**5. Future directions of non-destructive biogeomorphology at hillslopes**

Biogeomorphology is presently one of the most progressive branches of geomorphology, and thanks to its interdisciplinarity, it easily finds several issues in common with ecology, geobiology, and forest management, thus contributing significantly to the complex appreciation of Earth surface systems. The traditional unidirectional approach to a study of landform-biota interaction has gradually extended to cover the two-way linkages and feedbacks between Earth surface processes and landforms on the one hand and organisms on the other. Along with theoretical considerations, many studies show the feedback at concrete localities by employing different techniques. The biogeomorphologic research of hillslope processes is, however, traditionally engaged with destructive methods, such as dendrogeomorphologic sampling and exposure. These methods have been widely exploited in spatiotemporal analyses of mass transport in both high-altitude (e.g. rockfall, debris flows, etc.) and mid-altitude (e.g. landslides and sheet erosion) environments. The studies were carried out in order to understand regional geomorphologic effects of global environmental change (e.g. Evans, Clague, 1994) as well as to provide a scientific background for applied management measures (Panizza, 1996). On the other hand, the nondestructive techniques have been rather overlooked in this respect.

Non-destructive methods offer at least three important advantages, however. First, they can be applied in areas where destructive techniques cannot be performed. Second, they enable the performance of relatively fast and extensive field research in contrast to destructive sampling strategies, even though their results may not be as comprehensive, and there are still problems, which can be studied only by means of destructive sampling strategies (e.g., dendrochronology). Finally, these methods enable the study of some of those landformbiota interactions, which have been neglected. In some cases, these methods may also represent the only effective technique to study these interactions (e.g., short-term surface dynamics). In this respect, we see opportunities that should be more deeply explored by geomorphologists and which, in turn, certify the need for a bidirectional framework of biogeomorphology by employing ecological, ethological and biological knowledge. To name just one of the topics in which biogeomorphologists may more intensively draw upon nondestructive techniques, we would like to mention zoodisturbances at hillslopes.

As was mentioned in the first section, zoogeomorphology remains a "little sister" of dendrogeomorphology. Butler (1995) has shown the influences of the wide spectre of animals on Earth surface processes and landforms; however, only a few of these influences are studied systematically. The main focus has been burrowing animals (Hole, 1981; Volsamber & Veen, 1985) and animal trampling at rock-mantled slopes and in grasslands. The studies performed usually engaged experiments with manipulated animal density (e.g., Govers & Poesen, 1998) or detailed field mapping and soil sampling to reveal the physical and chemical properties of

11, which depicts sample trunk number 1 (Fig. 11 left; see position in Fig. 8) and a comparative case of log jam from Western Carpathians (Fig. 11 right). The reconstruction of evolutionary history based on the identification of tilting and rotation determined the main processes that play a role in consecutive stages of log jam evolution and the interrelation with the surface morphology and dynamics of the locality. These processes include the

**5. Future directions of non-destructive biogeomorphology at hillslopes** 

Biogeomorphology is presently one of the most progressive branches of geomorphology, and thanks to its interdisciplinarity, it easily finds several issues in common with ecology, geobiology, and forest management, thus contributing significantly to the complex appreciation of Earth surface systems. The traditional unidirectional approach to a study of landform-biota interaction has gradually extended to cover the two-way linkages and feedbacks between Earth surface processes and landforms on the one hand and organisms on the other. Along with theoretical considerations, many studies show the feedback at concrete localities by employing different techniques. The biogeomorphologic research of hillslope processes is, however, traditionally engaged with destructive methods, such as dendrogeomorphologic sampling and exposure. These methods have been widely exploited in spatiotemporal analyses of mass transport in both high-altitude (e.g. rockfall, debris flows, etc.) and mid-altitude (e.g. landslides and sheet erosion) environments. The studies were carried out in order to understand regional geomorphologic effects of global environmental change (e.g. Evans, Clague, 1994) as well as to provide a scientific background for applied management measures (Panizza, 1996). On the other hand, the non-

Non-destructive methods offer at least three important advantages, however. First, they can be applied in areas where destructive techniques cannot be performed. Second, they enable the performance of relatively fast and extensive field research in contrast to destructive sampling strategies, even though their results may not be as comprehensive, and there are still problems, which can be studied only by means of destructive sampling strategies (e.g., dendrochronology). Finally, these methods enable the study of some of those landformbiota interactions, which have been neglected. In some cases, these methods may also represent the only effective technique to study these interactions (e.g., short-term surface dynamics). In this respect, we see opportunities that should be more deeply explored by geomorphologists and which, in turn, certify the need for a bidirectional framework of biogeomorphology by employing ecological, ethological and biological knowledge. To name just one of the topics in which biogeomorphologists may more intensively draw upon non-

destructive techniques, we would like to mention zoodisturbances at hillslopes.

As was mentioned in the first section, zoogeomorphology remains a "little sister" of dendrogeomorphology. Butler (1995) has shown the influences of the wide spectre of animals on Earth surface processes and landforms; however, only a few of these influences are studied systematically. The main focus has been burrowing animals (Hole, 1981; Volsamber & Veen, 1985) and animal trampling at rock-mantled slopes and in grasslands. The studies performed usually engaged experiments with manipulated animal density (e.g., Govers & Poesen, 1998) or detailed field mapping and soil sampling to reveal the physical and chemical properties of

initial fall of the tree, sliding, rotation and trunk breach.

destructive techniques have been rather overlooked in this respect.

grazed land (Cluzeau et al., 1992; Trimble & Mendel, 1995). Despite producing important information about the rates of animal induced surface dynamics, these studies are scale dependent because their methodical background is time-exhaustive (detailed mapping and experiments). The opportunity to generalise the results of these studies lies in drawing from ethological information about the ecological behaviour of the studied species.

The example for consideration will be given from the study area, which was presented in the case studies in this chapter. The forest ecosystems of the studied catchment are diversified by patches of rock-mantled slopes and talus scree deposits, which have formed by the disintegration of rock-cliffs built by basaltic rocks since the Late Glacial Period. There are more than 100 such talus slope deposits exceeding an individual area of 400 m2. During the study of these deposits, we focused on different types of processes, among which zoodisturbances tend to play an important role. Nevertheless, the monitoring of animal trampling on talus slope deposits exceeded the possibility of the research, so the other approach had to be adopted. The major trampling specie in the area is mouflon (*Ovis musimon*), which is an introduced specie in the Czech Republic (Heroldova & Homolka, 2001). As shown by Cransac & Hewison (1997), the seasonal activity and selection of habitats of mouflon hordes in their original environment is dependent on several variables, such as feeding activity and climate. During the year, the hordes are partly bound to rocky habitats. In our study area, it was confirmed by observation that talus slope deposits indeed represent an alternative habitat for mouflon hordes. The information about mouflon ethology together with the observation at talus slope deposits, where the presence of mouflon hordes was confirmed, enabled the specification of results from the field mapping of microtopographic features (especially clast flows) present on talus slope deposits (Raska, 2010). A similar approach could be applied to reveal the spatial behaviour and specific effects of other trampling species or burrowing animals.

To summarise, we are aware that there are many biogeomorphologic studies that are relatively close to non-destructive approaches, but were not mentioned in this chapter due to its limited extent. We refer readers to more complete reviews of biogeomorphology, dendrogeomorphology, and zoogeomorphology as well as the problem of soil erosion, which is too broad to be discussed in detail herein. The main aim of the chapter was to emphasise the importance of non-destructive biogeomorphologic approaches for a better understanding of the interwoven relationships between the Earth surface and organisms and to document this with two methods, which are currently being developed and applied at the catchment scale within the presented case studies.
