Increase in forest structural complexity along a precipitation gradient is mediated by partial harvests in temperate Patagonian forests.

Increasing forest structural complexity is becoming a common goal in forestry worldwide. However, the lack of empirical quantification clouds its implementation. Here we quantified the long-term effects (> 30 y) of partial harvest on stand structural complexity and net primary productivity using the east-west precipitation gradient (318-2508 mm, mean annual precipitation-MAP) of western Patagonian as a study system. In this gradient, pairs of 1-ha plots on 20 sites (20 plots harvested and 20 plots unharvested) were installed. In each plot terrestrial laser scanning was used to quantify the stand structural complexity index (SSCI), and Sentinel satellite images to obtain the Enhanced Vegetation Index (EVI: proxy of net primary productivity). Generalized linear mixed-effect models were used to relate SSCI to MAP and EVI to SSCI, with harvesting as indicator variable, and site as random variable (two plots nested to same precipitation). Results showed that harvested plots on mesic-to-humid sites (but not on dry sites) had higher SSCI and EVI values compared to unharvested plots, likely due to a greater vertical canopy packing. These results show the influence of precipitation on SSCI, which resulted in a more diversified stand structure and higher EVI. Such insights support site-specific management aimed to increase forest structural complexity.

Environmental sustainability assessment of softwood and hardwood seedlings production in forest nurseries: A case study from Pakistan / Avaliação da sustentabilidade ambiental da produção de mudas de madeira macia e madeira dura em viveiros florestais: um estudo de caso do Paquistão

This article describes the environmental impacts of producing a single seedling in forest nurseries of selected districts (i.e., Haripur, Abbottabad, and Mansehra) of Hazara Division of Khyber Pakhtunkhwa, Pakistan using the life cycle assessment (LCA) approach. This study was based on the cradle-to-gate approach which begins with the pre-nursery stage and progresses toward the main nursery before transplanting seedlings into the plantation site. Data or life cycle inventory (LCI) of seedling production were collected through questionnaire surveys and personal meetings with forest nurseries managers and workers regarding consumption of different inputs such as electricity, diesel, fertilizers, herbicides, and polyethylene bags, organic manure, and water consumption. The SimaPro software version 8.5 and the CML2000 v2.05 environmental model was applied to perform life cycle impact assessment (LCIA) for a single seedling production in forest nurseries in the study area. In line with the objectives of the study, primary data regarding inputs and outputs of the nurseries were collected from 35 nurseries in the study area by using a random questionnaire method. In addition, secondary data were taken from online databases such as Eco-invent v.3.2 CORRIM and peer-reviewed published literature. For this study, a functional unit of a single seedling was considered. Production weighted average data were modeled in the latest environmental modeling software i.e., SimaPro v.8.5 for ten US-EPA most wanted environmental impacts, such as global warming potential (GWP), abiotic depletion (AD), eutrophication potential (EP), acidification potential (AP), freshwater aquatic eco-toxicity (FAE), marine water eco-toxicity (MWE), terrestrial eco-toxicity (TE), ozone layer depletion (OLD), photochemical oxidation (PO), and human toxicity (HT). The results showed that the highest environmental impact posed by a single seedling was marine aquatic eco-toxicity (11.31360 kg 1,4-DB eq), followed by global warming potential (0.02945 kg CO2 eq) and (0.01227 kg 1,4-DB eq) human toxicity. The primary reason for these environmental burdens was the use of synthetic fertilizers in forest nurseries and the consumption of fossil fuels in nursery mechanization and transportation activities. The total cumulative energy demand for a single seedling was (0.800 MJ) with more than 90% contribution from fossil fuel energy resources such as petrol and diesel. It is therefore highly recommended to use renewable energy resources and organic fertilizers instead of chemical fertilizers in forest nurseries to avoid and minimize greenhouse gas emissions (GHS) and other toxic emissions in the study area.

Este artigo descreve os impactos ambientais da produção de uma única muda em viveiros florestais de distritos selecionados (Haripur, Abbottabad e Manshera) da divisão Hazara, de Khyber Pakhtunkhwa, Paquistão, usando a abordagem de avaliação do ciclo de vida (ACV). Este estudo baseou-se na abordagem "do berço ao portão", que se inicia na fase pré-viveiro e progride em direção ao viveiro principal antes do transplante das mudas para o local de plantio. Os dados ou inventário de ciclo de vida (ICV) da produção de mudas foram coletados por meio de questionários e reuniões pessoais com o gerente e os trabalhadores dos viveiros florestais sobre o consumo de diferentes insumos, como energia elétrica, diesel, fertilizantes, herbicidas, sacos de polietileno, adubo orgânico e consumo de água. O software SimaPro, versão 8.5, e o modelo ambiental CML2000, v2.05, foram aplicados para realizar a avaliação de impacto do ciclo de vida (AICV) de uma única produção de mudas em viveiros florestais na área de estudo. Em consonância com os objetivos do estudo, os dados primários relativos às entradas e saídas dos viveiros foram coletados de 35 viveiros na área de estudo por meio de um método de questionário aleatório. Além disso, dados secundários foram obtidos de bancos de dados online, como Eco-invent v.3.2 CORRIM e literatura publicada revisada por pares. Para este estudo, foi considerada uma unidade funcional de uma única plântula. Os dados médios ponderados de produção foram modelados no software de modelagem ambiental mais recente, ou seja, SimaPro, v.8.5, para 10 impactos ambientais mais desejados pela US-EPA, como potencial de aquecimento global (PAG), depleção abiótica (DA), potencial de eutrofização (PE), potencial de acidificação (PA), ecotoxicidade de água doce (EAD), ecotoxicidade da água marinha (EAM), ecotoxicidade terrestre (ET), destruição da camada de ozônio (DCO), oxidação fotoquímica (OF) e toxicidade humana (TH). Os resultados mostraram que o maior impacto ambiental causado por uma única muda foi a ecotoxicidade da água marinha (11,31360 kg 1,4-DB eq), seguido pelo potencial de aquecimento global (0,02945 kg CO2 eq) e toxicidade humana (0,01227 kg 1,4-DB eq) eq). A principal razão para esses ônus ambientais foi o uso de fertilizantes sintéticos em viveiros florestais e o consumo de combustíveis fósseis nas atividades de mecanização e transporte de viveiros. A demanda total acumulada de energia para uma única muda foi de 0,800 MJ, com mais de 90% de contribuição de recursos energéticos de combustíveis fósseis, como gasolina e diesel. Portanto, é altamente recomendável usar recursos de energia renovável e fertilizantes orgânicos em vez de fertilizantes químicos em viveiros florestais para evitar e minimizar as emissões de gases de efeito estufa (GEE) e outras emissões tóxicas na área de estudo.

Wood volume is overestimated in the Brazilian Amazon: Why not use generic volume prediction methods in tropical forest management?

The Amazon has a range of species with high potential for sustainable timber harvesting, but for them to be utilized globally, the merchantable wood volume must be accurately quantified. However, since the 1950s, inadequate methods for estimating merchantable timber volumes have been employed in the Amazon, and Brazilian Government agencies still require some of them. The natural variability of the Amazon Forest provides an abundance of species of different sizes and shapes, conferring several peculiarities, which makes it necessary to use up-to-date and precise methods for timber quantification in Amazon Forest management. Given the employment of insufficient estimation methods for wood volume, this study scrutinizes the disparities between the actual harvested merchantable wood volume and the volume estimated by the forest inventory during the harvesting phase across five distinct public forest areas operating under sustainable forest management concessions. We used mixed-effect models to evaluate the relationships between inventory and harvested volume for genera and forest regions. We performed an equivalence test to assess the similarity between the volumes obtained during the pre-and post-harvest phases. We calculated root mean square error and percentage bias for merchantable volume as accuracy metrics. There was a strong tendency for the 100% forest inventory to overestimate merchantable wood volume, regardless of genus and managed area. There was a significant discrepancy between the volumes inventoried and harvested in different regions intended for sustainable forest management, in which only 22% of the groups evaluated were equivalent. The methods currently practiced by forest companies for determining pre-harvest merchantable volume are inaccurate enough to support sustainable forest management in the Amazon. They may even facilitate the region's illegal timber extraction and organized crime.

Production of dinizia excelsaducke (fabaceae) seedlings subjected to increasing doses of controlled release fertilizer / Produção de mudas de dinizia excelsaducke (fabaceae) submetidas a doses crescentes de fertilizante de liberação controlada

Dinizia excelsais one of the largest trees in the Amazon rainforest, with significant economic potential for the recovery of degraded areas. It is a key species for biodiversity and increased forestbiomass. However, studies related to seedling production of this species are still scarce. In this study, we evaluated the production and quality of D. excelsaseedlings in response to the application of controlled-release fertilizer doses. The experimental design was completely randomized, applying different doses of Osmocote®(T1=0; T2=4.1; T3=8.2; and T4=12.3 g.dm-³) with four replicates, using vermiculite and coconut fiber (1:1 v/v) as the substrate. We assessed the number of leaves and leaflets, shoot and root length, stem diameter, seedling height, shoot-to-stem diameter ratio, leaf area, dry mass of shoot, root, and total biomass. The data were subjected to analysis of variance and regression analysis. The seedlings responded positively to the use of Osmocote®, and starting from the 4.1 g.dm-³dose, biomass accumulation showed better results, making it a recommended practice that allows cost savings in seedling production of this species.(AU)

Dinizia excelsaé uma das maiores árvores da floresta amazônica, com grande potencial econômico para recuperação de áreas degradadas. Trata-se de uma espécie-chave para diversidade e aumento da biomassa florestal. Ainda são escassos os estudos relacionados à produção seminal de mudas da espécie. Nós avaliamos a produção e a qualidade de mudas de D. excelsaem resposta à aplicação de doses de adubo de liberação controlada. O delineamento adotado foi inteiramente casualizado, aplicando-se diferentes doses de Osmocote®(T1=0; T2=4.1; T3= 8.2 e T4=12.3 g.dm-³) com quatro repetições, utilizando-se como substrato vermiculita e fibra de coco (1:1 v/v). Foram avaliados número de folhas e folíolos, comprimento da parte aérea e raiz, diâmetro do coleto, altura das mudas, relação comprimento da parte aérea e diâmetro do coleto, área foliar, massa seca da parte aérea, raiz e total. Os dados foram submetidos à análise de variância e regressão. As mudas responderam positivamente ao uso do adubo Osmocote®e a partir da dose 4.1 g.dm-³o acúmulo de biomassa apresentou melhores resultados, podendo ser recomendada, permitindo uma economia nos custos de produção seminal de mudas da espécie.(AU)

When and where to protect forests.

Ongoing deforestation poses a major threat to biodiversity1,2. With limited resources and imminent threats, deciding when as well as where to conserve is a fundamental question. Here we use a dynamic optimization approach to identify an optimal sequence for the conservation of plant species in 458 forested ecoregions globally over the next 50 years. The optimization approach includes species richness in each forested ecoregion, complementarity of species across ecoregions, costs of conservation that rise with cumulative protection in an ecoregion, the existing degree of protection, the rate of deforestation and the potential for reforestation in each ecoregion. The optimal conservation strategy for this formulation initially targets a small number of ecoregions where further deforestation leads to large reductions in species and where the costs of conservation are low. In later years, conservation efforts spread to more ecoregions, and invest in both expanded protection of primary forest and reforestation. The largest gains in species conservation come in Melanesia, South and Southeast Asia, the Anatolian peninsula, northern South America and Central America. The results highlight the potentially large gains in conservation that can be made with carefully targeted investments.

Calibration of the Pilodyn instrument for the indirect in situ determination of the basic wood density of balsa / Calibração do instrumento Pilodyn para determinação indireta in situ da densidade básica da madeira de pau-de-balsa

Balsa wood is used widely in the nautical, aeronautical and wind-energy industries because of its low-density and high-resistance. In the Brazilian state of Mato Grosso, speculative producers with little knowledge of the culture have established balsa plantations using non-standardized and non-selected seedlings. In this sense, research is needed to improve balsa cultivation under Brazilian conditions to better explore the resource. The present study evaluated the efficiency of the Pilodyn instrument for the indirect determination of the basic wood density (BWD) of balsa. Twenty 12-year old balsa trees cultivated in Alta Floresta, Mato Grosso, were probed with the Pilodyn instrument on both north and south faces of the trunk at the base and at 1.30 and 3.10 m from the ground. Wood discs were subsequently collected from the probed sites and BWD determined according to the water-immersion method. Data were submitted to the Shapiro-Wilk normality test followed by analysis of variance and Pearson's correlation analysis with α=0.05. The BWD of balsa decreased in the direction from the base to the top of the tree. The penetration depth of the Pilodyn probe was inversely proportional to BWD with a correlation that was strong (R2=0.72) at heights of 1.30 and 3.10 m but considered weak (R2=0.46) at the base of the trunk. The reliability of the Pilodyn method was sufficient to allow the development of a linear equation that could be applied for the indirect determination of the BWD of balsa based on the penetration depth of the Pilodyn probe assessed at 1.30 m from the ground.

O pau-de-balsa é amplamente utilizado nas indústrias náutica, aeronáutica e de energia eólica devido à sua baixa densidade. No estado de Mato Grosso, produtores especulativos de balsa têm estabelecido plantios sem conhecimento sólido da cultura usando mudas não padronizadas e não selecionadas. Pesquisas são necessárias para melhorar o cultivo de balsa sob condições brasileiras para melhor explorar este recurso. O presente estudo teve como objetivo avaliar a eficiência do instrumento Pilodyn para a determinação indireta da densidade básica da madeira (DBM) de balsa. Vinte árvores de 12 anos de idade cultivadas em Alta Floresta, Mato Grosso, foram avaliadas com o instrumento Pilodyn nas faces norte e sul do tronco, na base e a 1,30 e 3,10 m do solo. Discos de madeira foram posteriormente coletados dos locais sondados e o DBM determinado de acordo com o método de imersão em água. Os dados foram submetidos ao teste de normalidade Shapiro-Wilk seguido de análise de variância e análise de correlação de Pearson com α=0,05. Os valores de DBM da balsa diminuiu da base em direção ao topo da árvore, enquanto a profundidade de penetração do Pilodyn foi inversamente proporcional. A correlação entre a profundidade de penetração do Pilodyn e o DBM foi fraca na base do tronco (R2=0,46), mas forte (R2=0,72) nos pontos de 1,30 e 3,10 m. O método Pilodyn foi suficientemente confiável que permitiu o desenvolvimento de uma equação para a determinação indireta do DBM do pau-de-balsa considerando o valor da profundidade de penetração a 1,30 m como uma das variáveis.

Evaluation of different silvicultural management techniques and water seasonality on yield of eucalyptus stands

Appropriate management of factors that influence forest development is essential to increase yield of forest plantations. The objective of this study was to evaluate the influence of water seasonality, nutritional management, and uniformity on yield of eucalyptus plantations and estimate the potential, attainable, and observed yield of adult eucalyptus stands. We evaluated Eucalyptus clonal stands in six regions of Minas Gerais State, Brazil, in a system of first and second rotation across four age classes using the twin-plots method (TP). In the study, 142 TPs were allocated alongside 142 plots in a continuous forest inventory (CFI) network of a private enterprise. The CFI received operational fertilization and additional fertilization was carried out in the TP. The trees were measured at the beginning of the experiment and at every six months to quantify the production in the wet (PW) and dry (PD) periods of the year. Uniformity of plantations was evaluated using Pvar 50 % and the optimal uniformity index. Potential, attainable, and observed yields were estimated using the average annual increase at seven years of age. The PW showed higher plant yield. There was an effect due to water availability and nutrient level on the yield of the stands. The driest semester of the year produces approximately 30 % of the current annual increase. The stands under the second rotation tend to have less uniformity than the in the first rotation. Potential yield varied depending on rainfall intensity where wetter regions had the highest yield.

Regional concentration of native fuelwood production in Rio Grande do Norte, Brazil (1990­2017) / Concentração regional da produção de lenha nativa no Rio Grande do Norte, Brasil (1990-2017)

This paper examined the regional concentration of native fuelwood production in Rio Grande do Norte, Brazil, between 1990-2017. Information on native fuelwood was gathered from forestry activities collected by the Brazilian Institute of Geography and Statistics (IBGE). This study analyzed the current situation and the spatial distribution of the state's fuelwood production by quartiles. The following indicators were used to measure market concentration: Gini Coefficient (G), Comprehensive Concentration Index (CCI), Herfindahl-Hirschman Index (HHI) and Concentration Ratio [CR(k)]. In Rio Grande do Norte, there was a -2.76% annual decrease in the production of native fuelwood, from 5,280 x10³ m³ (1990) to 777 x10³ m³ (2017). Classification of the municipalities by quartile revealed that most municipalities had low fuelwood production. The G inferred a very strong to absolute inequality for the municipalities and a weak to null inequality for the mesoregions.The CCI demonstrated no market concentration in the municipalities and a regional concentration in the mesoregions. The HHI corroborated the CCI by affirming the presence of a competitive market for the municipalities and microregions and a concentrated market in the mesoregions.The CR(k) of the four largest municipalities indicated a moderately low concentration. This study concluded that there is a competitive market structure for native fuelwood inthe state of Rio Grande do Norte.

Este artigo analisou a concentração regional da produção de lenha nativa do Rio Grande do Norte - Brasil, no período de 1990 a 2017. As informações da lenha nativa foram obtidas da produção da extração vegetal e da silvicultura, disponíveis no Instituto Brasileiro de Geografia e Estatística (IBGE). Analisou a conjuntura, a distribuição espacial da produção de lenha estadual por meio os quartis e mensurou a concentração por meio dos indicadores: Coeficiente de Gini (G), Índice de Concentração Compreensiva (CCI), Índice de Herfindahl-Hirschman (HHI) e Razão de Concentração [CR(k)]. Os resultados mostraram que houve decréscimo de -2,76% a.a. na produção de lenha nativa estadual, partindo de 5.280 x10³ m³ (1990) para 777 x10³ m³ (2017). O quartil municipal revelou que a maioria dos municípios produz pouca lenha; apesar do G ter inferido uma desigualdade muito forte a absoluta para os municípios produtores de lenha e fraca a nula para as mesorregiões, já o CCI mostrou para os municípios que é não concentrado e as mesorregiões tem concentração regional; HHI corroborou com esta afirmação mostrando um mercado altamente competitivo para os municípios e microrregiões e concentrado para as mesorregiões produtoras de lenha; o CR(k) dos quatro maiores municípios foi constatada uma concentração moderadamente baixa. Conclui-se que a lenha nativa do estado do Rio Grande do Norte possui estrutura de mercado competitiva.

Evaluation of different silvicultural management techniques and water seasonality on yield of eucalyptus stands

Appropriate management of factors that influence forest development is essential to increase yield of forest plantations. The objective of this study was to evaluate the influence of water seasonality, nutritional management, and uniformity on yield of eucalyptus plantations and estimate the potential, attainable, and observed yield of adult eucalyptus stands. We evaluated Eucalyptus clonal stands in six regions of Minas Gerais State, Brazil, in a system of first and second rotation across four age classes using the twin-plots method (TP). In the study, 142 TPs were allocated alongside 142 plots in a continuous forest inventory (CFI) network of a private enterprise. The CFI received operational fertilization and additional fertilization was carried out in the TP. The trees were measured at the beginning of the experiment and at every six months to quantify the production in the wet (PW) and dry (PD) periods of the year. Uniformity of plantations was evaluated using Pvar 50 % and the optimal uniformity index. Potential, attainable, and observed yields were estimated using the average annual increase at seven years of age. The PW showed higher plant yield. There was an effect due to water availability and nutrient level on the yield of the stands. The driest semester of the year produces approximately 30 % of the current annual increase. The stands under the second rotation tend to have less uniformity than the in the first rotation. Potential yield varied depending on rainfall intensity where wetter regions had the highest yield.

Climate change may induce connectivity loss and mountaintop extinction in Central American forests.

The tropical forests of Central America serve a pivotal role as biodiversity hotspots and provide ecosystem services securing human livelihood. However, climate change is expected to affect the species composition of forest ecosystems, lead to forest type transitions and trigger irrecoverable losses of habitat and biodiversity. Here, we investigate potential impacts of climate change on the environmental suitability of main plant functional types (PFTs) across Central America. Using a large database of occurrence records and physiological data, we classify tree species into trait-based groups and project their suitability under three representative concentration pathways (RCPs 2.6, 4.5 and 8.5) with an ensemble of state-of-the-art correlative modelling methods. Our results forecast transitions from wet towards generalist or dry forest PFTs for large parts of the study region. Moreover, suitable area for wet-adapted PFTs is projected to latitudinally diverge and lose connectivity, while expected upslope shifts of montane species point to high risks of mountaintop extinction. These findings underline the urgent need to safeguard the connectivity of habitats through biological corridors and extend protected areas in the identified transition hotspots.

Structural and functional shifts of soil prokaryotic community due to Eucalyptus plantation and rotation phase.

Agriculture, forestry and other land uses are currently the second highest source of anthropogenic greenhouse gases (GHGs) emissions. In soil, these gases derive from microbial activity, during carbon (C) and nitrogen (N) cycling. To investigate how Eucalyptus land use and growth period impact the microbial community, GHG fluxes and inorganic N levels, and if there is a link among these variables, we monitored three adjacent areas for 9 months: a recently planted Eucalyptus area, fully developed Eucalyptus forest (final of rotation) and native forest. We assessed the microbial community using 16S rRNA gene sequencing and qPCR of key genes involved in C and N cycles. No considerable differences in GHG flux were evident among the areas, but logging considerably increased inorganic N levels. Eucalyptus areas displayed richer and more diverse communities, with selection for specific groups. Land use influenced communities more extensively than the time of sampling or growth phase, although all were significant modulators. Several microbial groups and genes shifted temporally, and inorganic N levels shaped several of these changes. No correlations among microbial groups or genes and GHG were found, suggesting no link among these variables in this short-rotation Eucalyptus study.

Effect of forest management on tree diversity in temperate ecosystem forests in northern Mexico.

An important challenge for silvicultural practices is the conservation of tree diversity while fulfilling the traditional objectives of forest management, most notably timber harvesting. The purpose of this study was to compare the tree diversity before and after the application of silvicultural treatments in a temperate forest in northern Mexico. Fifteen experimental plots, each measuring 2500 m2, were established to evaluate the immediate effect of four silvicultural treatments. These treatments were identified by their levels of management: intensive (clearcut, removal 100%), semi-intensive (removal of 59-61% of basal area), conservative (removal of 29-31% of basal area), and a control group. New forest guidelines, in contrast to conventional approaches, were applied to the semi-intensive and conservative treatments based on health and diversity conditions. Basal area, canopy cover, tree and total volume were measured in each plot. The Importance Value Index, alpha diversity, and evenness were estimated before and after treatments. Eighteen species belonging to five genera and five families were found in the study area. The species with the highest ecological values were Pinus durangensis, P. teocote, Quercus sideroxyla, and Quercus convallata with IVI numbers between 13.6 and 24.5%. Alpha diversity was intermediate (Margalef: 2.9 to 3.8), while dominance and evenness were above average compared to other studies (Simpson: 0.69 to 0.77; Shannon-Wiener: 1.44 to 1.6; Pielou: 0.76 to 0.85). The species evenness index in the conservative treatment was high (Sorensen, Jaccard, quantitative Sorensen and Morisita-Horn; 88 to 99%), although abundance decreased. Overall, there were no significant differences in IVI values and diversity indicators before and after treatments, with the exception of the clearcut treatment. When associating the diversity indices with stand variables, only the Pielou's evenness index showed a significant relationship between them. We concluded that both the conservative and semi-intensive treatments did not generate significant changes in tree diversity, but the former had slightly higher alpha diversity indices. These results can provide a better insight on silvicultural practices and their effects on species composition.

Production and nutritive value of pastures in integrated livestock production systems: shading and management effects

This study aimed to evaluate the production characteristics of pastures in integrated livestock production systems. For that, an experiment was carried out in São Carlos, SP, Brazil, from 2013 to 2015. Forage development, production and nutritive value were evaluated in five beef cattle production systems: extensive continuous stocking (Urochloa decumbens) = EXT; intensive = INT; crop-livestock = iCL; livestock-forest = iLF and crop-livestock-forest = iCLF. Rotational stocking pastures in INT, iCL, iLF and iCLF systems were established with Urochloa brizantha cv. BRS Piatã. In iCL and iCLF, pastures were renovated by resowing the grass simultaneously with corn. In iLF and iCLF, eucalyptus (Eucalyptus urograndis clone GG100) was planted in Apr 2011 in single rows with 15 × 2 m spacing. In the 2013/2014 crop season, INT, iCL, and iCLF pastures were more productive than in iLF and EXT. Shading increase in the 2014/2015 season reduced pasture production in iLF and iCLF, compared with INT and iCL, but increased crude protein content and digestibility. In the shaded systems, pasture production was affected by proximity to trees, mainly due to reductions in solar radiation transmission. The principal component analyses showed that forage accumulation and leaf area index were associated with the position in the middle of the inter-row, and nutritive value was associated with the position at 1.5 m from the trees. In iCLF, solar radiation transmission greater than 60 % maintained forage accumulation similar to iCL, while in iLF, it reduced forage accumulation, evidencing that pasture renovation minimized shading effects in these systems.

Production and nutritive value of pastures in integrated livestock production systems: shading and management effects

This study aimed to evaluate the production characteristics of pastures in integrated livestock production systems. For that, an experiment was carried out in São Carlos, SP, Brazil, from 2013 to 2015. Forage development, production and nutritive value were evaluated in five beef cattle production systems: extensive continuous stocking (Urochloa decumbens) = EXT; intensive = INT; crop-livestock = iCL; livestock-forest = iLF and crop-livestock-forest = iCLF. Rotational stocking pastures in INT, iCL, iLF and iCLF systems were established with Urochloa brizantha cv. BRS Piatã. In iCL and iCLF, pastures were renovated by resowing the grass simultaneously with corn. In iLF and iCLF, eucalyptus (Eucalyptus urograndis clone GG100) was planted in Apr 2011 in single rows with 15 × 2 m spacing. In the 2013/2014 crop season, INT, iCL, and iCLF pastures were more productive than in iLF and EXT. Shading increase in the 2014/2015 season reduced pasture production in iLF and iCLF, compared with INT and iCL, but increased crude protein content and digestibility. In the shaded systems, pasture production was affected by proximity to trees, mainly due to reductions in solar radiation transmission. The principal component analyses showed that forage accumulation and leaf area index were associated with the position in the middle of the inter-row, and nutritive value was associated with the position at 1.5 m from the trees. In iCLF, solar radiation transmission greater than 60 % maintained forage accumulation similar to iCL, while in iLF, it reduced forage accumulation, evidencing that pasture renovation minimized shading effects in these systems.(AU)

Modeling residual biomass from mechanized wood harvesting with data measured by forest harvester.

The lack of accurate models for estimating residual biomass in wood harvesting operations results in underutilization of this co-product by forestry companies. Due to the lack of this information, forestry operations planning, such as chipping and transport logistics, are influenced, with a consequent increase in costs. Thereby, the aim of this study was to propose and evaluate statistical models to estimate residual biomass of Eucalyptus sp. in wood harvesting operations by means of tree variables measured from harvester processing head. Generalized linear models were composed through stepwise procedure for estimating residual biomass by tree covariates: diameter at breast height, commercial height, commercial limit diameter, and stem commercial volume, considering also their transformations and combinations. Residual biomass distributions with positive skew support the application of generalized linear model and Gamma distribution in random component, since normality assumption in traditional linear regression was a requirement not satisfied in this study. By stepwise procedure, tree variables associated to forest biomass were selected, whose linear combinations resulted in models with high statistical efficiency and accuracy. Thus, models developed in this study are innovative tools to estimate residual biomass in mechanized wood harvesting, in which can be inserted into harvester's hardware to provide real-time information.

Below- and aboveground production in cocoa monocultures and agroforestry systems.

Farmers expect yield reduction of cash crops like cocoa when growing in agroforestry systems compared to monocultures, due to competition for resources, e.g. nutrients and water. However, complementarities between species in the use of resources may improve resource use efficiency and result in higher system performance. Cocoa trees have a shallow rooting system while the rooting characteristics of the associated trees are mainly unknown. This work investigates fine root distribution and production in five cocoa production systems: two monocultures and two agroforestry systems under conventional and organic farming, and a successional agroforestry system. In the organic systems a perennial leguminous cover crop was planted and compost was added, while herbicides and chemical fertilizers were applied in the conventional ones. We measured cocoa fine root parameters in the top 10cm of soil and annual total fine root production at 0-25 and 25-50cm depth. We related the root data with both the aboveground performance (tree and herbaceous biomass), and the cocoa and system yields. Cocoa fine roots were homogenously distributed over the plot area. Around 80% of the total fine roots were located in the upper 25cm of soil. The total fine root production was 4-times higher in the agroforestry systems and the organic monoculture than in the conventional monoculture. The roots of the associated tree species were located in the same soil space as the cocoa roots and, in principle, competed for the same soil resources. The cocoa yield was lower in the agroforestry systems, but the additional crops generated a higher system yield and aboveground biomass than the conventional cocoa monocultures, implying effective resource exploitation. The leguminous cover crop in the organic monoculture competed with the cocoa trees for nutrients, which may explain the lower cocoa yield in this system in contrast with the conventional monoculture.

Illegal logging as a disincentive to the establishment of a sustainable forest sector in the Amazon.

Brazil recently began granting timber concessions in public forests to promote sustainable forest use. The effectiveness of this strategy hinges on the design and implementation of the concessions themselves as well as their competitive position within the logging sector as a whole. There is, however, a lack of information on the competitive interaction between legal and illegal logging and its effects on concessions profits. We address this knowledge gap by using a spatially explicit simulation model of the Amazon timber industry to examine the potential impact of illegal logging on timber concessions allocation and profits in a 30-year harvest cycle. In a scenario in which illegal logging takes place outside concessions, including private and public "undesignated" lands, concession harvested area would decrease by 59% due to competition with illegal logging. Moreover, 29 out of 39 National Forests (≈74%) would experience a decrease in harvested area. This "leakage" effect could reduce concession net rents by up to USD 1.3 Billion after 30 years. Federal and State "undesignated" lands, if not adequately protected, could have 40% of their total volume illegally harvested in 30 years. Our results reinforce the need to invest in tackling illegal logging, if the government wants the forest concessions program to be successful.

Plant growth, radiation use efficiency and yield of sugarcane cultivated in agroforestry systems: An alternative for threatened ecosystems.

Sugarcane (Sacharum officinarum L.) monocropping has had a great socio-economic and environmental impact in Brazil, and agroforestry systems have been considered as an alternative for more sustainable production; however, there is a lack of field research under such conditions. The aim of this study was to evaluate the growth rates, radiation use efficiency and yield traits in sugarcane cultivated in the understory of Aleurites fordii, in two agroforestry arrangements and monocropping systems. A field experiment was conducted from July 2015 to June 2016 in the city of Frederico Westphalen, Rio Grande do Sul, Brazil. The radiation use efficiency, assimilate partitioning, leaf area index, absolute growth rate, net assimilation rate, number of tillers, plant height, % of intercepted solar radiation, extinction coefficient, and yield in each system was evaluated. In agroforestry systems, the dynamic interactions between multiple plant species change with the time and can result in unique microclimates. The use of agroforestry systems in 12 x 12m arrangements should be prioritized because it enables greater yields and radiation availability in the understory. This study sought to provide new sustainable alternatives for farmers in order to increase the diversification of the rural property and maintain the preservation of existing agroecosystems.