Sensitivity of south‐east Atlantic planktonic foraminifera to mid‐Pleistocene climate change

Abstract: The last one million years are important in terms of climate development during the so‐called Mid‐Pleistocene Transition when amplification of the glacial–interglacial cycles occurred. This study describes abundance changes in fossil planktonic foraminifera in sediments from Core T89‐40, retrieved from the Walvis Ridge in the south‐east Atlantic, across this time period. Cycles between upwelling and subtropical planktonic foraminiferal assemblages are shown to mirror changes between glacial and interglacial periods, respectively. During interglacial marine isotopic stages (MIS) 9, 11 and 31, however, anomalously high abundances of the polar left‐coiled Neogloboquadrina pachyderma occur, presumably linked to unusual seasonal upwelling waters. The planktonic foraminiferal abundance record shows 41‐ky cyclic variations in the regional oceanography linked to cycles in insolation influenced by changes in the Earth’s axial tilt (obliquity). These orbitally induced oscillations in oceanographic change occurred throughout the entire record. The most conspicuous feature of the planktonic foraminiferal record is the near absence of left‐coiled Globorotalia truncatulinoides between 960 and 610 ka (MIS 26‐15). The abrupt disappearance of this species is synchronous with the onset of the Mid‐Pleistocene Transition in MIS 26.     

Greenhouse gas fluxes from tropical peatlands in south‐east Asia

The lowland peatlands of south‐east Asia represent an immense reservoir of fossil carbon and are reportedly responsible for 30% of the global carbon dioxide (CO₂) emissions from Land Use, Land Use Change and Forestry. This paper provides a review and meta‐analysis of available literature on greenhouse gas fluxes from tropical peat soils in south‐east Asia. As in other parts of the world, water level is the main control on greenhouse gas fluxes from south‐east Asian peat soils. Based on subsidence data we calculate emissions of at least 900 g CO₂ m^?2 a^?1 (～250 g C m^?2 a^?1) for each 10 cm of additional drainage depth. This is a conservative estimate as the role of oxidation in subsidence and the increased bulk density of the uppermost drained peat layers are yet insufficiently quantified. The majority of published CO₂ flux measurements from south‐east Asian peat soils concerns undifferentiated respiration at floor level, providing inadequate insight on the peat carbon balance. In contrast to previous assumptions, regular peat oxidation after drainage might contribute more to the regional long‐term annual CO₂ emissions than peat fires. Methane fluxes are negligible at low water levels and amount to up to 3 mg CH₄ m^?2 h^?1 at high water levels, which is low compared with emissions from boreal and temperate peatlands. The latter emissions may be exceeded by fluxes from rice paddies on tropical peat soil, however. N₂O fluxes are erratic with extremely high values upon application of fertilizer to wet peat soils. Current data on CO₂ and CH₄ fluxes indicate that peatland rewetting in south‐east Asia will lead to substantial reductions of net greenhouse gas emissions. There is, however, an urgent need for further quantitative research on carbon exchange to support the development of consistent policies for climate change mitigation.     

Tripleurospermum ziganaense (Asteraceae,Anthemideae), a new species from north‐east Anatolia,Turkey

A new species of Tripleurospermum Sch.Bip., Tripleurospermum ziganaense Inceer & Hay?rl?oglu‐Ayaz (Asteraceae, Anthemideae), is described and illustrated. The species grows in open places, on rocky slopes and on roadsides in north‐east Anatolia, Turkey. The diagnostic morphological characters that distinguish it from closely related taxa are discussed, and its conservation status is indicated. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 696–700.     

Distribution of saltmarsh plant communities associated with environmental factors along a latitudinal gradient on the south‐west Atlantic coast

Aim To produce an inventory of south‐west Atlantic saltmarshes (from latitude 31°48′ S to 43°20′ S) using remotely sensed images and field sampling; to quantify their total area; to describe the biogeographical variation of the main habitats characterized by dominant vascular plants, in relation to major environmental factors; to test the hypothesis of predominance of the reversal pattern in plant distribution (sedges and grasses dominate the lower, regularly inundated zones, while the upper zones are occupied by more halophytic species) previously described; and to compare these south‐west Atlantic saltmarshes with others world‐wide. Location South‐western Atlantic saltmarshes Methods Field samples of dominant emergent plant species positioned by the global positioning system (GPS) were obtained from most coastal saltmarshes (14) between southern Brazil and northern Patagonia, Argentina. Landsat satellite images were obtained and coastal saltmarsh habitats were quantified by supervised classification, utilizing points gathered in the field. Results Three main plant species dominated the low and middle intertidal saltmarsh, Spartina alterniflora Loesel., Spartina densiflora Brong. and Sarcocornia perennis (P. Mill.) A.J. Scott. The total area of the studied coastal saltmarshes was 2133 km², comprising 380 km² of Sp. alterniflora marsh, 366 km² of Sp. densiflora marsh, 746 km² of Sar. perennis marsh and 641 km² of brackish marsh (dominated by Juncus acutus L., Juncus kraussii Hochst., Scirpus maritimus L., Scirpus americanus Pers. and Phragmites australis (Cav.) Trin.). Cluster analysis showed three habitat types: saltmarshes dominated by (1) Sp. densiflora and brackish species,(2) Sp. alterniflora and Sar. perennis and (3) Sp.densiflora only. The analysis of abiotic variables showed significant differences between groups of habitats and coordinated gradients of the abiotic variables. The south‐west Atlantic coast showed decreasing mean annual rainfall (1200 to 196 mm) and increasing mean tidal amplitude (< 0.5 to > 2.5 m) from latitude 31° to 43°. Main conclusions South‐west Atlantic saltmarshes are globally important by virtue of their total extent. Remote sensing showed that the reversal pattern in plant distribution is not widespread. Indeed, south‐west Atlantic saltmarshes are better characterized by the presence of the halophytic genera Spartina and Sarcocornia. Our results support the interpretation that south‐west Atlantic saltmarshes constitute a class of temperate type (sensu Adam, 1990 ) with transitional characteristics between Australasian–South African saltmarshes and west Atlantic saltmarshes.     

Bioerosional structures and pseudoborings from Late Jurassic and Late Cretaceous-Paleocene shallow-water carbonates (Northern Calcareous Alps, Austria and SE France) with special reference to cryptobiotic foraminifera

Examples of bioerosional processes (boring patterns) are described from shallow-water limestones of the Late Jurassic Plassen Carbonate Platform (PCP) and the Late Cretaceous to Paleocene Gosau Group of the Northern Calcareous Alps, Austria. Some micro-/macro-borings can be related to distinct ichnotaxa, others are classified in open nomenclature. In the Alpine Late Jurassic, bioerosional structures recorded from clasts in mass-flows allow palaeogeographical conclusions concerning the source areas. In particular, these are borings of the Trypanites-ichnofacies detected from clasts (Barmstein limestones) of the PCP or special type of bored ooids of unknown source areas or restricted autochthonous occurrences. In the Lower Gosau Subgroup, Gastrochaenolites macroborings occur in mobile carbonate clast substrates of shore zone deposits (“Untersberg Marmor”). Different types of borings are recorded from rudist shells and coral skeleton, some of which are referable to the ichnotaxon Entobia produced by endolithic sponges. In the present study, special attention is paid to the occurrences of the cryptobiotic foraminifera Troglotella incrustans Wernli and Fookes in the Late Jurassic and Tauchella endolithica Cherchi and Schroeder in the Late Cretaceous. The latter is so far only known to be from the Early Cenomanian of France and is reported here for the first time from the Late Turonian-Early Coniacian stratigraphic interval where it was found in turbulent carbonate deposits within borings penetrating bivalve shells or coralline algae. The records of cryptobiotic foraminifera from the Northern Calcareous Alps are supplemented by a single finding from the Middle Cenomanian of SE France. A palaeoenvironmental interpretation of the occurrences of the cryptobiotic foraminifera is provided.     

Nest survival rates of Red‐crested Cardinals increase with nest age in south‐temperate forests of Argentina

ABSTRACT The main cause of nest mortality for most bird species is predation and nest survival rates often vary in relation to time‐specific variables. Few investigators have examined time‐specific patterns of nest survival in Neotropical birds, and most such studies have focused on tropical and subtropical species. To better understand age‐related patterns of nest survival, we studied nest survival of Red‐crested Cardinals (Paroaria coronata, Thraupidae) in a south‐temperate forest in Argentina. We modeled daily nest survival rates (DSR) using program MARK. We examined the relationship between nest age and nest survival rate, controlling for the effects of physical characteristics of nest sites and progression of the breeding season. We monitored 367 nests for a total of 4018 exposure days. We found that DSR increased with nest age and was higher in small isolated patches than in large continuous patches of forests. The increase of DSR with nest age could be a consequence of more vulnerable nests being predated early in the nesting cycle or a result of parents defending nests more vigorously as nestlings age because of their increasing reproductive value. Open areas of grassland that surrounded the small isolated patches of forests in our study may have been a barrier to predator movements, possibly explaining the lower predation rates. Nest survival rates in our study were lower than those reported for tropical or Nearctic temperate birds, but similar to those reported in other studies of Neotropical temperate birds. Reasons for the low nest survival rates of Neotropical temperate birds remain unclear, and additional studies of predator communities are needed to help elucidate this topic.     

Long‐term declines in multiple waterbird species in a tidal embayment,south‐east Australia

Worldwide, local extinctions and severe declines in waterbird densities are being reported from many important waterbird sites. Waterbird sites often exist as a network, collectively providing crucial habitat for different life history stages of different species. Therefore, population changes at one site may strongly influence others. In Australia, many waterbird species are highly mobile, and move rapidly over long distances in response to rainfall. Large tidal wetlands often serve as drought refugia or alternative breeding habitat for these species. These sites are also the migration terminus of many species of shorebirds that spend their non‐breeding season in Australia. One such site in south‐eastern Australia is Western Port, a Ramsar‐listed tidal embayment forming part of the East Asian–Australasian Shorebird Site Network. We measured waterbird population trends over nearly 40 years in Western Port to see whether changes showed consistent trends over time across multiple species. Thirty‐nine species were recorded often enough to allow an analysis of trends over time using dynamic linear models and, where appropriate, piecewise linear regression. Twenty‐two species had declined, including four species of duck, five species of fish‐eating bird (cormorants, terns and pelicans), one species each of grebe, gull and heron, and 10 species of shorebird. Only two species (Australian pied oystercatcher Haematopus longirostris and straw‐necked ibis Threskiornis spinicollis) increased significantly over the same time period. Patterns of decline in non‐migratory waterbirds may reflect diminishing wetland availability, local reductions in fish prey, increased predation pressure and changes in inland wetland resources. Declines in migratory shorebirds are most likely related to loss of habitat elsewhere in their trans‐equatorial migration routes. These trends in waterbirds that use Western Port reflect widespread impacts on populations elsewhere in Australia and overseas, necessitating more than simply local management of this tidal embayment.     

A high‐stress shelly fauna associated with sponge mud‐mounds in the Coniacian Arnager Limestone of Bornholm,Denmark

The benthic macrofaunas of the Upper Cretaceous chalk of NW Europe show characteristically high species‐richnesses and commonly high densities. They are predominated by bivalves, brachiopods, polychaetes, echinoids, crinoids, asteroids, sponges and towards the end of the Cretaceous also by bryozoans. The mound‐bedded chalk of the Coniacian Arnager Limestone on the island of Bornholm in the Baltic Sea, Denmark, differs from this general picture. It was deposited on a small fault block adjacent to the main Bornholm block, which was emerged during much of the Mesozoic and thus occupied a much more proximal position than most other Upper Cretaceous chalks in NW Europe. The Arnager Limestone contains a unique, exceptionally rich and well‐preserved fauna of mainly hexactinellid, lyssacinosan sponges. The low mud‐mounds are interpreted as formed by baffling and trapping of fine sediment particles by the dense sponge thickets. In contrast, the associated shelly fauna is unusually sparse, of very low richness and extremely low density, except for inoceramid bivalves. It represents a strongly depauparated version of the shelly faunas of contemporaneous chalks in NW Europe. The rare specimens of non‐inoceramid shelly species are interpreted to represent occasional successful spatfalls of benthic species from the deeper‐water chalk farther offshore in the Baltic area. The sponge mud‐mounds of the Arnager Limestone show remarkable resemblances with modern sponge mounds recently discovered on the continental shelf of western Canada. They form an important link between the well‐known older Mesozoic sponge mud‐mounds or ‘reefs’ and the modern mounds and are among the youngest examples of Mesozoic sponge mounds.     

Contrasting definitive hosts as determinants of the genetic structure in a parasite with complex life cycle along the south‐eastern Pacific

The spatial genetic structure (and gene flow) of parasites with complex life cycles, such as digeneans, has been attributed mainly to the dispersion ability of the most mobile host, which most often corresponds to the definitive host (DH). In this study, we compared the genetic structure and diversity of adult Neolebouria georgenascimentoi in two fish species (DHs) that are extensively distributed along the south‐eastern Pacific (SEP). The analysis was based on the cytochrome oxidase subunit I gene sequences of parasites collected between 23°S and 45°S. In total, 202 sequences of N. georgenascimentoi in Pinguipes chilensis isolated from nine sites and 136 sequences of Prolatilus jugularis from five sites were analysed. Our results showed that N. georgenascimentoi is a species complex that includes three different parasite species; however, in this study, only lineage 1 and 2 found in P. chilensis and P. jugularis, respectively, were studied because they are widely distributed along the coastline. Lineage 1 parasites had two common haplotypes with wide distribution and unique haplotypes in northern sites. Lineage 2 had only one common haplotype with wide distribution and a large number of unique haplotypes with greater genetic diversity. Both lineages have experienced recent population expansion. Only lineage 1 exhibited a genetic structure that was mainly associated with a biogeographical break at approximately 30°S along the SEP. Our finding suggests that host access to different prey (=intermediate hosts) could affect the genetic structure of the parasite complex discovered here. Consequently, difference between these patterns suggests that factors other than DH dispersal are involved in the genetic structure of autogenic parasites.     

Squalus bassi sp. nov., a new long‐snouted spurdog (Chondrichthyes: Squaliformes: Squalidae) from the Agulhas Bank

The long‐snouted African spurdog Squalus bassi sp. nov. is described based on material collected from the outer shelf and upper continental slope off South Africa and Mozambique. Squalus bassi shares with S. mitsukurii, S. montalbani, S. chloroculus, S. grahami, S. griffini, S. edmundsi, S. quasimodo and S. lobularis a large snout with prenarial length greater than distance between nostrils and upper labial furrows, dermal denticles tricuspidate and rhomboid and elevated number of vertebrae. Squalus bassi can be distinguished from all its congeners by a combination of body and fin colouration, external morphometrics, vertebral counts and shape of dermal denticles. Similar long‐snouted congeners from the Indo‐Pacific region, including S. montalbani, S. edmundsi and S. lalannei are compared in detail with the new species. This new species has been misidentified as the Japanese S. mitsukurii and the Mediterranean S. blainvillei due to the lack of comparative morphological analyses. The validity of the nominal species S. mitsukurii in the south‐eastern Atlantic Ocean and western Indian Ocean is also clarified herein, indicating it has a more restricted geographical distribution in the North Pacific Ocean.     

Effects of fire on vegetation and arthropods in a coastal heath,south‐east Queensland

Fire is an important part of many Australian ecosystems, and determining how it affects different vegetation communities and associated fauna is of particular interest to land managers. Here, we report on a study that used sites established during a 39‐year fire experiment in coastal heathland in southeastern Queensland to compare arthropod abundance and vegetation in 1.5–2.6 ha sites that were (i) long unburnt, (ii) burnt every 5 years and (iii) burnt every 3 years. We found that the abundance of ants was more than four times higher in the frequently burnt sites compared to long unburnt sits. Moreover, long unburnt sites had greater dominance of Xanthorrhoea johnsonii and Caustis recurvata, whereas burnt sites had greater cover of Lomandra filiformis, Leucopogon margarodes and Leucopogon leptospermoides. Our findings show that frequent fire can alter vegetation structure and composition, and this is matched by an increase in the relative dominance of ants in the arthropod community.     

Genetic connectivity and phenotypic plasticity in the cyprinodont Aphanius farsicus from the Maharlu Basin,south‐western Iran

Meristic and morphometric characteristics, including otolith data, of the Farsi tooth‐carp Aphanius farsicus, which is endemic to the endorheic Maharlu Basin in south‐western Iran, were analysed for a sample of 92 individuals from four spring‐streams; DNA sequence data (cytochrome b gene) are presented for 29 specimens. Some phenotypic variation was detected but the genetic data clearly indicate connectivity between the populations. Possible links between phenotypic variation and environmental variables such as water temperature, habitat size and absence or presence of predators and competitors are discussed. Based on a literature survey and the new data, it is concluded that population connectivity is maintained during times of droughts via large aquifers that formed during the late Pliocene to early Pleistocene, when the extant endorheic Maharlu Basin was created. Based on new data presented here and previous work, it is apparent that plastic and constant characteristics are present in Aphanius species, and that, if a population becomes isolated, a given trend of evolution may give rise to a taxonomically useful characteristic.     

Chloroplast DNA diversity associated with protected slopes and valleys for hybridizing Eucalyptus species on isolated ranges in south‐eastern Australia

Aim To relate genetic diversity to topographic features and to investigate genetic interactions between Eucalyptus species in a local centre of endemism and diversity in south‐eastern Australia. Location Grampian Ranges, Victoria, Australia. Methods We documented chloroplast DNA (cpDNA) variation for a group of endemic Eucalyptus species (E. serraensis, E. verrucata and E. victoriana) that dominate rocky, high‐elevation ridgelines of the Grampian Ranges and for one closely‐related, widespread species (E. baxteri) occupying flanking slopes and valleys. We documented genetic patterns across the landscape using cpDNA microsatellites, and related them to topographic features (exposed west‐facing versus protected east‐facing slopes and valleys). We also determined the extent of local haplotype sharing between populations of endemic species and neighbouring E. baxteri downslope with cpDNA microsatellites, and haplotype sharing between the endemic group and more distantly related species (E. obliqua, E. pauciflora and E. willisii) with sequences of the J_LA+ chloroplast region. Results We detected 26 cpDNA microsatellite haplotypes in a relatively small area of c. 20 km × 50 km. Populations of E. baxteri on east‐facing slopes and valleys had greater cpDNA microsatellite diversity than E. baxteri and endemic species on exposed west‐facing slopes. Endemic species frequently shared chloroplast haplotypes with E. baxteri downslope. Sharing of J_LA+ haplotypes with species outside the endemic group was mostly restricted to E. victoriana, which had cpDNA more similar to the species from other sections of Eucalyptus (E. obliqua, E. willisii and E. pauciflora). Main conclusions Intensive sampling of related species on small isolated mountain ranges allowed us to relate genetic diversity to fine‐scale habitats and to document extensive local haplotype sharing between species. This study contributes to a general understanding of the environmental conditions that enable plant population persistence by linking concentrations of genetic diversity to particular habitats.     

Evidence of increased net ecosystem productivity associated with a longer vegetated season in a deciduous forest in south‐central Indiana,USA

Observations of net ecosystem exchange (NEE) of carbon and its biophysical drivers have been collected at the AmeriFlux site in the Morgan‐Monroe State Forest (MMSF) in Indiana, USA since 1998. Thus, this is one of the few deciduous forest sites in the world, where a decadal analysis on net ecosystem productivity (NEP) trends is possible. Despite the large interannual variability in NEP, the observations show a significant increase in forest productivity over the past 10 years (by an annual increment of about 10 g C m^?2 yr^?1). There is evidence that this trend can be explained by longer vegetative seasons, caused by extension of the vegetative activity in the fall. Both phenological and flux observations indicate that the vegetative season extended later in the fall with an increase in length of about 3 days yr^?1 for the past 10 years. However, these changes are responsible for only 50% of the total annual gain in forest productivity in the past decade. A negative trend in air and soil temperature during the winter months may explain an equivalent increase in NEP through a decrease in ecosystem respiration.     

Disturbance‐induced changes in a high‐alpine cushionfield community,south‐central New Zealand

Long‐term effects of two nearby disturbances, mechanical blading 34 years ago and an approximately century‐old sheep graveyard, in high‐alpine cushionfield share certain vegetation features despite their contrasting soil nutrient status. Secondary succession following blading has continued beyond that recorded over the first 24 years with continued trends towards the adjacent undisturbed cushionfield: increased cover of several cushion species and the lichen Cetraria islandica ssp. antarctica. Several mid‐seral species remain prominent while bare soil and stone pavement continue to decrease. Additional shelter, facilitated by tall snow tussocks planted locally at near‐natural density on part of the bladed site, allowed establishment of some larger, thin‐leaved species. Soil factors remain little affected by the mechanical disturbance compared with the general enrichment persisting at the graveyard. Here three small indigenous grasses, which dominated 50 years earlier (Trisetum spicatum, Agrostis muelleriana, Poa colensoi), remain prominent among the relatively diverse community (50 species, including several calciphilic lichens on the degrading bones). By contrast, frequency of the cushionfield dominant, Dracophyllum muscoides and the lichen Alectoria nigricans, are negatively correlated with the presence of bones. The post‐disturbance temporal community changes are assessed in the context of the initial productivity of the habitat, competitive exclusion and the intermediate disturbance hypothesis.     

Microaerophilic Fe‐oxidizing micro‐organisms in Middle Jurassic ferruginous stromatolites and the paleoenvironmental context of their formation (Southern Carpathians,Romania)

Ferruginous stromatolites occur associated with Middle Jurassic condensed deposits in several Tethyan and peri‐Tethyan areas. The studied ferruginous stromatolites occurring in the Middle Jurassic condensed deposits of Southern Carpathians (Romania) preserve morphological, geochemical, and mineralogical data that suggest microbial iron oxidation. Based on their macrofabrics and accretion patterns, we classified stromatolites: (1) Ferruginous microstromatolites associated with hardground surfaces and forming the cortex of the macro‐oncoids and (2) Domical ferruginous stromatolites developed within the Ammonitico Rosso‐type succession disposed above the ferruginous microstromatolites (type 1). Petrographic and scanning electron microscope (SEM) examinations reveal that different types of filamentous micro‐organisms were the significant framework builders of the ferruginous stromatolitic laminae. The studied stromatolites yield a large range of δ⁵⁶Fe values, from ?0.75‰ to +0.66‰ with predominantly positive values indicating the prevalence of partial ferrous iron oxidation. The lowest negative δ⁵⁶Fe values (up to ?0.75‰) are present only in domical ferruginous stromatolites samples and point to initial iron mobilization where the Fe(II) was produced by dissimilatory Fe(III) reduction of ferric oxides by Fe(III)‐reducing bacteria. Rare‐earth elements and yttrium (REE + Y) are used to decipher the nature of the seawater during the formation of the ferruginous stromatolites. Cerium anomalies display moderate to small negative values for the ferruginous microstromatolites, indicating weakly oxygenated conditions compatible with slowly reducing environments, in contrast to the domical ferruginous stromatolites that show moderate positive Ce anomalies suggesting that they formed in deeper, anoxic–suboxic waters. The positive Eu anomalies from the studied samples suggest a diffuse hydrothermal input on the seawater during the Middle Jurassic on the sites of ferruginous stromatolite accretion. This study presents the first interpretation of REE + Y in the Middle Jurassic ferruginous stromatolites of Southern Carpathians, Romania.     

Modeling and empirical validation of long‐term carbon sequestration in forests (France, 1850–2015)

The development of appropriate tools to quantify long‐term carbon (C) budgets following forest transitions, that is, shifts from deforestation to afforestation, and to identify their drivers are key issues for forging sustainable land‐based climate‐change mitigation strategies. Here, we develop a new modeling approach, CRAFT (CaRbon Accumulation in ForesTs) based on widely available input data to study the C dynamics in French forests at the regional scale from 1850 to 2015. The model is composed of two interconnected modules which integrate biomass stocks and flows (Module 1) with litter and soil organic C (Module 2) and build upon previously established coupled climate‐vegetation models. Our model allows to develop a comprehensive understanding of forest C dynamics by systematically depicting the integrated impact of environmental changes and land use. Model outputs were compared to empirical data of C stocks in forest biomass and soils, available for recent decades from inventories, and to a long‐term simulation using a bookkeeping model. The CRAFT model reliably simulates the C dynamics during France's forest transition and reproduces C‐fluxes and stocks reported in the forest and soil inventories, in contrast to a widely used bookkeeping model which strictly only depicts C‐fluxes due to wood extraction. Model results show that like in several other industrialized countries, a sharp increase in forest biomass and SOC stocks resulted from forest area expansion and, especially after 1960, from tree growth resulting in vegetation thickening (on average 7.8 Mt C/year over the whole period). The difference between the bookkeeping model, 0.3 Mt C/year in 1850 and 21 Mt C/year in 2015, can be attributed to environmental and land management changes. The CRAFT model opens new grounds for better quantifying long‐term forest C dynamics and investigating the relative effects of land use, land management, and environmental change.     

An assessment of riparian restoration outcomes in two rural catchments in south‐western Victoria: Focusing on tree and shrub species richness,structure and recruitment characteristics

Riparian ecosystems are among the most degraded systems in the landscape, and there has been substantial investment in their restoration. Consequently, monitoring restoration interventions offers opportunities to further develop the science of riparian restoration, particularly how to move from small‐scale implementation to a broader landscape scale. Here, we report on a broad range of riparian revegetation projects in two regions of south‐western Victoria, the Corangamite and Glenelg‐Hopkins Catchment Management Areas. The objectives of restoration interventions in these regions have been stated quite broadly, for example, to reinstate terrestrial habitat and biodiversity, control erosion and improve water quality. This study reports on tree and shrub composition, structure and recruitment after restoration works compared with remnant vegetation found regionally. Within each catchment, a total of 57 sites from six subcatchments were identified, representing three age‐classes: <4, 4–8 and >8–12 years after treatment, as well as untreated (control) sites. Treatments comprised fencing to exclude stock, spraying or slashing to reduce weed cover, followed by planting with tube stock. Across the six subcatchments, 12 reference (remnant) sites were used to provide a benchmark for species richness, structural and recruitment characteristics and to aid interpretation of the effects of the restoration intervention. Vegetation structure was well developed in the treated sites by 4–8 years after treatment. However, structural complexity was higher at remnant sites than at treated or untreated sites due to a higher richness of small shrubs. Tree and shrub recruitment occurred in all remnant sites and at 64% of sites treated >4 years ago. Most seedling recruitment at treatment sites was by Acacia spp. This assessment provides data on species richness, structure and recruitment characteristics following restoration interventions. Data from this study will contribute to longitudinal studies of vegetation processes in riparian landscapes of south‐western Victoria.     

Faunal response to sea‐level and climate change in a short‐lived seaway: Jurassic of the Western Interior,USA

Understanding how regional ecosystems respond to sea‐level and environmental perturbations is a main challenge in palaeoecology. Here we use quantitative abundance estimates, integrated within a sequence stratigraphic and environmental framework, to reconstruct benthic community changes through the 13 myr history of the Jurassic Sundance Seaway in the western United States. Sundance Seaway communities are notable for their low richness and high dominance relative to most areas globally in the Jurassic, and this probably reflects steep temperature and salinity gradients along the 2000 km length of the Seaway that hindered colonization of species from the open ocean. Ordination of samples shows a main turnover event at the Middle–Upper Jurassic transition, which coincided with a shift from carbonate to siliciclastic depositional systems in the Seaway, probably initiated by northward drift from subtropical latitudes to more humid temperate latitudes, and possibly global cooling. Turnover was not uniform across the onshore–offshore gradient, but was higher in offshore environments. The higher resilience of onshore communities to third‐order sea‐level fluctuations and to the change from a carbonate to a siliciclastic system was driven by a few abundant eurytopic species that persisted from the opening to the closing of the Seaway. Lower stability in offshore facies was instead controlled by the presence of more volatile stenotopic species. Such increased onshore stability in community composition contrasts with the well‐documented onshore increase in taxonomic turnover rates, and this study underscores how ecological analyses of relative abundance may contrast with taxonomically based analyses. We also demonstrate the importance of a stratigraphic palaeobiological approach to reconstructing the links between environmental and faunal gradients, and how their evolution through time produces local stratigraphic changes in community composition.