparium of Engicerus major are compared with those of Chalcidomorphina aurata Enderlein, Cosmariomyia argyrosticta Kertész, Dactylodeictes lopesi Lindner and Vittiger schnusei Kertész, other species of the same subfamily.

Seeing the Wood through the Trees: The Current State of Higher Systematics in the Strepsirhini.

Strepsirhines comprise 10 living or recently extinct families, ≥50% of extant primate families. Their phylogenetic relationships have been intensively studied, but common topologies have only recently emerged; e.g. all recent reconstructions link the Lepilemuridae and Cheirogaleidae. The position of the indriids, however, remains uncertain, and molecular studies have placed them as the sister to every clade except Daubentonia, the preferred sister group of morphologists. The node subtending Afro-Asian lorisids has been similarly elusive. We probed these phylogenetic inconsistencies using a test data set including 20 strepsirhine taxa and 2 outgroups represented by 3,543 mtDNA base pairs, and 43 selected morphological characters, subjecting the data to maximum parsimony, maximum likelihood and Bayesian inference analyses, and reconstructing topology and node ages jointly from the molecular data using relaxed molecular clock analyses. Our permutations yielded compatible but not identical evolutionary histories, and currently popular techniques seem unable to deal adequately with morphological data. We investigated the influence of morphological characters on tree topologies, and examined the effect of taxon sampling in two experiments: (1) we removed the molecular data only for 5 endangered Malagasy taxa to simulate 'extinction leaving a fossil record'; (2) we removed both the sequence and morphological data for these taxa. Topologies were affected more by the inclusion of morphological data only, indicating that palaeontological studies that involve inserting a partial morphological data set into a combined data matrix of extant species should be interpreted with caution. The gap of approximately 10 million years between the daubentoniid divergence and those of the other Malagasy families deserves more study. The apparently contemporaneous divergence of African and non-daubentoniid Malagasy families 40-30 million years ago may be related to regional plume-induced uplift followed by a global period of cooling and drying. © 2013 S. Karger AG, Basel.

Consumer Advisory Bulletin, Tree-Trim Tips: Consumer Tips for Iowans with Storm-Damaged Trees, January 2008

The Attorney General’s Consumer Protection Division receives hundreds of calls and consumer complaints every year. Follow these tips to avoid unexpected expense and disappointments. This record is about: International Lottery Schemes: You're the Loser!

The dog that did not bark: Insider trading and crashes

This paper documents that at the individual stock level insiders sales peak many months before a large drop in the stock price, while insiders purchases peak only the month before a large jump. We provide a theoretical explanation for this phenomenon based on trading constraints and asymmetric information. We test our hypothesis against competing stories such as patterns of insider trading driven by earnings announcement dates, or insiders timing their trades to evade prosecution. Finally we provide new evidence regarding crashes and the degree of information asymmetry.

Genetic and hormonal regulation of cambial development.

The stems and roots of most dicot plants increase in diameter by radial growth, due to the activity of secondary meristems. Two types of meristems function in secondary plant body formation: the vascular cambium, which gives rise to secondary xylem and phloem, and the cork cambium, which produces a bark layer that replaces the epidermis and protects the plant stem from mechanical damage and pathogens. Cambial development, the initiation and activity of the vascular cambium, leads to an accumulation of wood, the secondary xylem tissue. The thick, cellulose-rich cell walls of wood provide a source of cellulose and have the potential to be used as a raw material for sustainable and renewable energy production. In this review, we will discuss what is known about the mechanisms regulating the cambium and secondary tissue development.

Temporal variation in the composition of ant assemblages (Hymenoptera, Formicidae) on trees in the Pantanal floodplain, Mato Grosso do Sul, Brazil

Temporal variation in the composition of ant assemblages (Hymenoptera, Formicidae) on trees in the Pantanal floodplain, Mato Grosso do Sul, Brazil. In this paper we investigate how seasonal flooding influences the composition of assemblages of ants foraging on trees in the Pantanal of Mato Grosso do Sul. During the flood in the Pantanal, a large area is covered by floods that are the main forces that regulate the pattern of diversity in these areas. However, the effects of such natural disturbances in the ant communities are poorly known. In this sense, the objective of this study was to evaluate the effect of temporal variation in assemblages of ants foraging on trees in the Pantanal of Miranda. Samples were collected during a year in two adjacent areas, one who suffered flooding during the wet period and another that did not suffer flooding throughout the year. In 10 sites for each evaluated habitat, five pitfall traps were installed at random in trees 25 m apart from each other. In the habitat with flooding, the highest richness was observed during the flooding period, while there was no significant change in richness in the area that does not suffer flooding. The diversity of species between the two evaluated habitats varied significantly during the two seasons. Most ants sampled belong to species that forage and nest in soil. This suggests that during the flood in flooded habitats, ants that did not migrate to higher areas without flooding adopt the strategy to search for resources in the tree canopy.

Senescent stem-galls in trees of Eremanthus erythropappus as a resource for arboreal ants

Senescent stem-galls in trees of Eremanthus erythropappus as a resource for arboreal ants. Members of the dipteran families Tephritidae and Cecidomyiidae are inducers of stem-galls in Eremanthus erythropappus (DC.) MacLeish (Asteraceae), a tree common in the state of Minas Gerais, Brazil. When senescent, these galls become available to other organisms, such as ants. The present study describes a community of ants having benefitted from this process of ecosystem-engineering. The colonies in question inhabit the senescent stem-galls of trees of E. erythropappus and were examined in view of answering the following questions: i) whether the presence of stem-galls had any bearing on the richness, composition, or size of the ant colonies therein; and ii) whether the ants displayed any preferences regarding the shape and/or size of the galls. The study was conducted in populations of E. erythropappus trees near the city of Ouro Preto, MG. A total of 227 galls were collected, 14% of which were occupied by ants, belonging to eight different species. Half of the species occupied galls of both morphotypes (fusiform and globular), although we observed a marked preference for larger, globular shapes. Overall, our results showed the galls to be an effective and abundant resource, helping to maintain the diversity of the ants in the canopy. We also observed the occurrence of outstations and polydomic nests, although an in-depth examination of the influence of galls on this type of structuring has not been investigated.

Study of the variability in chemical composition of bark layers of Quercus Suber L. from different production areas

Cork is the bark of the cork oak tree (Quercus suber L), a renewable and biodegradable raw bioresource concentrated mainly in the Mediterranean region. Development of its potential uses as a biosorbent will require the investigation of its chemical composition; such information can be of help to understand its interactions with organic pollutants. The present study investigates the summative chemical composition of three bark layers (back, cork, and belly) of five Spanish cork samples and one cork sample from Portugal. Suberin was the main component in all the samples (21.1 to 53.1%), followed by lignin (14.8 to 31%), holocellulose (2.3 to 33.6%), extractives (7.3 to 20.4%), and ash (0.4 to 3.3%). The Kruskal-Wallis test was used to determine whether the variations in chemical composition with respect to the production area and bark layers were significant. The results indicate that, with respect to the bark layer, significant differences were found only for suberin and holocellulose contents: they were higher in the belly and cork than in the back. Based on the results presented, cork is a material with a lot of potential because of its heterogeneity in chemical composition

Within-plot subsampling of trees for assessment in progeny trials of Scots pine

Summary

Organic material decomposition and nutrient dynamics in a mulch system enriched with leguminous trees in the Amazon

The new techniques proposed for agriculture in the Amazon region include rotational fallow systems enriched with leguminous trees and the replacement of biomass burning by mulching. Decomposition and nutrient release from mulch were studied using fine-mesh litterbags with five different leguminous species and the natural fallow vegetation as control. Samples from each treatment were analyzed for total C, N, P, K, Ca, Mg, lignin, cellulose content and soluble polyphenol at different sampling times over the course of one year. The decomposition rate constant varied with species and time. Weight loss from the decomposed litter bag material after 96 days was 30.1 % for Acacia angustissima, 32.7 % for Sclerolobium paniculatum, 33.9 % for Iinga edulis and the Fallow vegetation, 45.2 % for Acacia mangium and 63.6 % for Clitoria racemosa. Immobilization of N and P was observed in all studied treatments. Nitrogen mineralization was negatively correlated with phenol, C-to-N ratio, lignin + phenol/N ratio, and phenol/phosphorus ratios and with N content in the litterbag material. After 362 days of field incubation, an average (of all treatments), 3.3 % K, 32.2 % Ca and 22.4 % Mg remained in the mulch. Results confirm that low quality and high amount of organic C as mulch application are limiting for the quantity of energy available for microorganisms and increase the nutrient immobilization for biomass decomposition, which results in competition for nutrients with the crop plants.

Properties of top soil and the relationship between soil and trees in a boreal Scots pine stand

Summary

What trees tell us: dendrochronological and statistical analysis of the data

Trees are a great bank of data, named sometimes for this reason as the "silentwitnesses" of the past. Due to annual formation of rings, which is normally influenced directly by of climate parameters (generally changes in temperature and moisture or precipitation) and other environmental factors; these changes, occurred in the past, are"written" in the tree "archives" and can be "decoded" in order to interpret what hadhappened before, mainly applied for the past climate reconstruction.Using dendrochronological methods for obtaining samples of Pinus nigra fromthe Catalonian PrePirineous region, the cores of 15 trees with total time spine of about 100 - 250 years were analyzed for the tree ring width (TRW) patterns and had quite high correlation between them (0.71 ¿ 0.84), corresponding to a common behaviour for the environmental changes in their annual growth.After different trials with raw TRW data for standardization in order to take outthe negative exponential growth curve dependency, the best method of doubledetrending (power transformation and smoothing line of 32 years) were selected for obtaining the indexes for further analysis.Analyzing the cross-correlations between obtained tree ring width indexes andclimate data, significant correlations (p<0.05) were observed in some lags, as forexample, annual precipitation in lag -1 (previous year) had negative correlation with TRW growth in the Pallars region. Significant correlation coefficients are between 0.27- 0.51 (with positive or negative signs) for many cases; as for recent (but very short period) climate data of Seu d¿Urgell meteorological station, some significant correlation coefficients were observed, of the order of 0.9.These results confirm the hypothesis of using dendrochronological data as aclimate signal for further analysis, such as reconstruction of climate in the past orprediction in the future for the same locality.

Famous and Historical Trees of Iowa,1996.

This booklet takes a look at the role trees and woodlands play in the development of Iowa's history. It identifies the individual and groups of trees that have historical significance in the state.