International Journal of Forestry Research The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Assessing the Influence of Summer Organic Fertilization Combined with Nitrogen Inhibitor on a Short Rotation Woody Crop in Mediterranean Environment Tue, 15 Apr 2014 00:00:00 +0000 The European Union Directive 91/676/EEC, known as Nitrates Directive, has dictated basic agronomic principles regarding the use of animal manure source as well as livestock and waste waters from small food companies. The use of nitrification inhibitors together with animal effluents as organic fertilizers could be beneficial for nutrient recycling, plant productivity, and greenhouse gas emission and could offer economic advantages as alternative to conventional fertilizers especially in the Mediterranean region. The aim of the present study was to investigate differences in plant productivity between bovine effluent treatments with (or without) addition of a nitrification inhibitor (3,4 DMPP) in a short rotation woody crop system. Results of the field experiment carried out in a Mediterranean dry environment indicated that the proposed strategy could improve tree growth with indirect, beneficial effects for agroforestry systems. Anita Maienza, Giovanni Mughini, Luca Salvati, Anna Benedetti, and Maria Teresa Dell'Abate Copyright © 2014 Anita Maienza et al. All rights reserved. Effect of Seed Size of Afzelia quanzensis on Germination and Seedling Growth Wed, 26 Mar 2014 09:17:41 +0000 Afzelia quanzensis Welw is a valuable timber producing tree species in Africa. A study was conducted to evaluate the influence of seed size on seed germination and seedlings quality of Afzelia quanzensis. Seed was categorized into three groups in regard to their length, small (<1.5 cm), medium (≥ 1.5 ≤ 2.5 cm), and large (>2.5 cm). The treatments were completely randomized into four replications. Germination percentage was not significantly different between the treatments, although large seeds had the highest germination percentage of 94.9%. There were significant differences in seedling height and root collar diameter among the different seed sizes, with large seeds having the highest seedlings height and largest root collar diameter. This was attributed to differences in the food reserves. Survival of transplants from shoot dieback was significantly different such that seedlings from large seed attained the highest survival of 92%. It is therefore recommended that, for production of high quality transplants in the nursery, large seeds should be used. Kupatsa Mtambalika, Chimuleke Munthali, Dominic Gondwe, and Edward Missanjo Copyright © 2014 Kupatsa Mtambalika et al. All rights reserved. Brazil Nut (Bertholletia excelsa, Lecythidaceae) Regeneration in Logging Gaps in the Peruvian Amazon Tue, 25 Mar 2014 07:56:14 +0000 Brazil nut (Bertholletia excelsa Bonpl.) extraction serves as an important economic resource in the Madre de Dios region of Peru simultaneously promoting forest conservation, yet, under current management, it cannot compete with other land uses. This study investigated the effects of logging gaps on Brazil nut natural regeneration. A total of 48 paired logging gap-understory sites were visited in Brazil nut concessions in the Tambopata province of Madre de Dios, Peru. At each site, the number of Brazil nut recruits was counted and canopy openness and gap area were measured. Significantly higher levels of recruit density were found in logging gaps than in understory sites. Additionally, recruit density was positively correlated with canopy openness. Further, in experimental plantings in paired gap and understory sites, canopy openness, height, total leaf area, and number were recorded from August 2011 to February 2012. Height, total leaf area, and leaf number were significantly higher for tree-fall gap grown seedlings, lending further evidence to improved recruitment success of Brazil nuts in forest gaps. These results suggest that multiple-use forest management could be considered as an alternative for the sustainable extraction of Brazil nuts but also highlight that further studies are required. Julian Moll-Rocek, Matthew E. Gilbert, and Eben N. Broadbent Copyright © 2014 Julian Moll-Rocek et al. All rights reserved. Remote Sensing of Aboveground Biomass in Tropical Secondary Forests: A Review Sun, 23 Mar 2014 13:47:20 +0000 Tropical landscapes are, in general, a mosaic of pasture, agriculture, and forest undergoing various stages of succession. Forest succession is comprised of continuous structural changes over time and results in increases in aboveground biomass (AGB). New remote sensing methods, including sensors, image processing, statistical methods, and uncertainty evaluations, are constantly being developed to estimate biophysical forest changes. We review 318 peer-reviewed studies related to the use of remotely sensed AGB estimations in tropical forest succession studies and summarize their geographic distribution, sensors and methods used, and their most frequent ecological inferences. Remotely sensed AGB is broadly used in forest management studies, conservation status evaluations, carbon source and sink investigations, and for studies of the relationships between environmental conditions and forest structure. Uncertainties in AGB estimations were found to be heterogeneous with biases related to sensor type, processing methodology, ground truthing availability, and forest characteristics. Remotely sensed AGB of successional forests is more reliable for the study of spatial patterns of forest succession and over large time scales than that of individual stands. Remote sensing of temporal patterns in biomass requires further study, in particular, as it is critical for understanding forest regrowth at scales useful for regional or global analyses. J. M. Barbosa, E. N. Broadbent, and M. D. Bitencourt Copyright © 2014 J. M. Barbosa et al. All rights reserved. Forest Biomass, Carbon Stocks, and Macrofungal Dynamics: A Case Study in Costa Rica Thu, 20 Mar 2014 10:05:20 +0000 There are few published studies providing information about macrofungal biology in a context of forest dynamics in tropical areas. For this study, a characterization of above-ground standing tree biomass and carbon stocks was performed for four different forest subtypes within two life zones in Costa Rica. Fungal productivity and reproductive success were estimated and analyzed in the context of the forest systems studied and results showed fungal dynamics to be a complex and challenging topic. In the present study, fungal productivity was higher in forest patches with more tree density but independent from life zones, whereas fungal biomass was higher in premontane areas with ectomycorrhizal dominant trees. Even though some observed patterns could be explained in terms of climatic differences and biotic relationships, the high fungal productivity observed in dry forests was an interesting finding and represents a topic for further studies. Carlos Rojas and Erick Calvo Copyright © 2014 Carlos Rojas and Erick Calvo. All rights reserved. The Effect of Seed Sources Variation and Presowing Treatments on the Seed Germination of Acacia catechu and Elaeocarpus floribundus Species in Bangladesh Tue, 18 Mar 2014 00:00:00 +0000 The seed germination of seed sources and presowing treatments of Acacia catechu and Elaeocarpus floribundus seeds were conducted in the nursery of Bangladesh Agricultural University. The seeds were collected from matured and healthy trees from four different locations in Bangladesh and treated with six presowing methods. The germination test was conducted in polybags with a mixture of topsoil and cow dung in a ratio of 3 : 1. The results of ANOVA showed no significant differences among seed sources but statistically significant differences among the presowing treatments for both species. Thus the presowing methods affected the germination process of seeds, and then the highest germination success was found to be 91.26% in hot water (80°C for 10 min), treatment in Acacia catechu and the highest germination success (89.81%) of Elaeocarpus floribundus was found in H2SO4 treatment followed by 86.35% and 78.42% in treatments with hot water (100°C for 12 min) and scarification. The study also revealed that the interactions between seed source variation and presowing methods effect significantly differed in seed germination percentages. Therefore, it is concluded that hot water treatment can be suggested on seed germination of both species for developing nurseries and rural Bangladesh. Niamjit Das Copyright © 2014 Niamjit Das. All rights reserved. Effects of Drought Frequency on Growth Performance and Transpiration of Young Black Locust (Robinia pseudoacacia L.) Mon, 17 Mar 2014 16:40:17 +0000 Black locust (Robinia pseudoacacia L.) is a drought-tolerant fast growing tree, which could be an alternative to the more common tree species used in short-rotation coppice on marginal land. The plasticity of black locust in the form of ecophysiological and morphological adaptations to drought is an important precondition for its successful growth in such areas. However, adaptation to drought stress is detrimental to primary production. Furthermore, the soil water availability condition of the initial stage of development may have an impact on the tree resilience. We aimed to investigate the effect of drought stress applied during the resprouting on the drought tolerance of the plant, by examining the black locust growth patterns. We exposed young trees in lysimeters to different cycles of drought. The drought memory affected the plant growth performance and its drought tolerance: the plants resprouting under drought conditions were more drought tolerant than the well-watered ones. Black locust tolerates drastic soil water availability variations without altering its water use efficiency (2.57 g L−1), evaluated under drought stress. Due to its constant water use efficiency and the high phenotypic plasticity, black locust could become an important species to be cultivated on marginal land. Dario Mantovani, Maik Veste, and Dirk Freese Copyright © 2014 Dario Mantovani et al. All rights reserved. An Integrated Conceptual Framework for Adapting Forest Management Practices to Alternative Futures Wed, 12 Mar 2014 14:16:19 +0000 This paper proposes an integrated, conceptual framework that forest managers can use to simulate the multiple objectives/indicators of sustainability for different spatial patterns of forest management practices under alternative futures, rank feasible (affordable) treatment patterns for forested areas, and determine if and when it is advantageous to adapt or change the spatial pattern over time for each alternative future. The latter is defined in terms of three drivers: economic growth; land use policy; and climate change. Four forest management objectives are used to demonstrate the framework, minimizing wildfire risk and water pollution and maximizing expected net return from timber sales and the extent of potential wildlife habitat. The fuzzy technique for preference by similarity to the ideal solution is used to rank the feasible spatial patterns for each subperiod in a planning horizon and alternative future. The resulting rankings for subperiods are used in a passive adaptive management procedure to determine if and when it is advantageous to adapt the spatial pattern over subperiods. One of the objectives proposed for the conceptual framework is simulated for the period 2010–2059, namely, wildfire risk, as measured by expected residential losses from wildfire in the wildland-urban interface for Flathead County, Montana. Tony Prato and Travis B. Paveglio Copyright © 2014 Tony Prato and Travis B. Paveglio. All rights reserved. Opportunity Costs of REDD+ to the Communities of Mufindi District, Iringa, Tanzania Wed, 05 Mar 2014 15:29:41 +0000 The study was done to assess the opportunity costs of REDD+ to the communities of Mufindi District which is located in the Southern Highlands of Tanzania. The specific objectives were, to identify and assess the economic value of alternative land uses, the aboveground carbon stock of Idewa Forest Reserve (IFR), and the profitability of each land use as compared to REDD+ incentives. Data were collected using questionnaire survey, key informant interview, and forest inventory and data were analyzed using the Excel programme. Results showed that the main land uses were agriculture and tree planting with economic values of $2958.52 and $3272.94 per ha per year, respectively. The total aboveground carbon was 39.23 t/ha (143.97/ha). The opportunity costs of REDD+ was varying depending on the price per ton of carbon. The opportunity costs of REDD+ will be profitable if the price per tCO2e will be at least $23. It can therefore be concluded that there is no general unit price per ton of carbon dioxide equivalent (tCO2e), as it depends on REDD+ opportunity cost when compared with alternative land uses within a particular place. Therefore we recommend opportunity costs of REDD+ to communities be used to guide decision making on unit prices of carbon. Faraji Nuru, Jumanne Moshi Abdallah, and Yonika Mathew Ngaga Copyright © 2014 Faraji Nuru et al. All rights reserved. Assessing a Bayesian Approach for Detecting Exotic Hybrids between Plantation and Native Eucalypts Mon, 03 Mar 2014 15:48:24 +0000 Eucalyptus globulus is grown extensively in plantations outside its native range in Australia. Concerns have been raised that the species may pose a genetic risk to native eucalypt species through hybridisation and introgression. Methods for identifying hybrids are needed to enable assessment and management of this genetic risk. This paper assesses the efficiency of a Bayesian approach for identifying hybrids between the plantation species E. globulus and E. nitens and four at-risk native eucalypts. Range-wide DNA samples of E. camaldulensis, E. cypellocarpa, E. globulus, E. nitens, E. ovata and E. viminalis, and pedigreed and putative hybrids (n = 606), were genotyped with 10 microsatellite loci. Using a two-way simulation analysis (two species in the model at a time), the accuracy of identification was 98% for first and 93% for second generation hybrids. However, the accuracy of identifying simulated backcross hybrids was lower (74%). A six-way analysis (all species in the model together) showed that as the number of species increases the accuracy of hybrid identification decreases. Despite some difficulties identifying backcrosses, the two-way Bayesian modelling approach was highly effective at identifying , which, in the context of E. globulus plantations, are the primary management concern. Matthew J. Larcombe, René E. Vaillancourt, Rebecca C. Jones, and Brad M. Potts Copyright © 2014 Matthew J. Larcombe et al. All rights reserved. Does Proximity to Wetland Shrubland Increase the Habitat Value for Shrubland Birds of Small Patches of Upland Shrubland in the Northeastern United States? Thu, 20 Feb 2014 12:04:13 +0000 The loss of shrubland habitat is linked to population declines for many wildlife species, including several bird species of conservation concern. Conservation agencies in the northeastern United States encourage private landowners to clearcut patches of forest to create shrubland habitat. Many private landowners are only willing to create small clearcuts; therefore, it is important to understand how to maximize the impact of small clearcuts on bird habitat use. In this study we examined whether proximity to wetland shrubland increases the habitat value of small patches of upland shrubland. We conducted point counts at 22 sites containing small patches of upland shrubland ranging in size from 0.1 to 7 ha. Shrubland bird species richness was significantly positively correlated with the proportion of wetland shrubland habitat within 100 m of a site, and with the extent of all shrubland habitat within 100 m, but not with the proportion of upland shrubland. Occupancy modeling indicated that the size of adjacent wetland shrub patches increased occupancy at the sites for five of eight species observed with sufficient rates of detection. Our results suggest that creating clearcuts adjacent to existing areas of wetland shrubland may enhance the habitat value of the patches for shrubland birds. Bill Buffum and Richard A. McKinney Copyright © 2014 Bill Buffum and Richard A. McKinney. All rights reserved. Essential Oil Constituents and Yields from Leaves of Blepharocalyx salicifolius (Kunt) O. Berg and Myracrodruon urundeuva (Allemão) Collected during Daytime Mon, 17 Feb 2014 13:09:13 +0000 The purpose of this study was to evaluate the essential oil composition and yield from leaves of two Brazilian species (Myracrodruon urundeuva and Blepharocalyx salicifolius) harvested during daytime. Essential oils were obtained by steam distillation and had their yield determined. Blepharocalyx salicifolius presented yields of 0.049% (9 a.m.), 0.045% (1 p.m.), and 0.069% (5 p.m.). For Myracrodruon urundeuva, we found 0.13% (9 a.m.), 0.11% (1 p.m.), and 0.08% (5 p.m.). Finally, compound identification and quantification were carried out by GC-MS and GC-FID techniques, respectively. Thirteen major compounds were identified for Blepharocalyx salicifolius, representing 91.6% of the EOs, of which p-cymene (25.9%) was detected as amajor component. Nine major compounds were identified for Myracrodruon urundeuva, representing 90.3% of the EOs, whereas β-myrcene showed the greatest concentration (66.4%). Olívia Bueno da Costa, Cláudio Henrique Soares Del Menezzi, Luiz Eduardo Celino Benedito, Inês Sabioni Resck, Roberto Fontes Vieira, and Humberto Ribeiro Bizzo Copyright © 2014 Olívia Bueno da Costa et al. All rights reserved. Nontimber Forest Product Yield and Income from Thaumatococcus daniellii under a Mixed Tree Plantation System in Ghana Sun, 16 Feb 2014 11:57:45 +0000 Thaumatococcus daniellii is a wild sourced tropical understorey herb that is harvested for its foliage and fruits from which thaumatin—a proteinous sweetener—is extracted. With increased demand for natural sweeteners, uncontrolled harvesting of T. daniellii from the wild is suggested to be neither sustainable nor match industrial demands. This study determined the implication of controlled foliage harvesting of T. daniellii under a mixed indigenous tree plantation stand. T. daniellii plants within plots of dimension 3 m × 4 m were thinned to uniform foliage population of about 12 leaves/m2 and subsequently harvested at 16 weeks interval for 64 weeks at four different foliage harvesting intensities: (i) no harvesting (control), (ii) 25% harvest, (iii) 50% harvest, and (iv) 75% harvest. Data on agronomic characters and total income from the sale of fruit and harvested foliage were collected and analysed. We found that foliage harvest intensity affected number of flowers in the order: 18 (control) > 6 (25%) ≥ 1 (50%) and 0 (75%). Foliage harvest intensity also significantly influenced fruit number and ranged from 11458/ha for the control to 4583/ha for the 75% harvest. Total income from fruit and foliage sales was greatest for the 50% harvest (US $ 17,191.32), followed by 75% harvest (US $ 12, 310.24) and lowest for the no harvest treatment (US $ 107.44). Thus, proper management of T. daniellii through controlled harvesting of the foliage under mixed tree plantation system could promote sustainable yield and income to farmers. Samuel Boadi, Mark Baah-Acheamfour, Francis Ulzen-Appiah, and Ghulam Murtaza Jamro Copyright © 2014 Samuel Boadi et al. All rights reserved. Development of a Dispersal Model for Balsam Woolly Adelgid, Adelges piceae Ratzeburg (Hemiptera: Adelgidae), to Facilitate Landscape-Level Management Planning Wed, 05 Feb 2014 08:29:05 +0000 The balsam woolly adelgid (Adelges piceae Ratzeburg) attacks subalpine fir (Abies lasiocarpa (Hook.) Nutt.) in eastern Washington, Oregon, and northern Idaho. Historical balsam woolly adelgid distributions present an opportunity to understand climatic factors that influence the species’ distribution at a landscape scale. The distribution data allows for creation of predictive models that detail the likelihood of occurrence and associated geographic data allow modeling of species dispersal. Predictive variables linked to the distribution of the hosts and to abiotic environmental conditions were utilized to create a spatial probability model of occurrence. Balsam woolly adelgid predominantly disperses by wind, and hence, both wind speed and wind direction were used to create a dispersal probability model. Results from wind dispersal modeling suggested that two-thirds of the new infestations were due to July and August wind direction and speed. Average July winds ranged from 0.5 to 3.27 m/s, flowing south westerly, and August winds ranged from 0.43 to 1.55 m/s, flowing north easterly. Land managers can use the results of the predictive model to better understand where current infestations are likely to expand. Prediction of where the balsam woolly adelgid might move allows managers to adjust actions to respond to future insect movement and establishment. L. W. Lass, S. P. Cook, B. Shafii, and T. S. Prather Copyright © 2014 L. W. Lass et al. All rights reserved. Arbuscular Mycorrhizal Colonization Enhanced Early Growth of Mallotus paniculatus and Albizia saman under Nursery Conditions in East Kalimantan, Indonesia Tue, 28 Jan 2014 09:50:32 +0000 Forest over logging, forest fire, forest conversion, and opencast mining have promoted deforestation in Indonesia, and reforestation is needed immediately. However, reforestation is limited by low seedling quality and production, and slow seedling growth in nurseries. Native tropical tree and fast-growing species, Mallotus paniculatus and Albizia saman, are potential to promote the first rotation of reforestation. Arbuscular mycorrhizal (AM) fungi are known to promote nutrient uptake and plant growth. We examined the effects of two native AM fungi, Gigaspora decipiens and Glomus clarum, on the growth of M. paniculatus and A. saman seedlings under nursery conditions. At harvest, after six months, we determined AM colonization, shoot dry weight, and shoot N and P concentration. Approximately 90% and 50% of M. paniculatus and A. saman roots, respectively, were colonized by AM fungi, without any difference between the inoculation treatments. G. decipiens and G. clarum increased shoot height, leaf number, shoot dry weight, and shoot N and P uptake of both species. A positive correlation was observed between N and P uptake and shoot dry weight. These results suggest that AM fungi are effective in accelerating nutrient uptake and plant growth, which will, in turn, promote reforestation and sustainable forest timber production. Dewi Wulandari, Saridi, Weiguo Cheng, and Keitaro Tawaraya Copyright © 2014 Dewi Wulandari et al. All rights reserved. A Review of Forest Resources and Forest Biodiversity Evaluation System in China Sun, 29 Dec 2013 12:10:44 +0000 China is a country rich in diverse forest ecosystems due to the large span of the country, complex topography, and multiple climate regimes. In this paper, the basic information of forest resources in China was briefly introduced and the current state in the measurements of forest biodiversity and the establishment of forest biodiversity index systems in related studies were reviewed. The results showed that a lot of studies on forest biodiversity have been conducted mostly at landscape or stand level in China and the commonly used biodiversity indicators were identified and compared. Several comprehensive forest biodiversity index systems were proposed. However, there are still some problems during the construction of forest biodiversity assessment system. Due to the late establishment of biodiversity monitoring system in China, the availability of data that could be included in a forest biodiversity index system is limited, which hurdles the precise assessment of forest biodiversity. It is suggested to develop long-term monitoring stations and keep data recording consistently. Concerns should also be given to the construction of the framework of the forest biodiversity index system and the determination of the indicators’ weight. The results will provide reference for the establishment of national or regional forest biodiversity evaluation indicator systems in China. Jinzhuo Wu, Wenshu Lin, Xuanyi Peng, and Weiguo Liu Copyright © 2013 Jinzhuo Wu et al. All rights reserved. Human Influences on Tree Diversity and Composition of a Coastal Forest Ecosystem: The Case of Ngumburuni Forest Reserve, Rufiji, Tanzania Sun, 22 Dec 2013 10:11:38 +0000 This paper reports on the findings of an ecological survey conducted in Ngumburuni Forest Reserve, a biodiversity rich forest reserve within the coastal forests of Tanzania. The main goal of this study was to determine the influence of uncontrolled anthropogenic activities on tree species diversity and composition within the forest ecosystem. It was revealed that economic activities including logging, charcoaling, and shifting cultivation were the most important disturbing activities affecting ecological functioning and biodiversity integrity of the forest. Further to this, we noted that the values of species diversity, composition, and regeneration potential within the undisturbed forest areas were significantly different from those in heavily disturbed areas. These observations confirm that the ongoing human activities have already caused size quality degradation of useful plants, enhanced species diversification impacts to the forest ecosystem, and possibly negatively affected the livelihoods of the adjacent local communities. Despite these disturbances, Ngumburuni forest reserve still holds important proportions of both endemic and threatened animal and plant species. The study suggests urgent implementation of several conservation measures in order to limit accessibility to the forest resources so as to safeguard the richness and abundance of useful biodiversity stocks in the reserve. J. Kimaro and L. Lulandala Copyright © 2013 J. Kimaro and L. Lulandala. All rights reserved. Road Transport Vehicles for Hauling Uncomminuted Forest Energy Products in Sweden Thu, 12 Dec 2013 09:35:15 +0000 Forestry residues as a renewable energy source are becoming increasingly competitive to fossil fuels. An important issue, however, is effective transportation solutions for this type of material. In this paper we describe and discuss several alternative vehicle systems which have been used in Sweden. We describe and discuss a specialized vehicle for the transportation of loose residues, bundled residues, and tree sections; a specialized stump hauling vehicle; a recently developed vehicle for the transportation of bundled residues; a container system vehicle for stump transportation. All these different machineries have their merits and shortcomings depending on the type of forest energy product. Reza Mortazavi and Jerry Johansson Copyright © 2013 Reza Mortazavi and Jerry Johansson. All rights reserved. Modeling Growth and Yield of Schizolobium amazonicum under Different Spacings Mon, 02 Dec 2013 15:08:57 +0000 This study aimed to present an approach to model the growth and yield of the species Schizolobium amazonicum (Paricá) based on a study of different spacings located in Pará, Brazil. Whole-stand models were employed, and two modeling strategies (Strategies A and B) were tested. Moreover, the following three scenarios were evaluated to assess the accuracy of the model in estimating total and commercial volumes at five years of age: complete absence of data (S1); available information about the variables basal area, site index, dominant height, and number of trees at two years of age (S2); and this information available at five years of age (S3). The results indicated that the 3 × 2 spacing has a higher mortality rate than normal, and, in general, greater spacing corresponds to larger diameter and average height and smaller basal area and volume per hectare. In estimating the total and commercial volumes for the three scenarios tested, Strategy B seems to be the most appropriate method to estimate the growth and yield of Paricá plantations in the study region, particularly because Strategy A showed a significant bias in its estimates. Gilson Fernandes da Silva, Salvador Alejandro Gezan, Carlos Pedro Boechat Soares, and Luciano Zumerle Zaneti Copyright © 2013 Gilson Fernandes da Silva et al. All rights reserved. Modeling the Influence of Forest Structure on Microsite Habitat Use by Snowshoe Hares Tue, 19 Nov 2013 15:56:23 +0000 Snowshoe hare (Lepus americanus) is an important prey species for many Carnivora and has strong influences on community structure and function in northern forests. An understanding of within-stand (microsite) forest structural characteristics that promote high use by hares is important to provide forest management guidelines. We measured forest structural characteristics at the microsite-scale in north-central Maine and used an information-theoretic modeling approach to infer which characteristics were most strongly associated with use by hares during winter. We measured overwinter hare pellet density to model relationships among microsite-scale vegetation structure and hare use. Overwinter pellet density was positively associated with live stem cover (3 × coniferous saplings + deciduous saplings) and negatively associated with overstory canopy closure; the two variables explained 71% of the variation in microsite use by hares. The highest pellet densities were in grids with canopy closure <72% and stem cover units >22,000 stems/ha. Silvicultural practices that create dense areas of conifer and deciduous saplings should receive high within-stand use by hares in winter. These conditions can be achieved by promoting the release of advanced regeneration and reducing overstory cover to encourage establishment of shade-intolerant species; clearcutting is one such silvicultural prescription to achieve these conditions. Angela K. Fuller and Daniel J. Harrison Copyright © 2013 Angela K. Fuller and Daniel J. Harrison. All rights reserved. Scale-Dependent Browsing Patterns on Canada Yew (Taxus canadensis) by White-Tailed Deer (Odocoileus virginianus) Sun, 03 Nov 2013 17:50:17 +0000 Canada yew (Taxus canadensis) is a clonal shrub that forms discrete patches and was formerly an important component of forest understories in much of northeastern North America. Following Euro-American settlement, Canada yew has been extirpated or reduced in abundance throughout much of its former range, particularly in the USA; winter browsing by white-tailed deer (Odocoileus virginianus) has been implicated as responsible for much of its decline. Little is known about the factors affecting deer browsing intensity on Canada yew. We examined factors related to browsing intensity on Canada yew across three spatial scales in 29 forest stands in Michigan, USA. Browsing intensity on stems was related principally to two factors acting simultaneously across multiple spatial scales. Browsing intensity was negatively related to amount of Canada yew at the scale of the forest stand and negatively related to distance from the edge of Canada yew patches, effectively creating refugia from browsing. The browsing patterns we observed suggest that yew exists in two alternate stable states: (1) as loose aggregations of small stems or (2) large, dense patches of large stems. The implications of changes in deer density or snow cover to the probability of local persistence of Canada yew are discussed. Steve K. Windels and David J. Flaspohler Copyright © 2013 Steve K. Windels and David J. Flaspohler. All rights reserved. Effect of Climate Variables on Monthly Growth in Modeling Biological Yield of Araucaria angustifolia and Pinus taeda in the Juvenile Phase Thu, 31 Oct 2013 15:22:29 +0000 The aim of this study was to investigate the effect of climate variables on monthly growth in diameter and height of Araucaria angustifolia (Bert.) O. Kuntze and of Pinus taeda L., over a six-year period, as well as verifing the contribution of these variables in the composition of the Chapman-Richards model. To this end, we selected 30 trees of each species and measured monthly the diameter and height, between June 2006 and August 2012. The climate variables were obtained from two SIMEPAR meteorological stations near the plantings. A correlation matrix was constructed to determine the effect of climate variables on the monthly growth. Next a principal component analysis (PCA) was conducted to determine the climate variables to be included in the fit of the Chapman-Richards model. The results indicated that the climate variables with the highest correlation (about 0.6) with monthly growth in diameter and height of the species were temperature, photoperiod and atmospheric pressure, and precipitation for some years of the study. The fitted model that included climate variables showed reduced Syx% of about 0.8% compared to the traditional biological model. However, ANOVA showed no statistical difference between the production estimates obtained by both models. Naiara Teodoro Zamin, Sebastião do Amaral Machado, Afonso Figueiredo Filho, and Henrique Soares Koehler Copyright © 2013 Naiara Teodoro Zamin et al. All rights reserved. Rehabilitation of Degraded Tropical Rainforest Using Dipterocarp Trees in Sarawak, Malaysia Wed, 30 Oct 2013 16:16:44 +0000 To develop rehabilitation planting techniques in tropical degraded forests, we investigated (1) basic soil characteristics and light conditions; (2) growth and survival of seven dipterocarp seedlings over 81 months; and (3) the effect of environmental factors on the survival of seedlings grown in three degraded vegetations (grassland, secondary forest, and logged forest) in Sarawak, Malaysia. The soil was weakly acidic, and kaolin minerals dominated. The amount of exchangeable bases in surface soils, soil temperature (>35°C), and relative light intensity were all highest in the grassland. Seedling growth was also highest in the grassland, whereas many seedlings died there over 81 months. Growth and survivability were very similar in secondary and logged forests. The death of the seedlings in the grassland was attributable to an extremely high light intensity for all species. In contrast, the seedling growth rate in all species was also enhanced by light intensity. In conclusion, dipterocarp seedlings can be planted on highly degraded land such as grassland, although high light intensity limits their survival. Planting under nurse trees such as regenerated pioneer trees may be an effective method to enhance seedling survival under open conditions such as grassland. Hattori Daisuke, Kenzo Tanaka, Kendawang Joseph Jawa, Ninomiya Ikuo, and Sakurai Katsutoshi Copyright © 2013 Hattori Daisuke et al. All rights reserved. Dominant Height Model for Site Classification of Eucalyptus grandis Incorporating Climatic Variables Sun, 27 Oct 2013 08:38:33 +0000 This study tested the effects of inserting climatic variables in Eucalyptus grandis as covariables of a dominant height model, which for site index classification is usually related to age alone. Dominant height values ranging from 1 to 12 years of age located in the Southeast region of Brazil were used, as well as data from 19 automatic meteorological stations from the area. The Chapman-Richards model was chosen to represent dominant height as a function of age. To include the environmental variables a modifier was included in the asymptote of the model. The asymptote was chosen since this parameter is responsible for the maximum value which the dominant height can reach. Of the four environmental variables most responsible for database variation, the two with the highest correlation to the mean annual increment in dominant height (mean monthly precipitation and temperature) were selected to compose the asymptote modifier. Model validation showed a gain in precision of 33% (reduction of the standard error of estimate) when climatic variables were inserted in the model. Possible applications of the method include the estimation of site capacity in regions lacking any planting history, as well as updating forest inventory data based on past climate regimes. José Roberto Soares Scolforo, Romualdo Maestri, Antonio Carlos Ferraz Filho, José Márcio de Mello, Antônio Donizette de Oliveira, and Adriana Leandra de Assis Copyright © 2013 José Roberto Soares Scolforo et al. All rights reserved. Postfire Burnt-Wood Management Affects Plant Damage by Ungulate Herbivores Thu, 05 Sep 2013 10:21:50 +0000 I analyze the effect of post-fire burnt wood management on herbivore attack on a woody plant species (Ulex parviflorus). Two experimental plots of ca. 20 hectares were established at two elevations in a burnt area in a Mediterranean mountain (Sierra Nevada, Spain). Three replicates of three treatments differing in post-fire burnt wood management were established per plot: “no intervention” (NI, all trees remained standing), “partial cut plus lopping” (PCL, felling the trees, cutting the main branches, and leaving all the biomass in situ), and “salvage logging” (SL; removal of logs and elimination of woody debris). Risk of herbivory and damage intensity were monitored for two years. The pattern of attack by ungulate herbivores varied among treatments and years. In any case, there was an overall reduction in the risk of herbivory in the PCL treatment, presumably because the highest habitat complexity in this treatment hampered ungulate movement and foraging. As a result, the burnt logs and branches spread over the ground acted as a physical barrier that protected seedlings from herbivores. This protection may be used for the regeneration of shrubs and trees, and it is of interest for the regeneration of burnt sites either naturally or by reforestation. Jorge Castro Copyright © 2013 Jorge Castro. All rights reserved. Effects of Deer Settling Stimulus and Deer Density on Regeneration in a Harvested Southern New England Forest Wed, 04 Sep 2013 08:06:53 +0000 Elevated deer densities have led to reports of forest regeneration failure and ecological damage. However, there is growing evidence that the biophysical conditions of a forest that make it attractive to deer may be a contributing factor in determining browsing levels. Thus, an understanding of settling stimulus—how attractive an area is to deer in terms of food-independent habitat requirements—is potentially important to manage deer browsing impacts. We tested the settling stimulus hypothesis by evaluating the degree to which thermal settling stimulus and deer density are related to spatial variation in browsing intensity across different forest harvesting strategies over the course of a year. We determined if deer were impacting plant communities and if they resulted in changes in plant cover. We quantified the thermal environment around each harvest and tested to see if it influenced deer density and browsing impact. We found that deer had an impact on the landscape but did not alter plant cover or diminish forest regeneration capacity. Deer density and browse impact had a relationship with thermal settling stimulus for summer and fall months, and deer density had a relationship with browse impact in the winter on woody plants. We conclude that thermal settling stimulus is an important predictor for deer density and browsing impact. Kevin J. Barrett and Oswald J. Schmitz Copyright © 2013 Kevin J. Barrett and Oswald J. Schmitz. All rights reserved. Leaf Gas Exchange and Nutrient Use Efficiency Help Explain the Distribution of Two Neotropical Mangroves under Contrasting Flooding and Salinity Sun, 18 Aug 2013 08:46:14 +0000 Rhizophora mangle and Laguncularia racemosa cooccur along many intertidal floodplains in the Neotropics. Their patterns of dominance shift along various gradients, coincident with salinity, soil fertility, and tidal flooding. We used leaf gas exchange metrics to investigate the strategies of these two species in mixed culture to simulate competition under different salinity concentrations and hydroperiods. Semidiurnal tidal and permanent flooding hydroperiods at two constant salinity regimes (10 g L−1 and 40 g L−1) were simulated over 10 months. Assimilation (), stomatal conductance (), intercellular CO2 concentration (), instantaneous photosynthetic water use efficiency (PWUE), and photosynthetic nitrogen use efficiency (PNUE) were determined at the leaf level for both species over two time periods. Rhizophora mangle had significantly higher PWUE than did L. racemosa seedlings at low salinities; however, L. racemosa had higher PNUE and and, accordingly, had greater intercellular CO2 (calculated) during measurements. Both species maintained similar capacities for A at 10 and 40 g L−1 salinity and during both permanent and tidal hydroperiod treatments. Hydroperiod alone had no detectable effect on leaf gas exchange. However, PWUE increased and PNUE decreased for both species at 40 g L−1 salinity compared to 10 g L−1. At 40 g L−1 salinity, PNUE was higher for L. racemosa than R. mangle with tidal flooding. These treatments indicated that salinity influences gas exchange efficiency, might affect how gases are apportioned intercellularly, and accentuates different strategies for distributing leaf nitrogen to photosynthesis for these two species while growing competitively. Pablo Cardona-Olarte, Ken W. Krauss, and Robert R. Twilley Copyright © 2013 Pablo Cardona-Olarte et al. All rights reserved. Elk (Cervus elaphus) Seasonal Habitat Selection in a Heterogeneous Forest Structure Sun, 21 Jul 2013 13:59:01 +0000 Seasonal habitat selection by the reintroduced Burwash elk population, approximately 30 km south of Sudbury, Ontario, has been analysed in order to assist in the development of future management. Twenty-five adult females were radio-collared and tracked 1–3 times a week for 3 years. The most prominent patterns included selection of intolerant hardwood forests (trembling aspen, white birch, and balsam poplar) during all seasons, while Great Lakes-St. Lawrence pines (white and red pine dominated stands) were used less than expected based on availability for all seasons. The selection patterns are likely associated with seasonal climatic conditions and forage preferences. Because the selection behaviours displayed here varied greatly from other elk habitat studies, it is suggested that managers consider the importance of population-specific habitat studies before developing related strategies. Jesse N. Popp, David N. C. McGeachy, and Josef Hamr Copyright © 2013 Jesse N. Popp et al. All rights reserved. Agent-Based Modeling of Harvest Decisions by Small Scale Forest Landowners in Maine, USA Mon, 15 Jul 2013 12:57:05 +0000 Small-scale forests are an excellent example of coupled social-ecological systems, which involve human and biophysical subsystems with complex two-way feedback interactions. The multifaceted nature of landowner decisions drives a significant need to better understand decision-making processes, reactions to policy, and combined impacts on ecosystems in a comprehensive manner. Small-scale forests require an integrated approach to modeling the social and biophysical components comprehensively. Agent-based modeling involves modeling individualistic behavior and interpreting patterns that emerge. The interaction between agents and their environments makes this a valuable tool to assess repeated decisions of individual landowners responding to changing environmental conditions. Agent-based models can be used to determine potential ecological, economic, and social outcomes of landowner decisions and reactions to changing conditions. A forest landowner agent-based model experiment was developed to model timber harvesting in Maine, USA. We present baseline simulation results and compare the effect of a social change (an increased tax rate) and a biophysical change (a pest outbreak resulting in increased tree mortality) on the system. These three scenarios were analyzed using ANOVA and MANOVA tests on harvested hectares and landowner goal scores to assess landowner behavior and priorities by action. We conclude by reviewing implications for future modeling efforts. Jessica E. Leahy, Erika Gorczyca Reeves, Kathleen P. Bell, Crista L. Straub, and Jeremy S. Wilson Copyright © 2013 Jessica E. Leahy et al. All rights reserved. ForestSim Model of Impacts of Smallholder Dynamics: Forested Landscapes of the Upper Peninsula of Michigan Thu, 30 May 2013 09:18:08 +0000 Many forested landscapes in the United States contain a large number of small private landowners (smallholders). The individual decisions of these smallholders can collectively have a large impact on the structure, composition, and connectivity of forests. While models have been developed to try to understand this large-scale collective impact, few models have incorporated extensive information from individual decision-making. Here we introduce an agent-based model, infused with sociological data from smallholders, overlaid on a GIS layer to represent individual smallholders, and used to simulate the impact of thousands of harvesting decisions. Our preliminary results suggest that certain smallholder characteristics (such as relative smallholder age and education level as well as whether a smallholder is resident or absentee) and information flow among owners can radically impact forests at the landscape scale. While still in its preliminary stages, this modeling approach is likely to demonstrate in detail the consequences of decision-making due to changing smallholder demographics or new policies and programs. This approach can help estimate the effectiveness of programs based on landscape-scale programmatic goals and the impact of new policy initiatives. Audrey L. Mayer and Mark D. Rouleau Copyright © 2013 Audrey L. Mayer and Mark D. Rouleau. All rights reserved.