Special Issue

Nature Conservation 2009 — 1. 9. 2009 — Special Issue

Biological diversity and climate change

Současný stav a předpověď dalšího vývoje

In other words, anthropogenic GHG emissions are, as considered by some experts, most likely the cause of current global climate change (Solomon et al. 2007). Nevertheless, there also are different views on causes, patterns and future projections of climate changes.

Although ecosystems adapted themselves to changing conditions in the environment in past, the rate of current changes in biosphere is unusual compared to earlier changes in the Earth’s history. We suppose that even during this century global ave­rage temperature shall increase at a rate faster than at any time in the last 10,000 years. It seems that climate change has not been a linear process but it is accelerating. Therefore we should take into account that climate change shall be even more dynamic than expected. Generally, the faster climate change is, the worse it affects human and natural systems (Solomon et al. l.c.). Although biosphere (i.e., the global ecosystem) is a highly comprehensive and surprisingly dynamic system with a wide array of feed-forwards and feedbacks among its individual components, it is pretty obvious that climate change will influence biological diversity at all its three main levels (genes/individuals, populations/species, communities/ecosystems/the landscape). The extensive mega-scientific project Millennium Ecosystem Assessmentconcluded that by the end of this century climate change will become the most important driver influencing biodiversity (MA 2005). On the other hand, the appropriate biodiversity conservation and management could – to some extent – mitigate the climate change effects on human society and on ecosystem functionings and help them to effectively adapt to actual and projected climate changes.

Interlinkages between climate change and biodiversity are examined by specia­lized handbooks and reports (e.g., Gitay et al.2003, Green et al.2003, Secretariat of the Convention on Biological Diversity 2003, 2007, Loveloy & Hannah 2005, Brooker & Young 2006,Huntley 2007, Hawkins et al.2008, Campbell et al.2008, 2009, Royal Society 2008, Berry 2009). The review is a small part of the much more extensive exercise and it aims at a few important issues only, paying special attention to the Czech Republic’s conditions.

Biological diversity and climate change in the Czech Republic

Global climate change threatens global bio­diversity, ecosystem functions, and human well-being, with thousands of publications demonstrating impacts across a wide diversity of taxonomic groups, ecosystems, economics, and social structure (Hughes 2000, Parmesan & Yohe 2003, Walther et al.2005, Parmesan 2006, EEA 2008, Royal Society l.c.).

High habitat diversity as well as a relatively huge range of scenarios for the projected climate change has made assessment of possible climate change impacts on biological diversity in the Czech Republic rather difficult. Moreover, the current scenarios expect some warming, the vegetation period prolongation, changes in the seasonal precipitation regime, the lack of moisture caused by increasing evapotranspiration (the sum of evaporation and transpiration in a particular area) and increased frequency of extreme events, such as period of droughts, rainstorms, floods and tornados (Vašků 2007, Pretel 2009).

The main impacts of climate change on biological diversity in the Czech Republic can be summarised as follows:

• Natural and semi-natural ecosystems will be effected by the extinction of certain species and spreading of other ones incl. pathogens and invasive alien species (see below), in relation to the increasing latitude and altitude;
• Due to landscape patchiness and small size of some habitat patches as well as to relatively small territory of the Czech Republic, decline in and loss of some natural and semi-natural ecosystems, despite their location within the country, would be excepted;
• Climate change will negatively affect wild animal dispersal, movement and migration;
• Managed artificial ecosystems will be at risk particularly at low elevations, where they have been limited at present by water availability and where significant occurrence of newly arrived pathogens would be expected (Pretel in Brožová et al.2005).

The most vulnerable to climate change ecosystems in the Czech Republic include mountain ecosystems and residual primary grassland ecosystems. We suppose that climate changes will most heavily affect ecosystems above shifting upward top tree line in both the mountains where they occur (Krkonoše/Giant Mts., Hrubý Jeseník Mts.). Their vulnerability has been amplified by the small size. Climate change impacts on forest, aquatic, agricultural and urban ecosystems are discussed by Plesník & Pelc (2009).

The Czech Republic will be probably influenced by the main shift in wild plant and animal which is projected to occur across Europe, i.e.from Southwest to Northeast Europe (Thuiller et al. 2005a, Bakkenes et al.2006, Huntley et al.2007, EEA 2008). By the late 21st century, the mean potential range shift relative to the late 20th century is by a distance of several hundred kilometres in a north-eastward direction, although some individual species’ potential ranges are displaced in quite disparate directions and by distances in excess of 2,000 km. The mean rate of potential range shift is between a few times and more than an order of magnitude faster than past rates of range shift estima­ted from the Quaternary record or from historical data (Huntley l.c). Alpine wildlife species and subspecies will most likely become extinct as well taxa and guilds preferring microclimatically specific habitats (glacial cirques, raised peat-bogs, airborne sands). Mountain plant species and subspecies with the limited distribution ranges (mountain endemics), e.g. the hawkweed Hie­racium nivimontis, the Sudeten Mountains Carthusian Pink (Dianthus carthusianorumsubsp. sudeticus) or Sudeten Mountains Bohemian Bellflower (Campanula gelida) will be most negatively affected by climate change.

Of 431 plant species, occurring in the Czech Republic, Slovakia and Hungary and studied within the European vegetation model EUROMOVE, 40 are projected to disappear by 2100. On the other hand, 84 plant species will newly colonise the above three Central European countries (Bakkenes et al.l.c.).

The distribution range shift analysis in 119 butterfly species on the territory what is now the Czech Republic in 1950–2001 revealed that altitude shifts in the distribution of Czech butterflies are already detectable on the coarse scales of standard distribution maps (grids 11.1 ´ 12 km – Konvička et al.2003). The recent study shows clearly that climate change poses a considerable additional risk to European butterflies. Even under the moderate scenario, 54 % of the modelled species lose more than half of their present climatic niche by 2080. Using the extreme scenario, 24 % of the butterfly species studied lose more than 95 % of their present climatic niche by 2080 and additional 70 % lose more than 50 %: only 6 % of the butterfly species examined are rated as being at lower risk (Settele et al.2008).

In Europe, the average bird’s distribution range will be reduced in size by a fifth by the end of this century. Alarmingly, three quarters of all of European breeding birds are likely to suffer declines in range within the same period. The projections are based on the effects of a likely 3 °C increase in ave­rage global temperature above pre-industrial levels (Huntley et al.2007). Even if potential range changes were realised, the average number of species breeding per 50 ´ 50 km grid square would decrease by 6.8–23.2 % (Huntley et al.2008 – cf. Gregory et al.2009). The results of an analysis based on large-scale monitoring data (103 bird species, monitored from 1982 to 2006) showed that bird species with more northern latitudinal distributions had more negative population trends in the Czech Republic, particularly compared to southern species. The effect of climate change remained significant when habitat requirements (habitat selection) and the migratory strategy of each species were controlled (Reif et al.2008, 2009).

In some more southerly species (the European Praying Mantis Mantis religiosa, European Bee-eater Merops apiaster, Golden Jackal Canis aureus), it has been questionable whet­her their apparent distribution shifts towards the north in the Czech Republic can be attri­buted to climate change or to which extent has been caused by time-to-time repeated natural fluctuations of their distribution range.

Climate change and invasive alien species in the Czech Republic

Within conservation biology, invasive alien species are species whose introduction and/or spread outside their natural past or present distribution threatens biological diversity, particularly other species or habitats (Secretariat of the Convention on Biological Diversity 2002). In addition, many invasive alien species cause serious economic damage and some of them directly affect human health. One of the factors influencing successful establishment of an alien species in newly invaded habitats is matching climatic variables, i.e.simila­rity in climate between native and target regions (Thuiller et al. 2005b). Therefore, it is important when predicting spreading of an invasive alien species to assume both the native and invaded ranges (Broennimann & Guisan 2008, Beaumont et al.2009). Predicting how climate change will affect invasive alien species, and invasive alien species management, at local or even regional scale is more difficult to deduce than are these general indications.

Invasive alien species in the Czech Republic

At present, 1,378 plant species (of them, 184 are hybrids or hybridogenic taxa) are considered to be non-native to the Czech Republic which is one third of the whole flora of the country: 90 of them have been classified as invasive alien species that often irreversibly damage the communities into which they penetrate. Up to date, 817 of them have been temporarily introduced, while 444 have become na­turalized, i.e.they have established viable populations in the wild and reproduce without human assistance there (Pyšek et al. 2002). List of animal invasive alien species in the country has been also published (Šefrová & Laštůvka 2005).

It is assumed that the current and expected climate change may enhance invasive alien species spreading across the Czech Republic. While many native species shall, due to climate change and invasive alien species and co-influencing by other drivers such habitat fragmentation, destruction and loss, unsustainable use of wildlife population, nutrient deposition in and pollution of the environment, dramatically decline, some of them will be replaced by a few highly adaptable invasive alien species (homo­genization of biota– cf.Cílek 2009).

Biofuels and nature conservation and landscape protection in the Czech Republic

In the Czech Republic, detailed, ideally multi-specialty studies which would examine, using at least model components of biological diversity, impact of growing plants from which first generation biofuels, second generation biofuels respectively are produced have been missing.

Opinions on how much land would be needed for growing first and second generation biofuel plants in the Czech Republic vary substantially. Optimistic views suggest that the annual production of 200 kilotonnes of rapeseed methyl ester (RME) and 200 million hectolitres of bioethanol made from wheat would require 300,000 hectares, i.e.7.8 % of the total agricultural land in the Czech Republic (Ministry of Industry and Trade of the Czech Republic 2005). Estimations of the Independent Commission for Czech Energy Outlook (Pačes’ Commission) show that to replace 10 % of the petrol and diesel oil consumption by biofuels, 787,00 hectares plan­ted by wheat and rapeseed would be needed (Government of the Czech Republic 2008). Because the rapeseed harvest has exceeded the requirements of domestic processing factories, a significant part of the production is exported. In 2005, rapeseed was planted on 270,000 hectares in the Czech Republic: in the European Union, more land was put under the crop in Germany, France and Poland and in the U.K. only (EEA 2007). Nevert­heless, the area needed for annual RME production co­vered 190,000 hectares only (Ministry of Industry and Trade of the Czech Republic l.c.). In 2007 farmers put under rapeseed 337,000 hectares, a year later 357,000 hectares. To make comparison, in 1980 there were only 64,000 hectares cultivated by rapeseed in the Czech Republic, ten years later the rapeseed crop area was 105,000 hectares (Czech Statistical Office 2009). The total land available for biomass crop production in the Czech Republic for 2010 was estimated at 303,000 hectares based on such area under cultivation in 2005 (EEA 2006).

Moreover, if we take into account the specific habitat requirements of first and second generation bioenergy plants (elevation, climatic and soil conditions and water regime) we find that the Czech Republic’s landscape has the only limited capacity for reasonable energy biomass production, particularly in lowlands and some highlands. In addition, the area to be under cultivation by rapeseed is rather limited. The rapeseed can be planted on the same field only after five years and it has to be sown exclusively after the cereals which have to be harvested before.

In farmland, there have been small, but from a point of view of the nature conservation and landscape protection valuable residual habitats (Brožová et al.2005). They can harbour keystone species or guilds, e.g.insect pollinators and play an important role in supporting landscape connectivity, i.e.the degree to which the structure of a landscape helps or hiders the movement of wildlife species (Tischendorf & Fahring 2000).

The plants which are assumed to be possible source for biofuel production include some invasive alien species. At present, three plant genera and 23 species including hybrids have been tested for possible biomass production as a bioenergy source (STRILOG 2009). In the Czech Republic, probably the most problematic is the knotweed (Reynoutriaspp.) which is due its enormous productivity, high tolerance to cultivation and resistance to changing habitat conditions considered sometimes as an ideal bio­energy plant. The Ministry of the Environment of the Czech Republic Decree No. 482/2005 Gazette on Biomass Types, Methods and Parameters in Supporting the Generation of Electric Power from Biomass, as amended later, includes Annex II. Listing invasive and expansive higher plant species which in the Czech Republic damage and disturb ecosystem functionings and can cause damage: all the three knotweed species occurring in the country are listed there. Therefore, producing the biomass by the above species is not subsided: only energy generated from burning their biomass collected during their eradication from natural sites. Moreover, some other invasive alien plant species which have been considered as perspective bioenergy crop in the Czech Republic, e.g.the Coriander (Coriandrium sativum), Crambe (Crambe abyssinica), White Lupin (Lupinus albus) and Sida, also known as the Virginia Mallow (Sida hermophrodita – cf. Plíštil et al.2004) have not been listed in the above decree. Therefore, selecting low risk species, using risk assessment protocols to evaluate the risk of invasion by species in biofuel proposals, performing benefit/cost analysis and using native species whenever possible by creating incentives for the deve­lopment and use of native and non-invasive species that pose the lowest risk to biodiversity, is recommended (GISP 2008).

The by this time most comprehensive study on biofuel affects in Europe including the Czech Republic suggest that 40 % of the 1,300 assessed species (vascular plants, butterflies, freshwater fishes, amphibians, reptiles and birds) may be negatively affected by gro­wing the bioenergy plants. On the other hand, 7 % of the species examined will benefit from growing the bioenergy crops, particularly due to growing wood species on abandoned and agricultural lands (ECNC 2008).

Supporting sustainable biofuel production, developing and applying biodiversity--related criteria, standards and certification schemes and careful and reasonable land--use planning could help to find the necessary compromise between climate protection and biodiversity conservation interests. The entire carbon life cycle of each feedstock supply chain, including emissions from land use change on displaced crops must be fully assessed and policies put in place to ensure the greatest possible carbon savings are delivered by the biofuels industry. For the most open-minded assessment of biofuels, their possible importance for mitigating the climate change impacts, biological diversity, food safety and livelihoods (Reijnders 2006, UNEP l.c.).

The author is Adviser to Director at the Agency for Nature Conservation and Landscape Protection of the Czech Republic.