Analysis of the forest fires in the Antalya region of Turkey using the Keetch–Byram drought index     

Tugrul Varol  Mertol Ertugrul 《林业研究》2016,27(4):811-819

We investigated the correlation of large fires([300 ha) from 1992 to 2013 within the borders of the Antalya Regional Directorate of Forestry using the Keetch–Byram drought index(KBDI). Daily KBDI values were calculated for each year, and values for the period before the year 2000 differed significantly from those after2000. After 2000(large fires occurred in 2004, 2006, 2007,2008, 2010, and 2013), when KBDI values increased, the KBDI, but not the number of fires, was inversely correlated with the natural log of the burned area(NLBA). While there were both high and low KBDI values when the NLBA was small, only high KBDI values were associated with high NLBA values. Particularly for logarithmic values of 4 and higher, KBDI values increased in parallel with increases in NLBA values. On the basis of a Mann–Whitney U test done in addition to a Pearson correlation test, we found that when the burned areas were grouped according to small and large areas, the KBDI could be used to distinguish the two groups. Using a conditional probability analysis, we found that 4th, 5th and 6th class KBDI values may lead to large fires at the 60 % possibility.Similarly, the possibility of large fires greater than the median burned area in any given 6 years was found to be48 %. In addition, while the mean value of KBDI is 390.51 for the period from May to September for these 6 years, it is 359.93 for the other years. Consequently, the area burned also increased as the KBDI classes(Class 0: 0–99, Class 1:100–199, Class 2: 200–299, Class 3: 300–399, Class 4:400–499, Class 5: 500–599, Class 6: 600–699, and Class 7:700–800) increase.  相似文献   

Evapotranspiration estimation of <Emphasis Type="Italic">Platycladus orientalis</Emphasis> in Northern China based on various models     

Hailong Wu 《林业研究》2016,27(4):871-878

Platycladus orientalis is one of the most popular afforestation species and greening species for water management in arid and semi-arid regions of northern China. We applied various models to estimate and validate artificial P. orientalis forest evapotranspiration features with the goal of accurately estimating the water use of a P.orientalis plantation. The American Society of Civil Engineers Evapotranspiration–Penman–Monteith model(APM) and FAO56–Penman–Monteith model(FPM) are extensively applied for vegetation evapotranspiration estimation because their reliability has been validated by many scholars. The Priestley–Taylor model(PT) and Hargreaves model(HS) require only the daily maximum temperature,daily minimum temperature and solar radiation to estimate evapotranspiration and are thus widely applied to grasslands but not to forests. We used the Energy Balance Bowen Ratio(EBBR) system to validate the accuracy of the four models. The results indicated that:(1) Compared to the EBBR measurement annual value, APM was the most accurate, followed by FPM, and PT;(2) During the year, the accuracies of the four models varied. APM and FPM underestimated evapotranspiration during June, July and August, whereas PT and HS overestimated evapotranspiration during this period. In the rest of the year, the estimation accuracies were reversed;(3) An analysis of the possible reasons indicated that wind speed, air temperature and precipitation were the most important contributors.High temperatures were measured in June, July and August, which led to an overestimation by PT and HS because these two models only calculated the temperature and radiation without vegetation information. Underestimation also occurred when a low temperature was recorded. Though APM and FPM addressed both meteorological and vegetation factors, slight deviations still existed; and(4) The two models were modified based on EBBR-measured data. Relative humidity was introduced into PT, and parameter ‘‘A’’ in the HS estimation model was amended to1.41. The accuracy of the modified models significantly increased. The study highlighted the application, comparison and improvement of four models in estimating evapotranspiration and offers more approaches to assess forest hydrological functions.  相似文献   

Litterfall,decomposition and nutrient release of <Emphasis Type="Italic">Shorea robusta</Emphasis> and <Emphasis Type="Italic">Tectona grandis</Emphasis> in a sub-tropical forest of West Bengal,Eastern India     

Chittaranjan Das  Naba Kumar Mondal 《林业研究》2016,27(5):1055-1065

We studied leaf litter fall, decomposition and nutrient release patterns of Shorea robusta and Tectona grandis by using a litter bag technique to better understand the release pattern of nutrients to soil from leaf litter. Annual litterfall varied from 13.40 ± 2.56 t ha^?1 a^?1 for S. robusta to 11.03 ± 3.72 t ha^?1 a^?1 for T. grandis and the decay constant (k) of decomposed leaf litter was distinctly higher for T. grandis (2.70 ± 0.50 a^?1) compared to S. robusta (2.41 ± 0.30 a^?1). Biomass loss was positively correlated with the initial litter C, WSC, C/N and ash content in S. robusta and N, P and K concentration for T. grandis. Biomass was negatively correlated with lignin and L/N ratio for S. robusta and L, WSC, L/N and C/N ratio for T. grandis (P < 0.01). Nutrient use efficiency (NUE) and nutrient accumulation index (NAI) of S. robusta was higher than for T. grandis. The retranslocation of bioelements from senescent leaves ranked as P > N > K. Annual N, P and K input to soil through litterfall differed significantly between the two species in the following order: N>K>P. S. robusta was superior in terms of K and P return and T. grandis was superior in terms of N return. The two tree species showed a similar patterns of nutrient release (K > P > N) during decomposition of their leaf litter. Nutrients of N, K and P were the primary limiting nutrients returned to soil through litterfall with important roles in soil fertility and forest productivity.  相似文献   

A comparison of decomposition dynamics among green tree leaves,partially decomposed tree leaf litter and their mixture in a warm temperate forest ecosystem     

Juan Wang  Yeming You  Zuoxin Tang  Xiaolu Sun  Osbert Jianxin Sun 《林业研究》2016,27(5):1037-1045

Decomposition dynamics were compared among green tree leaves, partially decomposed tree leaf litter (i.e., decayed tree leaf litter on forest floor) and a mixture of the two in a warm temperate forest ecosystem in central China to test the influence of litter chemical quality on the degree of decomposition. The study was conducted in situ at two contrasting forest sites, an oak forest dominated by Quercus aliena var. acuteserrata Maxim., and a mixed pine and oak forest dominated by Pinus armandii Franch. and Q. aliena var. acuteserrata. We found marked differences in the rate of decomposition among litter types at both forest sites; the litter decomposition constant, k, was about 39 % greater at the oak forest site and more than 70 % greater at the pine-oak forest site, for green leaves than for partially decomposed leaf litter. The decomposition dynamics and temporal changes in litter chemistry of the three litter types also greatly differed between the two forest sites. At both forest sites, the higher rate of decomposition for the green leaves was associated with a higher nitrogen (N) content and lower carbon to N ratio (C/N) and acid-unhydrolyzable residue to N ratio (AUR/N). We did not find any non-additive effects when mixing green leaves and partially decomposed leaf litter. Our findings support the contention that litter chemical quality is one of the most important determinants of litter decomposition in forest ecosystems at the local or regional scale, but the effect of litter chemical quality on decomposition differs between the contrasting forest types and may vary with the stage of decomposition.  相似文献   

An easy,accurate and efficient procedure to create forest fire risk maps using the SEXTANTE plugin Modeler     

Lia Duarte  Ana Cláudia Teododo 《林业研究》2016,27(6):1361-1372

To prevent, detect, and protect against forest fires, forest personnel need to define rules for determining forest fire risk. In Portugal, all municipalities must annually produce forest fire risk(FFR) maps. To produce more reliable FFR maps more easily, we developed an open source model using the Modeler plugin of SEXTANTE in the program QGIS version 2.0 Dufour. The model provides all the maps involved in the FFR model(susceptibility map, hazard map, vulnerability map, economic value map,and potential loss map) and was produced according to Portuguese Forest Authority's(AFN, Autoridade Florestal Nacional) rules for determining the FFR. This model was tested for the Portuguese municipality Santa Maria da Feira, where 40 % of the total municipality area falls in the category ‘‘very high' or ‘‘high' fire risk. The ‘‘very high'fire risk area is mainly classified as broad-leaved forest and has the steepest slopes(15 %). The distance of burned areas to roads was also analyzed; the proportion of burned areas increased with increasing distance to the main roads.In addition, 92.6 % of the ‘‘high' and ‘‘very high' risk zones were located in areas with lower elevation. These results confirmed that forest fire is strongly influenced not only by environmental factors but also by anthropogenic factors. The procedure implemented here was compared with our open source application already available in QGIS and also to the same procedure implemented in GIS proprietary software. Although the results were obviously the same, the model developed here presents several advantages over the other two approaches. Besides being faster,it is easy to change the model parameters according to user needs(i.e., to the rules of different countries), and can be modified and adapted to other variables and other areas to create risk maps for different natural phenomena(e.g.,floods, earthquakes, landslides). The model is easy to use and to create risk and hazard maps rapidly in a free, open source environment that does not require any programming knowledge.  相似文献   

Estimates of stem wood increments in forest resources: comparison of different approaches in forest inventory: consequences for international reporting: case studyof European forests     

Andrius Kuliešis  Stein M. Tomter  Claude Vidal  Adrian Lanz 《Annals of Forest Science》2016,73(4):857-869

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Modelling agroforestry systems of cacao (Theobroma cacao) with laurel (Cordia alliodora) and poro (Erythrina poeppigiana) in Costa Rica II. Cacao and wood production,litter production and decomposition     

J. Heuveldop  H. W. Fassbender  L. Alpízar  G. Enríquez  H. Fölster 《Agroforestry Systems》1988,6(1-3):37-48

During 7 years (1979–1985) cacao harvests (beans and husks) have been recorded for the agroforestry systems ofTheobroma cacao underCordia alliodora andErythrina poeppigiana shade trees. The mean oven dry cacao yields were 626 and 712 kg.ha⁻¹.a⁻¹ cocoa beans underC. alliodora andE. poeppigiana respectively. Harvests have gradually increased over the years and the plantation has now reached maturity. Annual extraction of N, P, K, Ca and Mg in fruits, which is relatively small, was calculated on the basis of chemical analyses. The following average values were found (kg.ha⁻¹.a⁻¹): At the age of 8 years, theC. alliodora trees have reached 26.7 cm diameter (DBH) and 14.0 m in height. Mean annual growth (from age 5 to 7) is 14.6 m³.ha⁻¹.a⁻¹. Natural plant residue production has been measured for 4 years (Nov. 1981–Oct. 1985). UnderE. poeppigiana it has reached a value of 8.91 t.ha⁻¹.a⁻¹ and underC. alliodora 7.07 t.ha⁻¹.a⁻¹. The shade trees have contributed 57 and 47% respectively. Transference and decomposition rates are high and important in the nutrient cycles. The nutrient content of the litter was analysed and corresponding average yearly transfers were (kg.ha⁻¹.a⁻¹): For part I see Vol. 4, No. 3, 1986. Agroforestry Project, CATIE/GTZ (Tropical Agricultural Research and Training Center/Gesselschaft für Technische Zusammenarbeit), Turrialba, Costa Rica  相似文献   

The role of competitors for <Emphasis Type="Italic">Chrysomela lapponica</Emphasis>, a north Eurasian willow pest,in pioneering a new host plant     

Jürgen Gross  Nina E. Fatouros  Seppo Neuvonen  Monika Hilker 《Journal of pest science》2007,80(3):139-143

The Palaearctic leaf beetle Chrysomela lapponica usually feeds upon willows in the northern region of its occurrence. However, in Central Europe, some populations are known that have specialised on birch. In this study, we investigated the significance of other herbivores occurring together on the same host plants as possible exploitative competitors of C. lapponica. Two populations were studied: a population from Finland specialised on the willow Salix borealis, and a population from the Czech Republic, specialised on the birch Betula pubescens. Abundances of folivorous and suctivorous insects on both host plants were recorded at both population sites. The willow leaf beetle Phratora vitellinae was the most abundant herbivorous insect at both study sites on willow. A field study was conducted to examine the effects of P. vitellinae on the performance of C. lapponica. The presence of P. vitellinae larvae on the same twig upon which C. lapponica larvae were feeding did not affect increase of body weight in C. lapponica larvae. Thus, the high resource availability of both willows and birches suggest that interspecific competition is unlikely to be a selection factor driving the evolution of host shift in C. lapponica.  相似文献   

Root parameters of forest trees as sensitive indicators of acidifying pollutants: a review of research of Japanese forest trees     

Yasuhiro Hirano  Takeo Mizoguchi  Ivano Brunner 《Journal of Forest Research》2007,12(2):134-142

The root parameters of forest trees can be indicators of a changing environment. We summarize the results of root studies with regard to the effects of acidifying pollutants, especially soil acidification and aluminum toxicity, on various root parameters of Japanese forest trees under experimentally controlled conditions. All root parameters such as biomass, morphology, nutritional status, and physiology can be regarded as indicators, because, under laboratory conditions, root responses occur prior to the responses in the aboveground parts. However, considering the conditions of forest sites, the nutritional status and physiological changes are better indicators of soil acidification and Al stress than the biomass and morphological response. The currently available data suggest that the most important indicator is the Ca/Al molar ratio in roots of Japanese tree species. In order to predict and detect the initial effects of soil acidification, we postulate that the specific root response to the Ca/Al molar ratio of tree roots should be considered as a parameter for use in long-term forest monitoring sites.  相似文献   

Comparing the model forms estimating generalised diameter-height relationships in Tecomella undulata plantations in hot arid region of India   总被引：1，自引：0，他引：1  

Vindhya Prasad Tewari 《林业研究》2007,18(4):255-260

Four generalised diameter-height equations were developed and compared for pure and even-aged stands of Tecomella undulata in hot arid region of Rajasthan State in India. The data used to fit the equations consisted of 1 540 diameter-height observations collected from the plots laid out in uniformly stocked stands of varying age and density. The performance of four equations was tested by non-linear least squares regression and evaluated using different statistical criteria. Finally, these equations, with the same values of coefficients ob- tained during the fitting phase, were validated by an independent data set consisting of 854 diameter-height observations. Overall, equation （4） （Hui and Gadow function） was found to perform best for both the fitting data set as well as validation data set.  相似文献