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Article

The Relationship Between Burning Factors and Mediterranean Climatic Conditions in the Croatian Coastal Part

by
Roman Rosavec
1,
Damir Barčić
1,*,
Toni Rožman
2 and
Damir Ugarković
1
1
Faculty of Forestry and Wood Technology, University of Zagreb, 10000 Zagreb, Croatia
2
Hrvatske šume d.o.o., Ulica kneza Branimira 1, 10000 Zagreb, Croatia
*
Author to whom correspondence should be addressed.
Fire 2025, 8(1), 34; https://doi.org/10.3390/fire8010034
Submission received: 22 November 2024 / Revised: 2 January 2025 / Accepted: 17 January 2025 / Published: 19 January 2025
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Abstract

:
Climate conditions have long been recognised as an important factor influencing the start and spread of forest fires in Mediterranean areas. This is partly due to the long dry periods that characterise these regions. Mixed forest ecosystems are more stable than monocultures. This study was conducted at two sites, the city of Makarska (the southern coast of the Croatian Mediterranean) and the island of Rab (the northern island of the Croatian Mediterranean). The main variables examined, flammability, combustion and the moisture content of potential forest fuel, best define the start and spread of fires. The aim of the study was to examine the influence of climate factors on these variables using the example of mock privet (Phillyrea latifolia L.). The results showed that moisture content of fuel was a key variable in direct correlation with the influence of climate factors. Though the Mediterranean region is burdened by fires and they will continue to occur in the future due to changing conditions, the study results can contribute to reducing burned areas in fires for the purpose of preserving Mediterranean ecosystems.

1. Introduction

In the Mediterranean region, the warm climate supports the start of forest fires, particularly in summer when precipitation is low and temperatures are high, which reduces moisture content in biomass [1], turning it into potential forest fuel. The Mediterranean region is characterised by long dry periods in the summer months, and warm periods in the winter months [2]. The dry summer stresses and dries vegetation, leading to an increased likelihood of fire ignition [3]. Though plants have developed adaptive mechanisms to recover from fire [4], some studies have indicated the increased incidence of forest fires in the Mediterranean due to the dryer conditions expected to increase throughout the region due to climate change may be beyond the adaptive capacity of some species [5]. There is an increasing concern over the negative impacts of forest fires [6], and the risk of damages caused by forest fires is expected to increase [7]. The scope of damage depends on the intensity and frequency of fires [8]; intense fires are considered one of the most significant natural destabilisers and can cause long-term change [9]. These changes are most visible in the degradation of forests and forest habitats [10], and the distribution of species and vegetation dynamics in landscapes [11].
Mixed forest resources are more resilient to characteristic ecological disturbances in comparison with monocultures and forest sections containing only a single species [12]. In mixed forests, higher biodiversity results in better adaptation to global changes and challenges and reduces vulnerability to fire. They have a higher potential to mitigate fire damage [13] and different capacities for water and certain nutrients in relation to single-species forest resources [14]. Mixed forests are characterised by having the lowest ratio of burned surfaces of forest lands in southern Europe in relation to the total forested area [15]. In most studies, attention is focused on the main species in the area, while research on other species present in mixed stands is sparse [16]. It is important to properly manage mixed forest resources, and in order to reduce damage caused by fire, it is necessary to know the properties of different species of forest fuel. Among others, the mock privet (Phillyrea latifolia L.) is an important part of mixed holm oak (Quercus ilex L.) forests, and it is precisely for this reason that it was taken into consideration in this research.
All matter or mixtures of matter or biomass in the forest that are capable of igniting and burning are called forest fuel [17,18]. These fuels differ greatly in terms of their flammability [19]. The flammability and combustion properties of forest fuel must be known in order to assess the threat of forest fire, and this is also under the influence of many dynamic factors and variables. Therefore, flammability and combustion, intensity of the fire line, rate of spread, and consumption of available forest fuel are the result of interactions of properties of potential forest fuels, such as chemical composition, species, moisture content and impacts of climate conditions [20]. The climate conditions in a certain area play a key role in determining the fire properties of that forest [21,22]. Structural and chemical properties of leaf mass define how the plant impacts ecosystem properties [23]. Also, it is necessary to determine the available quantities of energy needed to start a forest fire and how the fire will behave [24,25]. Research has been conducted to date on different species to determine the morphology and chemical composition of leaf mass and how they influence flammability and combustion [24,26,27]. The moisture content of fuel is known to be a highly significant factor in the start and spread of forest fires [28]. Moisture content can vary in forest fuel, in response to the prevailing weather conditions [29]. Correlations have been established between the flammability of Mediterranean species and their moisture content [30,31], and most authors agree that flammability and combustion should be measured under controlled laboratory conditions, where the ecological parameters of fuel can be properly monitored [32,33].
However, within the Mediterranean region, a specific challenge is the fact that forest fires often re-occur on the same surface. These fires directly eliminate the most vulnerable species in the forest communities, thereby altering the vegetation composition which feeds into changes in the environmental conditions. These surfaces are then further degraded, and the forest fire becomes a powerful ecological factor that shapes the structure of forest communities [34]. Though the relationship between the frequency of forest fires and forest type is not completely clear [15,35], some research in Central and Southern Europe has shown that stand composition is the most important variable that predicts the likelihood of fire [36,37].
The aim of this study was to (i) determine the flammability and combustion of mock privet in the context of the importance of this species in mixed stands of holm oak in Mediterranean Croatia, and to (ii) to analyse the influence of certain climate conditions (temperature, humidity, and precipitation) on the flammability and combustion of mock privet.

2. Materials and Methods

The study was carried out at two sites in the Mediterranean part of Croatia (Figure 1). The first location was within the Rab Teaching and Experimental Forest on the island of Rab, which lies within the northern Croatian coastal area. The second location was in the research laboratory of the main Makarska weather station in the town of Makarska, located on the southern Croatian coast. These locations were selected to compare the conditions in the northern and southern coastal areas, in addition to island (Rab) and mainland (Makarska) conditions. The research was conducted once monthly at each location over a two-year period (2020–2022).
The flammability, combustion, and moisture content of live fuel of mock privet was tested. The term “flammability“ has no strict and clear definition. In this research, flammability represents the time that elapses from the moment of exposure of the sample to the source of ignition (in this case, the surface of the epiradiator) until the appearance of the flame, respectively ignition, measured in seconds, and combustion represents the time, measured in seconds, from the appearance of the flame to the extinguishing of the flame, respectively until the moment when does not consume and does not extinguish. Most authors agree that flammability and combustion should be measured in laboratory conditions.
This species is a regular component in holm oak forests, where it grows as a tree or shrub. It is naturally distributed in the southern Mediterranean basin [38,39], and in addition to evergreen forests in the Croatian coastal zone, it is also distributed around lowland karst fields [40], up to elevations of 700 m [41,42].
The prescribed methodology was used to test the flammability and combustion of live forest fuel [43], as this methodology has been used by other researchers [44,45]. Samples of leaf mass or live forest fuel were collected at identical sites at both locations, with approximately 150 g of leaf mass collected per session. In order to avoid any moisture loss in the sample between picking and testing, samples were placed in containers and hermetically sealed. The time between collection and testing was not more than 30 min. Testing was performed in two series, each with 25 samples, i.e., 50 samples were tested in each session at each location. This sample size can be considered representational and sufficient for further analysis. Samples of approximately 1 g each were distributed into plastic containers (Figure 2).
To measure flammability and combustibility, an epiradiator (electric laboratory heater) was used (type 534 Rc2, manufacturer Quartz Saint-Gobain, 500 W, Coventry, UK). The epiradiator consists of metal spirals situated in a pure silica disc with a diameter of 100 mm. Electric resistance gives infrared radiation of 3 μ (3 × 10−6) with 7.5 W (7.5 J/s) per cm2 (Figure 3).
The moisture content of tested samples was determined using the standardised equation for establishing moisture content (percentage of dry weight) by drying. To determine sample weight, four samples of live forest fuel weighing 5.00 ± 0.05 g were prepared and weighed on an electronic scale KERN 440 with the precision of 0.01 g. Samples were placed in the oven for 24 h at a temperature of 105 °C and then re-weighed.
The equation is:
L F M C = F W − D W D W ∗ 100
where:
  • LFMC—leaf fuel moisture content;
  • FW—fresh mass;
  • DW—dry mass.
For all statistical tests, a type I error (α) = 0.05 was considered statistically significant. Linear correlation analysis was used to determine the relationship between individual variables. To determine the relationship between the leaf fuel moisture content LFMC (%), mean monthly air humidity (%), mean monthly air temperature (°C), mean monthly maximum air temperature (°C), mean monthly minimum air temperature (°C) and mean monthly precipitation (mm) (independent variables) with flammability DI (s) and combustion DC (s) (dependent variables), we used multivariate linear regression. In the first model, all variables were included, and in the second model, a stepwise procedure was used to determine which of the listed variables best explained the dependent variable. All statistical analyses were performed using the statistical packages SAS 9.2. and STATISTICA 13.1.

3. Results

Table 1 shows that the flammability of mock privet samples in Makarska was between 4.53 s and 9.49 s, while in Rab it was between 5.03 s and 11.21 s. Combustion was shorter in Makarska and ranged from 8.32 s to 10.54 s, and on Rab it was between 9.25 s and 13.52 s. Leaf fuel moisture content was lower in Makarska compared to Rab. In Makarska, it was in the range from 41.74% to 101.34% and in Rab it was in the range from 60.96% to 146.02%.
According to Table 2, flammability (DI) for mock privet on the island of Rab does not correlate statistically significantly with the mean monthly amount of precipitation. Other correlations are statistically significant. For LFMC (0.51), the correlation is positive and strong, and for mean monthly humidity (0.40) it is also positive but moderate. For mean monthly air temperature (−0.41), mean monthly maximum air temperature (−0.42) and mean monthly minimum air temperature (−0.40) it is negative and mean. In Makarska, for mock privet, a statistically significant, positive and strong, DI correlates with LFMC (0.62), and a statistically significant, negative and strong DI correlates with the mean monthly air temperature (−73), the mean monthly maximum air temperature (−0.75) and mean monthly minimum air temperature (−0.72). With the mean monthly amount of precipitation (0.50), the correlation is statistically significant, positive and strong.
The results of the multivariate regression analysis of flammability (DI) for mock privet on the island of Rab indicated that there was no statistically significant dependence of DI on the examined variables. In Makarska, there was a statistically significant reliance of the DI of mock privet on mean monthly air temperature and mean monthly maximum air temperature, which explained 76% of DI (Table 3).
The DI of mock privet on Rab was statistically significantly dependent on LFMC, explaining 26% of DI, which was confirmed using the stepwise procedure of multivariate regression analysis. The stepwise procedure of the multivariate regression analysis found that DI was statistically significantly dependent on mean monthly maximum air temperature, which explained 56% of DI. There was also a statistically significant reliance of DI on mean monthly air temperature, which explained 17% of DI (Table 4).
Table 5 shows that combustion (DC) for mock privet (Phillyrea latifolia L.) on the island of Rab is statistically significantly negatively and moderately strongly correlated with LFMC (−0.48). In Makarska combustion (DC) for mock privet (Phillyrea latifolia L.) is statistically significantly negatively and low correlated with LFMC (−0.13).
Table 6 shows the results of the multivariate regression analysis for DC of mock privet on Rab, and it showed no statistically significant dependence of DC on the examined variables, which explained only 30% of the DC of mock privet on Rab. The results of the multivariate regression analysis for the DC of mock privet in Makarska, indicate a statistically significant dependence on LFMC, which explained 45% of DC.
Table 7 shows the results of the stepwise procedure of the multivariate regression analysis, indicating a statistically significant dependence of DC of mock privet on LFMC (R2 = 0.23). The results of the stepwise procedure of the multivariate regression analysis, indicating that the DC of mock privet in Makarska was significantly explained by LFMC (R2 = 0.20) and mean monthly maximum air temperature (R2 = 0.14).

4. Discussion

The mixed forests of the Mediterranean display varying vulnerability to fire [26,46]. Some species have conservative leaves with a higher ratio of dry matter in relation to saturated mass, which is seen in the slower production of biomass, longer lifespan, and more effective conservation of water resources and nutrients [47]. These types of leaves are slower to ignite, but in the sense of ignition consume more and release more heat. This directly influences the sustainability of fires and their speed of spread [48]. These leaves are also more exposed to other pressures and threats, such as limited availability of water and nutrients, the impacts of climate conditions, particularly solar radiation, and the impacts of livestock [49,50,51]. All these pressures positively influence the start and spread of fires.
Different methods were used in these studies, and these different methods showed different dependencies according to the variables used, especially according to LFMC and temperature. The reasons for this can be found in the pronounced importance of the climatic conditions of local areas. These results support the results of other methods and other studies because so far numerous studies have used different approaches and methods to show the characteristics of the comparison of flammability and combustibility of forest fuel of Mediterranean species and the results obtained are quite different. Therefore, the above points to the need to develop a standardized method for determining flammability and combustion, and it must be developed as a common classification for test results.
The moisture content of fuel is known to be the main and most critical cause of the start and further spread of fires [52,53]. Additionally, the moisture content of fuel must be considered regardless of the method used to determine flammability [54,55,56]. The results of the present study clearly show the impact of fuel moisture content on flammability. Moisture content is the best determinant of the capability of fuel to ignite, and once it does ignite, it determines how effective combustion will be [57]. Changes in moisture content are associated with atmospheric conditions and available moisture in the soil on the one hand, and physical properties of the species on the other, but also on the living conditions in the past. A low moisture content in fuel is the main reason for the start of fires in early autumn, due to the drying out of fuel over the summer months, and also in the spring before the new leaf mass begins its activities [58]. Fuel moisture content is also known to be a statistically significant factor for the flammability of mock privet. The range of fuel moisture in the study is similar to the findings of other authors [26,59,60]. The energy for initial ignition is higher with a higher moisture content. On the other hand, the moisture content affects fire behaviour, as when burning is reduced due to wet fuel, then further ignition is limited [61]. Even though it is the same type of flammability, combustion and moisture content are not in the same ranges at both locations. The area of Makarska belongs to the southern Croatian coast, which is more influenced by the Mediterranean climate and its characteristics. Rab is an island in the area of the northern Croatian coast where the influence of the Mediterranean climate is weaker compared to the southern Croatian coast. Because of this, it took a shorter time for the sample to ignite in Makarska, with range of 4.96 s (9.49 s–4.53 s), while in Rab the sample took a little longer to ignite, in range of 6.18 s (11.21 s–5.03 s). Also, the sample burned faster in Makarska, range of 2.22 s (10.54 s–8.32 s), compared to the island of Rab, a range of 4.27 s (13.52 s–9.25 s). Leaf fuel moisture content in Makarska is lower, range 59.60% (101.34–41.74%) compared to Rab, range 85.06% (146.02–60.96%). It is precisely because of the moisture content that the results of flammability and combustion were previously presented in such amounts and ratios. In the past, the capability of combustion was shown to be negatively correlated with flammability [62,63]. As in the case of flammability, the moisture content of fuel is known to be a key factor that significantly influences the combustion of mock privet as forest fuel. Climatic conditions are a key factor that influences moisture content [64,65,66]. The moisture content of fuel depends on both mid-term and long-term weather trends [51,67,68].
The research area belongs to the maritime-subtropic climate type, which is a type C climate according to the Koppen climate classification, with a moderately warm and rainy climate, with several transitional climate types and subtypes. The mean annual air temperature on the island of Rab is 15.5 °C with a mean annual precipitation of 1085.4 mm, while the mean annual air temperature in Makarska is 17.0 °C with a mean annual precipitation of 993.4 mm, for the period 1981–2023. Therefore, the results obtained from these studies show a clear influence of local climatic conditions. The area of the island of Rab, which has a lower mean annual air temperature and a higher mean annual precipitation, reacts better to an increase in temperature and thus an increase in the risk of ignition, that is, this location has a lower flammability to start with and near the upper bound for that vegetation. When it comes to precipitation (rain), it did not prove to be a decisive factor. The reason for this may be that it is possibly sufficiently high at both locations, or maybe at a climatologically drier location rainfall would be of more significance.
Climate conditions affect plant properties [69,70,71], and those properties in turn affect variations in flammability [72]. High temperatures lead to reductions in water resources and nutrients [73], while precipitation directly influences water content [74]. Climate change, particularly warming, creates positive conditions for flammability and combustion, and the influence of climate change on forest fires has been clearly shown. Many studies have highlighted the possible impacts of a changing climate on forest fire risk. Future studies of flammability and combustibility should address the clear and specific influences of climate change, and the results of these influences will be reflected in changes to the landscape and condition of the environment.

5. Conclusions

This study examined the influence of various environmental factors on the flammability of mock privet in two locations, Rab and Makarska, in Croatia. The results showed that in areas where the influence of the Mediterranean climate is more significant, the flammability is higher or faster (Makarska, range 4.96 s, Rab, range 6.18 s), burning is shorter (Makarska, range 2.22 s, Rab, range 4.27 s), and the moisture content is lower (Makarska, range 59.60%, Rab, range 85.06%). This work is consistent with similar research conducted in the Mediterranean regarding the relationship between climatic conditions, flammability, combustion and moisture content of forest fuel on the one hand, while on the other hand these researches, as well as the previous ones, confirm the need to create standardized method for determining flammability and combustion. The significance of these results is that they clearly indicate the importance of conducting such research in different locations because even though it is the same species, the results are not the same in different locations with different meteorological and climatic conditions (island of Rab, Makarska). These results can be applied to fire risk mapping. All these results, when applied in fire hazard assessment models, have a great, decisive significance, increasing the accuracy of the model, and representing the main starting points. Also, such research ensures the possibility of creating a map of vegetation ranked with regard to flammability and combustibility with the aim of practical application of the same in firefighting operations. Research confirms the need for future research that should be based on micro locations (smaller areas), especially in forest ecosystems where fire risk is recognized, but also for each plant species, individually when it comes to the relationship of flammability, combustion and moisture content.

Author Contributions

Conceptualization, R.R.; methodology, R.R.; software, D.U.; validation, R.R. and D.B.; formal analysis, D.B., R.R. and D.U.; investigation, R.R., T.R. and D.B.; resources, R.R., and D.B.; data curation, R.R.; writing—original draft preparation, R.R.; writing—review and editing, R.R. and D.B.; visualization, T.R. and D.U.; supervision, D.B.; project administration, R.R.; funding acquisition, D.U. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

The data presented in this study are available on request from the first author and corresponding author.

Conflicts of Interest

Author Toni Rožman was employed by the company Hrvatske šume d.o.o. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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Fire 08 00034 g001
Figure 1. Research area.
Figure 1. Research area.
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Figure 2. Samples prepared for testing.
Figure 2. Samples prepared for testing.
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Figure 3. Testing using the epiradiator.
Figure 3. Testing using the epiradiator.
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Table 1. Range (min and max) of flammability (DI), combustion (DC) and moisture content (LFMC).
Table 1. Range (min and max) of flammability (DI), combustion (DC) and moisture content (LFMC).
SpeciesFlammability
DI (s)		Combustion
DC (s)		Live Fuel Moisture Content
LFMC (%)
MakarskaRabMakarskaRabMakarskaRab
Mock privet 4.53–9.495.03–11.218.32–10.549.25–13.5241.74–101.3460.96–146.02
Table 2. Linear correlation coefficients of flammability (DI) for mock privet (Phillyrea latifolia L.) on the island of Rab and in Makarska. Correlations in red are significant at p < 0.05; N = 25.
Table 2. Linear correlation coefficients of flammability (DI) for mock privet (Phillyrea latifolia L.) on the island of Rab and in Makarska. Correlations in red are significant at p < 0.05; N = 25.
VariableDILFMCMean Monthly Air Humidity (%)Mean Monthly Air Temperature (°C)Mean Monthly Maximum Air Temperature (°C)Mean Monthly Minimum Air Temperature (°C)Mean Monthly Precipitation (mm)
Aleppo pine (Pinus halepensis Mill.)
Rab–DI1.000.510.40−0.41−0.42−0.400.11
Makarska–DI1.000.620.22−0.73−0.75−0.720.50
Table 3. Results of the regression analysis of flammability (DI) as the dependent variable for mock privet (Phillyrea latifolia L.) on the island of Rab and in Makarska. Correlations in red are significant at p < 0.05.
Table 3. Results of the regression analysis of flammability (DI) as the dependent variable for mock privet (Phillyrea latifolia L.) on the island of Rab and in Makarska. Correlations in red are significant at p < 0.05.
Island of Rab
DFSSMSFPr > FR2Parc. R2Coef.
Var.		RMSE
model622.9403.8232.1140.1030.4130.21717.2381.347
VariableDFProc.
Param.		Standard
Error		tPr > |t|
Intercept15.5605.8310.9500.353
LFMC10.0290.0142.0610.054
Mean monthly humidity10.0350.0670.5230.608
Mean monthly air temp.1−1.1641.687−0.6930.499
Mean monthly max. air temp.10.1240.8470.1520.885
Mean monthly min. air temp.11.0471.2240.8630.403
Mean monthly precipitation1−0.0060.0057−1.1110.281
Makarska
DFSSMSFPr > FR2Parc. R2Coef.
Var.		RMSE
model628.0244.6719.608<0.00010.7620.68310.8230.698
VariableDFProc.
Param.		Standard
Error		tPr > |t|
Intercept111.5622.5904.4630.001
LFMC10.0160.0121.3440.198
Mean monthly humidity1−0.0120.032−0.3660.720
Mean monthly air temp.12.1620.8382.5820.019
Mean monthly max. air temp.1−1.9340.559−3.4630.003
Mean monthly min. air temp.1−0.1530.416−0.3770.716
Mean monthly precipitation1−0.0010.003−0.1750.865
Table 4. Results of the stepwise regression analysis of flammability (DI) as the dependent variable for mock privet on the island of Rab and in Makarska. Correlations in red are significant at p < 0.05.
Table 4. Results of the stepwise regression analysis of flammability (DI) as the dependent variable for mock privet on the island of Rab and in Makarska. Correlations in red are significant at p < 0.05.
Island of Rab
VariableProc.
Param.		SETip II
SS		FPr > FParc. R2
Intercept4.4391.21823.76713.2840.002
LFMC0.0320.01114.4328.0660.0090.260
Makarska
VariableProc.
Param.		SETip II
SS		FPr > FParc. R2
Intercept10.8341.56720.50147.802<0.001
LFMC0.0160.0101.0712.5040.1290.029
Mean monthly temp.1.8800.5215.58013.0140.0020.171
Mean max monthly temp.−1.8010.4726.24014.5570.0010.555
Table 5. Linear correlation coefficients of combustion (DC) for mock privet (Phillyrea latifolia L.) on the island of Rab and in Makarska. Correlations in red are significant at p < 0.05; N = 25.
Table 5. Linear correlation coefficients of combustion (DC) for mock privet (Phillyrea latifolia L.) on the island of Rab and in Makarska. Correlations in red are significant at p < 0.05; N = 25.
VariableDCLFMCMean Monthly Air Humidity (%)Mean Monthly Air Temperature (°C)Mean Monthly Maximum Air Temperature (°C)Mean Monthly Minimum Air Temperature (°C)Mean Monthly Precipitation (mm)
Aleppo pine (Pinus halepensis Mill.)
Rab–DC1.00−0.48−0.06−0.010.000.00−0.04
Makarska–DC1.00−0.130.24−0.37−0.38−0.360.10
Table 6. Results of the regression analysis of combustion (DC) as the dependent variable for mock privet (Phillyrea latifolia L.) on the island of Rab and in Makarska. Correlations in red are significant at p < 0.05.
Table 6. Results of the regression analysis of combustion (DC) as the dependent variable for mock privet (Phillyrea latifolia L.) on the island of Rab and in Makarska. Correlations in red are significant at p < 0.05.
Island of Rab
DFSSMSFPr > FR2Parc. R2Coef.
Var.		RMSE
model69.8041.6341.2830.3160.2990.06510.0921.130
VariableDFProc.
Param.		Standard
Error		tPr > |t|
Intercept113.2854.8962.7120.014
LFMC1−0.0220.012−1.9120.073
Mean monthly humidity10.0050.05620.0910.933
Mean monthly air temp.1−1.1961.416−0.8430.410
Mean monthly max. air temp.10.5210.7110.7350.473
Mean monthly min. air temp.10.6651.0270.6560.525
Mean monthly precipitation10.0010.0050.1330.895
Makarska
DFSSMSFPr > FR2Parc. R2Coef.
Var.		RMSE
model646.6847.7812.4220.0680.4470.26213.4621.793
VariableDFProc.
Param.		Standard
Error		tPr > |t|
Intercept120.6046.6593.0960.006
LFMC1−0.08270.031−2.6640.016
Mean monthly humidity10.0960.0811.1850.253
Mean monthly air temp.13.1102.1531.4460.166
Mean monthly max. air temp.1−2.2091.437−1.5450.142
Mean monthly min. air temp.1−0.9841.068−0.9260.369
Mean monthly precipitation10.0010.0090.0320.980
Table 7. Results of the stepwise regression analysis of combustion (DC) as the dependent variable for mock privet on the island of Rab and in Makarska. Correlations in red are significant at p < 0.05.
Table 7. Results of the stepwise regression analysis of combustion (DC) as the dependent variable for mock privet on the island of Rab and in Makarska. Correlations in red are significant at p < 0.05.
Island of Rab
VariableProc.
Param.		SETip II
SS		FPr > FParc. R2
Intercept13.6630.952225.166206.111<0.001
LFMC−0.0230.0097.6817.0300.0140.234
Makarska
VariableProc.
Param.		SETip II
SS		FPr > FParc. R2
Intercept23.1413.132171.64154.592<0.001
LFMC−0.0680.02620.6036.5540.0180.197
Mean max monthly temp.−0.2050.06333.59710.6830.0040.141
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Rosavec, R.; Barčić, D.; Rožman, T.; Ugarković, D. The Relationship Between Burning Factors and Mediterranean Climatic Conditions in the Croatian Coastal Part. Fire 2025, 8, 34. https://doi.org/10.3390/fire8010034

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Rosavec R, Barčić D, Rožman T, Ugarković D. The Relationship Between Burning Factors and Mediterranean Climatic Conditions in the Croatian Coastal Part. Fire. 2025; 8(1):34. https://doi.org/10.3390/fire8010034

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Rosavec, Roman, Damir Barčić, Toni Rožman, and Damir Ugarković. 2025. "The Relationship Between Burning Factors and Mediterranean Climatic Conditions in the Croatian Coastal Part" Fire 8, no. 1: 34. https://doi.org/10.3390/fire8010034

APA Style

Rosavec, R., Barčić, D., Rožman, T., & Ugarković, D. (2025). The Relationship Between Burning Factors and Mediterranean Climatic Conditions in the Croatian Coastal Part. Fire, 8(1), 34. https://doi.org/10.3390/fire8010034

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