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IZLAGANJE NA ZNANSTVENOM SKUPU - PRESENTATION AT THE INTERNATIONAL SYMPOSIUM Šumarski list- SUPLEMENT (2005). 155-164 UDK 630* 116 + 114.2 i 425 ULOGA ŠUME U ZAŠTITI KVALITETE VODNIH RESURSA THE ROLE OF FLOODPLAIN FORESTS !N SOUTHERN MORAVIA IN THE PROTECTION OF QUALITY OF WATER RESOURCES Emil KLIMO, Jiri KULHAVY* SAŽETAK: Resursi visoko kvalitetne prirodne vode predstavljaju ozbiljan problem, posebice u ekonomski intenzivno iskorištavanim predjelima. U radu se daju primjeri važnosti šuma za zaštitu kvalitete vodnih resursa. U prvom slučaju, analizira se funkcija poplavne šume u bazenu rijeke Morave, posebno s gledišta intercepcije čestica zemlje koje dopiru iz izrazito gno jenih poljoprivrednih zemljišta putem krošanja poplavne šume i posljednično, visoke akumulacije elemenata kao što su N i P u sastojinipoplavne šume, koji bi inače predstavljali elemente zagađenja u vodi rijeke. Drugi slučaj odnosi se na područje visočja Drahany. Ocjenjuje se uloga šume u smislu čišćenja vodnih resursa u usporedbi sa susjednim poljoprivrednim kultiviranim dijelovima okoliša. U oba slučaja prikazuju se pozitivni učinci važnosti šume za očuvanje kvalitete vodnih resursa. Još jedan primjer odnosi se na promjenu u kvaliteti vodnih resursa pri obnovi čistom sječom, prilikom čega u vodne resurse mogu dospjeti veće količine nitrata. Procjenjuje se i funkcija biljne vegetacije u područjima čiste sječe, koja preuzima znatne količine dušika sve do pojave nove zatvorene sastojine, pa se tako smanjuje ulazak dušika u podzemnu vodu. 1. UVOD - Introduction Sa sve većim antropogenim utjecajima na prirodu, pod bukovom sastojinom, a mobilnost nitrata na posješume postaju sve važniji čimbenik u očuvanju kvalitete čenoj površini uzrokovalo je daje njihova koncentracija vodnih resursa. Međutim, moramo uzeti u obzir da neu pitkoj vodi premašila vrijednosni prag. Iako gornja gativni utjecaji čovjekovih aktivnosti također utječu na tvrdnja ne traba vrijediti općenito, činjenica je da je šumske ekosustave, pa se tako ta funkcija može smanjiproblem rctencije bioelemenata kao što su dušik i fosti. Stoga su od velike važnosti metode šumskog gospofor u biomasi šumskih ekosustava važan čimbenik u darenja i uporabe. Wilper t (2003) spominje da se očuvanju kvalitete vodnih resursa. Prema tome, treba kvaliteta vode smanjuje, a koncentracija nitrata raste titakođer obratiti pozornost inputu dušika iz atmosfere u jekom posljednjih desetljeća do iznosa od 2-5 mg.l"1 do šumske ekosustave, što može rezultirati (u nekim 10-30 mg.l" . Drugi je problem povećanje DOC, alumislučajevima) natapanjem šumskih ekosustava dušikom nija i teških metala. Stanje šume i njena udaljenost od i negativnim utjecajima na kvalitetu vode. Potencijalni prirodnih uvjeta može znatno utjecati na kvalitetu vorizici povećanog inputa dušika mogu također potaknuti de. Wilpert (2003) primijećuje daje pod sastojinom mineralizaciju humusa (F e g e r 2003). smreke nađeno veće protjecanje elemenata od onoga Prema Feger u (2003), konverzije čistih monokul tura norveške smreke u mješovitim šumama mogu ta kođer proizvesti pozitivne utjecaje na kvalitetu vode. * Prof. Emil Klimo, Doc. Jiri Kulhavy, Mendelovo sveučilište Stoga moderni trendovi potrajnog šumskog gospoda poljoprivrede i šumarstva, Brno renja uzimaju u obzir i zaštitu vodnih resursa. Ove su CZ-613 00 Brno, Zemedelska 3, Czech Republic |
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F.. Klimo. J. Kulhavy: ULOGA ŠUML U ZAŠTITI KVALITETE VODNIH RESURSA Šumarski list - SUPLLMLNT (2005). 155-164 ekstrakcije elemenata u biomasu šumskih ekosustava također važne za nemobilnost elemenata kao što su kadmij i cink. Wieshammer etal. (2003) spominju da npr. Salix caprea i Salix fragilis pokazuju velik potencijal povlačenja Cd, Zn, a ponekad i Pb, iz tla. Pozitivna uloga šume u retenciji N03-N, NH4-N i PO4-P bilježe Swank i Waide (1987) na primjeru projekta Coweeta. Swank (1987) također kaže, daje, npr. u sustavu obnove čistom sječom evapotranspiracija smanjena, površinsko otjecanje se povećava, a istovremeno se povećava izvoz nutrijenata. Proces transporta i pohranjivanja nutrijenata u šumskom ekosustavu uključuje nekoliko djelomičnih procesa. U utvrđivanju uloge šume u očuvanju kvalitete šumskih resursa važno je obratiti pozornost ovim parcijalnim procesima. Oni su: > Input elemenata u oborinama na površunu sklopa šumske sastojine; > Interakcija krošanja (učinak filtracije sklopa, reak cija sa suhim depozicijama, istjecanje nutrijenata iz tkiva biljaka, itd.); > Input nutrijenata s kišom što dopire kroz sklop do tla; > Input nutrijenata s kišom što se slijeva niz deblo; > Promjene u kvaliteti vode što prodire kroz profil tla; > Output elemenata iz ekosustava. Područje poplavnih šuma južne Moravske u aluviju rijeka Morave i Dyje pod znatnim je antropogenim utjecajem. Vode i rijeke, riječne okuke i podzemne vode također su zagađene, posebice intenzivnom poljoprivredom i industrijom hrane. Očuvanje kvalitete podzemne vode od velike je važnosti, jer se i ona rabi kao izvor pitke vode. 2. REZULTATI I DISKUSIJA - Results and discussion 2.1 Opći opis područja ispitivanja -General description of the study area Rijeka Morava, koja utječe u Dunav nad Bratislavom, važna je pritoka u središnjem dijelu Dunava, jer utječe na rijeku kako zbog izlijevanja, tako i u smislu kvalitete vode. Sliv rijeke Morave prirodna je teritorijalna jedinica smještena na liniji razdvajanja češkog visogorja, Zapadnih Karpata i Panonske provincije, a hidrologijski pripada bazenu Crnog mora. Površina teritorija Republike Čehoslovačke, Republike Slovačke i Austrije je 24.000 km", uključujući 3 % dunavskog sliva. Poplavne šume u regiji, stoje predmet studije, pokrivaju oko 7.500 ha. Sastav vrsta u ekosustavima je sljedeći: hrast 37 %, jasen 34 %, joha i vrba 4 %, topola 7,5 %, ostale listače 17,5 %, te četinjače 0,5 %. Ostale listače predstavljene su javorom, brijestom, grabom i lipom (Slika 1). Promjene u prirodnom hidrologijskom režimu, ekstenzivni hidroinženjerski radovi na donjim tokovima rijeka, te činjenica da bazeni Morave i Dyje uključuju gusto naseljena područja aglomeracija Brna, Zlina i Olomouca, te industrijskih područja i intenzivno obrađivanih zemljišta s industrijama poljoprivredne obrade, rezultiraju značajnim zagađenjem vodenih tokova i njihovom brzom eutrofikacijom. Ispuštanje i ispiranje materijala i propadanje kvalitete vode odražavaju se Slika 1. Pogled na ušće Morave i Dyje Fig. 1 General view of the confluence of the Morava and Dyje rivers (Foto -Photo: P. Vrba) uglavnom u režimu kisika, nitrata, sadržaju topivih i netopivih materijala i izvjesnim specifičnim mineralnim komponentama. Glavni izvori zagađenja su postrojenja za obradu, kao što su rafinerije šećera i tvornice škroba, koje u jesenskim mjesecima, tj. u vrijeme kada je učinak samočišćenja vodenih tokova na najnižem stupnju, znatno pogoršavaju kvalitetu vode. 2.2 Metode -Methods U svrhu postizanja ciljeva, istraživanje se orijentiAtmosferski input N i P, njihovo prenošenje iz veralo na sljedeće: getacije u tlo, te prijenos N i P u rastopinu tla. Stanje šumske vegetacije i akumulacija elemenata Vegetacija preuzima N i P. (N, P) u određenim komponentama ekosustava poplavne šume; |
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E. Klimo. .1. Kulhavy: ULOGA ŠUME U ZAŠTITI KVALITETE VODNIH RESURSA Šumarski list - SUPLEMENT (2005), 155-164 2.3 Budžet dušika i fosfora unutar ekosustava poplavne šume Nitrogen and phosporus budget within the floodplain forest ecosystem Za neke ekosustave, heterogeni je razvoj nekih komponenata cirkuliranja nutrijenata tipičan. To se također odnosi na većinu šumskih ekosustava. Na primjer, cirkuliranje elemenata unutar proučavanog ekosustava bilo je pod snažnim utjecajem velikih unosa elemenata uslijed redovitih poplava i blata bogatog nutrijentima deponiranim na površini tla. Iako je taj proces bio prekinut tehničkim poboljšanjima vodnog režima, on ipak djeluje na razinu primarne proizvodnje, te tako rezultira većim obrtanjem određenih hranjivih tvari, posebice dušika. Položaj ekosustava poplavne šume u krajoliku se također postupno izmijenio. Susjedno travnato zemljište (Slika) i šumski ekosustavi su se izmijenili, korak po korak, u intenzivno kultivirane agroekosustave, s visokim unosom gnojiva. Na taj način, poplavna je šuma poprimila karakter koridorskog ekosustava s atipičnim visokim unosima elemenata prenošenih iz susjednih ekosustava. Naša je studija orijentirana prema vrednovanju sadašnje situaciju u budžetu N i P. Na temelju podataka danih u Tablici 1, moguće je vidjeti daje dušik važan element za egzistenciju poplavne šume, pa tako šuma može ispuniti ulogu zadržavanja tog elementa kao zagađivača rijeka Moravc i Dyjc, od kojih je prva važna pritoka Dunava. Njegova ukupna vrijednost akumulirana u čitavom ekosustavu doseže 25 842 kg.ha" , od čega je najveći udjel akumuliran u okolišu tla, posebice u korijenskom sloju (14 846 kg.ha"´). Vrijednost dušika u biomasi šumske sastojine također je visoka u usporedbi s ostalim šumskim ekosustavima umjerene zone (1804 kg.ha"1). Akumulacija dušika i fosfora u površinskom humusu relativno je niska, stoje rezultat intenzivne razgradnje listinca. Unos dušika i fosfora u okoliš tla događa se posebice preko listinca iz svih komponenata ekosustavne biomase, ali isto preko unosa iz atmosfere bi Slika 2. Travni sustav u poplavnoj šumi Fig. 2 Grassland system in a floodplain forest (Foto-Photo: E. Klimo) lo kao suhe depozicije, ili oborinama (unos padom listinca i oborinama). Unos N i P u oborine pod jakim je utjecajem. Šuma oblikuje barijeru kojom štiti vodne ekosustave od zagađenja (Slika 2). Proces unosa N i P poplavnim vodama iz rijeka Dyje i Morave zaustavljen je izgradnjom rezervoara Nove Mliny godine 1972. Trenutno je to djelomično zamijenjeno umjetnim poplavljivanjem. Od 1972. redovne se prirodne poplave, a s njima i unosi mulja u poplavnu šumu, ne pojavljuju. Sedimcntacija mulja događa se tek na obalama vodotokova (Slika 3). _j^**C >, .. >ajgfc &*&U´: * jEr.´đ Liižiđ : = Slika 3. Promjene travnatih sustava u obradivo zemljište Fig. 3 Transformation of the grassland system in to arable land (Yo\o-Photo: E. Klimo) Tablica 1. Vertikalni raspored rezervi dušika u poplavnom šumskom ekosustavu Table 1 Vertical distribution of nutrient reserves in the floodplain forest ecosystem (kg. ha´1) (Klimo 1985) N P Krošnje, grane i lišće Tree crown, branches & leaves 473 41 Debla Trunks 1 044 42 Grmlje (na površini) Shrubs (abovegroundpart) 55 8 Prizemno rašće (izbojci) Herbs (shoots) 22 4 Ukupno -Total 1 594 95 Površinski humus, godišnji prosjek Surface humus, annual mean 99 6 Korijenje: stabla, grmlje Roots: trees, shrubs, herbs 210 34 Dušične rezerve: rizosfera Nutrient reserves: rhizosphere 14 846 4 953 Rezerve: bez rizosfere Reserves: without rhizosphere 9 093 5 085 Biljke ukupno Plants total 1 804 129 Tlo ukupno - Soil total 24 038 10044 Sveukupno Sum total 25 842 10173 |
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E. Klimo. J. Kulhavy: ULOGA ŠUME U ZAŠTITI KVALITETE VODNIH RESURSA Šumarski SUPLF.MENT (2005). 155-164 2.4 Uklanjanje nutrijenata - Nutrient removal Ekosustavi poplavnih šuma mogu preuzeti i vezati velike količine posebice dušika i fosfora zbog visokih razina proizvodnje biljne mase i značajnog kapaciteta adsorpcije tla (Tab. 4). Tablica 2. Ukupna težina elemenata koji ulaze u okolinu tla (godišnje u kg.ha"1) Table 2 Total weight of elements entering the soil environment (kg.ha´.year´) (Klimo 1985) N P Listinac: drveće - Litterfall: trees 76.5 11.2 Mrtvo korijenje - Dead roots 13.0 1.5 Listinac: grmlje i prizemno rašće Litterfall: shrubs & herbs 18.0 4.3 Oborine -Precipitation 5 4 Ukupno -Total 112.5 21.0 Tablica 3. Iskorištavanje hranjiva u šumskoj sastojim (godišnje u kg.ha"1) Table 3 Uptake of nutrients by the forest stand (kg.ha´.year´) (Klimo 1985) N P Stabla -Trees 178 11 Grmlje -Shrubs 24 3 Prizemno rašće -Herbs 22 4 Ukupno -Total 224 18 Tablica 4. Godišnja bilanca hranjiva u profilu tla Table 4 Annual balance of nutrients within the soil profile (1973) (Klimo 1985) Oslobođeno iz A Released from A Akumulirano u B Accumulation in B Pomak -Shift C N P kg.ha"´ % kg.ha"´ % kg. ha"1 % 146.7 100 10.0 100 18.5 100 120.3 82 6.5 65 17.0 92 26.4 18 3.5 35 1.5 8 Šuma preuzima nutrijente u iznosima od 18 kg.ha"´ na godinu"1 P i 224 kg. ha"´ na godinu ´ N. Maksimum obiju nutrijenata postigla su stabla; grmovi i trave doprinijele su znatno manje tom procesu (Tab. 3). Istovremeno, osim kapaciteta uklanjanja zagađivača, šumski ekosustav oblikuje barijeru protiv erozije od vjetra, što dolazi od teško gnojenih poljoprivrednih zemljišta u okolnom krajoliku (SI. 3). Uslijed tih činjenica, moguće je preporučiti očuvanje i povećanje ekosustava, kako bi se obnovila njihova funkcija u krajoliku. 2.5 Ekonomsko vrednovanje poplavnih šuma u južnoj Moravskoj Economic evaluation of floodplain forests in Southern Moravia Ekonomsko vrednovanje poplavnih šuma vezano je uz njihove sljedeće temeljne karakteristike: 1. Biološka vrijednost, biljna i životinjska raznolikost; 2. Primarna proizvodnja, tj. biomasa drveća, grmlja i trava; 3. Rrekrcacijska uloga područja; 4. Zaštita vodnih resursa (retencija elemenata); 5. obrazovna, estetska i znanstvena važnost. Izmjenjivanje ekosustava šume, travnjaka, močvare i voda (rijeke, jezera) tipično je za poplavne šume južne Moravske. Nema mnogo iskustva s ekonomskim vrednovanjem uloga šumskih ekosustava, pa su naši zaključci temeljeni uglavnom na publikaciji WWF "Economic Evaluation of Danube Floodplains" (1995). Stoga citiramo uvodni dio publikacije: U vrednovanju funkcije "čišćenja" poplavne šume kroz proces retencije N i P u ekosustavnim komponentama (drveću, grmlju, travama, humusu, tlu), nalazimo vrlo visoke akumulacije posebice N (25.842 kg.ha" ). Ako uzmemo da 1 kg N odgovara ECU 14, ukupna je količina jednaka 361.788 ECU ha"´. S obzirom na P, 10.173 kg.ha ´ je akumulirano, a kada 1 kg P odgovara ECU 4, tada je ukupna količina jednaka 40.692 ECU ha"´. Osim u stvarnim šumskim sastojinama, funkcija čišćenja usmjerena na vodne resurse pojavljuje se isto tako u drugim ekosustavima koji su komponenta poplavnih šuma. To se posebice odnosi na bare, riječne okuke i travnjake. Ovdje je ta funkcija u vezi s fitoplanktonom i retencijom dušika i fosfora u travnatim zemljištima, gdje se nadzemna biomasa troši kosidbom i pašom, a bogati korijenski sustav akumulira znatne količine elemenata. Slika 4. Sedimenti na obali vodotoka Fig. 4 Sediments on the hank of a watercourse (Foto-Photo: E. Klimo) |
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E. Klimo, J. Kulhavy: ULOGA ŠUME U ZAŠTITI KVALITETE VODNIH RESURSA Šumarski list - SUPLEMENT (2005), 155-164 Ulaz iz atmosfere poljoprivrednog zemljišta Input from atmosphere and agriculture land Akumulacija u sloju stabala Accumulation in tree layer Akumulacija u sloju grmlja Accumulation in shrub layer Akumulacija u sloju Biljka prizemnog rašća koristi Accumulation Uptake in herb layer by plant Otpalo biomass lišće Litterfall Akumulacija u listincu Accumulation in litter Akumulacija u profilu tla Accumulation in soil profile Y Ispiranje u podzemne vode Leaching to underground water Slika 5. Transport i akumulacija N i P u poplavnom šumskom ekosustavu Fig. 5 Transport and accumulation ofN and P within the floodplain forest ecosystem 3. ZAKLJUČCI - Conclusions Ekosustavi poplavne šume funkcioniraju kao prirodbiljnih zajednica i abiotičkog okoliša, pojavljuje se ni sustav, što uklanja i akumulira zagađivače vode, kao optimalni uvjet za ove ekosustave. posebice dušika i fosfora na relativno dugo vrijeme; Očuvanjem mješovite visoko produktivne šume s Poplavna šuma, što se pojavljuje pod stalnim optihrastom, jasenom, lipom i grmljem te travnim slojemalnim uvjetima za obnavljanje ravnoteže između vima na terenima s visokom razinom podzemne |
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E. Klimo. .1. Kulhavy: ULOGA ŠUMP U ZAŠTITI KVALITETE VODNIH RESURSA Šumarski list SUPLEMENT (2005), 155-164 vode i obalama vodotokova na kojima dominira vr ba i topola, čini se optimalnim uvjetom poplavnih šuma duž rijeka Morave i Dyje. 4. Kako bi se održavala funkcija poplavne šume s gledišta njene produktivnosti i na taj način i kao potencijalno uklanjanje zagađivača, potrebno je uvesti revitalizacijski projekt (regulaciju vodnog režima), što će pomoći u povećanju bioraznolikosti i ukla njanju zagađivača; 5. Uz šumske ekosustave, travnjaci i vodeni ekosustavi imaju važnu ulogu u očuvanju kvalitete vodnih resursa. 4. LITERATURA - References Economic Evaluation of Danube Floodplains, A WWF International Discussion Paper, March 1995, 24 pp. Feger, K.H., 2003: Water Quality and Sustainable Management of Forests: Problem and Challenges. In: Conference on Water and Society - Needs, Challenges and Restrictions, 19-21 November 2003, Vienna, BOKU. Klimo, E., 1985: Cycling of mineral nutrients. In: Pcnka. M. et all., Floodplain Forest Ecosystem 1, Academia, Praha, 425^158. Present and Future Role in Nutrient Removal from Surface Water by Wetlands, Floodplains and Reservoirs, Phare project 201/91, Task 2, Intern Report Phase 1, Water Research Institute, Bratislava, 1997,41 pp. Swank, W.T., J.B.Waide, 1988: Characterization of Baseline Precipitation and Stream Chemistry and Nutrient Budgets for Control Watersheds. In: W.T. Swank, D.A. Crosslcy Jr., Eds. Forest Hydrology and Ecology at Coweeta, Spring-Verlag, Ecological Studies 66, 57-79. Swank, W.T., 1988: Stream Chemistry Responses to Disturbance. In: W.T. Swank, D.A.Crossley Jr., Eds. Forest Hydrology and Ecology at Coweeta, Spring-Verlag, Ecological Studies 66, 340-357. Wieshammer, G. at all., 2003: Phytoextraction of Cadmium and Zink Using Willows: Microbial Effects. In: Conference on Water and Society Needs, Challenges and Restrictions, 19-21 November 2003, Vienna, BOKU. Wilpcrt, K. von, 2003: The Potential of Forestry for Water Preservation - Case Studies from Black Forests, Germany. In: Conference on Water and Society - Needs, Challenges and Restrictions, 19-21 November 2003, Vienna, BOKU. |
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E. Klimo. J. Kulhavy: THE ROLE OF FLOODPLAIN FORESTS IN SOUTHERN MORAVIA ... Šumarski list SUPLEMENT (2005). 155-164 CONCLUSIONS 1. Floodplain forest ecosystems function as a natural system which removes and accumulates water pollutants, particularly nitrogen and phosphorus for a relatively long time. 2. A floodplain forest occurring under permanent optimum conditions for the recreation of balance between plant communities and the abiotic environment appears to be an optimum condition for these ecosystems. 3. Preserving a mixed highly productive forest with oak, ash, lime and shrub and herb layers on sites with the high level of groundwater and banks of watercourses dominated by willow and poplar appears to be the optimum condition of floodplain forests along the Morava and Dyje Rivers. 4. In order to maintain the function of the floodplain forest from the aspect of its productivity and thus also of the potential removal of pollutants it is necessary to implement the revitalization project (water regime regulation) which will help to increase biodiversity and pollutant removal. 5. In addition to forest ecosystems grassland and aquatic ecosystems show an important role for the preservation of the quality of water resources. |
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PRESENTATION ATT! IH INTERNATIONAL SYMPOSIUM Šumarski list - SUPLEMENT (2005), 155-164 THE ROLE OF FLOODPLAIN FORESTS IN SOUTHERN MORAVIA IN THE PROTECTION OF QUALITY OF WATER RESOURCES Emil KLIMO, Jiri KULHAVY SUMMARY: Resources of drinking water of high quality are a serious problem particularly in the intensively economically used landscape. The paper gives examples of the importance of forests for the protection of quality of water resources. In the first case, the function of a floodplain forest is analysed in the basin of the Morava River, particularly from the viewpoint of intercepting soil particles carried from markedly fertilized agricultural soils by crowns of the floodplain forest and further the high accumulation of elements such as N and P in the floodplain forest stand which otherwise could be a pollution element for the river water. High primary production capable to retain high amounts of nitrogen and phosphorus is an important factor for the role of a floodplain forest. Channelization of rivers and construction of the Nove Mlyny reservoirs bring about the need of artificial flooding which is not, however, fully identical with natural floods particularly from the viewpoint of water quality. K ey w o rds: water quality, floodplain forests 1. INTRODUCTION With growing anthropogenic impacts on nature foment retention such as nitrogen and phosphorus in the rests become increasingly a more important factor for biomass of forest ecosystems is an important factor for the preservation of quality of water resources. However, the preservation of water resources quality. Thus, atwe have to take into account that negative impacts of tention is also paid to the input of nitrogen from atmoshuman activities affect also forest ecosystems and thus phere to forest ecosystems which can result (in certain this function can be reduced. Therefore, methods of focases) in the saturation of forest ecosystems by nitrorest management and use are of great importance. W i 1 -gen and negative effects on water quality. Potential pert (2003) mentions that water quality decreases and risks of the increased input of nitrogen can also stimuas for the concentration of nitrates it increases in the late mineralization of humus (F e g e r 2003). course of recent decades from typical outputs of water According to Fegc r (2003), conversions of pure from forest ecosystems amounting to 2-5 mg.f1 to Norway spruce monocultures to mixed forests can also 10-30 mg.r´. Another problem is the increase of DOC, bring positive impacts on water quality. Therefore, aluminium and heavy metals. The condition of a forest modern trends of sustainable forest management take and its distance from the natural condition can signifi into consideration also protection of water resources. cantly affect water quality. Wilper t (2003) notices These extractions of elements by the biomass of fo that the higher flux of elements was found under a rest ecosystems are also important for the immobility spruce stand than under a beech stand and nitrate mo of elements such as cadmium and zinc. Wiesham bility on a clear-felled area caused that their concentra m c r et all. (2003) mention that eg Salix caprea and tion in drinking water exceeded a threshold value. Alt Salix fragilis show a high potential to withdraw Cd, Zn hough the statement mentioned above does not have to and sometimes also Pb from soil. be general, there is a fact that the problem of bioele- The positive role of a forest in the retention of NO r N, NH4-N and P04-P note Swank and Waide * Prof. Emil Klimo, Doc. Jiri Kulhavy, Institute of Forest Ecology, (1987) on the example of Coweeta project. On the ot Mendel University of Agriculture and Forestry CZ-613 00 Brno, Zemcdelska 3, Czech Republic her hand, actual losses for a forest ecosystem were |
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F.. Klimo, J. Kulhavy: TI IF ROLF, OF FLOODPLAIN FORESTS IN SOUTHERN MORAVIA .Šumarski list SUPLEMENT (2005), 155-164 found in Ca, Na, K, Mg and Si02. S wan k (1987) also states that for example, in the clear-felling system of regeneration evapotranspiration is reduced, runoff increases and at the same time, exports of nutrients increase. A process of the transport and storage of nutrients in a forest ecosystem includes several partial processes. In the assessment of the role of a forest for the preservation of quality of forest resources it is necessary to pay attention to these partial processes. These are: > input of elements in precipitation to the surface of a forest stand canopy, > crown interactions (canopy filtration effect, reaction with dry depositions, leaching of nutrients from plant tissues, etc.), > input of nutrients in throughfall, > input of nutrients in stemflow, > changes in the quality of water penetrating through the soil profile, > output of elements from the ecosystem. The area of floodplain forests of southern Moravia in the alluvium of the Morava and Dyje rivers occurs under considerable anthropogenic impact, water in rivers, oxbows and also ground waters are polluted particularly by intensive agriculture and food industry. Preservation of the quality of ground water is of great importance because it is also used as the sources of drinking water. 2. RESULTS AND DISCUSSION 2.1 General description of the study area The Morava river flowing into the Danube above Bratislava is an important tributary in the central part of the Danube influencing the river both from the viewpoint of discharge and water quality. The Morava river watershed is a natural territorial unit situated on the dividing line of the Bohemian Uplands, Western Carpathians and Panonian Province belonging, from the point of hydrology, to the Black Sea Basin. The area of the territory of the Czech Republic, the Slovak Republic and of Austria amounts to 24 000 km" accounting for 3 % of the Danube watershed. Floodplain forests in the region under study cover about 7500 ha. Species composition in the ecosystems is as follows: oak 37 %, ash 34 %, alder and willow 4 %, poplar 7.5 %, other broadleaves 17.5 % and conifers 0.5 %. Other broadleaves are represented by maple, elm, hornbeam and lime (Fig. 1). Changes in the natural hydrological regime, extensive hydroenginecring works on the lower reaches of rivers, and the fact that the basins of the Morava and the Dyje include the densely inhabited areas of the Brno, Zlin and Olomouc agglomerations, as well as industrial areas and intensively farmed lands with agricultural processing industries result in the considerable pollution of the watercourses and their rapid eutrophication. The release and washing of materials, deterioration in the water quality are reflected mainly in the oxygen regime, nitrates, the content of soluble and insoluble materials, and certain specific mineral components. Major sources of pollution are processing plants such as sugar refineries and starch factories which in the autumn months, ie at a time when the self- cleaning effect of watercourses is at its lowest, considerably worsen the water quality. 2.2 Methods To fulfil the objectives the research is orientated as follows: The condition of forest vegetation and element accumulation (N, P) in particular components of the floodplain forest ecosystem. 2.3 Nitrogen and phosporus budget For same ecosystems, a heterogeneous development of some components of nutrient cycling is typical. It also applies to the majority of forest ecosystems. For example, the cycling of elements within the ecosystem under study was strongly affected by high inputs of elements resulting from regular floods and mud rich in nutrients deposited on the soil surface. Although this Atmospheric input of N and P, their transport from vegetation into soil and N and P transport into the soil solution. Uptake of N and P by vegetation. within the floodplain forest ecosystem process has been interrupted by technical improvements of the water regime, it still affects the level of primary production and thus results in a greater turnover of particular nutrients especially nitrogen. The position of the floodplain forest ecosystem within the landscape has also gradually changed. The neighbouring grassland (photo) and forest ecosystems ha |
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E. Klimo, J. Kulhavy: THE ROLF. OF FLOODPLAIN FORESTS IN SOUTHERN MORAVIA ... Šumarski list - SUPLEMENT (2005), 155-164 ve been changed, step by step, into intensively cultivated agroecosystems, with high inputs of fertilizers. In this way, the floodplain forest has assumed the character of a corridor ecosystem, with typical high inputs of elements transported from neighbouring ecosystems. Our study was oriented towards the evaluation of the present situation in N and P budget. Based on the data given in Tab. 1, it is possible to see that nitrogen is an important element for the existence of a floodplain forest and so the forest can also fulfil the role of retaining the element as a pollutant for the Morava and Dyje Rivers the former being an important tributary of the Danube River. Its total value accumulated in the whole ecosystem amounts to 25 842 kg.ha"´, the highest proportion of which being accumulated in the soil environment, particularly in the root layer (14 846 kg.ha"´). Nitrogen value in the forest stand biomass is also high as compared with other forest ecosystems in a temperate zone (1804 kg.ha"´). Nitrogen and phosphorus accumulation in a surface humus is relatively low the fact being the result of an intensive decomposition of litter. Nitrogen and phosphorus input into the soil environment occurs particularly through the litter from all components of the ecosystem biomass but also through the input from atmosphere either as dry depositions or as precipitation (input by litter fall and precipitation). N and P input in precipitation is markedly affected. The forest forms a barrier protecting the water ecosystems from pollution (Fig. 2). The process of N and P input by flood waters from the Dyje and Morava Rivers was stopped by the construction of Nove Mlyny reservoirs in 1972. At present, it is partly substituted by artificial flooding. Since 1972, regular natural floods and thus also inputs of sludges into the floodplain forest do not occur. Sedimentation of the sludges occurs only on banks of watercourses (Fig. 3). 2.4 Nutrient removal The floodplain forest ecosystem can uptake and bind large amounts of particularly nitrogen and phosphorus due to high levels of plant biomass production and considerable soil adsorption capacity (Tab. 4). Nutrient uptake by the forest stand was 18 kg.ha"1 year"1 P and 224 kg. ha"´ year"´ N. Maximum of both nutrients was obtained by trees; shrubs and herbs contributed in the process markedly less (Tab.3). At the same time, in addition to the pollutant removal capacity, the forest ecosystem forms a wind erosion barrier from heavily fertilized agricultural land in the surrounding landscape (Fig. 3). Due to the facts, it is possible to recommend preservation and enlargement of the ecosystems their function in the landscape to be restored. 2.5 Economic evaluation of floodplain forests in Southern Moravia Economic evaluation of floodplain forests is related to their basic characteristics which are as follows. 1. biological value, viz. plant and animal biodiversity; 2. primary production, ie tree, shrub and herb biomass; 3. recreational role of the region; 4. protection of water resources (retention of elements); 5. educational, aesthetic and scientific importance. Alternation of forest, grassland, wetland and water (rivers, ponds) ecosystems is typical of the floodplain forests of southern Moravia. There is not much experience with the economic evaluation of the roles of forest ecosystems and our conclusions are based mainly upon the WWF publication "Economic Evaluation of Danube Floodplains (1995). We quote, therefore, the introductory part of the publication here: In evaluating the "purification" function of the floodplain forest through the process of N and P reten tion in ecosystem components (trees, shrubs, herbs, humus, soil) we can find very high accumulation particularly of N (25.842 kg.ha"1). If we consider that 1 kg N corresponds to ECU 14 then total amount is equal to 361.788 ECU ha"´. As for P, 10.173 kg.ha"´ is accumulated and when 1 kg P corresponds to ECU 4 then total amount is equal to 40.692 ECU ha"´. In addition to actual forest stands the purification function aimed at water resources occurs also in other ecosystems which are the component of floodplain forests. It refers particularly to pools, oxbows and grasslands. Here, the function is applied of phytoplankton and retention of nitrogen and phosphorus in grasslands where aboveground biomass is consumed by mowing and grazing and a rich root system accumulates considerable amounts of elements. |