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1.
Sci Total Environ ; 698: 133761, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31493576

RESUMO

In Romania, natural Norway spruce forests are spread across upper mountain slopes (1300-1800 m). They perform multiple functions, being especially recognised for their economic value. However, where planted forests extend beyond the spruce's naturally occurring areas, they are frequently exposed to deleterious environmental factors. In Romania, forest planning is based on typological studies that were carried out between 1950 and 1970, and the regulations are applied in a somewhat flexible manner. In the context of the potential threats from climate change that could amplify induced destabilising phenomena, the risks to which these forests are becoming exposed can only be mediated through flexible management and the permanent adaptation of forest planning. For this reason, the purpose of this study was to develop a strategy for adapting forest management plan guidelines, with a view to improving ecosystem stability. A Norway spruce forest was chosen from the south-eastern Carpathians, which is included in the Natura 2000 Fagaras Mountains site. The models on which we based our current stand compositions resulted from long-term monitoring and analysis of species and stand structures. Stand structure - and forest structure, in general - is key to the continuous existence of stand functions and ecosystem services. Through design decisions, we promote biodiversity and the natural, better adapted, regeneration of local provenances. We highlight the rationale behind forest management planning and its regulations, with respect to the sustainable management of Norway spruce forests, which are vulnerable to potential changes in their structure as a result of climate change. Based on our findings, we propose the adaptation of measures used in forest management planning for Norway spruce forests to include protective functions that can be applied to all man-made Norway spruce forests introduced in former beech forest regions, and mixed coniferous/beech forests, that are vulnerable to changing environmental factors.


Assuntos
Mudança Climática , Agricultura Florestal/métodos , Florestas , Picea , Noruega , Romênia
2.
An Acad Bras Cienc ; 91(4): e20190194, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31800707

RESUMO

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.


Assuntos
Biomassa , Agricultura Florestal/métodos , Florestas , Modelos Estatísticos , Madeira
4.
Sci Total Environ ; 693: 133393, 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31374496

RESUMO

Black runoff occasionally flows from cutover areas of Eucalyptus plantations, polluting rivers and ponds, and resulting in fish death in severe cases. However, the occurrence patterns and environmental impacts of this black water remain unclear. Herein, we analyzed the major characteristics of black water at the occurrence sites, tested the complexation reaction of ground eucalyptus leaves with a solution of Fe3+, and determined the color and absorbance of the complex solution. The results showed that the water was dark blue, with weak acidity and strong light absorbance. The water contained a high level of dissolved organic matter content, while its chemical oxygen demand, total N, total P, NO3--N, and NH4+-N concentrations were significantly higher than those in the stream water from Eucalyptus, Pinus massoniana Lamb., and Cunninghamia lanceolata stands during the growth period. Additionally, the tannic acid concentration in the black water was 1.0 mg L-1 higher than that in the stream water from the Eucalyptus stand. The input of black water increases the concentration of tannic acid and NH4+-N, and the degradation of organic matter consumes dissolved oxygen in downstream ponds, leading to fish deaths. The presence of fresh logging residues and hot, humid weather also enable black water formation. Field investigations and simulation experiments revealed fresh Eucalyptus residues decompose rapidly under high-temperature and rainfall conditions, releasing large amounts of tannic acid, which reacts with Fe3+ to form a dark blue tannic acid­iron complex and results in black water. These results indicate that the rich Fe3+ in runoff may be a key factor in the occurrence of black water. The logging of Eucalyptus plantations during the dry season or on non-rainy days and a reduction in the logging area could prevent the occurrence of black water or mitigate the extent of its environmental hazards.


Assuntos
Eucalyptus , Peixes/fisiologia , Agricultura Florestal/métodos , Tanques/química , Água/química , Animais , China , Clima , Meio Ambiente , Qualidade da Água
5.
Environ Monit Assess ; 191(8): 502, 2019 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-31327078

RESUMO

The purpose of this study is to analyze the role of state ownership in forest governance in Turkey. It seeks to explore how property rights are affected by the complex, dynamic interplay of policies, economic influences, and the law. The historical development of state ownership, including its legal aspects, has been investigated in order to better understand the roots of current issues. An institutional approach has been followed. It is hypothesized that as the state exercises its property rights, it has both positive and negative effects on forest governance. This analysis confirms that state ownership may exceed its implementation capacity under the pressure of economic development objectives and that in areas where economic development is a priority, the loss of forests is inevitable. There is a need for a more adaptive approach to making policies related to property rights. The concept of the overriding public interest could be vital in achieving purposeful governance.


Assuntos
Política Ambiental , Agricultura Florestal/métodos , Florestas , Conservação dos Recursos Naturais/economia , Conservação dos Recursos Naturais/legislação & jurisprudência , Monitoramento Ambiental , Agricultura Florestal/economia , Agricultura Florestal/legislação & jurisprudência , Humanos , Propriedade , Formulação de Políticas , Turquia
6.
Environ Pollut ; 253: 636-645, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31330355

RESUMO

Timber harvest has many effects on aquatic ecosystems, including changes in hydrological, biogeochemical, and ecological processes that can influence mercury (Hg) cycling. Although timber harvest's influence on aqueous Hg transformation and transport are well studied, the effects on Hg bioaccumulation are not. We evaluated Hg bioaccumulation, biomagnification, and food web structure in 10 paired catchments that were either clear-cut in their entirety, clear-cut except for an 8-m wide riparian buffer, or left unharvested. Average mercury concentrations in aquatic biota from clear-cut catchments were 50% higher than in reference catchments and 165% higher than in catchments with a riparian buffer. Mercury concentrations in aquatic invertebrates and salamanders were not correlated with aqueous THg or MeHg concentrations, but rather treatment effects appeared to correspond with differences in the utilization of terrestrial and aquatic basal resources in the stream food webs. Carbon and nitrogen isotope data suggest that a diminished shredder niche in the clear-cut catchments contributed to lower basal resource diversity compared with the reference of buffered treatments, and that elevated Hg concentrations in the clear-cut catchments reflect an increased reliance on aquatic resources in clear-cut catchments. In contrast, catchments with riparian buffers had higher basal resource diversity than the reference catchments, indicative of more balanced utilization of terrestrial and aquatic resources. Further, following timber harvest THg concentrations in riparian songbirds were elevated, suggesting an influence of timber harvest on Hg export to riparian food webs. These data, coupled with comparisons of individual feeding guilds, indicate that changes in organic matter sources and associated effects on stream food web structure are important mechanisms by which timber harvest modifies Hg bioaccumulation in headwater streams and riparian consumers.


Assuntos
Cadeia Alimentar , Agricultura Florestal/métodos , Mercúrio/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Biota , Carbono , Ecossistema , Invertebrados , Mercúrio/análise , Compostos de Metilmercúrio , Isótopos de Nitrogênio , Rios/química , Poluentes Químicos da Água/análise
7.
Environ Monit Assess ; 191(8): 495, 2019 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-31302796

RESUMO

Benefiting from current unmanned air vehicle (UAV) and remote sensing techniques, the present study aims to estimate tree count (TC), tree height (TH), and tree crown cover area (TCCA) in a young Calabrian pine stand via canopy height model (CHM). Overlay images obtained using Quadcopter were used to generate two spatial three-dimensional (3D) cloud points in two different qualities. Point clouds were processed using R program in order to produce tree data using CHM. The sensitivity of CHM-based tree data was revealed using 318 tree measurements in 32 different sampling units. Estimation and measurement values were classified based on their structure from motion (SfM) quality and cover classes, and the statistical relationships among them were analyzed. Without any classification, R2 was calculated for TC, THMean, and TCCATotal estimations and field measurements. R2 values were calculated as 0.865, 0.778, and 0.869, respectively, for SfMHighest CHM, while they were calculated as 0.863, 0.736, and 0.843, respectively, for SfMMedium CHM. In addition, sensitivity and performance ranking in different groups were determined based on root mean square error (RMSE) and mean absolute percentage error (MAPE) values. A significant difference was observed among groups in terms of quality and cover for TH, while no significant differences were observed for TCCA. Therefore, it is possible to estimate the properties of SfM CHM-based young coniferous stand. It was understood that tree density, crown shape, and branching influenced the accuracy of the present study. The developed UAV (Drone)-SfM is a promising technique for further small-scale forestry studies.


Assuntos
Monitoramento Ambiental/métodos , Agricultura Florestal/métodos , Florestas , Pinus/crescimento & desenvolvimento , Tecnologia de Sensoriamento Remoto , Árvores/crescimento & desenvolvimento , Algoritmos , Processamento de Imagem Assistida por Computador , Análise Espacial , Turquia
8.
Artigo em Inglês | MEDLINE | ID: mdl-31261860

RESUMO

Short-term exposure to fire smoke, especially particulate matter with an aerodynamic diameter less than 2.5 µm (PM2.5), is associated with adverse health effects. In order to quantify the impact of prescribed burning on human health, a general health impact function was used with exposure fields of PM2.5 from prescribed burning in Georgia, USA, during the burn seasons of 2015 to 2018, generated using a data fusion method. A method was developed to identify the days and areas when and where the prescribed burning had a major impact on local air quality to explore the relationship between prescribed burning and acute health effects. The results showed strong spatial and temporal variations in prescribed burning impacts. April 2018 exhibited a larger estimated daily health impact with more burned areas compared to Aprils in previous years, likely due to an extended burn season resulting from the need to burn more areas in Georgia. There were an estimated 145 emergency room (ER) visits in Georgia for asthma due to prescribed burning impacts in 2015 during the burn season, and this number increased by about 18% in 2018. Although southwestern, central, and east-central Georgia had large fire impacts on air quality, the absolute number of estimated ER asthma visits resulting from burn impacts was small in these regions compared to metropolitan areas where the population density is higher. Metro-Atlanta had the largest estimated prescribed burn-related asthma ER visits in Georgia, with an average of about 66 during the reporting years.


Assuntos
Poluentes Atmosféricos/análise , Asma/epidemiologia , Serviço Hospitalar de Emergência/estatística & dados numéricos , Fogo , Agricultura Florestal/métodos , Material Particulado/análise , Poluição do Ar/análise , Georgia/epidemiologia , Humanos , Estações do Ano
9.
Artigo em Inglês | MEDLINE | ID: mdl-31151161

RESUMO

Short rotation poplar forests are a viable alternative in producing high quality wood for industrial applications. Their success depends on timely and high-quality implementation of a series of operations. Weed control operations are implemented to favor the trees in their competition for soil resources, and cultivation is an option typically used in many European countries. For the moment, a complete mechanization of such operations is virtually impossible, and they still require an intensive use of manual labor. Since information on work difficulty and risks in manual cultivation operations is limited, this study aimed to characterize this job. Evaluation was made in terms of work efficiency, cardiovascular workload, work intensity and postural risks by implementing a time and motion study combined with heart rate measurements, accelerometry and whole-body postural analysis. Work efficiency was particularly low even if the share of effective work time was high (70% of the observation time). Job was characterized as moderate to high intensity, which resulted into a moderate to high cardiovascular strain. While the postural analysis indicated rather small risks, the main problem was found for the back postures assumed during the work. Improvements should aim to extend mechanization, train the workers and appropriately design rest breaks.


Assuntos
Agricultura Florestal/métodos , Doenças Profissionais/epidemiologia , Postura , Carga de Trabalho , Adolescente , Adulto , Idoso , Eficiência , Florestas , Humanos , Masculino , Pessoa de Meia-Idade , Populus , Risco , Romênia/epidemiologia , Madeira , Adulto Jovem
10.
Ying Yong Sheng Tai Xue Bao ; 30(5): 1426-1434, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31106996

RESUMO

Changbai Mountain is located in the eastern mountain forest region of Northeast China, with broad-leaved Korean pine forest (BKF) as the climax vegetation type. The region is rich in species diversity and serves as an important carrier for precious wood production and forest belts in Northeast China. In the recent 120 years, the vast primary forests in Changbai Mountains have almost disappeared, and have been replaced by secondary forests, over-cut forests, and plantations. Since the founding of the People's Republic of China, the theory and technology of forest management for BKF in Northeast China have gradually improved along with the researches and understanding on the structure and function of BKF, the disputes of Korean pine regeneration characteristics, and the debate about clear cutting and selective cutting. However, the problem of insufficient Korean pine regeneration still exists, and forest management is very extensive. We tried to untangle the management technology trail and research history of BKF in the past 70 years, and to analyze the current forest types and the formation process of the management regulations, with the aim to provide reference for the sustainable management and quality improvement of natural forests in the region.


Assuntos
Conservação dos Recursos Naturais/métodos , Agricultura Florestal/métodos , Florestas , Pinus , China , Árvores
11.
Ying Yong Sheng Tai Xue Bao ; 30(5): 1469-1478, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31107001

RESUMO

Selective cutting changes tree species composition and stand structure, modifies tree competition intensity in the stand, with consequences on tree growth and population dynamics. Key tree species play a crucial role in maintaining community structure and ecosystem function. To clarify the competitive characteristics of three key species (Pinus koraiensis, Tilia amurensis, and Fraxinus mandshurica, which accounted for about 70% of growing stock) of typical forest types in broadleaved-Korean pine mixed forest, Hegyi competition index was used in four permanent 1-hm2 plots, i.e. virgin forest (VF), low-intensity cutting forest (LCF), moderate-intensity cutting forest (MCF) and high-intensity cutting forest (HCF). Compared with VF, the stand density and mean DBH of big trees (DBH≥20 cm) significantly decreased in MCF and HCF, but the stand density of young trees (2 cm≤DBH<10 cm) increased, but no significant changes of stand or DBH in LCF. In all the four forest types, individual competition index (CI) of the three species decreased with increasing DBH. There was a power function relation between CI and DBH. CI curve turned to be gentle at DBH reaching 20 cm, and this rule was not affected by selective cutting. In VF, LCF and HCF, most of competition pressure of young trees of all key species derived from other tree species in secondary canopy or understory, but the competition pressure of small trees (10 cm≤DBH<20 cm) and big trees of P. koraiensis originated mainly from intra-species and other species in secondary canopy or understory. The competition stress of F. mandshurica was mainly affected by P. koraiensis and other species in secondary canopy or understory. T. amurensis was mainly affected by intra-species and P. koraiensis. Betula platyphylla contributed most of the competition stress (over 50%) to all three key species in HCF. Our results suggested that removing the trees which are in secondary canopy or understory but suppress the three key trees species intensively would be beneficial to the regeneration and growth of key species before tree DBH exceeds 20 cm. We proposed to regulate the density of key tree species in overstory to cultivate large diameter timber according to the competition among the key trees species. Once tree DBH exceeds 20 cm, tree growth would not be affected by competition. This study had guiding significance for the cultivation of key tree species and rapid recovery of natural forests after selective cutting.


Assuntos
Agricultura Florestal/métodos , Florestas , Pinus , China , Ecossistema , Árvores
12.
Ying Yong Sheng Tai Xue Bao ; 30(5): 1651-1658, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31107022

RESUMO

Thinning, an important forest management strategy, can alter forest structure and stability, and consequently affect ecosystem biogeochemical cycles. The effects of thinning on soil carbon and nitrogen is far from conclusive especially due to the lack of long-term experiments. Here, we investigated soil carbon and nitrogen in Larix olgensis plantations in Mengjiagang Forest Farm, Heilongjiang Province, with four thinning treatments (i.e., 4 times low-intensity thinning, LT4; 3 times medium-intensity thinning, MT3; 2 times high-intensity thinning, HT2; and un-thinned control). The effects of thinning on soil total organic carbon and total nitrogen were examined from the perspective of the composition of labile and recalcitrant pools (labile carbon or nitrogen pool I; labile carbon or nitrogen pool II; and recalcitrant carbon or nitrogen pool) by an acid hydrolysis approach. The results showed that thinning significantly increased soil total organic carbon and nitrogen by 48.7%-50.3% and 28.9%-42.7%, respectively. The carbon and nitrogen contents in all the labile I, labile II, and recalcitrant pools were increased by thinning, with the magnitudes varying across different pools and thinning types. LT4, MT3, and HT2 improved the recalcitrant carbon by 71%, 69% and 75%, respectively, which was significantly higher than the increment of two labile carbon pools. In addition, the percentage of recalcitrant carbon in total organic carbon was increased by thinning. LT4 significantly increased microbial biomass and microbial quotient, but no significant change was found in MT3 and HT2 treatments. Overall, our results indicated that thinning might increase the input of soil recalcitrant carbon components such as suberin and lignin by producing more coarse woody residues, thus leading to decline of organic matter decomposition and ultimately enhancement of soil organic carbon.


Assuntos
Carbono/análise , Agricultura Florestal/métodos , Florestas , Larix/fisiologia , Nitrogênio/análise , Solo , Microbiologia do Solo
13.
Ying Yong Sheng Tai Xue Bao ; 30(5): 1659-1666, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31107023

RESUMO

Exploring the temperature sensitivity of leaf dark respiration is of significance for understanding forest carbon cycling and its response to climate change. However, its intra-specific variability and seasonality are not clear yet. In this study, we measured the temperature sensitivity coefficient (Q10) of leaf dark respiration for Dahurian larch (Larix gmelinii) that were transplanted from four latitudinal sites (i.e., Tahe, Songling, Heihe, and Dailing) in a common garden. Our specific aims were to explore the seasonal dynamics of Q10 and compare differences in Q10 among the indivi-duals from the four latitudinal sites. The results showed that the Q10 for the four sites exhibited similar seasonal trend, with the maximum Q10 in the middle growing season. The inter-site difference in Q10 was significant, ranging from (1.48±0.01) to (2.15±0.03). Furthermore, the inter-site difference showed the same pattern across the whole growing season, i.e., the warmer and lower latitudinal sites, the higher Q10. The Q10 was significantly and positively correlated with foliar nitrogen concentration and soluble sugar concentration, and mean annual temperature and mean annual precipitation in the transplanting sites. These findings suggested that the inter-site variation in Q10 and its seasonality could be mainly attributed to the foliar nutrient concentration and adaptation of trees to the climatic conditions of the transplanting sites, which should be considered in modeling and predicting responses of forest carbon cycling to climate change.


Assuntos
Agricultura Florestal/métodos , Larix , Folhas de Planta/metabolismo , Florestas , Temperatura Ambiente , Árvores
14.
Ying Yong Sheng Tai Xue Bao ; 30(5): 1699-1712, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31107027

RESUMO

Ecological resilience is characterized by the recovery capacity of forest ecosystem from a status affected by external disturbance to a stable status, which is one of the important targets for sustainable development of forests. Ecological resilience is sensitive to external factors, such as climate change, forest fire, and silvicutural management at large scales. Understanding the effects of those factors on ecological resilience is important for forest ecosystem management. In this study, we calculated ecological resilience with indicators including forest structure, composition and function. We used a landscape model LANDIS PRO to evaluate the effects of climate change, climate-induced fire, and silvicultural management on ecological resilience in boreal forests. We also evaluated whether the current thinning treatment could be implemented under the scenarios of climate change. The results showed that the initialized stand density and basal area from the year 2000 could represent the real forest landscape in year 2000, with no significant difference between the simulated landscape and the forest inventory data in the year 2010 at landscape scale. The results of simulated fire disturbance were consistent with the results from the field inventories in burned areas. The fire module parameters set adequately represented the current fire regimes in model simulation. The ecological resilience could increase by 15.7%-40.8% at landscape scale when fire intensity increased by 30%, whereas the ecological resilience decreased by 4.4%-24.6% when fire intensity increased by 200%. At the short and medium term, the effects of increased fire on forest ecological resilience were greater than that of climate change. Compared to the current base scenario, forest ecological resilience under B1 climate with fire intensity increased by 30% scenario and A2 climate with fire intensity increased by 200% scenario fluctuated in the ranges of -15.9%-38.9% and -60.4%-34.8% in the whole simulation period at landscape scale. Compared to no harvesting scenario, the current thinning strategy would decrease the ecological resilience at landscape scale under both B1 and A2 scenarios in all simulated periods. Under the scenario of B1 climate with 30% increases of fire intensity, no silvicultural management would be needed in the whole simulation period at landscape scale, whereas medium and high intensity of silvicultural management were suggested under the scenario of A2 climate with 200% increase of fire intensity.


Assuntos
Mudança Climática , Monitoramento Ambiental , Fogo , Agricultura Florestal/métodos , Florestas , China , Taiga , Árvores
17.
PLoS One ; 14(4): e0214888, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30947288

RESUMO

A reasonable micro-pits texture has been initially proved that it can improve friction characteristics between wood and cemented carbide surface and reduce surface friction coefficient. In order to study the cutting performance of the micro-texture when it is applied to the cutting tool for cutting wood more effectively, this paper selected micro-pit texture for studying influence of surface micro-texture cutting tool on wood cutting performance and cutting temperature, finding that when micro-pit cemented carbide cutting tool is adopted for turning the northeast China ash (Fraxinus spp.), it can reduce cutting force of turning and surface friction coefficient between rake face and cuttings. Moreover, for type A and type B cutting tools, when the texture parameters are that the diameter of the micro-pit is 80µm, the depth of the micro pit is: 10µm, area occupancy is 20% and the diameter of the micro-pit is 120µm, the depth of the micro-pit is 10µm and the area occupancy is 20%, the effect generated is the best. When a texture cutting tool is used for cutting, the decrease of the highest temperature in the cutting area is not very great, but the average temperature in the cutting area changes a lot, which is mainly caused by that micro-texture is processed at a position of the rake face close to the main cutting edge and that the highest temperature of cutting is mainly generated on the contact point between tool tip and wood. A reasonable micro-texture parameter can form a layer of liquid lubricating film on the up and down contact surfaces such that the direct contact between cemented carbide and northeast China ash is changed into indirect contact between lubricating films formed by the liquid so as to reduce the surface friction coefficient.


Assuntos
Agricultura Florestal/instrumentação , Madeira , China , Desenho de Equipamento , Agricultura Florestal/métodos , Fraxinus/ultraestrutura , Fricção , Temperatura Alta , Lubrificação , Fenômenos Mecânicos , Propriedades de Superfície , Madeira/ultraestrutura
18.
Sci Total Environ ; 670: 328-336, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-30904646

RESUMO

This is a study of the re-accumulation of bushfire fuels following both prescribed fire of low fireline intensity (<700 kW m-1) and wildfire of high intensity (>10,000 kW m-1) in Australian Eucalyptus open forests of differing annual rainfall. Repeated measurements over 5 to 7 years of litter, elevated fuels, coarse woody debris, and bark revealed more rapid fuel recovery in higher rainfall forests compared with lower rainfall forests, following prescribed fire. In prescribed-burnt forests with mean annual rainfall 900-950 mm all fuel categories recovered to very high within seven years, with elevated fuels exceeding pre-fire loads by up to 200%. No fuels in prescribed-burnt forests with mean annual rainfall 600-650 mm recovered to pre-fire loads after six years suggesting that rainfall is an important driver of the rate of fuels recovery. High intensity wildfire in lower rainfall forests (600-650 mm) stimulated the rapid recovery of elevated fuels to over 600% of pre-fire loads - effectively transforming open forest formations into shrublands over the 6 years after fire. The recovery of elevated fuels following both prescribed fire in high rainfall forests and wildfire in low rainfall forests did not follow a gradual negative exponential increase often approximated by an Olson curve, but peaked early after fires. This suggests that the Olson recovery function, the default for predicting loads for these fuels in the operational fire behaviour models in use in south-eastern Australia, may not be appropriate in all cases. Fire simulations were run for forests burnt in wildfires using default (forest) and observed (shrubland) vegetation types. Under weather conditions similar to the previous wildfire, predictions for fireline intensities and the rate of spread would be at least 50% greater in transitional shrubland than forest, emphasizing the importance of accounting for vegetation dynamics for safe response management.


Assuntos
Eucalyptus , Agricultura Florestal/métodos , Florestas , Incêndios Florestais/estatística & dados numéricos , Austrália , Incêndios Florestais/prevenção & controle
19.
PLoS One ; 14(3): e0212174, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30845222

RESUMO

The ecosystem services approach can inform decision-making by accounting for both short- and long-term benefits from different land use options. Here we used the InVEST toolkit to quantify and map key ecosystem services at the largest publicly-owned agro-silvo-pastoral farmstead in Portugal-a site representative for the montado landscape. We analyzed how Provisioning (cork production) and Regulating & Maintenance (carbon storage and sequestration) services would be affected under three land use change scenarios, which were developed in collaboration with the forest manager of the study area: Cattle Intensification, Forest Improvement, and Residential Development. Results show that increasing cattle or residential development would deliver substantially lower levels of services. We find that extensive management, improvements to forest quality, and promotion of traditional livestock grazing would provide the highest levels of assessed ecosystem services, resulting in 13.5% more carbon storage (worth between $0.34-$7.79 million USD depending on carbon price) and 62.7% more cork production (total value of USD $3.5 million) than the current land use. However, a shift in economic incentives to make sustainable cork harvesting and traditional low-density grazing of smaller ruminants like sheep and goats profitable are likely needed to reward traditional land stewardship and help support this iconic Mediterranean landscape in the future.


Assuntos
Agricultura/métodos , Conservação dos Recursos Naturais/métodos , Agricultura Florestal/métodos , Animais , Carbono/análise , Bovinos , Ecossistema , Florestas , Gado , Recursos Naturais , Portugal , Quercus/crescimento & desenvolvimento , Ovinos , Árvores/crescimento & desenvolvimento
20.
Environ Monit Assess ; 191(4): 200, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30825000

RESUMO

Clear-cutting of powerline corridors (PLCs) adversely affects ecosystem function by fragmenting intact forests and supports biodiversity with the development of a structurally diverse vegetation. The study aimed to determine diversity and composition caused by clear-cutting and monitor change in species composition on the PLC passing through Research Forest of IUC Faculty of Forestry. Species composition was monitored in 10 permanent plots on the clear-cut area (over 3 years) paired on the forest edge (over 2 years) and forest interior (first year). Diversity, the cover of invasive plants, and life form traits of the sample plots were compared. Change in species composition with time was determined with redundancy analysis (RDA) for repeated measures using CANOCO 5. Open-site conditions caused by clear-cutting promoted the number of hemicryptophyte and therophyte life forms which resulted in a high species richness on the clear-cut area (167 species), followed by forest edge (117 species) and forest interior (60 species). However, species richness which showed a peak in the second year was decreased at the end of 3 years. Total cover of invasives was considerably higher on the clear-cut area (23%) compared with the forest (3.78%) and did not make a significant effect on forest interior species in narrow corridors. Clear-cutting combined with slash piling promoted the undesired vertical development of tree sprouts and Robinia pseudoacacia which shortened management rotation in a short period. However, sites dominated by shrubs such as Cistus creticus and Cistus salviifolius suppressed the development and invasion of undesirable trees.


Assuntos
Ecossistema , Instalação Elétrica , Monitoramento Ambiental/métodos , Agricultura Florestal/métodos , Desenvolvimento Industrial , Árvores/classificação , Biodiversidade , Florestas , Plantas
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