Viesturs Melecis

Long-Term Observations of Soil Mesofauna

General problems connected with planning, sampling, and data processing of long-term research of soil mesofauna are discussed, based on two case studies: (i) the Bremen study of predatory mites (Gamasina) covering 20 years of secondary succession on a ruderal site in northern Germany and (ii) the Mazsalaca study of the effects of climate warming on Collembola of coniferous stands in the North Vidzeme Biosphere Reserve, Latvia, covering 11 years. The findings from both sites are embedded in an array of environmental data. The results from Bremen document the asynchrony of different biota in successional dynamics. The long-lasting increase of the species numbers of soil predatory mites (Gamasina) is contrasted by a decrease in plant species numbers. In the Baltic forests, climate change is indicated by the dynamics of collembolan community. Gradual decline in species richness has been observed from 1992 to 2002 attributed to global warming. The ‘temporal window’ or time unit to discern changes in soil mesofauna communities seems to span approx. 5 years, highlighting the necessity of long-term observations.

Long-Term Effects of Climate Warming on Forest Soil Collembola

Long-term changes in the collembolan community structure were studied in a Scots pine forest in northern Latvia over a period of 11 successive years (1992–2002). Soil Collembola were yearly sampled from three pine forest stands of different age – young (30 to 40 years old), middle-aged (50 to 70 years old) and old (150 to 200 years old). During the study period a statistically significant increase in sums of positive temperatures (>+4°C) was recorded and a gradual decrease in species richness of Collembola was observed in all forest stands. The study showed that sums of positive air temperatures produce statistically significant effects on collembolan populations. Community responses were strongly controlled by both temperature and precipitation. Our results indicated that changes in Collembola communities at different forest sites are not local but rather regional level phenomena.

What is socio-ecological research delivering? A literature survey across 25 international LTSER platforms

With an overarching goal of addressing global and regional sustainability challenges, Long Term Socio-Ecological Research Platforms (LTSER) aim to conduct place-based research, to collect and synthesize both environmental and socio-economic data, and to involve a broader stakeholder pool to set the research agenda. To date there have been few studies examining the output from LTSER platforms. In this study we enquire if the socio-ecological research from 25 self-selected LTSER platforms of the International Long-Term Ecological Research (ILTER) network has produced research products which fulfil the aims and ambitions of the paradigm shift from ecological to socio-ecological research envisaged at the turn of the century. In total we assessed 4983 publically available publications, of which 1112 were deemed relevant to the socio-ecological objectives of the platform. A series of 22 questions were scored for each publication, assessing relevance of responses in terms of the disciplinary focus of research, consideration of human health and well-being, degree of stakeholder engagement, and other relevant variables. The results reflected the diverse origins of the individual platforms and revealed a wide range in foci, temporal periods and quantity of output from participating platforms, supporting the premise that there is a growing trend in socio-ecological research at long-term monitoring platforms. Our review highlights the challenges of realizing the top-down goal to harmonize international network activities and objectives and the need for bottom-up, self-definition for research platforms. This provides support for increasing the consistency of LTSER research while preserving the diversity of regional experiences.

Ecosytem Services: A Rapid Assessment Method Tested at 35 Sites of the LTER-Europe Network

Abstract The identification of parameters to monitor the ecosystem services delivered at a site is fundamental to the concept’s adoption as a useful policy instrument at local, national and international scales. In this paper we (i) describe the process of developing a rapid comprehensive ecosystem service assessment methodology and (ii) test the applicability of the protocol at 35 long-term research (LTER) sites across 14 countries in the LTER-Europe network (www.lter-europe.net) including marine, urban, agricultural, forest, desert and conservation sites. An assessment of probability of occurrence with estimated confidence score using 83 ecosystem service parameters was tested. The parameters were either specific services like food production or proxies such as human activities which were considered surrogates for cultural diversity and economic activity. This initial test of the ecosystem service parameter list revealed that the parameters tested were relatively easy to score by site managers with a high level of certainty (92% scored as either occurring or not occurring at the site with certainty of over 90%). Based on this assessment, we concluded that (i) this approach to operationalise the concept of ecosystem services is practical and applicable by many sectors of civil society as a first screen of the ecosystem services present at a site, (ii) this study has direct relevance to land management and policy decision makers as a transparent vehicle to focus testing scenarios and target data gathering, but (iii) further work beyond the scale investigated here is required to ensure global applicability.

Experimental Study of Peat Humification Indicators

Experimental Study of Peat Humification Indicators An important parameter of organic matter in soils, peat, and fossil-carbon-containing deposits is their decomposition degree, which describes their transformation intensity—the humification degree of original living organic matter. In this article approaches to the analysis of humification degree are thoroughly described and14C dated peat columns extracted from several bogs in Latvia are investigated and compared. A new humification indicator is suggested: the ratio of the total amount of organic matter in peat in respect to the amount of humic substances. Svarīgi augšņu, kūdras un fosilo oglekli saturošu nogulumu organiskās vielas raksturlielumi ir to sadalīšanās pakāpe, kas raksturo sākotnējās biomasas pārveidošanās intensitāti, un humifikācijas pakāpe, kas raksturo jaunu organisko vielu - humusvielu veidošanās tempu no sākotnējās dzīvās vielas. Šajā rakstā ir pētītas un salīdzinātas humifikācijas analīzes metodes pilnīgi analizētām un datētām (14C) kūdras kolonnām no vairākiem Latvijas purviem. Ieteikts humifikācijas pakāpi definēt kā kopējās organiskās vielas kūdrā un humifikācijas gaitā veidoto humusvielu attiecību.

Long-Term Ecological Research in Latvia

The article describes the National Long-term Ecological Research (LTER) Network of Latvia, which includes five study sites and eight research projects. It is supported by the Latvian Council of Sciences. The main directions of the research are impacts of climate warming and anthropogenic factors on terrestrial and freshwater communities and ecosystems. Characteristics of research sites are presented. The main results of the long-term investigations and their implementation in ecological management projects are described.

CONCEPTUAL MODEL OF THE LONG-TERM SOCIO-ECOLOGICAL RESEARCH PLATFORM OF ENGURE ECOREGION, LATVIA

Abstract The article discusses the results of the national project aimed at elaboration of a conceptual integrated model of the Engure LT(S)ER (Long-Term Socio-Ecological Research) platform of Latvia. The platform represents the drainage basin of costal Lake Engure (644 km2) together with the coastal marine zone of the Gulf of Rîga. The core zone of the ecoregion is the Lake Engure Nature Park (LENP), which is a Ramsar site. The conceptual model is a slightly modified version based on the DPSIR (Drivers-Pressures-States-Impacts-Responses) concept. The socioecological system was spatially demarcated and drivers were subdivided in two groups - external and local ones. The Engure ecoregion was subdivided into seven zones or sub-regions mostly demarcated by natural geological and geographical barriers. Each zone has a specific set of drivers and pressures as well as a specific ecosystem structure and elements of biodiversity. Analysis of the governing drivers and pressures was performed separately for each sub-region during three time periods: 19th century - beginning of 20th century, period of Soviet occupation (1940-1991), and period after restoration of independence of Latvia (1991 - up to now). Characteristics of the state of ecosystems and biodiversity are given. Responses of the socioeconomic component of the socio-ecological system are represented mainly by external factors to the ecoregion, including environmental legislation and funding necessary for research and ecological management. Two alternative scenarios of the development of the Engure ecoregion are discussed: (i) depopulation and land abandonment, and (ii) intensification of agriculture, small-scale industry and building construction. In both cases the present state of ecosystems and the structure of species diversity would be subjected to significant change. Sustainable development of the ecoregion can be provided only by implementation of certain environmental management measures accompanied by long-term socio-ecological research and ecological monitoring. Abstract in Latvian Rakstā apskatīti nacionālā pētījumu projekta rezultāti, kuru mērķis - izstrādāt Latvijas LT(S)ER (Ilgtermiņa socioekoloģisko pētījumu) platformas - Engures ekoreģiona integrēto konceptuālo modeli. Engures ekoreģionu veido piekrastes ezera sateces baseins (644 km2) ar Rīgas līča krasta un jūras piekrastes zonu. Ekoreģiona centrālo daļu veido Engures ezera dabas parks (EEDP) - Ramsāres vieta. Konceptuālā modeļa pamatā ir DPSIR (virzošie spēki-slodzes-stāvokļi-ietekmes-rīcības) koncepcija. Socioekoloģiskā sistēma tika telpiski strukturēta un virzošie spēki iedalīti divās grupās - ārējos un lokālos. Engures ekoreģions sadalīts septiņās zonās vai apakšreģionos ar izteiktām ģeoloģiskām un ģeogrāfiskām robežām. Katrai zonai raksturīgi specifiski virzošie spēki un slodzes kā arī specifiska ekosistēmu struktūra un biodaudzveidības elementi. Analizēti katra apakšreģiona galvenie virzošie spēki un slodzes trijos laika periodos: 19. gs. - 20 gs. sākums, padomju okupācijas periods (1940.-1991. g.), periods pēc Latvijas neatkarības atgūšanas. Sniegti ekosistēmu stāvokļa un biodaudzveidības raksturojumi. Socioekonomiskās sistēmas aktīvā komponenta - cilvēka rīcības veido galvenokārt ekoreģionam ārējie faktori, tai skaitā vides likumdošana un finansu plūsmas zinātniskajiem pētījumiem un ekosistēmu apsaimniekošanai. Apskatīti divi alternatīvi Engures ekoreģiona attīstības scenāriji: 1) iedzīvotāju skaita samazināšanās un lauksaimniecības zemju aizaugšana; 2) lauksaimniecības, vietējās ražošanas uzņēmumu un būvniecības intensifikācija. Abos gadījumos ekosistēmu pašreizējais stāvoklis un sugu daudzveidības struktūra tiktu būtiski izmainīti. Reģiona ilgtspējīgu attīstību, saglabājot cilvēkam vēlamo ekosistēmu struktūru, iespējams nodrošināt, vienīgi ieviešot ekosistēmu apsaimniekošanas pasākumus, kas bāzēti uz ilgtermiņa socioekoloģisko pētījumu un ekoloģiskā monitoringa rezultātiem.

Increase in abundance and species richness of flies (Diptera, Brachycera) in the Lake Engure Nature Park, Latvia: effects of climate warming?

Abstract The article discusses changes in species richness and numbers of flies (Diptera, Brachycera) in the Lake Engure Nature Park (LENP) during 1995-2012. The study was performed within the framework of the National Long Term Ecological Research (LTER) network of Latvia. During the period of study, a statistically significant increase in positive temperature sums (> 4 °C) was observed at the local meteorological station (R2 = 0.489; P < 0.01). Insects were collected three times per season (June, July, and August) by entomological sweep net from twelve sample plots, which represented a variety of habitats of the LENP - dry xerophytic, mesophytic and humid hygrophytic ones. In total 411 species from 35 families were identified. Dry sample plots showed a statistically significant increase in species richness and/or numbers of flies during the period of study. Humid sample plots did not show any statistically significant trends except for two grassland plots where large herbivores were introduced in 2005 for grassland management purpose. Pooling the data from all sample plots, except those grazed by large herbivores, yielded a statistically significant trend of increase in species richness of flies (R2 = 0.647; P < 0.01). Among the main trophic groups zoophagous species showed the largest number of statistically significant positive trends mostly within the dry sample plots. For several sample plots significant positive correlations were recorded between species richness of zoophagous flies and annual sums of positive temperatures. It was hypothesised that climate warming may have an indirect effect via interaction with other environmental factors such as moisture regime, nitrogen pollution, and vegetation structure. Abstract in Latvian Rakstā apskatītas divspārņu (Diptera, Brachycera) skaita un sugu bagātības izmaiņas laikā no 1995. gada līdz 2012. gadam 12 Engures ezera dabas parka pastāvīgajos parauglaukumos. Pētījumi veikti Latvijas nacionālā Ilgtermiņa ekoloģisko pētījumu (LTER) tīkla ietvaros. Pētījumu periodā pēc vietējās meteostacijas datiem konstatēts statistiski būtisks (R2 = 0.489; P < 0.01) pozitīvo temperatūru (> 4° C) summas pieaugums. Kukaiņi ievākti trīs reizes sezonā (jūnijs, jūlijs, augusts) ar entomoloģisko tīkliņa „pļāvienu” metodi, virzoties pa noteiktu maršrutu parauglaukumā. Ievāktajā materiālā noteiktas 411 mušu sugas no 35 dzimtām. Parauglaukumi tika sadalīti divās grupās - sausie, ksero- un mezofītiskie un mitrie higrofītiskie biotopi. Gandrīz visos sausajos parauglaukumos konstatēts statistiski būtisks mušu sugu bagātības un/vai indivīdu skaita pieaugums. Mitrajos parauglaukumos statistiski būtiskas izmaiņas netika konstatētas, izņemot divos mitro pļavu biotopos, kur 2005. gadā uzsākta zālāju apsaimniekošana, ieviešot lielos savvaļas zālēdājus. Apvienojot parauglaukumu datus, izņemot tos, kuros tika ieviesti zālēdāji, konstatēts statistiski būtisks sugu bagātības pieaugums (R2 = 0.647; P < 0.01). No trim trofiskajām grupām - zoofāgiem, fitofāgiem un saprofāgiem - zoofāgiem konstatēts vislielākais statistiski būtisko pozitīvo trendu skaits, pa lielākai daļai tieši sausajos parauglaukumos. Vairākos parauglaukumos konstatēta statistiski būtiska pozitīva sugu bagātības un skaita korelācija ar pozitīvo temperatūru summu. Izvirzīta hipotēze par iespējamu netiešo klimata pasiltināšanās ietekmi uz sugu bagātību mijiedarbībā ar tādiem faktoriem kā mitruma režīms, slāpekļa piesārņojums un veģetācijas struktūra.

Environmental quality assessment of the drainage basin of Lake Engure using Scots pine as a bioindicator

Environmental quality assessment of the drainage basin of Lake Engure using Scots pine as a bioindicator Environmental quality assessment of the Lake Engure drainage area, which is the LT(S)ER region of the Latvian National Long-term Ecological Research network (Latvia LTER), was conducted using three bioindication methods based on Scots pine Pinus sylvestris L.: unspecific bioindication by pine needle tip necrosis, ground level ozone assessment by pine needle chlorotic mottling, and chemical analysis of pine bark. Samples were collected from 40 sites of the region in November 2010. Extent of needle tip necroses did not exceed class 4 (maximum possible value 6). The highest value of index of needle damage by ozone was Idam = 1.62 (maximum possible value 6). Multiple regression analysis of variables describing bark chemistry and needle damage in relation to distance from the sea, nearest roads and villages was performed. Pine bark acidity pH(KCl) and concentration of Mg and Fe decreased significantly (βpH(KCl) = -0.672, P < 0.001; βMg = -0.676, P < 0.001; βFe = -0.514, P < 0.001) with distance of sample site from gravel roads. Electric conductivity (EC) of pine bark and the extent of ozone damage of the first year needles Idam significantly decreased with distance from the sea (βozone = -0.507, P < 0.01; βEC = -0.453, P < 0.01). PCA of the pine bark chemistry data showed dust pollution from gravel roads to be the main factor responsible for the 33% variation of data. No statistically significant correlations were found between different bioindicator characteristics, except between first and second year ozone damage (ρ = 0.589, P = 0.01). Vides kvalitātes novērtējums Engures ezera sateces baseina teritorijā, izmantojot parasto priedi kā bioindikatoru Veikta vides kvalitātes novērtēšana Engures ezera sateces baseina teritorijā, kas Latvijas nacionālā ilgtermiņa ekologisko pētījumu tīkla (Latvia LTER) ietvaros pārstāv LT(S)ER regionu. Kā bioindikators izmantota parastā priede Pinus sylvestris L., kurai pētītas trīs bioindikatīvās pazīmes: nespecifiskā bioindikācija, ko raksturo skuju galu nekrotizācijas pakāpe, piezemes ozona bioindikācija, ko raksturo hlorotiski plankumi uz skujām, un mizas ķīmiskās analīzes. Paraugi ievākti 40 vietās 2010. gada novembrī. Skuju galu nekrotizācijas pakāpe nepārsniedza 4. klases līmeni (maksimāli iespējama 6. klase). Ozona bojājumu pakāpi raksturojošā indeksa Idam vērtības nepārsniedz 1.63 (maksimālā iespējamā vērtība 6). Daudzfaktoru lineārās regresijas analīze parādīja, ka pH(KCl), magnija un dzelzs saturs palielinās lauku lielceļu tuvumā augošo priežu mizā. Savukārt elektrovadītspēja EC un ozona bojājumu līmenis uz pirmā gada skujām pieaug jūras tuvumā. Galveno komponentu analīzē pirmo asi raksturo lauku lielceļu radīto putekļu emisija, bet trešo asi sāļu ienese no jūras. Netika konstatētas statistiski ticamas korelācijas starp pētītajiem bioindikatīvajiem rādītājiem, izņemot pirmā un otrā gada ozona bojājumus. Secināts, ka katrs no tiem atspoguļo specifisku piesārņojošo vielu plūsmu un tādēļ nav aizvietojams.

Probleme des Boden-Biomonitorings

Wahrend der letzten Jahrzehnte fanden Bodenorganismen zunehmend Beachtung als Bioindikatoren von Storungen des Bodenokosystems, die durch unterschiedliche Aspekte menschlicher Aktivitaten verursacht wurden. Die meisten veroffentlichten Befunde belegen ihre Sensitivitat gegenuber derartigen Eingriffen, vor allem bei Verschmutzung durch Chemikalien (siehe Reviews von Edwards u. Thompson 1973; Iglisch 1985; Paoletti et al. 1991; Krivolutsky 1994; Koehler 1996).