Estimating tree bole volume using artificial neural network models for four species in Turkey

Tree bole volumes of 89 Scots pine (Pinus sylvestris L.), 96 Brutian pine (Pinus brutia Ten.), 107 Cilicica fir (Abies cilicica Carr.) and 67 Cedar of Lebanon (Cedrus libani A. Rich.) trees were estimated using Artificial Neural Network (ANN) models. Neural networks offer a number of advantages including the ability to implicitly detect complex nonlinear relationships between input and output variables, which is very helpful in tree volume modeling. Two different neural network architectures were used and produced the Back propagation (BPANN) and the Cascade Correlation (CCANN) Artificial Neural Network models. In addition, tree bole volume estimates were compared to other established tree bole volume estimation techniques including the centroid method, taper equations, and existing standard volume tables. An overview of the features of ANNs and traditional methods is presented and the advantages and limitations of each one of them are discussed. For validation purposes, actual volumes were determined by aggregating the volumes of measured short sections (average 1 meter) of the tree bole using Smalian's formula. The results reported in this research suggest that the selected cascade correlation artificial neural network (CCANN) models are reliable for estimating the tree bole volume of the four examined tree species since they gave unbiased results and were superior to almost all methods in terms of error (%) expressed as the mean of the percentage errors.     

I will not go,I cannot go: cultural and social limitations of disaster preparedness in Asia,Africa, and Oceania

While much work has been invested in addressing the economic and technical basis of disaster preparedness, less effort has been directed towards understanding the cultural and social obstacles to and opportunities for disaster risk reduction. This paper presents local insights from five different national settings into the cultural and social contexts of disaster preparedness. In most cases, an early warning system was in place, but it failed to alert people to diverse environmental shocks. The research findings show that despite geographical and typological differences in these locations, the limitations of the systems were fairly similar. In Kenya, people received warnings, but from contradictory systems, whereas in the Philippines and on the island of Saipan, people did not understand the messages or take them seriously. In Bangladesh and Nepal, however, a deeper cultural and religious reasoning serves to explain disasters, and how to prevent them or find safety when they strike.     

Perspectives on Disconnects Between Scientific Information and Management Decisions on Post-fire Recovery in Western US

Environmental regulations frequently mandate the use of “best available” science, but ensuring that it is used in decisions around the use and protection of natural resources is often challenging. In the Western US, this relationship between science and management is at the forefront of post-fire land management decisions. Recent fires, post-fire threats (e.g. flooding, erosion), and the role of fire in ecosystem health combine to make post-fire management highly visible and often controversial. This paper uses post-fire management to present a framework for understanding why disconnects between science and management decisions may occur. We argue that attributes of agencies, such as their political or financial incentives, can limit how effectively science is incorporated into decision-making. At the other end of the spectrum, the lack of synthesis or limited data in science can result in disconnects between science-based analysis of post-fire effects and agency policy and decisions. Disconnects also occur because of the interaction between the attributes of agencies and the attributes of science, such as their different spatial and temporal scales of interest. After offering examples of these disconnects in post-fire treatment, the paper concludes with recommendations to reduce disconnects by improving monitoring, increasing synthesis of scientific findings, and directing social-science research toward identifying and deepening understanding of these disconnects.     

Exploring the current status of water governance and outcomes of community-based monitoring across the Oak Ridges Moraine,Southern Ontario,Canada

ABSTRACT

Community-based monitoring (CBM) activities are becoming increasingly prevalent in response to multiple factors, including reduced governmental capacity and increased public interest in environmental management. This research aims to explore how CBM has evolved in the Oak Ridges Moraine (ORM), southern Ontario, including an examination of strengths and challenges. Interviews with CBM stakeholders, provincial government staff, and conservation authority staff were combined with document analysis to explore the evolution and outcomes of ORM CBM activities. Results indicate that there is active CBM on the ORM and conservation authorities play a role in the shaping of CBM activities, although significant barriers remain to civil society participation in water governance. The case study results from the ORM were also considered in light of research emerging from the Nova Scotia experience of numerous civil society organisations involved in CBM.     

Feeding responses to selected alkaloids by gypsy moth larvae, Lymantria dispar (L.)

Deterrent compounds are important in influencing the food selection of many phytophagous insects. Plants containing deterrents, such as alkaloids, are generally unfavored and typically avoided by many polyphagous lepidopteran species, including the gypsy moth Lymantria dispar (L.) (Lepidoptera: Lymantriidae). We tested the deterrent effects of eight alkaloids using two-choice feeding bioassays. Each alkaloid was applied at biologically relevant concentrations to glass fiber disks and leaf disks from red oak trees (Quercus rubra) (L.), a plant species highly favored by these larvae. All eight alkaloids tested on glass fiber disks were deterrent to varying degrees. When these alkaloids were applied to leaf disks, only seven were still deterrent. Of these seven, five were less deterrent on leaf disks compared with glass fiber disks, indicating that their potency was dramatically reduced when they were applied to leaf disks. The reduction in deterrency may be attributed to the phagostimulatory effect of red oak leaves in suppressing the negative deterrent effect of these alkaloids, suggesting that individual alkaloids may confer context-dependent deterrent effects in plants in which they occur. This study provides novel insights into the feeding behavioral responses of insect larvae, such as L. dispar, to selected deterrent alkaloids when applied to natural vs artificial substrates and has the potential to suggest deterrent alkaloids as possible candidates for agricultural use.     

Estimation of temporary emigration in male toads

Male boreal toads (Bufo boreas) are thought to return to the breeding site every year but, if absent in a particular year, will be more likely to return the following year. Using Pollock's robust design we estimated temporary emigration (the probability a male toad is absent from a breeding site in a given year) at three locations in Colorado, USA: two in Rocky Mountain National Park and one in Chaffee County. We present data that suggest that not all male toads return to the breeding site every year. Our analyses indicate that temporary emigration varies by site and time (for example, from 1992 to 1998, the probability of temporary emigration ranged from 10% to 29% and from 3% to 95% at Lost Lake and Kettle Tarn, respectively). Although the results provide weak evidence that males are more likely to return after a year's hiatus, a general pattern of state-dependent temporary emigration was not supported. We also hypothesized relationships between temporary emigration and a number of weather variables. While some competitive models included weather covariates, imprecise and variable estimates of the effects of these covariates precluded fully defining their impact on temporary emigration.     

Experimental Demonstration of an Allee Effect in American Ginseng

Abstract: Harvesting of wild American ginseng (   Panax quinquefolius ) for the herbal trade has lowered natural population sizes. We tested for reproductive limitation due to small population size (a form of the Allee effect) by experimentally planting "natural" populations numbering 4, 16, and 64 using 4-year-old cultivated plants. Plant size traits and reproductive traits ( bud, flower, green fruit, and mature fruit) were recorded through the ensuing summer. Fruit production per flower and per plant increased in proportion to flowering population size (  p = 0.0063 and p = 0.0017, respectively), strongly suggesting that an Allee effect occurs in very small populations. The increase in fruit production was not explained by either plant or inflorescence size differences. Although population size-dependent pollination, through insufficient pollinator visitation rate or pollen transfer rate, seems the most likely cause of the observed effects, our limited observations of pollinators were not sufficient to demonstrate a change in pollination rates as a function of population size. Knowledge of the presence as well as the mechanism underlying this Allee effect may be especially useful for management and determination of minimum viable population size of the species in the wild.