Limestone Cliffs Research Articles

Rock climbing alters plant species composition, cover, and richness in Mediterranean limestone cliffs.

Rock climbing is among the outdoor activities that have undergone the highest growth since the second half of the 20th century. As a result, cliff habitats, historically one of the least disturbed by human colonization worldwide, are facing more intense human pressure than ever before. However, there is little data on the impact of this activity in plant-communities, and such information is indispensable for adequate manager decision-making. The goal of this study was to determine the impact of rock climbing on plant communities in terms of cover, richness, and composition in relation to climbing intensity on typical Mediterranean limestone cliffs. Three rock-climbing sites were selected in the Baetic range (SE Spain), corresponding to qualitative categories of climbing frequentation: i)“low” (low frequentation with intermittent climbing), ii)“medium” (high frequentation without overcrowding), and iii) “high” (high frequentation with overcrowding). Within each site, we selected climbing routes and adjacent areas free of climbing, then we carried out a photoplot-based sampling by rappelling. We analysed the images to calculate: richness, species cover, and total cover. This study shows that rock climbing negatively affected the cliff plant community at all three study sites. A significant decrease in plant cover, species richness and a shift in the community composition were recorded for climbed areas, the cover being the variable most sensitive to rock climbing. Impact observed proved to be related to the frequentation level. Low-frequentation sites, with usually more specialized climbers, underwent relatively mild damages, whereas at high frequentation sites the impact was severe and the conservation of the species, especially rare ones, became jeopardized. Our study is the first one available to investigate climbing impact on plant communities in Mediterranean areas, but more research on the impact of rock climbing is needed to assess the regulation of this activity. Regarding management guidelines, we propose a management guideline protocol to evaluate climbing routes and design: i) “Sites free of climbing”, ii) “Strictly regulated climbing routes”, iii) “Mildly regulated climbing routes”, or iv) “Free climbing routes”.

Erosion of Brassica incana Genetic Resources: Causes and Effects

Brassica incana Ten., possessing a number of useful agronomic traits, represents a precious genetic resource to be used in plant breeding programs to broaden the genetic base in most Brassica crop species. B. incana that grows on limestone cliffs is at risk of genetic erosion for environmental constraints and human activities. We studied the pedological conditions of a Calabrian site where the B. incana grows, and we correlated the soil properties to the physiological and biochemical aspects of B. incana to identify the causes and effects of the genetic erosion of this species. Our results evidenced that physical soil conditions did not affect B. incana growth and nutraceutical properties; conversely, biological soil properties modified its properties. We identified leaf pigments and secondary metabolites that can be used routinely as early warning indicators of plant threat, to evaluate in a short term the dynamic behavior of plants leading to species extinction.

Numerical modeling of tidal notch sequences on rocky coasts of the Mediterranean Basin

AbstractTidal notches have had the potential to form at sea level from ~6.5 kyr B.P. in the Mediterranean Basin and preserve a symmetrical shape comparable to a quadric polynomial. Continuous erosion, predominantly by biological agents, affects a limestone cliff face from low‐ to high‐tide level at <1 mm/yr. Statically determined, the roots of a quadric polynomial are defined by the tidal range representing the limits of effective erosion. However, gradual variations of eustatic sea level rise (slow) and coseismic uplift/subsidence (fast) in tectonically active regions contribute to vertical shifts in the erosional base at coastlines. As a consequence, the cliff morphology gets modified through time resulting in widening, deepening, and separation of notches and possible overprinting of older features. In order to investigate successive modifications of coastal cliff morphology, we developed a numerical model that considers the erosion rate, the erosion zone relative to sea level, the regional sea level curve, and tectonic motion. The results show how slow and rapid sea level changes bias the modern cliff face and highlight that the present‐day notch sequence from top descending to sea level is not inevitably of decreasing age. Furthermore, the initiation of notch formation is not necessarily linked to the date of a certain seismic event. Especially in extensional tectonic settings where coseismic uplift is low and coastal morphological marks are not as distinct, knowledge about coastal evolution is beneficial for paleoseismological research.

Calculation of the rockwall recession rate of a limestone cliff, affected by rockfalls, using cosmogenic chlorine-36. Case study of the Montsec Range (Eastern Pyrenees, Spain)

Cliff erosion may be a major problem in settled areas affecting populations and producing economic and ecological losses. In this paper we present a procedure to calculate the long-term retreat rate of a cliff affected by rockfalls in the Montsec Range, Eastern Pyrenees (Spain). It is composed of low, densely fractured limestones; and the rockwall is affected by rockfalls of different sizes. The rockfall scars are clearly distinguishable by their regular boundaries and by their orange colour, which contrast with the greyish old reference surface (S0) of the cliff face. We have dated different stepped surfaces of the rockwall, including S0, using cosmogenic 36Cl. The total amount of material released by rockfall activity was calculated using a high definition point cloud of the slope face obtained with a terrestrial laser scanner (TLS). The present rockwall surface has been subtracted from the reconstructed old cliff surface. This has allowed the calculation of the total volume released by rockfalls and of the retreat rate. The latter ranges from 0.31 to 0.37mm·a−1. This value is of the same order of magnitude as that obtained by other researchers in neighbouring regions in Spain, having similar geology and affected by rockfalls.

Cultural spaces inside and outside caves: a study in Guam, western Micronesia

Abstract

Site formation processes and Late Natufian domestic spaces at Baaz Rockshelter, Syria: A micromorphological perspective

Geoarchaeological research at Baaz Rockshelter focuses on reconstructing geogenic and anthropogenic formation processes at the site and examining post-depositional alterations of the archaeological record. Baaz is set in a rockshelter at the base of a limestone cliff and its archaeological sequence includes seven layers documenting the repeated use of the site during the Upper Paleolithic and Late Natufian, including a Late Natufian house, as well as several phases of Neolithic occupation. Based on lithic, faunal, and botanical analysis, Upper Paleolithic people used the site sporadically and centered their activities on hunting. During the Late Natufian and Neolithic, occupations were also short term, but more intense. Here, we present results of a geoarchaeological investigation of the deposits and the first systematic micromorphological study of a constructed, Late Natufian floor. Throughout the sequence, the main formation process is the weathering of limestone, in addition to minor but regular aeolian input of silt-sized quartz grains and mica. Post-depositional processes are rare and include minor secondary gypsum formation in all horizons and bioturbation that is most pronounced in the upper two layers. Anthropogenic processes vary in type and intensity. The Upper Paleolithic deposits contain mostly geogenic components with rare, microscopic anthropogenic components, supporting the argument for sporadic site use during this time. The Late Natufian deposits contain the remains of a house that exhibits some characteristics typical of structures from this time period, including an artificially lowered surface, a wall, the round shape of the house and a constructed floor. The floor is composed of silty clay and shows microscopic structural alterations resulting from intensive use. The house also shows unconventional features for the Late Natufian, such as a built-in mortar, built-in hearth, and a possible ash dump. The uppermost deposits with Late Natufian and Neolithic occupation have a mixed appearance and contain pits and lenses of herbivore dung.

A Country of Edges

A Country of Edges Sean Patrick Hill (bio) I had not lived there a week before my feet wore a path from my door to the pond-side; and though it is five or six years since I trod it, it is still quite distinct. It is true, I fear that others may have fallen into it, and so helped to keep it open. The surface of the earth is soft and impressible by the feet of men; and so with the paths which the mind travels. How worn and dusty, then, must be the highways of the world, how deep the ruts of tradition and conformity! —Henry David Thoreau, Walden I The villagers of nineteenth century Massachusetts were generally not a people who loved the woods. Aside from a woodlot, a stream to power a mill, or ground that might be cleared to farm, there was little profit to be found in [End Page 114] the forests and mountains. By and large, the pragmatic New Englanders were not a kind of people to wander aimlessly among the trees, sketching flowers. For this reason, Henry David Thoreau was an oddity. The people of Concord, as Thoreau noted, clung largely to the town and its commerce. By the time Thoreau arrived on the pond in 1845, a change in attitudes toward nature, especially among writers and artists, was only then beginning to take deeper root. Thomas Cole had just begun his painting of the Catskills, founding what would be known as the Hudson River School, and Emerson's Nature had been published less than a decade before. Americans simply didn't think of the woods yet as a retreat, let alone a place for recreation. Thoreau was among those describing what the ordinary citizen of America was slow to realize: the value of nature beyond our commodification of it. Given the attitudes of the time, Thoreau's revolutionary proposition for Americans, at least in part, was that there was more to nature than land to farm, trees to harvest, or granite to quarry. No wonder people thought him idle. In the fall of 1867, John Muir would have appeared equally strange when he began his extended hike from Indiana to the Gulf of Mexico, documented in his book A Thousand-Mile Walk to the Gulf. His long sojourn was an utterly transcendental experience, if not a lonely one, transcribed into his journal in lush and detailed phrases alongside his pressed flowers. To see such a traveler—he didn't even have a horse—in the South in the wake of the Civil War must have seemed incredible. After all, the woods teemed with armed outliers and thieves. To be so bold as to travel alone in what was still largely a wilderness must have bordered, to the common mind, on stupidity. Muir and Thoreau's compulsion to record, to save for posterity and, ultimately, to share through publication the [End Page 115] wonders of the natural world, is a sentiment I well understand. I appreciate their records as a reader. A colleague once loaned me Muir's Thousand-Mile Walk, published posthumously, to read as an introduction to Kentucky, to which I had only recently moved. Muir knew the names of the flowers, and I didn't, and therefore my reading this book, a kind of early guide to the region, was edifying. But as a writer myself, I also find purpose in sharing my findings. Writing about trails, I could almost think of myself as a scientist, a researcher publishing papers. In 2011, my enthusiasm for Kentucky's Red River Gorge and the undeniable urge to describe it, to inform readers of a place they should see and experience for themselves, verged on obsessive. Had John Muir, on his journey southward from Indiana, jogged a few hundred miles to the east, he might have seen what is now the federally designated Red River Gorge National Geologic Area of Kentucky. This roughly forty-foursquare-mile circle of sandstone arches, imposing limestone cliffs, and dense hardwood forests would have been a wonder to him, along with the endangered white-haired goldenrod. Likewise, at the time of his journey, he would have seen...

Pleocnemia siamensis (Dryopteridaceae), a new fern species from southern Thailand

A new fern species, Pleocnemia siamensis (Dryopteridaceae), is described and illustrated from Yala Province, southern Thailand. Pleocnemia siamensis is most similar to P. macrodonta in the dissection of laminae and morphology of sinuses, but the former has sori in one row on each side of the costules and located at the ends of the veinlets (rarely on the back of the veinlets), while the latter has sori in two rows on each side of the costules and located on the back of veinlets. Pleocnemia siamensis is described from limestone cliffs in a national park and is classified as CR-critically endangered IUCN category.

Mazus sunhangii (Mazaceae), a New Species Discovered in Central China Appears to Be Highly Endangered.

Mazus sunhangii, a new species of Mazaceae from central China is described and illustrated based on evidence from morphology and molecular phylogeny. This new species is morphologically similar to M. puchellus and M. omeiensis but differs in erect habit, inflorescence position, leaf pattern and corolla color. Phylogenetic analysis based on four chloroplast DNA regions (rbcL, rps16, trnL-F, and psbA-trnH) identified the new species as the independent lineage sister to the other East Asian Mazus species. The new species is known only from a single location in Mt. Shennongjia area in northwest Hubei province, at the elevation of 760 m. The species grows on the limestone cliff, and, because a tourist arterial highway is located along this cliff, its habitat can be easily disturbed or destroyed. We propose that the only known species location is recognized as critical habitat (i.e., as the habitat required to ensure the persistence of a species) and the species listed as Critically Endangered based on the International Union for Conservation of Nature Red List Categories and Criteria B2a.

846. TRICYRTIS MACRANTHA

SummaryTricyrtis macrantha Maxim. (Liliaceae), an endemic species to Japan, is illustrated. It is distributed in a small area in Shikoku (Kochi Prefecture), and grows on limestone cliffs. Tricyrtis macrantha and its allied species, T. macranthopsis Masam., distributed in Kii Peninsula in western Honshu, and T. ishiiana (Kitag. & T. Koyama) Ohwi & Okuyama, distributed in Pacific coast side of central Honshu, comprise one natural group.

Impact assessment of intense sport climbing on limestone cliffs: Response of rock-dwelling land snails

Exposed limestone cliffs in the Swiss Jura Mountains harbour a diverse gastropod community with some rare species. Sport climbing has recently increased in popularity on these cliffs. We examined the effects of sport climbing and microtopographical features of rock faces on terrestrial gastropods by assessing species diversity and abundance on climbing routes and in unclimbed areas of seven isolated cliffs in the Northern Swiss Jura Mountains. We considered exclusively living individuals resting attached to rock faces. In total, 19 gastropod species were recorded. Six of them were specialized rock-dwelling species, whose individuals spend their entire life on rock faces, feeding on algae and lichens. Plots along climbing routes harboured fewer species of rock-dwelling snails as well as other gastropod species (usually living in the leaf litter layer at the cliffs’ base) than plots in unclimbed control areas. Similarly, both the density of individuals and frequency of occurrence in plots were reduced in both groups of snails on climbing routes. The complexity of the rock surface had little influence on the species richness and abundance of gastropods. Pyramidula pusilla, the species with the smallest shell and a preference to rest underneath overhangs, was less affected by sport climbing than snail species with larger shells and a preference to rest on exposed smooth rock surface. Our findings indicate land snail diversity and abundance are suitable indicators for impact assessment in rocky habitats. Future management plans and actions should therefore not only rely on plants; they ought to consider also gastropods and other invertebrates. Any management plan should include a comprehensive information campaign to show the potential impact of intensive sport climbing on the specialized flora and fauna with the aim of educating the climbers and increasing their compliance with such measures.

Buried in ashes: Site formation processes at Lapa do Santo rockshelter, east-central Brazil

Few archaeological sites in the Americas contain high concentrations of human burials dating back to the early Holocene. The tropical karstic region of Lagoa Santa, in central Brazil (state of Minas Gerais) is one of the richest bioanthropological records available to study the behaviors and funerary practices of early Holocene South Americans, with more than 200 skeletons found so far. One of the key locations to examine the history of human settlement in Lagoa Santa is the site of Lapa do Santo, a rockshelter known to contain the oldest rock art and the earliest evidence of funerary complexity in the continent. In this geoarchaeological investigation we focus on the early Holocene settlement at Lapa do Santo (7.9–12.7 cal kyBP) applying high-resolution geoarchaeological techniques, such as micromorphology, organic petrology and μFTIR, on both archaeological, modern reference and experimental samples. This is the first time that a micro-contextual approach integrated with experimental geoarchaeology has been applied to study the formation of rockshelter deposits in a tropical setting. Our results show that the stratigraphic sequence formed under the dual influence of anthropogenic sedimentation—through continuous combustion activities—and geogenic sedimentation in the form of oxisol aggregates which fell from above the limestone cliff into the rockshelter. Intact hearths and remobilized combustion debris, possibly hearth rake-out, are close to the graves suggesting repeated burning activities as part of the ritual behavior of early Holocene South Americans. Large amounts of ash are intermixed with heated and unheated oxisol aggregates. Heated termite mound fragments were also found mixed within the sediments. Post-depositional alteration of the site includes limited bioturbation and localized, low energy surface water and sub-surface concentrations of moisture, leading to precipitation of dense, secondary carbonates. The age inversions can be attributed to the human action of reworking the ashy sediments and not to post-abandonment processes. Despite this, the overall preservation of the sediments is good and most human burials can be considered to be in primary context.

Influence of meteorological factors on rockfall occurrence in a middle mountain limestone cliff

Abstract. The influence of meteorological conditions on rockfall occurrence has been often highlighted, but knowledge of it is still not sufficient due to the lack of exhaustive and precise rockfall databases. In this study, rockfalls have been detected in a limestone cliff by annual terrestrial laser scanning, and dated by photographic survey over a period of 2.5 years. A near-continuous survey (one photo every 10 min) with a wide-angle lens has made it possible to date 214 rockfalls larger than 0.1 m3, and a monthly survey with a telephoto lens has dated 854 rockfalls larger than 0.01 m3. Analysis of the two databases shows that the rockfall frequency can be multiplied by a factor as high as 7 during freeze–thaw episodes and 26 when the mean rainfall intensity (since the beginning of the rainfall episode) is higher than 5 mmh−1. Based on these results, a three-level scale has been proposed for predicting the temporal variations of rockfall frequency. The more precise database and freeze–thaw episode definition make it possible to distinguish different phases in freeze–thaw episodes: negative temperature cooling periods, negative temperature warming periods and thawing periods. It appears that rockfalls occur more frequently during warming and thawing periods than during cooling periods. It can be inferred that rockfalls are caused by thermal ice dilatation rather than by dilatation due to the phase transition. But they may occur only when the ice melts, because the cohesion of the ice–rock interface can be sufficient to hold the rock compartment which has been cut.

An Arrowhead Injury in a Late Neolithic/Early Chalcolithic Human Cuneiform from the Rockshelter of La Peña de Marañón (Navarre, Spain)

AbstractThe current paper describes a projectile injury found among human remains recovered from La Peña de Marañón, a small natural rockshelter located in a limestone cliff hanging over the Ega River (Navarre, northern Spain), very close to other well‐known sites with similar evidence (San Juan ante Portam Latinam, Longar, Las Yurdinas II). The site was used as burial place during the Late Neolithic/Early Chalcolithic, and comprises a burnt bone assemblage of at least 28 individuals in a commingled state. In the process of re‐examining the anthropological collection a small fragment of flint was found embedded in a right lateral cuneiform. Both macroscopic and microscopic analysis and computer tomography confirm the presence of signs of healing. No other indications of trauma were observed in the human bone sample. The finding represents the first Spanish example of a prehistoric arrowhead wound on a foot and adds to the very few other archaeological case descriptions available in Europe. Copyright © 2015 John Wiley & Sons, Ltd.

Breeding Season Home Range and Habitat Use of Mexican Spotted Owls (Strix occidentalis lucida) Below the South Rim of Grand Canyon National Park

ABSTRACT We studied breeding season home range characteristics and habitat of paired male Mexican Spotted Owls (Strix occidentalis lucida) below the south rim of Grand Canyon National Park from 2004–2005. Adult male owls (n = 5) were captured and radio-tracked using tail-mounted VHF transmitters. We used minimum convex polygons and 90% fixed kernels to estimate breeding season home range size (mean = 355 ha and 372 ha, respectively). We also generated adaptive kernel home range estimates to describe areas of concentrated use within home ranges. Home ranges were located in the upper reaches of relatively narrow rocky canyons, and Spotted Owls showed limited use of adjacent forested plateaus. We conducted an analysis of habitat use and selection at two scales and found that owls selected (i.e., used disproportionate to availability) limestone cliffs present in their home ranges. Home ranges were approximately centered on nest and associated roost sites located on limestone cliffs within canyons. Our results...

Genetic diversity and genetic structure of Corydalis tomentella Franch. (Papaveraceae), an endangered herb species from Central China

Corydalis tomentella Franch. (Papaveraceae), a species endemic to Central China, occurs within specialized habitats of limestone cliffs. To date, extensive harvesting by local people for medical use has led to a sharp decline in wild populations of this plant. To investigate the genetic diversity and genetic structure of the species, differences in the composition of one nuclear DNA (nDNA) locus (NADPH) and two chloroplast DNA (cpDNA) fragments (trnH-psbA and trnG introns) from wild populations of this plant were analysed. Six chlorotypes and 17 nuclear genotypes were identified in a survey of 8 populations distributed in the current geographic regions of C. tomentella. Two cpDNA haplotypes were shared in two present distribution regions, Shennongjia and Nanchuan in Central China, while there were no similar nDNA genotypes in these regions. As a whole, Shennongjia's populations had greater gene diversity than found in Nanchuan's population of C. tomentella. Greater population differentiation was also detected along with low gene flow in the distribution regions. This may result from the plants predominantly self-mating system, the short-distance dispersal system associated with the plant, and the specific habitat requirements for growth. These data suggest that Shennongjia region should be regarded as the priority area for conservation of C. tomentella due to its greater diversity of this plant found there.

Inaccessible Biodiversity on Limestone Cliffs: Aster tianmenshanensis (Asteraceae), a New Critically Endangered Species from China.

Aster tianmenshanensis G. J. Zhang & T. G. Gao, a new species of Asteraceae from southern China is described and illustrated based on evidence from morphology, micromorphology and molecular phylogeny. The new species is superficially similar to Aster salwinensis Onno in having rosettes of spatulate leaves and a solitary, terminal capitulum, but it differs by its glabrous leaf margins, unequal disc floret lobes and 1-seriate pappus. The molecular phylogenetic analysis, based on nuclear sequences ITS, ETS and chloroplast sequence trnL-F, showed that the new species was nested within the genus Aster and formed a well supported clade with Aster verticillatus (Reinw.) Brouillet et al. The new species differs from the latter in having unbranched stems, much larger capitula, unequal disc floret lobes, beakless achenes and persistent pappus. In particular, A. tianmenshanensis has very short stigmatic lines, only ca. 0.18 mm long and less than 1/3 of the length of sterile style tip appendages, remarkably different from its congeners. This type of stigmatic line, as far as we know, has not been found in any other species of Aster. The very short stigmatic lines plus the unequal disc floret lobes imply that the new species may have a very specialized pollination system, which may be a consequence of habitat specialization. The new species grows only on the limestone cliffs of Mt. Tianmen, Hunan Province, at the elevation of 1400 m. It could only be accessed when a plank walkway was built across the cliffs for tourists. As it is known only from an area estimated at less than 10 km2 and a walkway passes through this location, its habitat could be easily disturbed. This species should best be treated as Critically Endangered based on the International Union for Conservation of Nature Red List Categories and Criteria B2a.

Gastony’s Cliffbrake (<em>Pellaea gastonyi</em>) in Manitoba: new records and assessment of conservation status

Gastony’s Cliffbrake (Pellaea gastonyi Windham) is a globally rare fern (Pteridaceae) that grows on limestone cliffs and ledges, including those associated with alvars. Until now, the only record in Manitoba was from a location just north of Fisher Branch. We report additional records and locations, one of which is over 250 km north of the initial collection. We also provide a conservation status assessment of this species in Manitoba that indicates that this species is rare in the province and is threatened in at least a portion of its range by habitat loss and degradation.

Impacts of fracturing patterns on the rockfall susceptibility and erosion rate of stratified limestone

The erosion of steep rock slopes is largely controlled by rockfalls, which are a relevant hazard in mountainous regions. The deposition of blocks allows us to quantify rockfall activities and analyze the fracturing pattern that is the key to understand the processes that result in rockfalls. At Monte Generoso (in southern Switzerland), we compared the calculated rockfall susceptibility with the measured rockfall activity for a thinly stratified limestone cliff area. Thus, we were able to determine the erosion rate for the past 40years and verify the reliability of the method used to perform the rockfall susceptibility analysis. The geomorphology of the area and the fracturing pattern have been accurately analyzed and quantified in the field and using airborne laser scanning techniques. These results have been used to perform a rockfall susceptibility assessment based on the frequency of joints and the distribution of failure mechanisms. Five joint sets have been detected, and the large influence of wedge sliding is demonstrated. The emptying works carried out on a series of protective barriers and nets resulted in detailed data regarding the magnitude distribution of the blocks that fell over a period of 40years. This information, coupled with the inventory of the present day rock slope instabilities, results in a method that can be used to correct the erosion rate. Power laws have been fit with the blocks and instability data. Then, several calibration options have been tested to consider the additional amounts of erosion due to larger and less frequent potential rockfall events. The rockfall susceptibility, calculated with the distribution of the failure mechanisms, is correlated well with the measured rockfall activity. This approach allows us to characterize the erosion processes in a steep geomorphological context to obtain new insights regarding the evolution of rock slopes.

Elongated tufaceous stalagmites in the entrance of Batu Cave (Selangor, Malaysia)

Research on the microbiology of cave environments and biologically mediated freshwater calcium carbonate deposits has been active in the past few decades. Among these deposits, tufaceous stalactites are common in tropical cave entrances and limestone cliffs. Their soft porous texture, irregular bulbous and generally positive phototropic morphologies reflect biological influences, principally those of cyanobacteria, algae and mosses. Despite the abundance of tufaceous stalactites, tufaceous stalagmites have rarely been documented and biologically mediated stalagmites have been reported only in a few locations worldwide. Four unusual elongated tufaceous stalagmites in the entrance passage of Temple Cave at Batu Caves (Selangor, Malaysia) are reported here. Their location, morphology and features indicate constructive and destructive biological influences. Some of their features resemble those of crayback stalagmites suggesting that similar processes played a role in their formation. Other features, such as prograding noses, macro-porosity, and internal stalactites, resemble those observed in non-spelean biologically mediated calcium carbonate deposits like tufa waterfalls. One of the stalagmites also has small scale erosive microrelief, including striations and rods. These are oriented parallel to incoming light from the cave entrance and are identified as photokarren, a particular and rare form of biokarst. This is the first published record of photokarren in a West Malaysian cave. The morphology of biologically influenced stalagmites is found to be more varied than previously thought and they are not particularly rare, but may have gone unrecognized in many tropical cave entrances. A conceptual model of asymmetrical stalagmite growth is presented with abiotic and biotic factors.