Using species niche models to inform strategic management of weeds in a changing climate

The expansion of the global area planted in fast-growing forest species seems likely as a means of offsetting carbon dioxide emissions and developing a sustainable bio-energy resource. Selecting appropriate sites for these plantations will require consideration of the effect of climate change on plantation growth and risks from abiotic and biotic factors. Buddleja davidii has been identified as a weed that has a major impact on plantation forest production in New Zealand. While it is at present restricted mainly to the North Island, a large proportion of the area identified for forest expansion is in eastern and southern regions of the South Island where the weed is presently relatively scarce. In this study we use a process-oriented climatic niche model (CLIMEX) to identify climatically suitable areas for B. davidii under current climate and future climate during the 2080s. This analysis indicates areas most at risk from invasion by B. davidii are in eastern and southern regions of the South Island. As B. davidii predominantly colonises disturbed areas, the likely increases in plantation forest area within this region can be expected to promote the spread of B. davidii. Strategies that could be implemented to manage B. davidii in this region are discussed. This study highlights the general utility of process-oriented niche models in identifying possible threats to planned primary production activities from invasive weed species. This type of knowledge is invaluable in planning and allocation of often scarce resources to most effectively control high impact weeds. Without the synoptic view of the invasion and the assets at risk, there is a strong potential for regional pest management to be parochial, and consequently less effective at all scales.     

Risk assessment of the gypsy moth, <Emphasis Type="Italic">Lymantria dispar</Emphasis> (L), in New Zealand based on phenology modelling

The gypsy moth is a global pest that has not yet established in New Zealand despite individual moths having been discovered near ports. A climate-driven phenology model previously used in North America was applied to New Zealand. Weather and elevation data were used as inputs to predict where sustainable populations could potentially exist and predict the timing of hatch and oviposition in different regions. Results for New Zealand were compared with those in the Canadian Maritimes (New Brunswick, Nova Scotia, and Prince Edward Island) where the gypsy moth has long been established. Model results agree with the current distribution of the gypsy moth in the Canadian Maritimes and predict that the majority of New Zealand’s North Island and the northern coastal regions of the South Island have a suitable climate to allow stable seasonality of the gypsy moth. New Zealand’s climate appears more forgiving than that of the Canadian Maritimes, as the model predicts a wider range of oviposition dates leading to stable seasonality. Furthermore, we investigated the effect of climate change on the predicted potential distribution for New Zealand. Climate change scenarios show an increase in probability of establishment throughout New Zealand, most noticeably in the South Island.     

Evolution and biogeography of New Zealand's longjaw galaxiids (Osmeriformes: Galaxiidae): the genetic effects of glaciation and mountain building

1. The biological impact of glaciation in Southern Hemisphere freshwaters is poorly understood. Several large rivers of eastern South Island, New Zealand, represent a mosaic of glaciated and non-glaciated regions, and are thus well-suited for studies of post-glacial recolonization.
2. We conducted mtDNA analyses of South Island's endemic non-migratory longjaw galaxiids Galaxias prognathus and G. cobitinis (Osmeriformes: Galaxiidae) to test hypotheses of post-glacial recolonization, and to assess the vicariant effects of Pleistocene mountain building.
3. We analysed the phylogeography of longjaw cytochrome b sequences from 38 sites in central South Island ( n  = 83). On the basis of our sampling it seems that G. prognathus and G. cobitinis have a parapatric distribution in the Waitaki River system, their disjunction broadly coinciding with three large post-glacial lakes. Waitaki clades of both species are deeply divergent relative to conspecific taxa in drainages to the north and south.
4. Tests for recent population growth – predicted under post-glacial expansion of G. prognathus – do not refute recent recolonization of streams above glaciated lakes in the Waitaki River drainage. The apparent absence of potential 'source' populations from non-glaciated regions suggests a post-glacial population decline for G. prognathus below the Waitaki lakes.
5. Molecular clock calibrations based on several freshwater vicariant events elsewhere in New Zealand supported the geologically-derived hypothesis of Waitaki–Canterbury drainage isolation approximately 300 ka.     

Crying wolf, crying foul, or crying shame: alien salmonids and a biodiversity crisis in the southern cool-temperate galaxioid fishes?

The galaxioid fishes are the dominant, most speciose group of freshwater fishes (with >50 species) in the lands of the cool southern hemisphere, with representatives in western and eastern Australia, Tasmania, New Caledonia, Lord Howe Island, New Zealand, the Chatham, Auckland and Campbell Islands, Patagonian South America (Chile, Argentina), the Falkland Islands and South Africa. The group is most diverse in Australia and New Zealand. Lepidogalaxiidae is found only in Australia, Retropinnidae in Australia and New Zealand, and Galaxiidae across the entire range of the group. Many species are in serious conservation crisis for a diversity of reasons, including habitat deterioration and possibly fisheries exploitation, but there is enduring and pervasive information that shows that the group has been seriously impacted by the acclimatisation of salmonid fishes originating in the cool-temperate northern hemisphere, particularly brown and rainbow trout. With few exceptions, where these trout have been introduced there has been major decline in the galaxioids, especially Galaxiidae, as a result of a complexly interacting series of adverse impacts from these introduced fishes. In some places, centrarchids and cichlids may also have adverse impacts. In addition, there appear to have been adverse impacts from the translocation of galaxioids into communities where they do not naturally occur. In many instances it appears that displacement of the galaxioids has led to a situation where galaxioids and salmonids no longer co-occur, owing either to displacement or predation, leading to fish communities in which there is no explicit evidence for displacement. These effects are resulting in the galaxioid fishes being amongst the most seriously threatened fishes known.     

Arrival of an Australian anguillid eel in New Zealand: an example of transoceanic dispersal

Anguilla reinhardtii, hitherto known from eastern Australia, New Caledonia, Norfolk Island, and Lord Howe Island, has recently been discovered in rivers of northern New Zealand. Identification, based on morphological and genetic characteristics, is unequivocal; eight consecutive year classes have been found. The only reasonable explanation of this occurrence is transoceanic dispersal to New Zealand, probably from subtropical oceanic spawning grounds north of New Zealand. This corroborates past hypotheses that the strongly diadromous freshwater fish fauna of New Zealand is derived by transoceanic dispersal of known marine life intervals. This revised version was published online in July 2006 with corrections to the Cover Date.     

BOTANICAL BRIEFING Fire, Forest Regeneration and Links with Early Human Habitation: Evidence from New Zealand

New Zealand forests burn less frequently than tussock grasslands,heath or shrublands. Species composition, past disturbance andstand condition determine inflammability and fuel load, andconsequent fire intensity and spatial extent. Before peoplearrived, fires were ignited by lightning during drought yearson the eastern sides of both islands. Volcanism occurring every300–600 years was associated with fires in the centralNorth Island. A review of radiocarbon-dated charcoal from theeastern South Island, and of evidence for fire in pollen profilesfrom the North Island, provide the basis for an assessment offire frequency. Forest fires have occurred on both New Zealand'sislands throughout the Holocene at least every few centuries,until the last millennium when frequency increased. The ‘returntime’ of fire at any one place in the forested landscapewas probably one or two millennia. Burned areas usually succeededto forest again before the next inflagration. Consequently fireadaptation is infrequent in the New Zealand flora, and Polynesianforest clearance was rapid and largely permanent. There is anindication of an increase in fire frequency in the late Holocene,and a clear signal associated with people approx. 700 yearsBP. Separating the earliest anthropogenic fires from the backgroundlevel of natural burning will be difficult without additionalevidence.Copyright 1998 Annals of Botany Comapny Fire history, New Zealand, palynology, Maori, climate, volcanism.     

A Retrospective Analysis of the Establishment and Dispersal of the Introduced Australian Parasitoids Xanthopimpla rhopaloceros (Krieger) (Hymenoptera: Ichneumonidae) and Trigonospila brevifacies (Hardy) (Diptera: Tachinidae) within New Zealand

Two Australian parasitoids, Xanthopimpla rhopaloceros (Krieger) and Trigonospila brevifacies (Hardy), were introduced to New Zealand to control the light-brown apple moth (Epiphyas postvittana Walker). Dispersal by the parasitoids has since occurred naturally and with the aid of releases in fruit-growing areas. The present geographical range of the parasitoids includes all the North Island and some offshore islands to latitude 41 20 S. X. rhopaloceros is also present to latitude 41 48 S in the South Island. Comparisons of these distributions with those in Australia indicate that climatic conditions may have played a major role in the areas of establishment of both species in New Zealand. The mean winter temperature may be a limiting factor in the dispersal of T. brevifacies and X. rhopaloceros in New Zealand. Other factors that have probably aided the successful dispersal of the parasitoids include the wide distribution of host Tortricidae and the occurrence of tortricid host plants. The areas of New Zealand that appear suitable for further colonization by T. brevifacies include northern areas of the South Island, and both parasitoids could disperse further into suitable climate areas of the east and west coasts of the central South Island. The rate of dispersal for X. rhopaloceros was estimated at 13-24 km/year, and for T. brevifacies at 8-15 km/year.     

Extensive genetic differentiation in Gobiomorphus breviceps from New Zealand

Partial mitochondrial DNA sequences for parts of the cytochrome b gene and control region were obtained for 89 upland bullies Gobiomorphus breviceps from 19 catchments in New Zealand. There were two highly distinctive mtDNA clades: a northern clade corresponding to the North Island, northern South Island and west coast South Island, and a south‐east clade, in the southern and eastern South Island. Within these major clades there were further distinct clades that correlated with geographic sub‐regions and catchments. The marked genetic differentiation has occurred in the absence of obvious morphological divergence. Based on cytochrome b sequence divergences and the molecular clock hypothesis, the northern and southeastern clades correspond with the uplift of the Southern Alps during the Pliocene, while populations in the North Island and northern South Island were estimated to have diverged during the Pleistocene. The widescale geographic divergences were similar to those observed in the galaxiids, Galaxias vulgaris and Galaxias divergens , but biogeographic management boundaries may not be the same, reflecting different evolutionary histories for non‐diadromous species occupying the same areas.     

Is Didymosphenia geminata an introduced species in New Zealand? Evidence from trends in water chemistry,and chloroplast DNA

Defining the geographic origins of free‐living aquatic microorganisms can be problematic because many such organisms have ubiquitous distributions, and proving absence from a region is practically impossible. Geographic origins become important if microorganisms have invasive characteristics. The freshwater diatom Didymosphenia geminata is a potentially ubiquitous microorganism for which the recent global expansion of nuisance proliferations has been attributed to environmental change. The changes may include declines in dissolved reactive phosphorus (DRP) to low levels (e.g., <2 mg/m³) and increases in dissolved inorganic nitrogen (DIN) to >10 mg/m³ because both these nutrient conditions are associated with nuisance proliferations of D. geminata. Proliferations of D. geminata have been observed in South Island, New Zealand, since 2004. We aimed to address the ubiquity hypothesis for D. geminata in New Zealand using historical river water nutrient data and new molecular analyses. We used 15 years of data at 77 river sites to assess whether trends in DRP or DIN prior to the spread of D. geminata were consistent with a transition from a rare, undetected, species to a nuisance species. We used new sequences of chloroplast regions to examine the genetic similarity of D. geminata populations from New Zealand and six overseas locations. We found no evidence for declines in DRP concentrations since 1989 that could explain the spread of proliferations since 2004. At some affected sites, lowest DRP occurred before 2004. Trends in DIN also did not indicate enhanced suitability for D. geminata. Lack of diversity in the chloroplast intergenic regions of New Zealand populations and populations from western North America is consistent with recent dispersal to New Zealand. Our analyses did not support the proposal that D. geminata was historically present in New Zealand rivers. These results provide further evidence countering proposals of general ubiquity in freshwater diatoms and indicate that, as assumed in 2004, D. geminata is a recent arrival in New Zealand.     

Historical biogeography of the New Zealand freshwater crayfishes (Parastacidae,Paranephrops spp.): Restoration of a refugial survivor?

Abstract

New Zealand's two species of freshwater parastacid crayfishes have allopatric distributions, with one species in the North Island and northwestern South Island and the other in the eastern and southern South Island and Stewart Island. This gives the appearance of a vicariance event driven by uplift of the Southern Alps beginning in the Pliocene, and of former land connections across both Cook Strait and Foveaux Strait. However, separation of the two species may date from before the Southern Alps were formed. A diverse series of historical geological events is invoked to explain details of the distributions of these two species. Absence of Paranephrops from intermontane valleys of eastern flanks of the Southern Alps is notably different from patterns seen in freshwater fish species.     

Distribution and movements of Buller's albatross (Diomedea bulleri) in Australasian seas

Abstract

The distribution and movements of Buller's albatross in Australasian seas are analysed using results of shipborne surveys (13 238 10‐min counts), counts from trawlers, banding data, recoveries on beaches and fishing vessels, and records from the literature. Patterns of marine distribution are documented by monthly accounts and maps. During the breeding season, highest abundances are recorded over shelves and slopes off southern New Zealand (The Snares shelf to 41–43°S off the South Island, D. b. bulleri), around the Chatham Islands and over oceanic subtropical waters east of New Zealand (probably D. b. platei), with marked seasonal variations observed off southern New Zealand. Both subspecies disperse mostly outside Australasian waters during the non‐breeding season. Birds banded on The Snares were recovered off south‐eastern New Zealand (Stewart Island to Cook Strait) and in the eastern tropical Pacific. Immatures accounted for only 0.25% of birds censused during the ship‐borne surveys; they are recorded around the New Zealand mainland in August‐October and February‐May, off south‐eastern Australia and in the Tasman Sea in November‐December, February, and June‐July. Around New Zealand, males predominate among birds recovered along the eastern seaboard, whereas the sex ratio in south‐western waters tends to vary according to water depth and season. Distribution patterns and movements in New Zealand and Australian seas are discussed in relation to breeding events and breeding status.     

Predictors of invasion success by Daphnia species: influence of food, temperature and species identity

Non-indigenous North American Daphnia ‘pulex’ has recently invaded lakes and reservoirs in South Island, New Zealand, that formerly contained only native Daphnia carinata. New Zealand is characterised by a wide range of freshwater ecosystems and low species diversity of planktonic crustaceans, particularly Cladocera. The potential success of a species to invade and establish in a new community is likely to be predicted more accurately when reproductive response norms and fitness of key resident species, as well as the non-indigenous species, have been established under a range of relevant environmental conditions. Based on the results of experiments to test aspects of reproduction and fitness of the invader, D. ‘pulex’, and D. carinata when grown together at a range of relevant temperatures (8–23 °C) and related photoperiods, I predict the species-specific potential of D. ‘pulex’ to be dispersed and colonise New Zealand lentic habitats, and the potential of D. carinata to persist with the invader in these habitats. Larger population densities of D. ‘pulex’ compared to D. carinata at higher temperatures and food level, and larger densities of D. carinata at low temperatures, imply a potential for both species to coexist in New Zealand lakes, facilitated by seasonal succession; increased water temperature and nutrient input associated with climate and land use changes appear likely to promote the wider establishment of D. ‘pulex’, with both negative and positive implications for the conservation and management of New Zealand’s freshwater ecosystems.     

Phylogeography of a high‐dispersal New Zealand sea‐star: does upwelling block gene‐flow?

New Zealand's (NZ) geographical isolation, extensive coastline and well-characterized oceanography offer a valuable system for marine biogeographical research. Here we use mtDNA control region sequences in the abundant endemic sea-star Patiriella regularis to test the following literature-based predictions: that coastal upwelling disrupts north-south gene flow and promotes population differentiation (hypothesis 1); and that an invasive Tasmanian population of the species was introduced anthropogenically from southern New Zealand (hypothesis 2). We sequenced 114 samples from 22 geographical locations, including nine sites from North Island, nine from South Island, one from Stewart Island and three from Tasmania. Our analysis of these sequences revealed an abundance of shallow phylogenetic lineages within P. regularis (68 haplotypes, mean divergence 0.9%). We detected significant genetic heterogeneity between pooled samples from northern vs. southern New Zealand (FST = 0.072; P = 0.0002), consistent with the hypothesis that upwelling disrupts gene flow between these regions (hypothesis 1). However, we are currently unable to rule out the alternative hypothesis that Cook Strait represents a barrier to dispersal (North Island vs. South Island; FST = 0.031; P = 0.0467). The detection of significant spatial structure in NZ samples is consistent with restricted gene flow, and the strong structure evident in northern NZ may be facilitated by distinct ocean current systems. Four shared haplotypes and nonsignificant differentiation (FST = 0.025; P = 0.2525) between southern New Zealand and Tasmanian samples is consistent with an anthropogenic origin for the latter population (hypothesis 2).     

Use of ISSR profiles and ITS-sequences to study the biogeography of alpine cushion plants in the genus Raoulia (Asteraceae)

Nuclear ITS sequences and ISSR profiles provide evidence that Raoulia rubra is endemic to the Tararua Range in the southern part of the North Island of New Zealand. Populations in the South Island previously ascribed to R. rubra are better ascribed to R. eximia. Our findings suggest that glaciation of the central mountains of the South Island during the last ice age have had a major impact on the evolution of the South Island cushion Raoulia species in New Zealand. However, simple hypotheses accounting for the effect of Pleistocene climate change are insufficient to explain patterns of endemism in the group.     

Conservation of New Zealand's tussock grassland moth fauna

New Zealand has a relatively rich moth fauna associated with tussock grasslands, reflecting the historic importance of plant communities containing native grasses in the New Zealand landscape. Extensive grassland communities were most common in the eastern and central regions of New Zealand’s South Island where what now remains of these communities is contained within more than 350 Pastoral Leases managed for pastoral farming. Because these various grassland communities are distributed from coastal areas to the limit of vegetation on mountains there has been an uneven human impact. Grasslands at sea-level (including those on sand dunes and alluvial plains) have almost been eliminated while those in montane valleys have until now escaped intensive development. Alpine grasslands, like those of montane areas are now much less woody as a result of both Polynesian and more recent burning. From the late 1970s, based on public concern that continuing development was eliminating the natural landscapes and conservation values of the distinctive tussock grasslands of the South Island, a concerted programme of identification of the broad conservation values of the remaining grassland dominated regions was initiated. Implementation of the recommendations in the resulting published reports relating to priority areas for conservation and the subsequent full-scale review of Pastoral Leases has resulted in the formation of large grassland Conservation Parks and the reservation of a multitude of smaller areas, based on a suite of recreation, landscape and biological values. This important ongoing Tenure Review process has important implications for the conservation of tussock grassland biota including numerous native moths and their habitats.     

Reconstructing spatial vulnerability to forest loss by fire in pre‐historic New Zealand

Aim Despite small and transient populations, early Māori transformed large areas of New Zealand's forest landscapes. We sought to isolate the biophysical predictors that explain forest loss in the pre‐historic (i.e. pre‐European) period in New Zealand. Location New Zealand. Methods We used resampled boosted regression trees to isolate the key predictors of forest loss from a suite of 19 topographic, climatic, soil‐related and archaeological predictors at a 1‐km spatial resolution across New Zealand. Results The key predictors of fire‐driven forest loss during New Zealand's pre‐history relate to moisture and elevation gradients, with sites characterized by low moisture levels and gentle slopes being most vulnerable. Proxies for human activity were important in the North Island, where Māori population densities were higher, but not the South Island. The predicted pattern of forest loss and its relationship with biophysical variables suggest that early Māori neither deliberately protected fire‐prone regions nor systematically burnt less fire‐prone ones. Main conclusions Before Māori settlement of New Zealand fire was naturally rare, despite biophysical conditions being conducive to fire spread. The introduction of an ignition source by humans made widespread forest loss inevitable, even in the absence of sustained and deliberate use of fire. Rapid forest loss at the time of human settlement is recurrent across eastern Polynesia, so understanding this dynamic in New Zealand has implications for the region as a whole.     

Phylogeography and ecological niche modelling implicate coastal refugia and trans‐alpine dispersal of a New Zealand fungus beetle

The Last Glacial Maximum (LGM) severely restricted forest ecosystems on New Zealand’s South Island, but the extent of LGM distribution for forest species is still poorly understood. We used mitochondrial DNA phylogeography (COI) and ecological niche modelling (ENM) to identify LGM refugia for the mycophagous beetle Agyrtodes labralis (Leiodidae), a forest edge species widely distributed in the South Island. Both the phylogenetic analyses and the ENM indicate that A. labralis refuged in Kaikoura, Nelson, and along much of the South Island’s west coast. Phylogeography of this species indicates that recolonization of the largely deforested east and southeast South Island occurred in a west–east direction, with populations moving through the Southern Alps, and that the northern refugia participated little in interglacial population expansion. This contradicts published studies of other New Zealand species, in which recolonization occurs in a north–south fashion from many of the same refugia.     

Two species of adventive weevil (Coleoptera: Curculionidae) from Europe,hitherto unrecorded from New Zealand

Two curculionid weevils, Orthochaetes setiger (Beck, 1817) and Exomias pellucidus (Boheman, 1834) are recorded in New Zealand for the first time. The former has a wide distribution through the eastern South Island, while the latter has so far only been located in a single suburban garden in Dunedin. Both species are polyphagous and flightless. Although neither is expected to cause notable economic damage, their potential to invade native ecosystems makes them worthy of further investigation.     

Phylogeography of Australian and New Zealand spray zone spiders (Anyphaenidae: Amaurobioides): Moa's Ark loses a few more passengers

Amaurobioides are restricted to the spray zone of southern continents, where they live in small, isolated populations and hunt from silk retreats built in rock crevices. A Star BEAST species tree based on ITS1 nuclear and ND1 mitochondrial genes did not support the hypothesis that this unusual niche linked the evolutionary history of these spiders to geological events reshaping Gondwana into present‐day Australia and New Zealand. Instead, it showed that Amaurobioides reached Australia approximately 4.5 Mya and dispersed twice to New Zealand. Approximately 2.37 Mya, spiders from Tasmania colonized the Deep South of the South Island and, approximately 0.38 Mya, those from South Australia colonized more northern regions. Thus, the present study further limits the scope of the Moa's Ark hypothesis of vicariant New Zealand biogeography.     

Determinants of regional and local patterns in the floras of braided riverbeds in New Zealand

Aim To determine the composition and biogeographical origins of the native and naturalized flora of braided shingle riverbeds in New Zealand and whether the proportion of naturalized species is greater than in similar habitats elsewhere in the world. To test whether regional species pools, landscape matrix configuration, and local riverbed environment are all equally important in determining community structure in these systems. Location The braided reaches of four catchments on each of the eastern and western sides of North Island and South Island, New Zealand. Methods Plotless records of all native and naturalized seed plant and fern species on disturbed mobile surfaces were made over the length of four rivers. Altitude, climate variables, riverbed attributes, and surrounding land‐cover from maps were recorded for each site. For all species, the taxonomy, life form, origin and history, and presence within the province through which the rivers flowed, was obtained from published floras. Direct and indirect ordination and variance partitioning were employed to examine how native and naturalized species composition varies among and within rivers, and the degree to which this variation reflects climate, characteristic of riverbeds, and the surrounding land‐cover. Regression was used to determine how much introduction date and native geographical range influence the frequency of naturalized species. Results The total riverbed flora of 289 species comprises 40% native species and 60% naturalized species, both dominated by Asteraceae and Poaceae. The relative contributions of other plant families differ, and the two groups comprise different life‐form spectra. Native species occur across fewer rivers (mean 1.6 rivers) than naturalized species (mean 2.1 rivers). Species common in at least one river system tend to be widespread, occurring in at least three rivers. The rivers differ in their floras, with distinctions between North Island and South Island, and eastern and western rivers. The South Island rivers have more native species and a higher proportion of their regional native species pools than North Island rivers, whereas they have a lower proportion of their naturalized species pools. Introduction date and native geographical range are correlated with frequency of individual naturalized species. Geographical position and climate, riverbed variables of substrate size and seepage presence, and the type of adjacent land‐cover, differ between rivers and are significantly related to species composition. Land‐cover variables alone account for 46% of the explained variation in species composition, environmental variables alone 32% and components of the environment and land‐cover that co‐vary, 22%. Main conclusions New Zealand shingle riverbeds are among the riparian communities in the world most invaded by naturalized species but comparisons are difficult because studies of similar riverbeds are rare. New Zealand riverbeds are dominated by short‐lived terrestrial species from Eurasia. Native species are most frequent in South Island rivers draining extensive high mountains, and their abundances are determined to a greater extent by riverbed processes than are those of the naturalized species, which are more abundant when the surrounding landscape is modified. The distribution of the naturalized flora is not yet at equilibrium with the environment. Each river has a distinctive flora determined by ambient environmental factors, aspects of the riverbed environment itself, adjacent land‐cover reflecting the presence of native vegetation, the intensity of human modification or use, and invasion history.