Vertical Rock Faces Research Articles

Historical sedimentation at an artificial lake margin, Bangudae Petroglyphs site, SE Korea

The Bangudae Petroglyphs is Korea’s National Treasure No. 285, carved on a vertical rock face on the riverside of a mountain stream (Daegokcheon) near Ulsan. Since the construction of the Sayeon Dam in the downstream area in 1965, the petroglyphs was repeatedly flooded and submerged, raising concerns of erosion and water damage of the prehistoric rock-art motifs. Recent excavation of the fluvial sediments in front of the petroglyphs provided an opportunity to investigate the changes in sedimentation pattern before and after the construction of the dam and the consequences of human activity on natural environments. Sedimentological observations of trench sections and radiocarbon, OSL, and garbage dating of sediments reveal that the sediments comprises gravelly to sandy fluvial sediments in the lower part that accumulated since the early to middle Holocene or early to middle Neolithic Era until 1965. Above this, 25 units of alternating horizontally laminated sand and massive, mottled mud with abundant rootlets occur. This sand/mud sequence is interpreted to have accumulated after the construction of the Sayeon Dam in 1965, which caused repetitive flooding and submergence of the study area every year or two. The alternations of horizontally laminated sand and massive mud are interpreted to have resulted from rainfall-induced floods and subsequent suspension settling of fines in stagnant water after the area was inundated and temporarily transformed into a lacustrine margin setting. Afterwards, the depositional site was exposed and vegetated until the next flood event. Comparison of the deposit features with the precipitation data in Ulsan area, the water level data of the Sayeon Dam, and age data suggests that this flood-related sedimentation occurred almost every year until 2005 when the water level of the Sayeon Dam was lowered permanently because of the construction of another dam in the upstream section of the stream. This study thus provides a good example of a dramatic environmental change of a mountain stream caused by artificial disturbance of a river system due to construction of dams and an example of high-resolution sedimentary records of meteorologically induced floods in an artificial lake margin.

The Lichens of Point Pleasant Park, Halifax, Nova Scotia

The peninsula on which the city of Halifax is located ends in a park that has remained mostly wooded since 1749, despite being periodically disturbed and partially cleared by military activities and storms. This first detailed study of the lichens of Point Pleasant Park is based on collections from almost 300 survey sites, which showed a remarkably diverse flora of 164 species, varying from pollution-tolerant lichens such as Lecanora conizaeoides at the northern end of the park, to members of the Lobarion community at the southern end. In 2003, Hurricane Juan felled a large number of the larger, older trees, which explains the current high proportion of crustose species established on the smaller, younger, trees. The baseline data reported in this study will be of value to follow the succession of lichens on trees as the bark surfaces change from smooth to ridged, with age, over the next few decades. The rich lichen flora of the park also reflects the fact that there are rock outcrops and vertical rock faces. These substrates support a lichen flora of 43 species, and the terricolous habitats are colonized by a further 23 species, including 18 species of Cladonia.

Kindia (Pavetteae, Rubiaceae), a new cliff-dwelling genus with chemically profiled colleter exudate from Mt Gangan, Republic of Guinea.

A new genus Kindia (Pavetteae, Rubiaceae) is described with a single species, Kindia gangan, based on collections made in 2016 during botanical exploration of Mt Gangan, Kindia, Republic of Guinea in West Africa. The Mt Gangan area is known for its many endemic species including the only native non-neotropical Bromeliaceae Pitcairnia feliciana. Kindia is the fourth endemic vascular plant genus to be described from Guinea. Based on chloroplast sequence data, the genus is part of Clade II of tribe Pavetteae. In this clade, it is sister to Leptactina sensu lato (including Coleactina and Dictyandra). K. gangan is distinguished from Leptactina s.l. by the combination of the following characters: its epilithic habit; several-flowered axillary inflorescences; distinct calyx tube as long as the lobes; a infundibular-campanulate corolla tube with narrow proximal section widening abruptly to the broad distal section; presence of a dense hair band near base of the corolla tube; anthers and style deeply included, reaching about mid-height of the corolla tube; anthers lacking connective appendages and with sub-basal insertion; pollen type 1; pollen presenter (style head) winged and glabrous (smooth and usually hairy in Leptactina); orange colleters producing a vivid red exudate, which encircle the hypanthium, and occur inside the calyx and stipules. Kindia is a subshrub that appears restricted to bare, vertical rock faces of sandstone. Fruit dispersal and pollination by bats is postulated. Here, it is assessed as Endangered EN D1 using the 2012 IUCN standard. High resolution LC-MS/MS analysis revealed over 40 triterpenoid compounds in the colleter exudate, including those assigned to the cycloartane class. Triterpenoids are of interest for their diverse chemical structures, varied biological activities, and potential therapeutic value.

Breeding Biology of Fire-Tailed Myzornis (Myzornis pyrrhoura) In An Alpine Environment In Southwestern China

ABSTRACT We studied the breeding biology of the Fire-tailed Myzornis (Myzornis pyrrhoura) in an alpine environment (3000–3800 m) of the Gaoligong Mountains in southwestern China during its breeding seasons in 2013 and 2014. Nests were built by both sexes and mainly contained moss and rhododendron flakes. They were located on vertical banks or rock faces, about 20–152 cm above the ground. This species was socially monogamous and sexually dimorphic both in plumage pattern and body size. Egg-laying was mainly initiated in mid-April and ended in early July, and the mean date of clutch initiation was 25 April in 2013 (n = 4) and 27 April in 2014 (n =5), respectively. The clutch size averaged 3.00 ± 0.15 (n = 10), and fresh eggs weighed 1.84 ± 0.19 g (n = 11). Males and females made virtually equal contributions in breeding activities, including incubation, provisioning, brooding, and nest sanitation. Incubation lasted for 15 days (n = 2) with a notably high nest attendance (eggs were incubated 99.48% of the ti...

Relocating A Historical Black Swift Nest and the Importance of Nest Sites to the Species

In British Columbia, the Black Swift (Cypseloides niger) is thought to breed throughout the southern half of the province (Campbell and others 1990); however, relatively few Black Swift nests have been located and described. Grant (1966) located the 1st active Black Swift nest in the province 29 km north of Vernon at Harlan Creek. Tyson (2004) located the 2nd active nest at Cascade Falls 16 km northeast of Mission. In 2004, I located an active nest at Brandywine Falls 14 km south of Whistler. There are additional accounts that suggest nesting, but active nests have not been located or described. The 1st breeding evidence of Black Swifts was a developing egg in a bird collected on 16 June 1901 near Chilliwack (Brooks 1917). Jobin (1955) reported breeding colonies of Black Swift on cliffs near the north arm of Quesnel Lake, and 10 km northwest of Kleena Kleene. During wildlife inventories in Kootenay National Park, Black Swifts were observed flying near Helmut Falls, Sinclair Canyon, and Marble Canyon; nesting was suspected at the latter site (Poll and others 1984). In June 2001, during a cave inventory west of Prince George, a dead juvenile Black Swift was found at the entrance of Redemption Cave; Black Swifts were observed entering the cave in July, but active nests were not located (Northern BC Caving Club 2015). Black Swifts have been observed flying from sea caves near Hotsprings Cove (Campbell and others 1990) and near Port Renfrew (Tyson 2004). Given the limited number of known Black Swift nest sites in British Columbia, each of the known nest sites are increasingly valuable to the conservation of the species and determining the status of unconfirmed sites should be a priority. Beebe (1959) provided the 1st evidence of Black Swift nesting in British Columbia. On 16 August 1958, a flightless Black Swift nestling was delivered to Beebe’s home in Victoria. Apparently, the nestling was 1 of 2 Black Swift nestlings that were collected by a teenage boy on 15 August from a single nest located 4.57 m on a vertical rock face adjacent to a waterfall, approximately 2 mi north of Clinton, British Columbia. Beebe cared for the nestling by feeding the bird goat’s milk, termites, and crickets; the nestling survived and was successfully released in Victoria, British Columbia on 25 August. There is no indication that Beebe attempted to relocate the nest site, nor that it has ever been relocated (Campbell and others 1990). There are a number of reasons that would deter readers of Beebe’s account from attempting to relocate the Clinton nest site: (1) the site location is a second-hand account from an unnamed teenage boy; (2) the waterfall is unnamed; and (3) the area surrounding Clinton is generally not known for waterfalls. The mention of 2 nestlings being removed from a single nest raises doubt of Beebe’s account. It is now well established that Black Swifts lay a single egg per nest (Lowther and Collins 2002; Hirshman and others 2007); therefore, if 2 nestlings were collected in 1958, this would suggest 2 active nests were involved. In 2014, 56 years after Beebe’s nest account, I relocated what is presumed to be the original nesting site described by Beebe (1959). On 29 July 2014, I visited a series of waterfalls located approximately 6.4 km north of Clinton (Fig. 1), and conducted a 2-h search for evidence of nesting Black Swifts. I found 1 active Black Swift nest, but it was immediately clear that a more thorough inventory of the site was needed. I revisited the site on 3 August, and conducted a 7-h inventory over the approximately 500-m length of the Clinton Creek waterfall complex. No additional active Black Swift nests were located; however, I observed 4 empty nest structures that appeared to be Black Swift nests from previous years. The active Black Swift nest was beside the southern edge GENERAL NOTES

Geological mapping and fold modeling using Terrestrial Laser Scanning point clouds: application to the Dents-du-Midi limestone massif (Switzerland)

Geological mapping in vertical rock faces is extremely challenging because of access difficulties and limited possibilities of recognition, localization and measurement of features at large distance with traditional tools. Moreover, vertical areas can be of primary interest since they often display good quality outcrops and relevant geological information. This study focuses on the detailed remote identification of rock types and fold structures using intensity values acquired by Terrestrial Laser Scanning. A correction of the intensity is proposed proportional to the square of the range and to the cosine of the incidence angle. Furthermore, two methods of remote lithological mapping in 3D have been developed using a manual and a semi-automatic approach. Both delivered good results that are consistent with the spatial distribution of rock-types and allowed us to generate an accurate 3D lithological map of Dents-du-Midi massif (Valais, Swiss Alps). The bedding orientation near the hinge of a Km scale fold was measured on LiDAR data in order to define the fold axis. Then, the result was used to build a model of the hinge in 3D.

Geological layers detection and characterisation using high resolution 3D point clouds: example of a box-fold in the Swiss Jura Mountains

The detection and characterisation of geological layers, as well as the precise quantification of their geometrical properties, is of primary interest in several domains of geology. Nevertheless, geological data gathering is commonly limited by access issues during fieldwork investigations. Here we present complementary and alternative tools aimed at allowing the investigation of areas with limited accessibility, such as vertical rock faces. We used 3D point clouds acquired from Terrestrial Laser Scanning and terrestrial photogrammetry to: 1) identify and model (reconstruct) the geometry of the geological layers and 2) semi-automatically segment the different lithologies according to their intensity signature. Our results show that the presented procedures are fast, reliable and efficient compared to traditional fieldwork. In particular, the geometrical analysis led to a very detailed characterisation of the bedding planes, which couldn't be targeted with sufficient precision based on fieldwork alone. The lithological mapping procedure, which was obtained through a semi-automatic segmentation process of a single intensity channel, is highly capable since nearly all the layers were correctly attributed to their corresponding lithology. The performance of the segmentation script was closely related to our prior fieldwork investigation, yielding validation of our semi-automatic point cloud segmentation.

Permafrost in Alpine Rock Faces from Jotunheimen and Hurrungane, Southern Norway

ABSTRACTThe warming and degradation of mountain permafrost within alpine areas is an important process influencing the stability of steep slopes and rock faces. In the mountains of southern Norway (Jotunheimen), an increase in ground temperatures has been recorded during the last 12 years, and modelling studies suggest the possible degradation of most mountain permafrost during the 21st century. To better estimate the thermal state of permafrost in steep rock walls in Norway, five temperature loggers were installed in 2009 and 2010, measuring the near‐surface rock wall temperatures in vertical rock faces. Surface temperatures in rock walls in Norway are on average higher than the ambient air temperature, by about 1 °C in shaded faces to more than 3 °C in faces with other aspects. An aspect dependency of rock wall temperatures is mainly visible during summer, with deviations of up to 4 °C between north‐ and south‐facing walls. Based on a 1D transient heat flow model, the active‐layer thickness at the study sites was estimated to be in the range of 3 m to 5 m at 2300 m asl and 1600 m asl, respectively. As a first‐order approximation, a spatial regression model based on elevation and potential incoming short‐wave radiation was used to estimate the lower limit and distribution of rock wall permafrost under present‐day conditions and for a scenario with average air temperatures increased by 2 °C. Today, the lower limit ranges from 1200–1300 m asl to 1600–1700 m asl in north‐ and south‐facing rock walls, respectively. With a warming of 2 °C, the lower limit would increase to about 1700 m and 2100 m, respectively, which corresponds to a loss of 70 per cent of the rock walls underlain by permafrost today in the study area, where more than half of the rock walls potentially containing permafrost are situated below 1800 m asl. Copyright © 2014 John Wiley & Sons, Ltd.

Erosion rates and weathering history of rock surfaces associated with Aboriginal rock art engravings (petroglyphs) on Burrup Peninsula, Western Australia, from cosmogenic nuclide measurements

The Burrup Peninsula and surrounding Dampier Archipelago, in Western Australia, contain the world's largest known gallery of rock art engravings (petroglyphs), estimated to number up to 1 million images. The peninsula is also the site of major industrial development and there are concerns that industrial emissions may adversely affect the stability and longevity of the rock art. We have studied the natural processes and rates of weathering and erosion, including the effects of fire, that affect the stability of rock surfaces and hence the longevity of the rock art, using cosmogenic nuclides. The concentration of 10Be in quartz yields erosion rates in the range 0.15–0.48 mm/1000 years on horizontal rock surfaces and 0.34–2.30 mm/1000 years on vertical rock faces. The former, largely caused by mm-scale surface flaking, are amongst the lowest erosion rates measured by cosmogenic nuclides anywhere in the world. The latter are inferred to represent a combination of mm-scale flaking and very rare centimetre- to metre-scale block falls, controlled by failure along joint planes. Such low erosion rates result from a combination of resistant rocks, low relief and low rainfall, favouring long-term preservation of the petroglyphs – long enough to encompass the known period of human settlement in Australia.

Spatial and Temporal Trends of Freshwater Mussel Assemblages in the Meramec River Basin, Missouri, USA

Abstract The Meramec River basin in eastcentral Missouri has one of the most diverse unionoid mussel faunas in the central United States with 40 species identified. Data were analyzed from historical surveys to test whether diversity and abundance of mussels in the Meramec River basin Big, Bourbeuse, and Meramec rivers, representing 400 river miles decreased between 1978 and 1997. We found that over 20y, species richness and diversity decreased significantly in the Bourbeuse and Meramec rivers but not in the Big River. Most species were found at fewer sites and in lower numbers in 1997 than in 1978. Federally endangered species and Missouri Species of Conservation Concern with the most severe temporal declines were Alasmidonta viridis, Arcidens confragosus, Elliptio crassidens, Epioblasma triquetra, Fusconaia ebena, Lampsilis abrupta, Lampsilis brittsi, and Simpsonaias ambigua. Averaged across all species, mussels were generally being extirpated from historical sampling sites more rapidly than colonization was occurring. An exception was one reach of the Meramec River between river miles 28.4 and 59.5, where mussel abundance and diversity were greater than in other reaches and where colonization of Margaritiferidae, Lampsilini, and Quadrulini exceeded extirpation. The exact reasons mussel diversity and abundance have remained robust in this 30mile reach is uncertain, but the reach is associated with increased gradients, few long pools, and vertical rock faces, all of which are preferable for mussels. Complete loss of mussel communities at eight sites 16 with relatively diverse historical assemblages was attributed to physical habitat changes including bank erosion, unstable substrate, and sedimentation. Mussel conservation efforts, including restoring and protecting riparian habitats, limiting the effects of instream sand and gravel mining, monitoring and controlling invasive species, and protecting water quality, may be warranted in the Meramec River basin.

Conservation value of waterfalls as habitat for lotic insects of western Victoria, Australia

ABSTRACT The conservation significance of waterfalls for insect assemblages is not well known, but there are aquatic insect species known to be waterfall specialists. If waterfalls support distinct insect assemblages, they may make a disproportionately large contribution to regional freshwater insect diversity. The aim of the present study was to determine whether waterfalls in western Victoria, Australia, support distinct insect assemblages compared with other, fast‐flowing habitat (e.g. riffles). Twelve waterfalls were sampled during autumn and winter 2009, with three positions sampled at each waterfall: the vertical rock face; directly below the waterfall rock face; and an adjacent riffle. Insect assemblages on vertical rock faces differed from those in riffles and below waterfalls. Insects positively associated with waterfall rock faces were coleopterans, plecopterans or trichopterans. Turnover (beta‐diversity) of taxa was higher among waterfall rock faces in autumn than among riffles or below waterfalls at either sampling time. The mean (± SE) number of insect taxa was greater in riffles (autumn 11 spp. ± 1.5; winter 15 ± 1.4) than rock faces (autumn 9 spp. ± 0.9; winter 7 ± 0.5). Some species were found only on waterfall rock faces. The total number of taxa was higher on waterfalls with a higher percentage cover of moss. Waterfall habitat appears to support the existence of certain insect species and may provide a refuge for rheophilic species during periods of low flow. Conservation of waterfall habitat is thus important for conserving aquatic insect diversity, and waterfall‐dependent and rheophilic taxa will be threatened by disturbances such as drought and river regulation that reduce stream flows. Environmental water allocations could be used to preserve fast‐flowing waterfall habitat, but flow requirements of waterfall insects need to be further investigated and included in river flow management.Copyright © 2012 John Wiley & Sons, Ltd.

High-resolution three-dimensional imaging and analysis of rock falls in Yosemite Valley, California

We present quantitative analyses of recent large rock falls in Yosemite Valley, California, using integrated high-resolution imaging techniques. Rock falls commonly occur from the glacially sculpted granitic walls of Yosemite Valley, modifying this iconic landscape but also posing signifi cant potential hazards and risks. Two large rock falls occurred from the cliff beneath Glacier Point in eastern Yosemite Valley on 7 and 8 October 2008, causing minor injuries and damaging structures in a developed area. We used a combination of gigapixel photography, airborne laser scanning (ALS) data, and ground-based terrestrial laser scanning (TLS) data to characterize the rock-fall detachment surface and adjacent cliff area, quantify the rock-fall volume, evaluate the geologic structure that contributed to failure, and assess the likely failure mode. We merged the ALS and TLS data to resolve the complex, vertical to overhanging topography of the Glacier Point area in three dimensions, and integrated these data with gigapixel photographs to fully image the cliff face in high resolution. Three-dimensional analysis of repeat TLS data reveals that the cumulative failure consisted of a near-planar rock slab with a maximum length of 69.0 m, a mean thickness of 2.1 m, a detachment surface area of 2750 m 2 , and a volume of 5663 ± 36 m 3 . Failure occurred along a surfaceparallel , vertically oriented sheeting joint in a clear example of granitic exfoliation. Stress concentration at crack tips likely propagated fractures through the partially attached slab, leading to failure. Our results demonstrate the utility of high-resolution imaging techniques for quantifying far-range (>1 km) rock falls occurring from the largely inaccessible, vertical rock faces of Yosemite Valley, and for providing highly accurate and precise data needed for rock-fall hazard assessment.

Relationship of Bryophyte Occurrence to Rock Type in Upstate New York and Coastal Maine

Bryophytes are often noted for their growth on specific rock types and their value as indicator species. However, some evidence suggests that restriction of a species to specific rock types may be less rigid and could vary under different environmental conditions. We assessed richness and distribution patterns of bryophytes at 22 rock outcrop locations in upstate New York (NY) and coastal Maine (ACAD). At each location, detailed surveys were done in five replicate 5-m by 2-m plots on vertical rock faces. We report on the 194 bryophyte species found in these surveys and present detailed analyses for the 137 species that occurred at two or more of the 22 locations. In general, liverworts were less likely to be dominant within a plot than mosses. Within-site dominance and frequency of liverworts were less well correlated to larger-scale frequency (number of locations and regions of occurrence). In NY, although there was no significant difference in bryophyte richness by rock type, rare species were more often found on calcium-containing rock types. Rock type, soil influence, number of liverwort species, and region were significant correlates with bryophyte species composition patterns. The importance of rock type in explaining species composition patterns was still significant though weaker when ACAD locations were included in the analysis. This difference resulted from a higher prevalence of leafy liverwort species on calcium-containing rock types in ACAD. Our results present further evidence that apparent restrictions to specific rock types may shift depending on environmental conditions such as increased humidity and narrower temperature extremes that occur along the north Atlantic coast.

Megalyra baltica Poinar and Shaw n. sp. (Hymenoptera: Megalyridae), a long-tailed wasp from Baltic amber

The wasp family Megalyridae includes eight living genera of presumed idiobiont ectoparasitoids, most of which are associated with relict primary tropical forests (Shaw 1990b, 2006). Their biology is poorly known except for a few species. Their behavior and host range appear to be diverse since one Australian species, Megalyra fasciipennis Westwood, parasitizes cerambycid beetle larvae in wood, while the much smaller Australian M. troglodytes Naumann parasitizes sphecid wasp larvae in mud nests on vertical rock faces (Shaw 1990a). The long ovipositor of many Megalyra species, as well as the phylogenetic analysis of Shaw (1990b), suggests that parasitism of immature wood-boring beetles is the ancestral and more generalized behavior for the genus. It is presumed that ancient megalyrids, like many of their modern descendants, would have been attracted to dead and dying beetle-infested trees, where they might become trapped in sap flows, and eventually fossilized as amber inclusions.

Escaping predators on vertical surfaces: Lacerta perspicillata in limestone quarries of Lithaca

Escape behavior of the Mediterranean lizard Lacerta perspicillata was studied experimentally in a limestone quarry at Lithica on the island of Menorca, Balearic Islands, Spain. These lizards are exposed to avian predators while active on vertical rock faces. Simulated kestrel attacks using a cardboard model elicited escape responses from nearly all lizards approached. Methods of escape included entering a crevice, retreating over or around an edge, running behind a shrub growing against the rock surface, running behind a shrub and dropping to the ground ("bush to ground"), and retreating under or behind a rock isolated from a rock face. Most lizards fled directly to the closest available refuge or to alternative refuges only slightly farther away. Nevertheless, lizards that initially perched near crevices more frequently fled to other types of refuge than lizards that were initially near other refuges. The latter usually fled to the closest refuge. Lizards predominantly fled parallel to the ground or directly toward it (down) into a refuge regardless of the direction of attack (above, below, straight on). Direction of attack affected the type of refuge used. Lizards approached from above were more likely to flee to bush-ground or crevices than those approached from below or the same height. Straight-line retreat directly to a refuge appears to be the most viable escape strategy for these lizards when faced with attacks by avian predators, but the direction of attack may influence decisions based on risk.

Subglacial meltwater channels at Lymm Dam, Cheshire

Small-scale erosion features in the lowlands of Britain have only previously been described from the Wirral, Cheshire. In this paper a suite of similar erosion forms located within a subglacial meltwater channel is described and compared with those previously reported. The forms consist of almost linear channels incised into soft Triassic sandstone bedrock to a depth of up to 1.76 m and a group of scallops occupying a vertical rock face. The channels show two preferred orientations, one parallel to the last (Late Devensian) ice flow and another transverse to the ice flow. Two possible types of erosion processes are identified: (i) erosion by phreatic (below the water table) subglacial water flow, which produced the subglacial gorge, channels orientated parallel to the ice flow, and scallops; and (ii) erosion by vadose (above the water table) subglacial water flow, which produced the channels orientated parallel to the local bedrock slope (transverse to the ice flow). The implications for Late Devensian glaciation of the area are: (i) deglaciation was accompanied by active ice; (ii) deglaciation was achieved under warm base conditions; (iii) vertical ice thickness was greater than 40 m; and (iv) the hydraulic potential gradient was possibly orientated N14°E at the formation of the features.

The effects of insolation and grazing on populations of the splash zone alga Prasiola meridionalis (Chlorophyta)

Field experiments at two sites assessed the effects of insolation and gastropod grazing on the distribution and abundance of Prasiola meridionalis Setchell et Gardner, a green alga that occurs in the upper splash zone (supralittoral) on guano-covered rocks. At site 1, a sun-exposed horizontal rock where the alga occurs seasonally and grazers were rare, blades appeared in the early spring and died back in early summer. Lack of gastropod grazers and persistence of blades in experimentally shaded plots showed that increased insolation or some associated factor (or factors) was responsible for temporal variation at this site. At site 2, the alga grew in a distinct, perennial band on a shaded vertical rock face with abundant gastropod grazers. These grazers were excluded from long vertical plots that extended from the lower portion of the P. meridionalis band down to a zone of the red alga Endocladia muricata (Postels et Ruprecht) J. Agardh more than 2 m below. The results showed that grazing set the proximate lower limit of P. meridionalis at site 2, and variation in the abundance of the alga within its zone at this site was associated with seasonal climate changes and feeding by mites. Thus, while insolation and grazing can both affect populations of P. meridionalis, their relative importance varied between sites.

Senecio aetfatensis (Asteraceae: Senecioneae), a New Species from Zimbabwe

A new species, Senecio aetfatensis, is described from the Chimanimani Mountains of eastern Zimbabwe. During the AETFAT post-congress excursion in the mountains of eastern Zimbabwe in February 1997, I was fortunate to find and collect an undescribed species of Senecio. It is a pleasure to name the new species for the Association pour l'IJtude Taxonomique de la Flore d'Afrique Tropicale (AETFAT), which held its XVth Congress in Harare on 3-7 February 1997. Senecio aetfatensis B. Nordenstam, sp. nov. TYPE: Zimbabwe. Chimanimani National Park, along footpath from entrance office to Mountain Hut, ca. 1600 m, 11 Feb. 1997, Nordenstam 9292 (holotype, S; isotypes, K, MO, SRGH). Figure 1. Herba perennis ramosissima 0.6-1.5 m alta et lata. Caules et rami brevi-villosi. Folia alterna sessilia herbacea 3-6(-8) cm longa 1.5-3.5 cm lata plana pinnatisecta sparse hirsutula, basin versus angustata, basi semiamplexicaulia auriculata; lobis utrinque 3-5 oblongis pinnatilobatis vel dentatis acutis. Capitula 3-10 corymbosa radiata pedunculis gracilibus 1-5 cm longis. Involucrum campanulatum; involucri bracteae 13-21 subuniseriatae lineari-lanceolatae 4-5.5 mm longae 0.5-1.5 mm latae virides glabrae nervis 1-2 resiniferis marginibus anguste membranaceis apicibus acutis-acuminatis puberulis. Calyculi bracteae 5-8 anguste triangulares acutae. Receptaculum planum nudum alveolatum. Flosculi radii plerumque 8 flavi. Flosculi disci numerosi, corolla flava tubulosa superne dilatata quinquelobata. Antherae basi breviter sagittatae, collum filamenti basi dilatatum. Styli rami lineares, areis stigmaticibus separatis, apicibus truncatis pilis eferrentibus brevibus. Cypsela anguste elliptico-oblonga costata breviter villosa. Pappi setae numerosae graciles minute barbellatae caducae. Much-branched herb forming a bushy rounded clump 0.6-1.5 m high and wide. Stems and branches somewhat brittle, shortly villous. Leaves alternate, sessile, herbaceous, soft, doubly pinnatisect, 3-6(-8) cm long, 1.5-3.5 cm wide, flat, shortly hirsute, green above, paler below, with 4-5 lobes on each side, narrowed toward the base and petiolariform; leaf lobes 3-5 on each side, oblong, pinnately lobed or dentate, acute; leaf base half-clasping and auriculate with dissected or dentate small ears. Capitula 3-10 in a terminal, laxly branched corymbiform synflorescence; peduncles 1-5 cm long, slender. Involucre campanulate; involucral bracts 13-21, subuniseriate, linear-lanceolate, 45.5 mm long, 0.5-1.5 mm wide, green with narrow membranous margins, 1-2-veined with resiniferous veins, acute to acuminate, tips puberulous, otherwise glabrous. Calycular bracts 5-8, 1-2 mm long, narrowly triangular, flat, acute. Receptacle flat, naked, alveolate. Ray florets (5-)8; corolla yellow; tube 2-3 mm long, somewhat glandular-puberulous; lamina elliptic-oblong, 4.5-8 mm long, 2.53.5 mm wide, 4-veined, patent or rolled back. Disc florets ca. 40-60; corolla yellow, tubular, widening ab ve to a narrowly campanulate limb 2-3 mm long, 5-lobed, 3.5-4.5 mm long; lobes deltoid or triangular-ovate, 0.5-0.7 mm long, minutely papillate outside toward the apex, with a central resiniferous vein. Anthers 1.3-1.7 mm long including ppendage; apical appendage oblong-ovate, obtuse; anther base shortly sagittate; filament collar basally swollen (balusterform). Style branches linear, 0.7-1 mm long with stigmatic areas separated, apex truncate with short sweeping-hairs. Cypsela narrowly elliptic-oblong, terete, 2-2.5 mm long, ca. 0.6 mm wide, with ca. 8 light brown ribs, white-villous on and between ribs, hairs mucilaginous when soaked. Pappus bristles numerous, erect, 3-4 mm long, slender, minutely barbellate, white, caducous. The single individual seen by me was growing from a crevice on a vertical rock face with a western aspect, and the specimens collected by Wild were stated to grow among crags. The new species belongs to Senecio sect. Senecio, but it is difficult to point out any very close relatives. There are a number of Senecio species with pinnatisect leaves in southern Africa, but they are all clearly distinct. Some are annuals with either purple florets (e.g., S. cakilefolius DC., S. eenii (S. Moore) Merxmtiller) or yellow florets, but then with smaller capitula (e.g., S. cryphiactis O. Hoffmann, S. piptocoma O. Hoffmann). Some forms of S. consanguineus DC. are NovoN 9: 245-247. 1999. This content downloaded from 157.55.39.186 on Tue, 11 Oct 2016 04:32:58 UTC All use subject to http://about.jstor.org/terms

The Australian species of Neozavrelia Goetghebuer (Diptera: Chironomidae: Tanytarsini)

The genus Neozavrelia Goetghebuer (Chironomidae: Diptera) is represented in Australia by two species, described here for the first time. The species conform well in all life‐history stages to diagnoses based on Holarctic congeners. An associated female allows provision of a modern description of the female genitalia for the first time. In the larval and pupal stages, both Australian species form tough silk tubes within sandgrain cases in the hygropetric zone of seepages across rock surfaces. One species, N. optoputealis sp.n., was found on a limestone seepage in a road cutting in the Blue Mountains, north‐west of Sydney. The second species, N. bowmani sp.n., came from a seepage on a vertical rock face in a sandstone canyon in an unusual gorge area of central Arnhemland, Northern Territory, where some gondwanan refugial taxa co‐occur in a monsoonal/relictual rainforest habitat. The biology of Neozavrelia is reviewed, with a suggestion that the hygropetric and perhaps more eurythermic habit appears to be more common than lotic and cool stenothermic habitats.

The Australian species of Neozavrelia Goetghebuer (Diptera: Chironomidae: Tanytarsini)

AbstractThe genus Neozavrelia Goetghebuer (Chironomidae: Diptera) is represented in Australia by two species, described here for the first time. the species conform well in all life‐history stages to diagnoses based on Holarctic congeners. an associated female allows provision of a modern description of the female genitalia for the first time. In the larval and pupal stages, both Australian species form tough silk tubes within sandgrain cases in the hygropetric zone of seepages across rock surfaces. One species, N. optoputealis sp.n., was found on a limestone seepage in a road cutting in the Blue Mountains, north‐west of Sydney. the second species, N. bowmani sp.n., came from a seepage on a vertical rock face in a sandstone canyon in an unusual gorge area of central Arnhemland, Northern Territory, where some gondwanan refugial taxa co‐occur in a monsoonal/relictual rainforest habitat. the biology of Neozavrelia is reviewed, with a suggestion that the hygropetric and perhaps more eurythermic habit appears to be more common than lotic and cool stenothermic habitats.