Life Sciences Commons^™

Mixed Species Plantations: Prospects And Challenges, J Doland Nichols, Mila Bristow, Jerome K. Vanclay

Professor Jerome K Vanclay

About 2% of English-language literature on plantations deals with mixed-species plantations, but only a tiny proportion (<0.1%) of industrial plantations are polycultures. Small landholders are more innovative, with 12% of Australia’s farm forestry plantations under mixed-species plantings, and 80% of Queensland’s farm forestry as polycultures. We examine reasons for this discrepancy, and explore the history, silviculture and economics of polycultures. Financial analyses suggest that a yield stimulus of 10%, depending on product and rotation length, may be sufficient to offset increased costs associated with planting and managing a mixed-species plantation, a stimulus that has been demonstrated in many field …

Genetic Structure Of East Antarctic Populations Of The Moss Ceratodon Purpureus, L. J. Clarke, D. J. Ayre, Sharon A. Robinson

Sharon Robinson

The capacity of the polar flora to adapt is of increasing concern given current and predicted environmental change in these regions. Previous genetic studies of Antarctic mosses have been of limited value due to a lack of variation in the markers or non-specificity of the methods used. We examined the power of five microsatellite loci developed for the cosmopolitan moss Ceratodon purpureus to detect genetically distinct clones and infer the distribution of clones within and among populations from the Windmill Islands, East Antarctica. Our microsatellite data suggest extraordinarily high levels of variation reported in RAPD studies were artificially elevated by …

Mixed-Species Plantation Of Eucalyptus With Nitrogen Fixing Trees: A Review, David I. Forrester, Jürgen Bauhus, Annette L. Cowie, Jerome K. Vanclay

Professor Jerome K Vanclay

Mixed-species plantations of Eucalyptus with a nitrogen (N2) fixing species have the potential to increase productivity while maintaining soil fertility, compared to Eucalyptus monocultures. However, it is difficult to predict combinations of species and sites that will lead to these benefits. We review the processes and interactions occurring in mixed plantations, and the influence of species or site attributes, to aid the selection of successful combinations of species and sites. Successful mixtures, where productivity is increased over that of monocultures, have often developed stratified canopies, such that the less shade-tolerant species overtops the more shade-tolerant species. Successful mixtures also have …

Growth And Species Interactions Of Eucalyptus Pellita In A Mixed And Monoculture Plantation In The Humid Tropics Of North Queensland, Mila Bristow, Jerome K. Vanclay, Lyndon O. Brooks, Mark Hunt

Professor Jerome K Vanclay

This study investigated whether mixed-species designs can increase the growth of a tropical eucalypt when compared to monocultures. Monocultures of Eucalyptus pellita (E) and Acacia peregrina (A) and mixtures in various proportions (75E:25A, 50E:50A, 25E:75A) were planted in a replacement series design on the Atherton Tablelands of north Queensland, Australia. High mortality in the establishment phase due to repeated damage by tropical cyclones altered the trial design. Effects of experimental designs on tree growth were estimated using a linear mixed effects model with restricted maximum likelihood analysis (REML). Volume growth of individual eucalypt trees were positively affected by the presence …

Forest Dynamics In Flood Plain Forests In The Peruvian Amazon: Effects Of Disturbance And Implications For Management, Gustav Nebel, Lars Peter Kvist, Jerome K. Vanclay, Hector Vidaurre

Professor Jerome K Vanclay

Forest dynamics were studied from 1993 to 1997 for individuals > 10 cm DBH in nine 1 ha permanent sample plots. They were established in natural flood plain forests located on the lower Ucayali river in the Peruvian Amazon. After inventories of three plots in each of three forest types, a light and a heavy felling treatment were applied to each of the two plots, while a third plot was kept untreated. Average annual stem mortality and recruitment rates in the untreated plots were among the highest observed in neotropical rain forests: mortality 2.2-3.2% per year, recruitment 3.0-4.6% per year. Dead …

Experiment Designs To Evaluate Inter- And Intra-Specific Interactions In Mixed Plantings Of Forest Trees, Jerome K. Vanclay

Professor Jerome K Vanclay

A review of three mixed-species trials reveals the utility of competition indices for evaluating inter- and intra-specific interactions between trees, the desirability of experiments that span a range of tree spacing and composition to inform calibration of these competition indices, the need for extremes of species composition and stand density to calibrate response surfaces, and the far-reaching impact of edge-effects. Experiment layouts commonly used for mixed-species trials in forestry (such as replacement series) rarely provide a strong basis to calibrate competition indices and response surfaces. Alternative designs involving systematic changes in species composition may offer a better basis for calibrating …

Maximum Likelihood Estimates Of Species Trees: How Accuracy Of Phylogenetic Inference Depends Upon The Divergence History And Sampling Design, John Mccormack, Huateng Huang, L. Knowles

John E. McCormack

The understanding that gene trees are often in discord with each other and with the species trees that contain them has led researchers to methods that incorporate the inherent stochasticity of genetic processes in the phylogenetic estimation procedure. Recently developed methods for species-tree estimation that not only consider the retention and sorting of ancestral polymorphism but also quantify the actual probabilities of incomplete lineage sorting are expected to provide an improvement over earlier summary-statistic based approaches that discard much of the information content of gene trees. However, these new methods have yet to be tested on truly challenging evolutionary histories …

Life History, Sexual Dimorphism And 'Ornamental' Feathers In The Mesozoic Bird Confuciusornis Sanctus., Winfried S. Peters, Dieter Stefan Peters

Winfried S. Peters

Deforestation In The Tropics: Reconciling Disparities In Estimates For India, Shaily Menon, Kamaljit S. Bawa

Shaily Menon

Here we examine recent disparate estimates of deforestation obtained for India. We discuss the sources of disparity and the implications of inaccurate estimates and suggest ways in which future attempts at estimating deforestation might reconcile the disparity. Despite the importance of deforestation and its consequences, no attempt has been made to reconcile the different estimates obtained for India.

Identifying Conservation-Priority Areas In The Tropics: A Land-Use Change Modeling Approach, Shaily Menon, R. Gil Pontius Jr., Joseph Rose, M. Khan, Kamaljit Bawa

Shaily Menon

Most quantitative methods for identifying conservation-priority areas require more detailed knowledge about the extent and distribution of biodiversity than is currently available. Accelerated and irreversible losses of biodiversity call for the development of alternative methods to identify priority sites for biodiversity inventory and protection. We focused on the state of Arunachal Pradesh, a biodiversity-rich region in northeast India. We used a geographic information system and spatially explicit modeling to examine the correlation of land-cover and land-use patterns with biogeophysical characteristics and to project future patterns of land-use change. In 1988, 70% of Arunachal Pradesh was covered by forest. We project …

Projected Climate Change Effects On Nuthatch Distribution And Diversity Across Asia, Shaily Menon, M. Zafar-Ul Islam, A. Townsend Peterson

Shaily Menon

We used ecological niche modeling approaches to explore climate change implications for one family of birds, the Sittidae, in Asia. Quantitative niche models based on present-day distributions for each of 13 species were projected onto future climate change scenarios. Species’ potential distributional areas tended to be predicted to retract along their fringes, and at lower elevations along mountain ranges. As observed in other studies, montane systems were relatively more robust to the horizontal effects of climate change on species’ distributions compared to flatland systems, so range contractions were focused in Southeast Asia and peninsular India.

Preliminary Analysis Of The Ecology And Geography Of The Asian Nuthatches (Aves: Sittidae), Shaily Menon, Zafar-Ul Islam, Jorge Soberon, A. Townsend Peterson

Shaily Menon

We explored distributions of Asian nuthatch species in ecological and geographic space using ecological niche modeling based on occurrence data associated with specimens and observations. Nuthatches represent a well-defined clade occurring throughout the Northern Hemisphere, but are most diverse in southern Asia where 15 of the 24 species occur and where the lineage is believed to have evolved. Species richness was focused in a narrow east-west band corresponding to the forested parts of the Himalayas with a maximum number of nine species predicted present in these foci. The distributional predictions have a mid-elevation focus with highest species diversity between 1,000 …

Road-Killed Bats, Highway Design, And The Commuting Ecology Of Bats, Amy L. Russell, Calvin M. Butchkoski, Leslie Saidak, Gary F. Mccracken

Amy L. Russell

Landscape Genetics Of California Mule Deer (Odocoileus Hemionus): The Roles Of Ecological And Historical Factors In Generating Differentiation, Katherine Pease, Adam Freedman, John Pollinger, John Mccormack, Wolfgang Buermann, Jeff Rodzen, Jim Banks, Erin Meredith, Vernon Bleich, Robert Schaefer, Ken Jones, Robert Wayne

John E. McCormack

Landscape genetics is an emerging discipline that utilizes environmental and historical data to understand geographic patterns of genetic diversity. Niche modelling has added a new dimension to such efforts by allowing species–environmental associations to be projected into the past so that hypotheses about historical vicariance can be generated and tested independently with genetic data. However, previous approaches have primarily utilized DNA sequence data to test inferences about historical isolation and may have missed very recent episodes of environmentally mediated divergence. We type 15 microsatellite loci in California mule deer and identify five genetic groupings through a Structure analysis that are …

A New Species Of Streptanthus (Brassicaceae) From Three Peaks In Lake County, California, Rebecca W. Dolan, Richard O'Donnell

Rebecca W. Dolan

Streptanlhus vernalis is a newly described species inhabiting serpentine rock outcrops in the Three Peaks area in Lake County, California. Morphological and allozyme data indicate that this taxon is related to the S. morrisonii complex.

The Value Of A Net‐Cage As A Fish Aggregating Device In Southern California, Daniel Pondella

Daniel Pondella

There is an urgent need for primary data that can be used to quantify the value of marine aquaculture facilities that also describe influences on the surrounding natural ecosystem and its wild fish communities. Divers completed 360 transect replicates below a net-cage and at nearby and distant rocky reefs off Catalina Island, California, estimating the species abundance and size class of all conspicuous fishes in the water column. We observed 10,234 fishes aggregating below the net-cage with a mean annual density of 142 (SE ± 30) per 100 m2 and diversity H′ 2.29. At the adjacent reference reef, we counted …

New Species Of Pristimantis (Anura: Strabomantidae) From The Amazonian Lowlands Of Southern Peru, Edgar Lehr, Rudolf Von May

Edgar Lehr

We describe a new species of Pristimantis from the Amazonian lowlands in southern Peru (Madre de Dios Region). The new species has a snout–vent length of 22.8–23.4 mm in two adult males (females are unknown), a tympanum barely visible, a W-shaped scapular ridge, the iris bearing a dark vertical bar forming a cross or a T, a cream venter with brown blotches, and groin and concealed surfaces of shanks with a contrasting pattern consisting of yellow and black. It is tentatively assigned to the unistrigatus species Group and is most similar to Pristimantis diadematus and Pristimantis eurydactylus.

Paul Crook, Darwin’S Coat-Tails. Essays On Social Darwinism., David Depew

David J Depew

No abstract provided.

Tadpole Of Telmatobius Mayoloi (Anura: Ceratophryidae), Edgar Lehr, Cesar Aguilar

Edgar Lehr

The tadpole of Telmatobius mayoloi from central Peru (Departamento de Ancash) is described based on specimens ranging from Gosner Stage 28–41. The tadpole of T. mayoloi is similar to other Telmatobius larvae with pond type morphology. Geographically closest to T. mayoloi are Telmatobius carrillae and Telmatobius rimac. The tadpole of T. mayoloi differs from the latter in reaching a maximum total length of 102.1 mm at Stage 38 whereas T. carrillae (maximum total length = 99.20 mm at Stage 39) and T. rimac (maximum total length = 77. 70 mm at Stage 36) are smaller. Furthermore, the snout of the …

Three New Species Of Bryophryne (Anura: Strabomantidae) From The Region Of Cusco, Peru, Edgar Lehr, Alessandro Catenazzi

Edgar Lehr

We describe three new species of Bryophryne from the Region of Cusco in southern Peru, increasing the number of currently known Bryophryne to six. One of the new species differs from all species of Bryophryne in having a tympanic annulus and tympanic membrane. Males of this species have vocal slits, a vocal sac, and produce a call, which we analyze herein. This species is found at San Luis, a montane cloud forest along the road from Abra Málaga to Quillabamba at elevations between 3272 and 3354 m. The second new species has an orange throat and groin and is found …

Skeletal Advance And Arrest In Giant Non-Metamorphosing African Clawed Frog Tadpoles (Xenopus Laevis: Daudin), Ryan Kerney, Richard Wassersug, Brian Hall

Ryan Kerney

This study examines the skeletons of giant non-metamorphosing (GNM) Xenopus laevis tadpoles, which arrest their development indefinitely before metamorphosis, and grow to excessively large sizes in the absence of detectable thyroid glands. Cartilage growth is isometric; however, chondrocyte size is smaller in GNM tadpoles than in controls. Most cartilages stain weakly with alcian blue, and several cartilages are calcified (unlike con- trols). However, cartilages subjacent to periosteum-derived bone retain strong affinities for alcian blue, indicat- ing a role for periosteum-derived bone in the retention of glycosaminoglycans during protracted larval growth. Bone formation in the head, limb, and axial skeletons is …

A New Species Of Minute Noblella (Anura: Strabomantidae) From Southern Peru: The Smallest Frog Of The Andes, Edgar Lehr, Alessandro Catenazzi

Edgar Lehr

We describe a new species of Noblella from the upper Cosnipata Valley in southern Peru (Cusco Region). Specimens were found in the leaf litter of a cloud forest between 3025 and 3190 m elevation. The most distinctive character of the new species is its diminutive size (maximum SVL female 12.4 mm, male 11.1 mm). With an average snout–vent length of 11.4 mm (n = 7) in adult specimens, the new species is the smallest Andean frog, and one of the smallest anurans in the world. The new frog is rare (between 30 and 75 frogs/ ha) and found only in …

A New Species Of Scinax (Anura: Hylidae) From The Area Of Iquitos, Amazonian Peru, Edgar Lehr, Jiri Moravec, Illich Tuanama, Pedro Perez

Edgar Lehr

We describe a new species of the hylid frog genus Scinax from the Peruvian Upper Amazonian Lowlands (area of Iquitos, Region Loreto, Peru). The new species belongs to the Scinax ruber clade and differs from all its members by having the dorsal skin slightly to coarsely shagreen, by lacking conspicuous ulnar and tarsal tubercles, and in life by having a distinct light olive-green coloration on dorsum, bright yellow flanks with distinct black spots, black posterior surfaces of thighs, and gold to bronze iris.

Sky Islands, John Mccormack, Huateng Huang, L. Knowles

John E. McCormack

No abstract provided.

Tracking Bacterial Responses To Global Warming With An Ecotype-Based Systematics, Frederick M. Cohan

Frederick M. Cohan

No abstract provided.

Multiple Colonisations Of The Western Indian Ocean By Pteropus Fruit Bats (Megachiroptera: Pteropodidae): The Furthest Islands Were Colonised First, John O'Brien, Carol Mariani, Link Olson, Amy L. Russell, Ludovic Say, Anne D. Yoder, Tom J. Hayden

Amy L. Russell

Forest Regeneration From Pasture In The Dry Tropics Of Panama: Effects Of Cattle, Exotic Grass, And Forested Riparia, Heather P. Griscom, B.W. Griscom, P.M.S. Ashton

Heather P. Griscom

No abstract provided.

Life In The Slow Lane: Palmetto Seedlings Exhibit Remarkable Survival But Slow Growth In Florida's Nutrient-Poor Uplands, W. G. Abrahamson, C. R. Abrahamson

Warren G. Abrahamson, II

The palmettos Serenoa repens and Sabal etonia are crucial foundation species in many peninsular Florida vegetative associations. We monitored the survival and growth of individual palmetto seedlings using two cohorts found in different vegetative associations. Seedling cohorts containing both S. repens and S. etonia were individually tagged in 1989 and have been monitored until 2008, a period of 19 years. One cohort (N = 100 seedlings) occurs in a xeric, “inopina-phase” scrubby flatwoods and a second cohort (N =78 seedlings) lives in a well-drained, “wiregrass-phase” flatwoods. The soils at both sites are very nutrient-poor Entisols that show rapid permeability, low …

Animal Pleasure And Its Moral Significance, Jonathan P. Balcombe

Jonathan Balcombe, Ph.D.

No abstract provided.

Interactions Of Native And Non-Native Lady Beetle Species (Coleoptera: Coccinellidae) With Aphid-Tending Ants In Laboratory Arenas, Christy Finlayson, Andrei Alyokhin, Erin Porter

Andrei Alyokhin

Interactions between lady beetles and the European fire ant (Myrmica rubra L.) tending potato aphids [Macrosiphum euphorbiae (Thomas)] were compared in the laboratory. Lady beetle species native to North America (Coccinella trifasciata perplexa Mulsant, Coleomegilla maculata lengi Timberlake, Hippodamia convergens Guerin-Meneville) and non-native species of Palearctic origin [Coccinella septempunctata L., Harmonia axyridis (Pallas), Hippodamia variegata (Goeze), Propylea quatuordecimpunctata L.)] were evaluated. Harmonia axyridis consumed a significantly greater number of aphids compared with all other species but C. septempunctata. Ant stings affected H. variegata and C. septempunctata to a greater extent than other species. Ants showed a significantly greater amount of …