Search

Estuaries are productive ecosystems that are vulnerable to human impacts and environmental disturbances. Estuaries are often inhabited by foundation species that facilitate other organisms by creating and modifying habitats. However, spatiotemporal variability and underpinning drivers of facilitation from estuarine foundation species are poorly studied, especially in the context of monitoring and conservation. Here, we combined the analyses of satellite, drone, and camera images, close‐up field sampling of quadrats and individuals, and laboratory microscopy, to quantify co‐occurrences between the cockle Austrovenus stutchburyi and green macroalga Ulva spp., and their associated invertebrate communities, across spatial resolutions and environmental gradients in a New Zealand estuary. We found higher abundance of Ulva in winter and higher abundance of Austrovenus at a site near the ocean. Furthermore, Ulva was, across space and time, often attached to Austrovenus, either live or dead shells, suggesting a hierarchy between a primary (cockle) and secondary (macroalgae) foundation species. Finally, Ulva provided a better habitat for mobile invertebrates than Austrovenus, and thereby increased estuarine diversity through a density‐dependent facilitation cascade, which also was consistent in space and time. Overall, our study showed that facilitation cascades can be indirectly inferred and monitored through remote sensing of foundation species using supplementary imaging methods, and that integration of data across scales allows researchers to better understand the drivers and consequences of facilitation from foundation species. These insights may aid in the development of efficient monitoring strategies and ultimately improve the management of estuarine ecosystems. [ABSTRACT FROM AUTHOR]

Sea urchin overgrazing has caused widespread phase shifts from kelp forests to "urchin barrens" on many temperate reefs, reducing habitat complexity, productivity, and biodiversity. Sea urchin removal is increasingly used for kelp restoration; however, few studies have quantified the efficiency and effectiveness of different removal methods, resulting in limited understanding of their practicality. In this study, the efficiency (removal rate) and effectiveness (proportion removed) of four removal methods were evaluated in northeastern New Zealand. We compared culling or collecting sea urchins by either SCUBA or freediving in 128 small‐scale plots (25 m2). We also evaluated the efficiency and effectiveness of culling in four large (1.6–2 ha) barren areas, scales relevant for restoration. On average, culling sea urchins was 1.9–4.4 times faster than collecting, and SCUBA was 1.5–3.3 times faster than freediving. Removal rates increased with sea urchin density, especially for culling on SCUBA, while freediving removal rates increased with experience. Effectiveness was lower in large‐scale removals (86–93% of sea urchins ≥40 mm removed) compared to small‐scale removals (98–99%), but sufficient for restoration objectives. Estimated time per area (using SCUBA culling) was similar across large‐scale removals (49–57 hours/ha), despite an almost 2‐fold variation in initial sea urchin densities (approximately 4–8 urchins/m2), suggesting area may better predict total removal time than simply number of sea urchins across low‐density ranges. While sea urchin removal provides a rapid, feasible, and effective approach to restoring kelp in urchin barrens, restoration plans need to also address the causes of sea urchin overpopulation to ensure long‐term benefits. [ABSTRACT FROM AUTHOR]

Understanding the responses of organisms to different environmental drivers is critical for improving ecosystem management and conservation. Estuarine ecosystems are under pressure from multiple anthropogenic stressors (e.g. increasing sediment and nutrient loads, pollution, climate change) that are affecting the functions and services these ecosystems provide. Here, we used long-term estuarine benthic invertebrate monitoring data (∼30 year time-series) to evaluate the responses of macrobenthic invertebrate communities and indicator species to climatic, oceanic, freshwater, and local environmental drivers in New Zealand estuaries. We aimed to improve our ability to predict ecosystem change and understand the effects of multiple environment drivers on benthic communities. Our analyses showed that the abundance and richness of macrobenthic fauna and four indicator taxa (bivalves known to have differing tolerances to sediment mud content: Austrovenus stutchburyi , Macomona liliana , Theora lubrica , and Arthritica bifurca) responded to unique combinations of multiple environmental drivers across sites and times. Macrobenthic responses were highly mixed (i.e., positive and negative) and site-dependent. We also show that responses of macrobenthic fauna were lagged and most strongly related to climatic and oceanic drivers. The way the macrobenthos responded has implications for predicting and understanding the ecological consequences of a rapidly changing environment and how we conserve and manage coastal ecosystems. • Long-term estuarine monitoring data (∼30 yrs) was used to evaluate the responses of macrofauna to environmental drivers. • Macrofauna responded to unique combinations of multiple environmental drivers. • Macrofaunal responses to environmental drivers were idiosyncratic and site-mediated. • Macrofaunal responses were mostly related to lagged permutations of climatic and oceanic drivers. • We highlight the complexity of predicting macrofauna responses to environmental change. [ABSTRACT FROM AUTHOR]

In settler-colonial nations such as Aotearoa, New Zealand, ecosystem degradation and restoration of coastal estuaries and their catchments are typically framed through a scientific lens and often privilege patriarchal beliefs and epistemologies. A consequence of colonization in Aotearoa is that sediment(ation) pollution is deemed undesirable, and science is needed to control and solve such ecosystem challenges. However, there remains a tendency to prioritize science over other ways of knowing. Therefore, ecosystem management strategies and restoration practices fail to attend to the dynamics of social differentiation within Indigenous groups concerning settler-colonial power. Indigenous peoples bring nuanced ways of knowing and being whereby relational ontologies and ethics are imperative starting points. Relational ontologies reshape knowledge production to ensure more ethical and just relationships with nature. We use an intersectional lens to highlight the gendered, ethnic, and natured dimensions of sediment(ation) pollution. We show how pollution manifests differently across intimate scales (body, local), demonstrating the far-reaching effects of settler-colonialism violence. This article presents Indigenist geo-creative narratives from four Māori women regarding their lived experiences and realities of sediment(ation) pollution. Using practices familiar to and chosen by them, narratives are richly nuanced, political and recalled in relational and affective terms. We intend to disrupt and bring forth a relational vision of sediment(ation) pollution as a socially just and equitable way of managing and restoring ecosystems. [ABSTRACT FROM AUTHOR]

Floodplain ecosystems are focal points for human settlement, and consequently are often subjected to extensive modification and infrastructure development. Establishment of non‐native species in floodscapes presents a range of challenges when they become problematic and drive changes in native aquatic communities and ecosystems. These non‐native species are often tolerant of reduced water and habitat quality, conferring a competitive advantage over native species. The coupled effects of invasive alien species, landscape modification and floodscape hydrological control collectively reduce ecological resilience, creating feedback loops that reinforce negative effects on native fish. The regulated lower Waikato River floodplain is a New Zealand hotspot for fish introductions, with their proliferation exacerbating the effects of agricultural development, urban expansion, and flood control infrastructure. We argue that the resilience of native fish assemblages to these pressures can be improved through utilizing a series of complementary measures, including enhanced catchment management, strategic alterations to the location, design, and operation of floodplain infrastructure (e.g., gates, pumpstations, and stopbanks), habitat restoration for native fish, and targeted management of invasive species. These measures will need to consider the likely persistence of invasive alien fish, however, to limit their expansion in the face of a changing climate. Although knowledge and implementation gaps exist, tying these strands together presents an opportunity to enhance the resilience of native fisheries into the future. Key to success will be re‐thinking floodplain management to include ecosystem services, and this will require ongoing commitment and cooperation amongst all stakeholders to address knowledge gaps and enable effective implementation. Plain Language Summary: River floodplains are important areas for human settlement, and as a result have been modified for urban, agricultural, and other infrastructure development. Associated water and habitat quality declines aid the proliferation of non‐native species in these vulnerable ecosystems, and contribute to further impacts on native biodiversity. Here, we discuss the ecological consequences of the combined effects of invasive alien fish species, landscape modification and flood control infrastructure in the context of the Waikato River floodplain, New Zealand, which is a hotspot for fish introductions. We explore a series of measures to make improvements for native fish species, including enhanced catchment management, strategic alterations to the location, design, and operation of infrastructure within the floodplain, habitat restoration for native fish, and targeted management of invasive species. Although knowledge and implementation gaps exist, collaboratively tying these strands together presents an opportunity to improve the survival and health of native fish populations now and into the future. Key Points: Complex biotic and abiotic interactions between invasive fish species and floodplain infrastructure have impacted native fish communitiesOpportunities exist to increase ecological resilience of native fish species in modified floodplainsImproving conditions for native species will require control of invasive alien species and modification to existing floodplain management [ABSTRACT FROM AUTHOR]

Over the past 1000 years New Zealand has lost 40–50% of its bird species, and over half of these extinctions are attributable to predation by introduced mammals. Populations of many extant forest bird species continue to be depredated by mammals, especially rats, possums, and mustelids. The management history of New Zealand's forests over the past 50 years presents a unique opportunity because a varied program of mammalian predator control has created a replicated management experiment. We conducted a meta‐analysis of population‐level responses of forest birds to different levels of mammal control recorded across New Zealand. We collected data from 32 uniquely treated sites and 20 extant bird species representing a total of 247 population responses to 3 intensities of invasive mammal control (zero, low, and high). The treatments varied from eradication of invasive mammals via ground‐based techniques to periodic suppression of mammals via aerially sown toxin. We modeled population‐level responses of birds according to key life history attributes to determine the biological processes that influence species' responses to management. Large endemic species, such as the Kaka (Nestor meridionalis) and New Zealand Pigeon (Hemiphaga novaeseelandiae), responded positively at the population level to mammal control in 61 of 77 cases for species ≥20 g compared with 31 positive responses from 78 cases for species <20 g. The Fantail (Rhipidura fuliginosa) and Grey Warbler (Gerygone igata), both shallow endemic species, and 4 nonendemic species (Blackbird [Turdus merula], Chaffinch [Fringilla coelebs], Dunnock [Prunella modularis], and Silvereye [Zosterops lateralis]) that arrived in New Zealand in the last 200 years tended to have slight negative or neutral responses to mammal control (59 of 77 cases). Our results suggest that large, deeply endemic forest birds, especially cavity nesters, are most at risk of further decline in the absence of mammal control and, conversely suggest that 6 species apparently tolerate the presence of invasive mammals and may be sensitive to competition from larger endemic birds. Article impact statement: Management of introduced mammals across New Zealand has preferentially benefited large and endemic forest birds. [ABSTRACT FROM AUTHOR]

Sustaining ecosystem services (ES) is a key interest in the management of land use in multifunctional landscapes (i.e. ES that support ecosystem function and sustain human livelihoods). In making land management decisions, it is important to understand the relationships and spatial distributions of multiple ES, and the synergies and trade-offs between them. We analysed nine ES in a catchment in the Bay of Plenty region, New Zealand, to identify areas in the catchment are high (hotspots) and low (coldspots) in supplying multiple ES, the relationships among ES, and where ES trade-offs and synergies occur. We found ES hotspots occurred mainly in indigenous forest. Synergies occurred among provisioning services (milk and meat) and dis-service nitrogen leaching as well as synergies with carbon sequestration and wood supply. Trade-offs occurred between regulating services and a supporting service. We identified ES bundles (services that occur repeatedly together) of provisioning services and those associated with exotic forest. Spatial concurrences and relationships of different ES provide a way to optimise the supply of multiple ES. These results may be used to guide landscape management whereby spatial prioritisation can be used to conserve areas of high ES supply or bundles of ES. [ABSTRACT FROM AUTHOR]

Determining the factors driving population dynamics of stream salmonids across broad landscapes is important for understanding stream ecosystem functioning and for the management and conservation of the populations of such fish. A few studies have described the determinants of the early life history of salmonids across catchments, but none of them have examined how this spatial variation develops temporally.We hypothesised that: (1) spatiotemporal dynamics of young‐of‐the‐year (YoY) trout populations vary within the catchment, with loss rates (emigration plus mortality) being higher in lower elevation, downstream reaches than in higher elevation, upstream ones; and (2) loss rate would be density dependent, leading to reduced intra‐ and inter‐cohort competition and supporting establishment of resident populations.We tested the first hypothesis by examining relationships between geomorphic characteristics of spawning streams and temporal dynamics of YoY brown trout density, loss rate and biological traits through an austral summer across the catchment of New Zealand's fourth‐longest river, the Taieri River. To test the second hypothesis, we examined whether initial YoY density in spring and other biotic determinants affected loss rate and cohort structure dynamics, resulting in density‐dependent self‐thinning of YoY fish to avoid resource limitation.Spring YoY density and subsequent loss rate was higher in low elevation sites, corresponding to stream accessibility to migratory spawners. These significant correlations of YoY density and related biotic variables with elevation disappeared later in the season, indicating that regardless of their origin, brown trout YoY tend to form stream resident populations with multicohort structure and densities low enough to limit intraspecific competition.Our findings provide evidence that geomorphological features of the landscape affect temporal dynamics of YoY trout populations driven by density‐dependent self‐regulatory mechanisms that can control the abundance of growing fish. [ABSTRACT FROM AUTHOR]

Worldwide, introduced pest species create significant challenges to native biodiversity and individual health. New Zealand has an extensive history of attempting to protect biodiversity from introduced pests such as the Brushtail possum (Trichosurus vulpecula [Diprotodontia: Phalangeridae]). Success has been achieved on a small scale, but the transition to the whole country management poses new issues. Therefore, this review uses the framework of 'Predator Free 2050' to summarize current practices and scrutinize new technologies. Importantly, we include a toxicology focus to the discussion, providing detail on the mechanism(s) of action that inform decisions regarding the pros and cons for the use of various chemical agents. Currently, the New Zealand government supports the use of sodium fluoroacetate (1080) for predator control on a mass scale, but this comes with a social opposition that is not always reflective of the underlying science. Understanding this controversy is vital if new strategies are to be deployed to achieve large-scale pest management. We use New Zealand as a case study in this area because its unique and isolated ecosystem provides a global opportunity for understanding new technologies and best practice. [ABSTRACT FROM AUTHOR]

Indigenous people often manage natural environments and resources based on landscape features. Rights and management responsibilities that follow pathways of water from their source in alpine areas down and ultimately into and out to sea are common. Contemporary frameworks that seek to support management of the environment, ecosystems and resources from marine areas to alpine zones are not so connected.The East Otago Taiāpure and Waikouaiti Mātaitai are Customary Protection Areas (CPAs) that connect from fresh water into the marine environment. These CPAs fall within the cultural landscape of Kāti Huirapa ki Puketeraki, the hapū (sub‐tribe) of Ngāi Tahu, the iwi (tribe) who holds mana whenua (authority) over East Otago. CPAs may provide a way for iwi and hapū to manage a catchment as a whole, and to allow for traditional approaches to management within a contemporary legislative framework.Despite local successes in restoring habitat, changing legislation, gaining knowledge and building community support for change, fundamental issues remain. Members of the East Otago Taiāpure Committee reflect on the last 15 years of management and identify constraints and enablers of community‐led management across inherently connected ecosystems using a kaupapa Māori approach. A compartmentalized view of connected ecosystems, complex legislation and government‐focused processes emerge as issues that make even seemingly simple issues complicated for community managers.If locally led management models are to work, continuity of the relationships between government agencies and the community, an understanding of the long‐term and connected view of community groups, resourcing and support beyond the issue of the day, and clear pathways to affect change are key.For true community‐led ecosystem management to be effective, we must focus on the needs and the perspectives of the community and move away from structures designed to ease the role of government in managing natural resources and the environment. [ABSTRACT FROM AUTHOR]

The article discusses the issues that consenting authorities face in implementing their statutory functions around maintenance and protection of indigenous biodiversity in New Zealand. It further discusses focusing on the professional practice and implementation of Ecological Impact Assessment (EciA); loss of habitats supporting indigenous ecosystems and species; and the Protected Natural Areas Program (PNAP) for the maintenance of all indigenous biodiversity.

Conservation of the endangered yellow-eyed penguin (Megadyptes antipodes) in New Zealand has principally sought to manage terrestrial threats, while relatively little has been done to understand or address marine threats, such as reduced prey availability, commercial fisheries interactions, and habitat destruction. We assessed spatial similarities between mainland yellow-eyed penguin marine distribution and resources (prey), risks (fisheries interactions), and areas of refugia (marine protected areas, MPAs). We determined if suitable penguin foraging habitat, based on environmental predictors using a Maxent species distribution model (SDM), also supports a high diversity of key prey species identified using a stacked SDM. We also created a novel index to predict areas of potential commercial fisheries interactions and mapped the overlap of penguin distribution and MPAs. Areas along the middle of the continental shelf had the highest prey diversity and probability of penguin presence, which overlapped with gillnet fisheries in these regions. Suitable penguin habitat also overlaps with trawl fisheries inshore along much of the South Island coast. <1 % of the penguin range overlaps with current MPAs, and the proposed South-East Marine Protected Areas network would protect only 3.6 % of the current penguin foraging distribution. This study takes an ecosystem approach to assess complex interactions between commercial fisheries, marine ecosystems, and MPAs, which is urgently required for marine spatial planning and adaptive ecosystem management of not only this endangered seabird but for southeast New Zealand coastal habitat and biota also. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ecosystem-based management (EBM) was integrated with geodesign framework. • Collaboration with the farmers was carried out to obtain farm information and co-design the landscapes. • Multifunctional farmed landscapes (MFC) can provide a wide range of ES and meet multiple demands. • Increasing landscape diversity and complexity is a key to achieving more sustainable MFC. • The integration of EBM and geodesign is an effective approach for sustainable MFC planning. An ecosystem-based management approach (EBM) is suggested as one solution to help to tackle environmental challenges facing worldwide farming systems whilst ensuring socio-economic demands are met. Despite its usefulness, the application of this approach at the farm-scale presents several implementation problems, including the difficulty of (a) incorporating the concept of ecosystem services (ES) into agricultural land use decision-making and (b) involving the farmer in the planning process. This study aims to propose a solution to overcome these challenges by utilising a geodesign framework and EBM approach to plan and design a sustainable multifunctional agricultural landscape at the farm scale. We demonstrate how the proposed approach can be applied to plan and design multifunctional agricultural landscapes that offer improved sustainability, using a New Zealand hill country farm as a case study. A geodesign framework is employed to generate future land use and management scenarios for the study area, visualize changes, and assess the impacts of future land use on landscape multifunctionality and the provision of associated ES and economic outcomes. In this framework, collaboration with the farmer was carried out to obtain farm information and co-design the farmed landscapes. The results from our study demonstrate that farmed landscapes where multiple land use/ land cover types co-exist can provide a wide range of ES and therefore, meet both economic and environmental demands. The assessment of impacts for different land use change scenarios demonstrates that land use change towards increasing landscape diversity and complexity is a key to achieving more sustainable multifunctional farmed landscapes. The integration of EBM and geodesign, is a transdisciplinary approach that can help farmers target land use and management decisions by considering the major ES that are, and could be, provided by the landscapes in which these farm systems are situated, therefore maximising the potential for beneficial outcomes. [ABSTRACT FROM AUTHOR]

To investigate regional drivers of spatial patterns in macro- and meio-faunal community structure (abundance, biomass and taxonomic diversity) and ecosystem function (sediment community oxygen consumption [SCOC]), we sampled two regions in close proximity on New Zealand's continental margin—the Chatham Rise and the Challenger Plateau. Sites (n= 15) were selected in water depths ranging from 266–1212 m to generate a gradient in sedimentary properties and, in particular, surface pelagic productivity. Both macro- and meio-fauna abundance and biomass was 2–3.5 times higher on the Chatham Rise than on the Challenger Plateau, reflecting regional differences in pelagic primary production. We also found significant inter- and intra-regional differences in macro-fauna taxonomic diversity with two distinctive site groupings in each region. Univariate and multivariate measures of macro-fauna community attributes were most strongly correlated with sediment photosynthetic pigment (explaining 24%–59% of the variation). Sediment pigment content was as equally important in explaining meio-fauna community structure (36%–7%). Unlike community structure, SCOC was most strongly correlated with depth (44%), most likely reflecting temperature effects on benthic metabolism. Our results highlight the importance of a benthic labile food supply in structuring infaunal communities on continental margins and emphasise a tight coupling between pelagic and benthic habitats. [ABSTRACT FROM PUBLISHER]

One quarter of all terrestrial native bird species have become extinct since human arrival in New Zealand, leading to a pervasive silence in many natural environments due to the decrease in native bird song. Passive acoustic techniques are a potential tool for environmental monitoring, especially for testing whether the control of mammals can reverse the 'silent forest' effect. Here we compare soundscapes from two nearby sites within the Waitakere Ranges Regional Park, New Zealand, that have contrasting predator control levels: one with high-level pest mammal control, and the other with low-level pest control. Measurements of twelve acoustic indices extracted from two seasons of passive acoustic recordings are split into 20 acoustic regions to identify which regions best discriminate between the two management regimes. We define the acoustic regions as units of analysis bounded by a specific time period and frequency range chosen to capture the main groups of biologically relevant acoustic events within a soundscape. Analysis of variance and pairwise comparisons indicated the acoustic region bounded from 9 pm to 11:59 pm and a range of 0.988–3.609 kHz in autumn presented the greatest differences between sites. The sounds responsible for these acoustic differences were generated by invasive mammals in the site with no pest control. Results also supports spring season as the most important for bird monitoring in New Zealand. Acoustic indices analysis did not detect a reversal of the "silence forest" effect in the site with high-level predator control. • Acoustic indices split into acoustic regions facilitate soundscape comparisons. • Acoustic regions are defined by frequency and time ranges. • Pest control did not reverse the silent forest effect in the Waitakere. • Acoustic regions enable detecting soundscape differences. [ABSTRACT FROM AUTHOR]

The paradigm shift to holistic management rests on the insight that exploitation affects all aspects of the ecosystem. While scholars and policy-makers all want ecosystem based management (EBM), few, if any, have achieved it in practice. Adaptive governance promises effective EBM, but guidance remains elusive. Looking back to an ecosystem people such as the indigenous Maori in the south of New Zealand and analyzing their resource management system using Ostrom's (1990) eight-principle framework for common property rights regimes allows us to answer three central questions. How did Ngai Tahu, the dominant tribe on the South Island, manage the complex linkages, uncertainty and interactions with nature while exploiting their environment? Was resource exploitation sustainable? And what can be drawn from their management system for modern governance structures? The application of Ostrom's framework shows that kaitiakitanga (stewardship) as an integrated management system generally aligns with the principles necessary for successful EBM and provided Ngai Tahu with the necessary tools to control and adapt measures across space and time, mirroring the modern tenets of adaptive management. Studying a people that practiced EBM successfully provides the insight that EBM may be achieved by governing ecosystems through an integrated common property management system. [Copyright &y& Elsevier]

Bruce Clarkson is recognised as one of New Zealand's foremost authorities on ecological restoration, with a research and management focus on restoring indigenous vegetation communities in cities. He urges optimism in the face of change, by emphasising the importance of long-term and broad-scale perspectives. [ABSTRACT FROM AUTHOR]

Untangling the relative influences of environmental filtering and biotic interactions on species coexistence at various spatial scales is a long-held issue in community ecology. Separating these processes is especially important to understand the influences of introduced exotic species on the composition of native communities. For this aim, we investigated coexistence patterns in New Zealand exotic and native birds along multiple-scale habitat gradients. We built a Bayesian hierarchical model, contrasting the abundance variations of 10 native and 11 exotic species in 501 point counts spread along landscape and local-scale gradients of forest structure and composition. Although native and exotic species both occurred in a wide range of habitats, they were separated by landscape-level variables. Exotic species were most abundant in exotic conifer plantations embedded in farmland matrices, while native birds predominated in areas dominated by continuous native forest. In exotic plantation forests, and to a lesser extent in native forests, locally co-occurring exotic and native species were segregated along a gradient of vegetation height. These results support the prediction that exotic and native bird species are segregated along gradients related to anthropogenic disturbance and habitat availability. In addition, native and exotic species overlapped little in a multivariate functional space based on 10 life history traits associated with habitat selection. Hence, habitat segregation patterns were probably mediated more by environmental filtering processes than by competition at landscape and local scales. [ABSTRACT FROM AUTHOR]

Understanding how plant communities respond to plant invasions is important both for understanding community structure and for predicting future ecosystem change. In a system undergoing intense plant invasion for 25 years, we investigated patterns of community change at a regional scale. Specifically, we sought to quantify how tussock grassland plant community structure had changed and whether changes were related to increases in plant invasion. Frequency data for all vascular plants were recorded on 124, permanent transects in tussock grasslands across the lower eastern South Island of New Zealand measured three times over a period of 25 years. Multivariate analyses of species richness were used to describe spatial and temporal patterns in the vegetation. Linear mixed-effects models were used to relate temporal changes in community structure to the level and rate of invasion of three dominant invasive species in the genus Hieracium while accounting for relationships with other biotic and abiotic variables. There was a strong compositional gradient from exotic- to native-dominated plant communities that correlated with increasing elevation. Over the 25 years, small-scale species richness significantly decreased and then increased again; however, these changes differed in different plant communities. Exotic species frequency consistently increased on some transects and consistently declined on others. Species richness changes were correlated with the level of Hieracium invasion and abiotic factors, although the relationship with Hieracium changed from negative to positive over time. Compositional changes were not related to measured predictors. Our results suggest that observed broad-scale fluctuations in species richness and community composition dynamics were not driven by Hieracium invasion. Given the relatively minor changes in community composition over time, we conclude that there is no evidence for widespread degradation of these grasslands over the last 25 years. However, because of continuing weed invasion, particularly at lower elevations, impacts may emerge in the longer term. [ABSTRACT FROM AUTHOR]

Abstract: The ecosystem services approach to resource management considers all services provided by ecosystems to all sections of the community. As such, it could be used to assess sustainability of human development and equity in resource use. To facilitate the approach, tools are required at the level of detail at which policy and management decisions are made. We have developed spatially explicit models of indicators of important ecosystem services in New Zealand: regulation of climate, control of soil erosion, regulation of water flow (quantity), provision of clean water (quality), provision of food and fibre, and provision of natural habitat. The models were developed using lookup tables from process-based models to allow rapid evaluation of land-use scenarios. We demonstrate the application of the models to assess ecosystem services in a simulation of hill-country afforestation in the Manawatu catchment, which has recently seen increasing soil erosion in the hills leading to sedimentation of waterways. Each ecosystem service was assessed by calculating the change in the indicator relative to two extremes. The ecosystem services with the largest relative changes were control of soil erosion, carbon sequestration, and provision of wood. [Copyright &y& Elsevier]

One method of enhancing the health of receiving water ecosystems is to ensure that local plans and practices guiding urban development are underpinned by appropriate design principles. This paper reports on a policy and practices framework developed in New Zealand, and investigates the uptake and implementation of Low Impact Urban Design and Development (LIUDD). A hierarchy of LIUDD principles has been developed as a foundation for policy development in statutory and non-statutory plans and guidelines. Each principle is accompanied by practical implementation methods using sustainable technologies in a local context. Greenfield developments in urban growth areas in the Netherlands, Australia and New Zealand are assessed with respect to elements of the framework. The assessments show that the LIUDD principles are relevant internationally across greenfield developments of similar town and catchment scales. Application of the principles can inform decision makers so that they become more critically aware of aquatic sustainability imperatives in the urban design and redevelopment process. [ABSTRACT FROM AUTHOR]

The article discusses the ecosystem principles approach (EPA) as a simplified method used in the management of goods and services in marine coastal ecosystems. It cites several local and international programs that led to the development of ecosystem goods and services, including the Study of Critical Environmental Problems (SCEP), the International Biological Programme, and the Convention of Biological Diversity (CBD). It presents the New Zealand Soft Sediment Marine Coastal System as an example of an EPA application.

The history of conifers introduced earlier elsewhere in the southern hemisphere suggests that recent invasions in Argentina, Brazil, Chile and Uruguay are likely to increase in number and size. In South Africa, New Zealand and Australia, early ornamental introductions and small forestry plantations did not lead to large-scale invasions, while subsequent large plantations were followed with a lag of about 20-30 years by troublesome invasions. Large-scale conifer plantation forestry in South America began about 50-80 years later than in South Africa, Australia and New Zealand, while reports of invasions in South America lagged behind those in the latter nations by a century. Impacts of invading non-native conifers outside South America are varied and include replacement of grassland and shrubland by conifer forest, alteration of fire and hydrological regimes, modification of soil nutrients, and changes in aboveground and belowground biotic communities. Several of these effects have already been detected in various parts of South America undergoing conifer invasion. The sheer amount of area planted in conifers is already very large in Chile and growing rapidly in Argentina and Brazil. This mass of reproductive trees, in turn, produces an enormous propagule pressure that may accelerate ongoing invasions and spark new ones at an increasing rate. Regulations to control conifer invasions, including measures to mitigate spread, were belatedly implemented in New Zealand and South Africa, as well as in certain Australian states, inspired by observations on invasions in those nations. Regulations in South America are weaker and piecemeal, but the existing research base on conifer invasions elsewhere could be useful in fashioning effective regulations in South America. Pressure from foreign customers in South Africa has led most companies there to seek certification through the Forestry Stewardship Council; a similar programme operates in Australia. Such an approach may be promising in South America. [ABSTRACT FROM AUTHOR]

This paper draws on a New Zealand case study, Motuihe Island, to examine the challenges of conserving cultural heritage in places renowned for natural heritage values. In keeping with the broader trend toward the ecological restoration of islands close to Auckland, Motuihe Island is undergoing conversion into an ecosystem of native flora and fauna. Issues and tensions relating to the management of natural and cultural heritage will be discussed and influencing aspects investigated: the nature/culture dualism, the effect of New Zealand's history and identity, and the influence of islandness on heritage management. [ABSTRACT FROM AUTHOR]

Many researchers have noted that not only natural ecosystems but also landscapes actively modified by humans (engineered or designed ecosystems) can significantly impact the level of ecosystem goods and availability of services, thereby impacting human and social welfare. In New Zealand, agricultural lands are the largest area of engineered ecosystems on the national landscape. Study of the welfare effects of ecosystem services delivered by agricultural land can provide important insights into the management of engineered or designed ecosystems. This paper uses the contingent valuation method (CVM) and choice modelling to estimate values of four key ecosystem services: climate regulation, water regulation, soil retention and scenic views, for New Zealand land used for arable farming. [ABSTRACT FROM AUTHOR]

Managing adequately the exploitation of commercial species subject to technical interactions is a key step towards the ecosystem approach to fisheries. We evaluate here, using a bio-economic modelling approach building on the ISIS-Fish simulation platform, the relative impact of total allowable commercial catches (TACC) and of taxes applicable to over-quota landings (deemed value) on the sustainability of a selection of species exploited by the New Zealand hoki (Macruronus novaezelandiae) fishery. We investigate some aspects of the hoki mixed fisheries, consisting of four fleets and nineteen métiers, by considering the technical interactions between hoki and Southern hake (Merluccius australis). The dynamics of effort allocation were modelled using gravity model, using value per unit of effort (VPUE) as attractivity coefficient. Several management scenarios, based on different levels of TACC, effort limits and deemed value have been defined. The impact of these strategies on spawning biomass and catches has been investigated. The results confirm that the deemed value may, in combination with TACC, be an efficient management tool. By increasing the hoki deemed value, we could somehow limit the decrease in the hoki TACC needed to harvest Western hoki sustainably. Constraining hoki fishing also restricts Southern hake fishing in the Chatham Rise and in the West Coast South Island, but leads to increased targeting of this species in the Sub-Antarctic area. The relative costs of renting/buying quota or paying the deemed value are most constraining when the hoki TACC is at relatively low level and when the hoki deemed value is more than 1.5 times the current value. [ABSTRACT FROM AUTHOR]

We attached 11 g (1.4% body-mass equivalent) global location sensing (GLS) archival tag packages to tarsi of 25 breeding sooty shearwaters (Puffinus griseus, titi) on Whenua Hou (Codfish Island), New Zealand during the chick-rearing period in 2005. Compared with chicks reared by non-handled adults that did not carry tags, deployment of tags on one or both adult parents ultimately resulted in 35% reduction in chick body mass and significantly reduced chick skeletal size preceding fledging (19 April). However, body mass between chick groups was not significantly different after controlling for skeletal size. Effects on chicks were more pronounced in six pairs where both parents carried tags. Chick mass was negatively related to the duration that adults carried tags. in this study, none of the chicks reared by pairs where both parents were tagged, 54% of chicks reared by pairs where one parent was tagged, and 83% of chicks reared by non-handled and non-tagged parents achieved a previously determined pre-fledging mass threshold (564 g; Sagar & horning 1998). Body mass of adults carrying tags and returning from trans-equatorial migration the following year were 4% lighter on average than non-tagged birds, but this difference was not statistically significant. Reduced mass among chicks reared by adults carrying tags during the chick-provisioning period indicated that adults altered "normal" provisioning behaviours to maintain their own body condition at the expense of their chicks. Population-level information derived from telemetry studies can reveal important habitat-linked behaviours, unique aspects of seabird foraging behaviours, and migration ecology. information for some species (e.g., overlap with fisheries) can aid conservation and marine ecosystem management. we advise caution, however, when interpreting certain data related to adult provisioning behaviours (e.g., time spent foraging, provisioning rates, etc.). if effects on individuals are of concern, we suggest shorter-term deployments, smaller and lighter tags, and alternative attachment techniques, especially when investigating threatened or endangered species. [ABSTRACT FROM AUTHOR]

This study of customary harvests of sooty shearwater Puffinus griseus chicks by Rakiura Maori compares the utility of Traditional Ecological Knowledge (TEK) and ecological science for understanding patterns in prey availability. We recorded TEK of 28 muttonbirders about emergence patterns and variation in chick size at different aspects of 14 breeding islands and in their coastal fringe compared to inland areas. Spatial and temporal variation of chick availability were measured using the methods of ecological science in the 2001 harvest season across Putauhinu island, south west of Rakiura, New Zealand. as predicted by TEK, titi emerged earlier from west than east coast locations on Putauhinu. Scientific measures were also consistent with an earlier emergence in coastal compared to inland areas as asserted by TEK, but conclusive inference is potentially confounded by movement of chicks between burrows just before fledging. A TEK construct predicting heavier chicks on the west coast was not supported by scientific measurements. We also measured the characteristics of areas preferred for harvesting so that we could gauge representativeness of the areas "sampled" by the muttonbirders to accumulate their TEK. Within forested habitat, areas harvested by muttonbirders had 62-65% higher chick density than unharvested areas. The muttonbirders concentrated harvesting where there was less ground cover and taller canopy cover and only hunted on nights and times of the season when harvesting was most profitable. Therefore, TEK may be less able to detect wider-scale variation and harvest impacts on prey in particular. Short runs of scientific information from spatially and temporally stratified sampling will complement and assist inference from longer term TEK. as shown in this case study, TEK and science often agree on pattern, but are likely to disagree on why a pattern exists. [ABSTRACT FROM AUTHOR]

O'Driscoll, R. L., Gauthier, S., and Devine, J. A. 2009. Acoustic estimates of mesopelagic fish: as clear as day and night? – ICES Journal of Marine Science, 66: 1310–1317.The pelagic ecosystem on the Chatham Rise east of New Zealand has been monitored annually using acoustic surveys since 2001. Most of the acoustic backscatter comes from diurnally migrating mesopelagic fish, which are the major prey of hoki (Macruronus novaezelandiae) and other valuable commercial species. Mesopelagic schools and layers typically occur at 100–400 m depth during the day and migrate above 200 m depth at night. Previous acoustic estimates of the biomass of mesopelagic fish on the Chatham Rise were based only on night-time estimates from the upper 200 m and may significantly underestimate actual biomass. Paired day–night comparisons found that an estimated 20% of the total daytime backscatter migrates to depths of 0–14 m at night, where it is too shallow to be detected by hull-mounted acoustic instruments. In contrast, there is a positive bias associated with acoustic estimates of mesopelagic organisms during the day because they can occur close to the bottom mixed with demersal fish. Two alternative approaches for estimating biomass of diurnally migrating mesopelagic species are suggested. The first applies a correction based on the estimated proportion of backscatter migrating into the surface deadzone to night-time estimates of backscatter in the upper 200 m. The second uses night-time estimates of demersal backscatter, which remains deeper than 200 m at night, to correct daytime estimates of total backscatter. Both methods gave similar estimates of abundance and demonstrated that there was no statistically significant trend in mesopelagic fish biomass on the Chatham Rise over the past seven years. [ABSTRACT FROM PUBLISHER]

The article presents a study on the best management practices (BMP) for the restoration of the Waiokura Stream in New Zealand. The study aimed to provide the dairy farmers of riparian management techniques that would result in a better environmental performance such as a better stream water quality and long-term sustainability of dairy farming. It suggests that the absence of forest streams near the Waiokura Stream hinders the improvements in biological community structure.

Urban ecosystems include many habitat types supporting native flora and fauna. These habitats may also sustain populations of introduced mammalian pests, although relatively little is known about the composition or distributions of these species in urban environments. We made a preliminary survey of the distribution and relative abundance of pest mammals across three urban habitat types (gully, amenity park, residential) in Hamilton, New Zealand. Tracking tunnel and WaxTag® surveys showed that: (1) rats (Rattus rattus or R. norvegicus), mice (Mus musculus) and brushtail possums (Trichosurus vulpecula) were detected most often and in highest abundances in gullies, were relatively rare in amenity parks, and were not detected in residential areas; (2) hedgehogs (Erinaceus europaeus) were regularly detected in all habitats; and (3) mustelids were not detected in any habitat. Live trapping in areas where rats were detected captured 21 rats, of which 19 were R. rattus. Scat and animal sign surveys found evidence of lagomorphs in amenity parks and gullies but not in residential areas. Cats (Felis catus) were detected in all habitats. These data suggest that important mammalian pests other than cats are either absent (mustelids) or comparatively rare (rats) in urban Hamilton and largely confined to gully habitats. Further research is needed to determine whether detection probabilities of target species vary significantly between the species and habitats we sampled, and to quantify the impact that mammalian pests might have in limiting populations of other animals, especially avifauna. [ABSTRACT FROM AUTHOR]

Cases of mast seeding, involving highly variable seed production synchronized over large geographic areas, provide dramatic examples of resource pulses that have been documented for most major world land masses. Here, we compare the dynamic behavior of two of these systems, with the goal of understanding differences in the long-term consequences of masting events to their respective communities. Responses to mast events in deciduous oak forests in eastern North America are characteristically complex and of low resilience. That is, each event produces long-lasting cascading effects in the community, ultimately influencing not only seed consumers such as rodents and deer, but also the parasites and prey of those consumers, diseases transmitted by those parasites, and outbreaks of insect herbivores. In contrast, despite more extreme resource pulsing in New Zealand Nothofagus forests, responses to mast events there are less complex and more resilient, i.e., producing only short-term (<2 years), smoothly damped, numerical responses by a few species, except after (rare) ‘double-mast’ events in consecutive years. A detailed examination of the two systems suggests some tentative explanations for the strongly contrasting dynamics of these systems. Firstly, the higher number of species involved in North America seems to reduce resilience by increasing food chain length, lags, and alternative prey, all of which increase the dynamic complexity compared with that in New Zealand. Secondly, lack of a shared evolutionary history among species did not necessarily reduce resilience. Some exotic species showed well-damped fluctuations (e.g., stoats ( Mustela erminea L.) in New Zealand), while other exotics showed complex dynamics (e.g., gypsy moths ( Lymantria dispar L.) in North America). Thirdly, recent extinctions of species such as the passenger pigeon ( Ectopistes migratorius L.), once the dominant acorn predator in eastern North American forests, have likely produced qualitative changes in system dynamics in both communities. Fourthly, the North American community has more lags and hysteresis, which probably contribute to the greater dynamic complexity in eastern North America than in New Zealand Nothofagus forests. However, positive feedback loops present in North America seem to have little influence on system dynamics. Because the massive perturbations induced by masting events are major recurring challenges to an ecosystem, disentangling the causes of different system responses is likely to lead us to a better understanding of ecosystem function, resilience and stability. [ABSTRACT FROM AUTHOR]

Abstract: Few urban studies of avian diversity discriminate between native and exotic species, although highly modified urban environments typically support significant numbers of non-native species. High overall diversity may mask poor native diversity. We identify which native species are successful in a variety of urban habitats in a New Zealand city, and examine the roles that garden size and complexity, native fragments, and vegetation composition and cover play in explaining variations in native and exotic avian diversity. Nearly half (44%) of 39 species recorded were exotic: four (three exotic and one native) comprised 45% of birds counted. While there was little variation between habitats in combined native and exotic species richness, the number and abundance of bush-dependent natives differed. Similarity measures identified three groups: (1) commercial, industrial and residential areas with small structurally simple gardens where 3–4 exotic species were numerically dominant and few bush natives made up <10% of the total count; (2) suburbs with medium/large gardens dominated by lawns, shrubs and trees, with many exotic species but also several bush natives (comprising 24–32% of the total count); and (3) bush fragments where both diversity and species richness of bush natives were highest (comprising 50–75% of the total count), including four insectivores absent from all residential areas. Vegetation structure, composition and cover, and proximity to fragments did not explain much of the variation in total or native species richness and diversity, but did explain 69% and 72% of bush-native species richness and abundance respectively. [Copyright &y& Elsevier]

Establishing new populations by transferring founder individuals from source populations has been effective for managing the recovery of many threatened species including some weta (Orthoptera: Anostostomatidae) in New Zealand. These large-bodied flightless insects are ‘flagship species’ for insect conservation in New Zealand and many are rare or threatened. The declining abundance of most weta species, particularly giant weta, can be attributed to the introduction of mammalian predators, habitat destruction, and habitat modification by introduced mammalian browsers. New populations of some weta have been established in locations, particularly on islands, where these threats have been eliminated or severely reduced in order to reduce the risk of extinction. Some populations were established to provide food for endemic vertebrates, ecosystem restoration and ready access for the general public. We illustrate how methods for both transferring weta and monitoring them have become more sophisticated by using a series of case studies. Other transfers of weta not included in the case studies are also summarised. We conclude by re-iterating the importance of documenting the transfer and post-release monitoring for all insect transfers, both for biogeographical reasons and to provide information to improve future transfers. [ABSTRACT FROM AUTHOR]

The relationships between functional linkages within communities and community dynamics are fundamental to biodiversity-stability relationships. By teasing apart the hidden layers within artificial neural networks (ANNs), we developed webs defining how functional groups influence each other's temporal dynamics. ANNs were based on 15 years of bimonthly monitoring of macrobenthic communities on three intertidal sandflats in Manukau Harbor (New Zealand). Sites differed in web topology and diversity, with the site dominated by one functional group exhibiting only a few strong links, the lowest α-, β-, and γ-diversity, and the highest temporal stability in a-diversity. However, positive interactions between functional groups, nonconcordant with harborwide or sitespecific environmental variables, always dominated the interaction webs. The increased number of links we observed with increased temporal variation of species richness within functional groups and overall diversity supports the insurance hypothesis. While our findings suggest that there may be no consistent model characterizing the topology of temporal interactions between functional groups, decreasing diversity is likely to decouple interactions between functional groups and decrease ecosystem functionality. [ABSTRACT FROM AUTHOR]

The article presents a study that assesses the roles of ecological connectivity and regional variation in biotic community structure in the recovery of species richness, total abundance and biotic community composition in Mahurangi Harbour, New Zealand. Researchers of the study have observed apparent significant differences in recovery between sites, which suggest that recovery rates were controlled by a combination of physical and ecological features operating across spatial scales. The authors contend that the observed dynamic and complex interplay of ecological and environmental processes driving patch recovery across the estuarine landscape are integral to recovery from disturbances in heterogeneous environments.

1. Faced with widespread degradation of riverine ecosystems, stream restoration has greatly increased. Such restoration is rarely planned and executed with inputs from ecological theory. In this paper, we seek to identify principles from ecological theory that have been, or could be, used to guide stream restoration. 2. In attempts to re-establish populations, knowledge of the species’ life history, habitat template and spatio-temporal scope is critical. In many cases dispersal will be a critical process in maintaining viable populations at the landscape scale, and special attention should be given to the unique geometry of stream systems 3. One way by which organisms survive natural disturbances is by the use of refugia, many forms of which may have been lost with degradation. Restoring refugia may therefore be critical to survival of target populations, particularly in facilitating resilience to ongoing anthropogenic disturbance regimes. 4. Restoring connectivity, especially longitudinal connectivity, has been a major restoration goal. In restoring lateral connectivity there has been an increasing awareness of the riparian zone as a critical transition zone between streams and their catchments. 5. Increased knowledge of food web structure – bottom-up versus top-down control, trophic cascades and subsidies – are yet to be applied to stream restoration efforts. 6. In restoration, species are drawn from the regional species pool. Having overcome dispersal and environmental constraints (filters), species persistence may be governed by local internal dynamics, which are referred to as assembly rules. 7. While restoration projects often define goals and endpoints, the succession pathways and mechanisms (e.g. facilitation) by which these may be achieved are rarely considered. This occurs in spite of a large of body of general theory on which to draw. 8. Stream restoration has neglected ecosystem processes. The concept that increasing biodiversity increases ecosystem functioning is very relevant to stream restoration. Whether biodiversity affects ecosystem processes, such as decomposition, in streams is equivocal. 9. Considering the spatial scale of restoration projects is critical to success. Success is more likely with large-scale projects, but they will often be infeasible in terms of the available resources and conflicts of interest. Small-scale restoration may remedy specific problems. In general, restoration should occur at the appropriate spatial scale such that restoration is not reversed by the prevailing disturbance regime. 10. The effectiveness and predictability of stream ecosystem restoration will improve with an increased understanding of the processes by which ecosystems develop and are maintained. Ideas from general ecological theory can clearly be better incorporated into stream restoration projects. This will provide a twofold benefit in providing an opportunity both to improve restoration outcomes and to test ecological theory. [ABSTRACT FROM AUTHOR]

The article investigates the habitat loss for diadromous fish because of physical barriers, degradation of migratory passage related to structured land use and deforestation, and site-scale land use features in South Island, New Zealand. It has been noted that wide habitat losses can be caused by land-use changes that interrupts the diffusion networks used by migratory species. Furthermore, habitat loss was cited as one of the most crucial causes of local and global extinction of many species. In New Zealand, the most accessible habitats for migratory galaxiid species are the low gradient streams in coastal areas and their reestablishment could be initiated by creating protective forested buffer zones around streams in order to limit access by livestock and reducing farm sedimentation.

Treatment of wastewater generally results in elevated natural 15 N abundance (d 15 N) in the effluent and sludges. For example, high d 15 N values are found in treated sewage effluent, biosolids, and other wastes that are commonly applied to land. In contrast, N deficient coniferous forest soils usually have a low d 15 N. When wastes with high d 15 N values are applied to land, their distinctive d 15 N signature can potentially be used to trace the fate of waste-derived N in the ecosystem. In this paper, we provide an overview of the use of d 15 N in land application of wastes, including New Zealand case studies on tracing nitrogen in forest ecosystems. [ABSTRACT FROM AUTHOR]

In recent years, the trend in environmental ethics has been to criticize the traditional Western anthropocentric attitude toward nature. Many environmentalists have looked toward some of the views held by indigenous peoples in various parts of the world and argue that important ecological lessons can be learned by studying their beliefs and attitudes toward nature. The traditional Western viewpoint has been labeled as a form of shallow environmentalism, allowing few rights for anything other than human life. In contrast, indigenous peoples are seen as respecting all things. Thus, the claim is made that the latter's ecological views are deeper than those of Western views. John Locke is often placed at the center of this tradition that is associated with indifference to the environment. Yet, a comparison of the fundamental beliefs that drive the env iron- mental ethics of the Maori people with those of John Locke reveals surprising similaries. It may well be the case that any adoption by the West of another culture's view would be too difficult given that there are so many foundational beliefs that are alien to the West, but which are nevertheless required to drive such an ethic. Nevertheless, if we can find similarities between various views, such as those of the Maori and Locke, we may have a greater appreciation of one another's beliefs and hence less reluctance to adopt them if they will benefit the environment. Our efforts could then perhaps be directed toward putting environmental ethics into practice rather than fighting over which doctrine is the correct one. [ABSTRACT FROM AUTHOR]

An index of biotic integrity (IBI) was developed for freshwater fish in New Zealand streams. Data on freshwater fish occurrence for 5497 sites over the entire country were obtained from the New Zealand freshwater fish database for the period 1980-2002. Environmental habitat descriptors for the stream watersheds above or at each of these sites were obtained from an existing river environment classification using a geographic information system. Of the many IBI metrics in use globally, only six were adapted and applied because of differences between the fish faunas of New Zealand and the United States. A number of evaluation methods showed that all six metrics contributed to the overall IBI scores with high levels of consistency. The IBI assessment of sites sampled at different times showed high levels of temporal concordance. The IBI scores differed significantly among the geological areas, the sampling method used, and the year of survey. Overall, the results presented demonstrate the potential for New Zealand freshwater fish to be used to assess river condition at large spatial scales in New Zealand in the absence of specifically selected reference sites. This application demonstrates the effectiveness of the IBI approach even with a fauna of limited diversity and limited ecological specialisation as in the New Zealand fish fauna. [ABSTRACT FROM AUTHOR]

Two, field experiments were performed to examine the impacts on stream invertebrates of crayfish (Paranephrops zealandicus) as predators and bioturbators. A density manipulation experiment involved three treatments with different crayfish densities in streamside channels (0, 5, and 10 crayfish/m²) in which accrual of fine sediment, leaf decomposition, and associated invertebrates were measured. During the 50-d experiment, leaf decomposition was not affected by the presence of crayfish, whereas fine sediment was reduced to similar extents in both crayfish treatments. Some invertebrates followed a similar pattern to that of sediment accrual, suggesting that removal of fine, sediment by crayfish was a primary mechanism underlying differences in invertebrate densities. Medium (4-6 mm body length) and large (≥7 mm) Tanypodinae were rare in crayfish treatments, probably as a result of selective predation. Conversely, crayfish appeared to. facilitate Deleatidium mayflies, as predicted by a trophic cascade (large Tanypodinae predator removal) or shred-der-collector facilitation (fine particulate organic matter production). In many cases, the response of dependent variables was equally strong at both crayfish densities. In a sediment flush experiment, sediment removal treatments were established, along with no-crayfish control and crayfish treatments, to assess the relative impacts of predation and sediment removal on each invertebrate taxon. Crayfish had little impact on leaf decomposition, although decomposition rate was significantly faster than in sediment flush treatments, where collector-scraper invertebrates were reduced as a result of sediment removal. Despite the fact that fine sediment was similarly reduced in crayfish and flush treatments, the response of invertebrates to treatments differed according to invertebrate taxon and size class. [ABSTRACT FROM AUTHOR]

Discusses a paradigm for informed ecosystem management that provides a quantitative and rigorous foundation for informing conservation decisions and sustainable ecosystem management. Basic tenets of the pyramid; Higher levels of the pyramid that are entirely derived from a foundation of underlying data; Rule that the process of generalization and integration upward should be objective and explicit; Pyramids for different purposes that overlap, with common data and common methods for integration; Need for all levels of the pyramid to be developed together, including base data, methods and kinds of integration, and algorithms for using the information for planning and decision-making; Observation that information pyramids are a powerful approach to organizing research science, and provide a mechanism by which research, data collection, storage and generalization can be focused on conservation outcomes; Finding that common data and methods lead to increased efficiency, while also allowing for separate disciplines and programs; Discussion of a case study of an integrated pyramid from New Zealand, which illustrates the characteristics of information pyramids; Examination of components of this pyramid that provide examples of integration and generalization at various levels of the pyramid, from base data, to derived data, to spatial predictions and classifications, to a method of integrating this information into conservation decisions.