Hiilidioksidi

Käyttää kasvit hyväkseen jotka yhteyttäessään tuottavat elämälle tärkeää happea. Kun seuraa kulkiessaan tienvarsia, niin siinä kasvaa ruohot,puuntaimet ja kaikki kasvit, paremmin kuin syvemmällä metsässä. Mistähän mahtaa johtua, siitäkö että saavat typpeä ja hiilidioksiidia riittävästi?

old_profile_31762 kirjoitti:

Käyttää kasvit hyväkseen jotka yhteyttäessään tuottavat elämälle tärkeää happea. Kun seuraa kulkiessaan tienvarsia, niin siinä kasvaa ruohot,puuntaimet ja kaikki kasvit, paremmin kuin syvemmällä metsässä. Mistähän mahtaa johtua, siitäkö että saavat typpeä ja hiilidioksiidia riittävästi?

Autoista kasvit eivät kyllä hyödy. Päästöhiukkaset ja pöly peittää lehdet estäen niiden hengitystä ja valon pääsyä, ja useat muut päästökaasut typpi- ja rikkioksidi, otsoni jne. ovat kasveille varsin vahingollisia.

Mutta, koska tienvarressa ei ole puita sieppaamassa valoa niin matalat kasvit kasvavat siellä paremmin kuin keskellä metsää, niinhän useimmat ruukkukukatkin tykkää enemmän olla ikkunalaudalla kuin vaatekomerossa).

enemmän valoa kirjoitti:

Autoista kasvit eivät kyllä hyödy. Päästöhiukkaset ja pöly peittää lehdet estäen niiden hengitystä ja valon pääsyä, ja useat muut päästökaasut typpi- ja rikkioksidi, otsoni jne. ovat kasveille varsin vahingollisia.

Mutta, koska tienvarressa ei ole puita sieppaamassa valoa niin matalat kasvit kasvavat siellä paremmin kuin keskellä metsää, niinhän useimmat ruukkukukatkin tykkää enemmän olla ikkunalaudalla kuin vaatekomerossa).

Meneppä metsäautotien varteen ja katsele, sielläpä ei metsä ja kasvit kasva samaten kuten valtateiden varressa, missä mahtaa olla syy valossa vai energian saannissa?

old_profile_31762 kirjoitti:

Meneppä metsäautotien varteen ja katsele, sielläpä ei metsä ja kasvit kasva samaten kuten valtateiden varressa, missä mahtaa olla syy valossa vai energian saannissa?

Pakokaasut taitavat muuttaa maisemaa: menin tarkistamaan mitä on julkaistu ja tässä linkki yhteen skotlantilaiseen tutkimukseen (copypasteattuna myös alla)

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VB5-4FJD9FH-4&_user=949111&_coverDate=07%2F31%2F2005&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000049116&_version=1&_urlVersion=0&_userid=949111&md5=709e9535c3628ce11be3211290cd437b

Vegetation composition of roadside verges in Scotland: the effects of nitrogen deposition, disturbance and management

A.M. Truscotta, , S.C.F. Palmera, G.M. McGowana, 1, J.N. Capeb and S. Smartc
aCentre for Ecology and Hydrology, Banchory Research Station, Hill of Brathens, Banchory, Aberdeenshire, AB31 4BW, UK
bCentre for Ecology and Hydrology, Edinburgh Research Station, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK
cCentre for Ecology and Hydrology, Lancaster Research Station, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, LA1 4AP, UK
Received 30 January 2004; accepted 3 December 2004. Available online 23 February 2005.



Abstract

Vehicular emissions of NOx and NH3 result in elevated concentrations of nitrogen at roadside verges. To determine the extent that vehicular nitrogen emissions, disturbance and management affect the vegetation composition of road verges, a survey of 92 verges in Scotland was carried out with sites stratified by background nitrogen deposition and road type. NOx and NH3 concentrations were monitored at 15 key sites for a year, and showed a decreasing gradient with increasing distance from the road. Ellenberg fertility indices of the vegetation communities also showed a general decrease with increasing distance from the road, but there was no straightforward correlation with NOx and NH3 air concentrations between sites. Cover of bare ground, ruderal species and salt-tolerant species were highest at the verge edge. The proximity of the verge to traffic is important both in terms of NOx and NH3 gradients, but also for deposited salt, grit and physical disturbance.

NOx, NH3 and road verge vegetation Ellenberg fertility indices decline with distance from traffic.

Keywords: Ellenberg; Fertility; Nitrogen; Pollution; Roadside verges

1. Introduction

International concern and research on the ecological effects of road traffic is increasing (Angold, 1997, Spellerberg, 1998, Forman, 2000 and Ashenden et al., 2003). Roadside verges form a network of linear habitats estimated to cover 87 000 ha in Scotland (Haines-Young et al., 2000), with verges becoming increasingly important for their conservation value and as wildlife corridors as habitat loss and fragmentation continue. Understanding the impacts of nitrogen pollution, disturbance and verge and road management on the flora of roadside verges is crucial to the development of future management strategies.

Road use continues to increase. The number of motor vehicles in Scotland in 2002 (2.3 million) was 27% higher than in 1992 (Scottish Executive, 2003) with the estimated total volume of traffic on Scotland's roads 18% more in 2002 (c. 41×109 vehicle km) than in 1993 (Department for Transport, 2003). This trend is set to continue, with a predicted increase in growth in traffic in the UK from 1996 to 2016 of 38% and from 1996 to 2031 of 60% (Department of Transport, 1997). In the United States the 6.2 million km system of public roads used by 200 million vehicles (National Research Council, 1997) has been estimated to have ecological effects on one-fifth of the US land area (Forman, 2000). If vehicular emissions were added to this estimate, the cumulative effect of the road system would be still greater.

Road transport accounts for half of the total UK NOx emissions (AQEG, 2003) and over a third of total US NOx emissions (US Department of Transportation, 2002). The fitting of cars with catalytic converters has led to a major increase in vehicular NH3 emissions, as the catalytic reduction of NO to N2 is not complete (Sutton et al., 2000). Durbin et al. (2002) demonstrated that NH3 emissions were approximately 10% of NOx emissions consistent with Cape et al. (2004), with increased emissions at faster speeds (Durbin et al., 2002). It is therefore important to consider exposure to both NOx and NH3 and the zone of impact when investigating the effects of vehicular nitrogen pollution on vegetation.

The effects of increasing traffic volumes may already be apparent, as there was evidence for increased eutrophication and species richness in infertile grassland road verges in Scotland between 1990 and 1998 (Haines-Young et al., 2000). Direct and indirect effects of vehicular pollutants will be species-specific (Ashenden et al., 2003). Sarkar et al. (1986) recorded stunted growth in plants near highways in Calcutta. The impacts of traffic and local verge management strategies are unlikely to be spatially or temporally uniform. The effects of nitrogen deposition on verges may be mediated by verge structure, surrounding land use and verge management techniques, e.g. timing and intensity of cutting (Parr and Way, 1988). Physical disturbance and compaction at the edge of the verge may increase the amount of bare ground and lead to colonisation by ruderal species. In addition, the application of salt and grit to the roads in the winter may affect plant growth (Thompson and Rutter, 1986 and Viskari and Karenlampi, 2000) and the species composition of verge communities (Scott, 1985).

The aims of this work were to assess the vegetation composition of a range of verges typical of Scottish roads and to test the following hypotheses:

1. High traffic volumes and hence elevated nitrogen deposition levels result in high vegetation fertility indices.

2. Disturbance, as affected by road type, traffic volume and distance from the verge, results in increased cover of bare ground and ruderal species.

3. Road and verge management, especially spreading of salt, are important determinants of vegetation composition.

2. Methods

2.1. Site selection

We conducted a botanical survey of 92 Scottish road verge sites during June and July 2001 (hereafter the ‘extensive survey’). Sites were selected on the basis of a 5×3 stratification of annual background nitrogen deposition and road type (Fig. 1). The annual background nitrogen deposition was classified into five classes on the basis of modelled deposition at 5 km square resolution (NEGTAP, 2001):

1. high N deposition from NH3 (>20 kg N ha−1 year−1; >60% from NH3);

2. high wet N deposition (>20 kg N ha−1 year−1; >50% from wet deposition, usually from cloud, so typically at higher altitudes classes 1 and 3);

3. high NOx urban areas (urban land use >30% of the square);

4. low N deposition, high altitude (100 m);

5. low N deposition, low altitude (

kyllä ne kirjoitti:

Pakokaasut taitavat muuttaa maisemaa: menin tarkistamaan mitä on julkaistu ja tässä linkki yhteen skotlantilaiseen tutkimukseen (copypasteattuna myös alla)

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VB5-4FJD9FH-4&_user=949111&_coverDate=07%2F31%2F2005&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000049116&_version=1&_urlVersion=0&_userid=949111&md5=709e9535c3628ce11be3211290cd437b

Vegetation composition of roadside verges in Scotland: the effects of nitrogen deposition, disturbance and management

A.M. Truscotta, , S.C.F. Palmera, G.M. McGowana, 1, J.N. Capeb and S. Smartc
aCentre for Ecology and Hydrology, Banchory Research Station, Hill of Brathens, Banchory, Aberdeenshire, AB31 4BW, UK
bCentre for Ecology and Hydrology, Edinburgh Research Station, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK
cCentre for Ecology and Hydrology, Lancaster Research Station, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, LA1 4AP, UK
Received 30 January 2004; accepted 3 December 2004. Available online 23 February 2005.



Abstract

Vehicular emissions of NOx and NH3 result in elevated concentrations of nitrogen at roadside verges. To determine the extent that vehicular nitrogen emissions, disturbance and management affect the vegetation composition of road verges, a survey of 92 verges in Scotland was carried out with sites stratified by background nitrogen deposition and road type. NOx and NH3 concentrations were monitored at 15 key sites for a year, and showed a decreasing gradient with increasing distance from the road. Ellenberg fertility indices of the vegetation communities also showed a general decrease with increasing distance from the road, but there was no straightforward correlation with NOx and NH3 air concentrations between sites. Cover of bare ground, ruderal species and salt-tolerant species were highest at the verge edge. The proximity of the verge to traffic is important both in terms of NOx and NH3 gradients, but also for deposited salt, grit and physical disturbance.

NOx, NH3 and road verge vegetation Ellenberg fertility indices decline with distance from traffic.

Keywords: Ellenberg; Fertility; Nitrogen; Pollution; Roadside verges

1. Introduction

International concern and research on the ecological effects of road traffic is increasing (Angold, 1997, Spellerberg, 1998, Forman, 2000 and Ashenden et al., 2003). Roadside verges form a network of linear habitats estimated to cover 87 000 ha in Scotland (Haines-Young et al., 2000), with verges becoming increasingly important for their conservation value and as wildlife corridors as habitat loss and fragmentation continue. Understanding the impacts of nitrogen pollution, disturbance and verge and road management on the flora of roadside verges is crucial to the development of future management strategies.

Road use continues to increase. The number of motor vehicles in Scotland in 2002 (2.3 million) was 27% higher than in 1992 (Scottish Executive, 2003) with the estimated total volume of traffic on Scotland's roads 18% more in 2002 (c. 41×109 vehicle km) than in 1993 (Department for Transport, 2003). This trend is set to continue, with a predicted increase in growth in traffic in the UK from 1996 to 2016 of 38% and from 1996 to 2031 of 60% (Department of Transport, 1997). In the United States the 6.2 million km system of public roads used by 200 million vehicles (National Research Council, 1997) has been estimated to have ecological effects on one-fifth of the US land area (Forman, 2000). If vehicular emissions were added to this estimate, the cumulative effect of the road system would be still greater.

Road transport accounts for half of the total UK NOx emissions (AQEG, 2003) and over a third of total US NOx emissions (US Department of Transportation, 2002). The fitting of cars with catalytic converters has led to a major increase in vehicular NH3 emissions, as the catalytic reduction of NO to N2 is not complete (Sutton et al., 2000). Durbin et al. (2002) demonstrated that NH3 emissions were approximately 10% of NOx emissions consistent with Cape et al. (2004), with increased emissions at faster speeds (Durbin et al., 2002). It is therefore important to consider exposure to both NOx and NH3 and the zone of impact when investigating the effects of vehicular nitrogen pollution on vegetation.

The effects of increasing traffic volumes may already be apparent, as there was evidence for increased eutrophication and species richness in infertile grassland road verges in Scotland between 1990 and 1998 (Haines-Young et al., 2000). Direct and indirect effects of vehicular pollutants will be species-specific (Ashenden et al., 2003). Sarkar et al. (1986) recorded stunted growth in plants near highways in Calcutta. The impacts of traffic and local verge management strategies are unlikely to be spatially or temporally uniform. The effects of nitrogen deposition on verges may be mediated by verge structure, surrounding land use and verge management techniques, e.g. timing and intensity of cutting (Parr and Way, 1988). Physical disturbance and compaction at the edge of the verge may increase the amount of bare ground and lead to colonisation by ruderal species. In addition, the application of salt and grit to the roads in the winter may affect plant growth (Thompson and Rutter, 1986 and Viskari and Karenlampi, 2000) and the species composition of verge communities (Scott, 1985).

The aims of this work were to assess the vegetation composition of a range of verges typical of Scottish roads and to test the following hypotheses:

1. High traffic volumes and hence elevated nitrogen deposition levels result in high vegetation fertility indices.

2. Disturbance, as affected by road type, traffic volume and distance from the verge, results in increased cover of bare ground and ruderal species.

3. Road and verge management, especially spreading of salt, are important determinants of vegetation composition.

2. Methods

2.1. Site selection

We conducted a botanical survey of 92 Scottish road verge sites during June and July 2001 (hereafter the ‘extensive survey’). Sites were selected on the basis of a 5×3 stratification of annual background nitrogen deposition and road type (Fig. 1). The annual background nitrogen deposition was classified into five classes on the basis of modelled deposition at 5 km square resolution (NEGTAP, 2001):

1. high N deposition from NH3 (>20 kg N ha−1 year−1; >60% from NH3);

2. high wet N deposition (>20 kg N ha−1 year−1; >50% from wet deposition, usually from cloud, so typically at higher altitudes classes 1 and 3);

3. high NOx urban areas (urban land use >30% of the square);

4. low N deposition, high altitude (100 m);

5. low N deposition, low altitude (

Skotlannista metsät kadonneet? Suomalaisetko syyllisiä? Jollei sinulla ole omaa mielipidettä asioista vaan sinun täytyy turvautua jonkun skotin tutkimukseen niin lopetetaan tähän??

old_profile_31762 kirjoitti:

Skotlannista metsät kadonneet? Suomalaisetko syyllisiä? Jollei sinulla ole omaa mielipidettä asioista vaan sinun täytyy turvautua jonkun skotin tutkimukseen niin lopetetaan tähän??

tekstin vai ei? Ei siinä mistään metsien katoamisesta kerrottu yhtään mitään? Jos tyypit kartoittavat tyyliin mitä tapahtuu metrin etäisyydellä liikenneväylästä, niin miten se muka kertoisi mitään metsistä? mittasivat maaperän typpipitoisuutta eri etäisyyksillä eri paljon liikennettä kantavistaa teistä, ja näki että maaperän lisääntynyt typpi suosi vähän eri kasveja kuin parin metrin päässä oli, ja sen lisäksi kasvit jotka oli tienvarressa oli yleensä sellaisia lajikkeita jotka sietävät suolaa hyvin, talvellahan sitä välillä laitetaan teille...

old_profile_31762 kirjoitti:

Skotlannista metsät kadonneet? Suomalaisetko syyllisiä? Jollei sinulla ole omaa mielipidettä asioista vaan sinun täytyy turvautua jonkun skotin tutkimukseen niin lopetetaan tähän??

Siinä on taas hyvä esimerkki siitä mitä Matti Meikäläinen ymmärtää tieteen tekemisestä. "Mitä tässä tutkimuksia tarvitaan! Lisää hiilidioksidia vaan kehiin niin parvekekukat kasvaa!"