Jari Niemelä

Ground beetles (Coleoptera: Carabidae) as bioindicators

One of the primary goals of research on bioindicators is to identifyspecies or other taxonomic units that would reliably indicate disturbances inthe environment, and reflect the responses of other species or the overallbiodiversity. However, there is no perfect bioindicator and selecting the mostsuitable one depends to a great extent on the goal of the survey. In this paperwe examine the suitability of carabids as bioindicators. Carabids are frequentlyused to indicate habitat alteration. They have been used in grasslands andboreal forests where species number and/or abundances have been noted to changealong a habitat disturbance gradient. A common trend is that large, poorlydispersing specialist species decrease with increased disturbance while smallgeneralist species with good dispersal ability increase. Some species are notaffected by moderate disturbance. There is, however, not enough research todetermine how suitable carabids are for biodiversity studies, or how well theyrepresent the response of other species. We conclude that carabids are usefulbioindicators, but as crucial understanding of their relationship with otherspecies is incomplete, they should be used with caution.

Ecology and urban planning

Urban areas harbour diverse nature ranging from semi-natural habitats to wastelands, parks and other highly human-influenced biotopes with their associated species assemblages. Maintenance of this urban biodiversity for the residents and for its intrinsic value in the face of increasing population and expanding cities requires that ecological knowledge should be better integrated into urban planning. To achieve this goal understanding of ecological patterns and processes in urban ecosystems is needed. The first step in the necessary urban ecological research is to find out what kind of nature exists in cities. Second, knowledge about ecological processes important in urban nature is required. Although ecological processes in cities are the same as in rural areas, some of them, such as invasion by alien species, are more prevalent in urban than in rural conditions. Third, based on ecological knowledge, management schemes maintaining the diversity of urban nature should be designed. These procedures should also include protection of urban nature, e.g. in urban national parks. Finally, as ecology alone cannot provide the complex information about human influence on urban ecosystems, interdisciplinary research involving natural and social sciences is imperative for a holistic approach to integrating ecology into the process of urban planning.

The fragmented Atlantic rain forest of Brazil: size, shape and distribution of forest fragments

The geographical characteristics of a total of 1839 forest fragments surrounded by sugar cane fields were studied in the Brazilian Atlantic rain forest region of the northeastern state of Pernambuco. The size and shape of the fragments as well as inter-fragment distances and the effects of varying edge width were examined using a geographical information system. The analyses show that the fragments are relatively small and close to each other. Approximately 48% of the rain forest fragments are <10 hectares, while only about 7% are >100 hectares. Forest fragments are close to each other, as fragments located 50m or less apart formed groups that included ca. 50% of the total forest area. At 350m inter-fragment distance, 98% of the rain forest area was included in groups of fragments. Due to the small size and irregular shape of the fragments, the total area of edge zone exceeds that of the interior habitat when the edge width is ca. 60m. At an edge width of 300m ca. 94% of the total fragment area is edge zone. For conservation purposes, ways of establishing networks of forest fragments connected by corridors and stepping stone fragments are demonstrated using GIS. Simulations using these techniques show that reforestation of sugar cane fields between the forest fragments would considerably increase the area of interior forest habitat and connectivity between fragments.

Functional traits as indicators of biodiversity response to land use changes across ecosystems and organisms.

Rigorous and widely applicable indicators of biodiversity are needed to monitor the responses of ecosystems to global change and design effective conservation schemes. Among the potential indicators of biodiversity, those based on the functional traits of species and communities are interesting because they can be generalized to similar habitats and can be assessed by relatively rapid field assessment across eco-regions. Functional traits, however, have as yet been rarely considered in current common monitoring schemes. Moreover, standardized procedures of trait measurement and analyses have almost exclusively been developed for plants but different approaches have been used for different groups of organisms. Here we review approaches using functional traits as biodiversity indicators focussing not on plants as usual but particularly on animal groups that are commonly considered in different biodiversity monitoring schemes (benthic invertebrates, collembolans, above ground insects and birds). Further, we introduce a new framework based on functional traits indices and illustrate it using case studies where the traits of these organisms can help monitoring the response of biodiversity to different land use change drivers. We propose and test standard procedures to integrate different components of functional traits into biodiversity monitoring schemes across trophic levels and disciplines. We suggest that the development of indicators using functional traits could complement, rather than replace, the existent biodiversity monitoring. In this way, the comparison of the effect of land use changes on biodiversity is facilitated and is expected to positively influence conservation management practices.

Carabid beetle assemblages (Coleoptera, Carabidae) across urban-rural gradients: an international comparison

We studied communities of carabid beetles in residual forest patchesalong urban-suburban-rural gradients in three cities (Helsinki, Finland; Sofia,Bulgaria and Edmonton, Canada) to examine their responses to urbanisation. OnlyFinnish carabids showed a marked division of community structure along thegradient. In Bulgaria and Canada, carabids did not separate into distincturban,suburban and rural communities. Our results provide some support for thepredictions that species richness will decrease, that opportunistic specieswillgain dominance, and that small-sized species will become more numerous underdisturbance such as that provided by urbanisation. The rather weak and variedresponse of carabids to this disturbance suggests that local factors and theirinteraction are of primary importance for community composition. Occurrence ofreasonably similar carabid communities across the gradient at each of the threelevels of urbanisation suggests that habitat changes commonly associated withurbanisation have not affected the ecological integrity of carabid assemblagesin residual urban forest patches.

Using the ecosystem services approach for better planning and conservation of urban green spaces: a Finland case study

Ecosystem services are vital for humans in urban regions. However, urban development poses a great risk for the ability of ecosystems to provide these services. In this paper we first address the most important ecosystem services in functional urban regions in Finland. Well accessible and good quality recreational ecosystem services, for example, provided by urban nature, are an important part of a high-quality living environment and important for public health. Vegetation of urban regions can have a role in carbon dioxide sequestration and thus in climate change mitigation. For instance, estimates of carbon sinks can be compared to total CO2 emissions of an urban region, and the municipality can aim at both increasing carbon sinks and decreasing CO2 emissions with proper land-use planning. Large and contiguous core nature areas, smaller green areas and ecological connections between them are the essence of regional ecological networks and are essential for maintaining interconnected habitats for species and thus biological diversity. Thus, both local and regional level ecological networks are vital for maintaining ecosystem services in urban regions. The impacts of climate change coupled with land-use and land cover change will bring serious challenges for maintaining ecosystem services in urban areas. Although not yet widely used in planning practices, the ecosystem services approach can provide an opportunity for land-use planning to develop ecologically sustainable urban regions. Currently, information on ecosystem services of urban regions is lacking and there is a need to improve the knowledge base for land-use planning.

Towards sustainable land use: identifying and managing the conflicts between human activities and biodiversity conservation in Europe

Conflicts between biodiversity conservation and human activities are becoming increasingly apparent in all European landscapes. The intensification of agricultural and silvicultural practices, land abandonment and other land uses such as recreation and hunting are all potential threats to biodiversity that can lead to conflicts between stakeholder livelihoods and biodiversity conservation. To address the global decline in biodiversity there is, therefore, a need to identify the drivers responsible for conflicts between human activities and the conservation of European biodiversity and to promote the management of these conflicts. Here, the drivers of biodiversity conflicts are analysed in a European context for five habitat types: agricultural landscapes, forests, grasslands, uplands and freshwater habitats. A multi- disciplinary approach to conflict management is described, with active stakeholder involvement at every stage of conflict identification and management as well as a range of other approaches including stakeholder dialogue and education, consumer education, improvement of political and legislative frameworks, financial incentives, and planning infrastructure.

The search for common anthropogenic impacts on biodiversity: a global network

We introduce an initiative to assess and compare landscape changes related to human activities on a global scale, using a single group of invertebrates. The GLOBENET programme uses common field methodology (pitfall trapping), to appraise assemblages of ground beetles (Coleoptera, Carabidae) in visually-similar land-mosaics (urban-rural gradients). Carabids were selected as the focal taxon as they are sufficiently varied (both taxonomically and ecologically), abundant and sensitive to the environment. However, work on other taxa is comparable with the GLOBENET framework. The continuum of decreasing human pressure from city centres into the surrounding countryside was selected to represent human-caused disturbance for this initial stage of GLOBENET because these gradients can be found virtually all over the world. Through the broad-scale assessment envisioned in the GLOBENET programme, we seek to separate general, repeated effects on biodiversity from those that depend on local environments or particular biotic assemblages. Based on this understanding we aim to develop simple tools and protocols for assessing ecological effects of human-caused landscape changes, which could help to sustainably manage landscapes for biodiversity and for human requirements. For instance, the response of different functional groups of carabids to these landscape changes may help guide management practices. Further GLOBENET developments and information are available at our website: http://www.helsinki.fi/science/globenet/

Management in relation to disturbance in the boreal forest

Disturbances and the consequent habitat heterogeneity are natural features of the boreal forest. Natural disturbances occurring at the level of populations, communities and ecosystems (meters to kilometers and years to hundreds of years), that is, at the ‘meso-scale’ may provide useful guidelines for forest management. This approach is based on the assumption that species are adapted to the disturbance regime of the forest-type that they occupy. However, natural disturbance and human-caused disturbance, such as clear-cutting, may differ substantially in their ecological effects. Potential differences occur on several scales. On the stand scale, removal or destruction of important habitat structures, such as coarse woody debris, during traditional clear-cutting may affect species. On the landscape scale, fragmentation may cause local extinctions and hamper the recolonization of maturing sites by old-growth specialists. The effect of these differences on boreal biota needs to be assessed. On the stand scale, the degree of recovery (resilience) of populations and communities after human-caused disturbance versus natural disturbance, that is, the succession process, could be a useful criterion when developing new forestry methods. On the landscape scale, it is important to maintain enough patches of suitable habitat for the old-growth species in order to prevent local extinctions and to promote recolonizations. Natural landscapes could be used as a reference here. In conclusion, although possibilities of matching forestry with maintenance of taiga biota through development of harvesting methods that mimic natural disturbance seem reasonably good, there is an urgent need to establish criteria for the assessment of the success or failure of such methods. The resilience of forest ecosystems as reflected in population changes of surrogate taxa after disturbance could be used to guide management. # 1999 Elsevier Science B.V. All rights reserved.

Is there a need for a theory of urban ecology

Although urban ecosystems are governed by the same ecological “laws” as rural ecosystems, the relative importance of certain ecological patterns and processes differs between the two types of ecosystems. For instance, as compared to rural areas, urban habitats are usually more islandlike, more often represent early successional stages, and more easily invaded by alien species. All these features are results of the intense human influence on urban landscapes. The question then arises whether a distinct theory of urban ecology is needed for understanding ecological patterns and processes in the urban setting. The answer is no, because urban ecosystems can be successfully studied using existing ecological theories, such as the metapopulation theory. However, due to the intense human presence approaches that include the human aspect are useful in studying urban systems. For instance, the “human ecosystem model,” which emphasizes human impact by identifying social components with connections to ecology, is a useful approach in urban studies. This model, combined with the urban–rural gradient approach, forms an effective tool for studying key ecological features of urban ecosystems. Better understanding of these features would increase our ability to predict changes that land use causes in urban ecosystems, and would help to integrate ecology better into urban planning.