## 4 Conclusions  
The Leaf Area Index (LAI) determines the abundance of leaves at the given measurement site, which influences the amount of solar radiation reaching it and may thereby influence the presence of various species of reptiles. In our study we examined the variability of the LAI in reptile habitats in the area of the Solska Forest and Roztocze National Park, Poland. By means of an LAI-2000 device, we measured the distributions of LAI values over the period of 2011 to 2013 at 11 sites and conducted herpetological surveillance. We found six reptile species in the investigated area.  
Our results demonstrate that the relationship between the occurrence of reptiles and LAI values distributions depend on the reptile species. From among the species investigated in our study, the common viper, grass snake and blind worm were the only ones that were observed in habitats with higher median yearly LAI values. However, the sand lizard and the common lizard occurred in habitats where LAI values were seasonally variable. The smooth snake, the grass snake, the common viper and blind worm, on the other hand, were found in habitats with broad LAI distributions and similar LAI medians.  
Figure 8: LAI monthly variability depending on sighted reptile species.  
Importantly, our studies have also found a relationship between LAI and reptile biodiversity and abundance of individuals. It appeared that the optimal distribution of LAI values for reptile habitats ranged from 0.17 to 5.17, which was considered broad. The narrower LAI ranges were linked with a lower number of sighted reptiles. The distribution of LAI values also was associated with the biodiversity of reptiles; a greater number of species was detected at sites with higher median LAI values. However, with increasing biodiversity, LAI distribution became narrower. This could have resulted from a smaller number of reptile observations in habitats with lower LAI values.  
The aim of this research was to examine the utility of the LAI as a habitat index for reptiles inhabiting our study area in Poland. Based on our results, we can conclude that the LAI is a suitable habitat index for the observed reptiles' biodiversity. Moreover, LAI distributions within an area can provide information about the presence or absence of the common viper and grass snake and, to some extent, about reptile abundance. However, due to broad LAI distributions, it cannot be used as a threshold variable to determine reptile abundance or the presence or absence of individual species. It is also worth noting that LAI distributions are seasonally variable for the common lizard and sand lizard. These findings stress the necessity of taking into account LAI seasonal variability and distributions for studies on the relationship between this index and reptile occurrence, e.g., whilst developing spatial models of reptile habitats. Our results can also be used as a guide for reptile protection, such as for planning new protection areas or managing existing areas in scope of LAI.  
For future research, it would be interesting to create a more detailed habitat model depicting the occurrence of reptiles in the area of the Solska Forest and Roztocze National Park. Such a model could include LAI values obtained from remote sensing data and serving as an independent variable. In the studies to come, it would be very important to stress that for successful modelling of reptile occurrences, seasonal variability and spatial diversification of habitat attributes warrant consideration, such as the LAI.