FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W1574646622> ?p ?o ?g. }

• W1574646622 abstract "Following four years of CO2 enrichment (2001-2004) of trees and their understory dwarfheath, and a one-time tree defoliation treatment in the spring of the second year at theSwiss treeline FACE site on Stillberg (Davos, Switzerland), this dissertation summarizesresponses from both the above- and below-ground components of this treeline ecosystem.At the tree physiological level (Handa et al. 2005, chapter 2), we found thatelevated CO2 enhanced photosynthesis in both Larix decidua and Pinus uncinata by ca.40% and led to increased nonstructural carbohydrate concentrations in the needles of bothspecies, but to no significant decrease in stomatal conductance. There was no evidencefor photosynthetic downregulation in either of the conifer species. Irrespective of CO2concentration, defoliation in both species stimulated photosynthesis (Larix, +7 %; Pinus+52%) and increased stomatal conductance (Larix, +42%; Pinus, +108%) in remainingcurrent-year needles in the treatment year and reduced leaf nitrogen concentration (-11%in Larix only) in the year following defoliation. These results are by and large consistentwith what has been observed in multiple other CO2 enrichment experiments to date(Ceulemans et al. 1999, Norby et al. 1999, Nowak et al. 2004, Zotz et al. 2005) and thestrong physiological effects on the trees from the carbon source removal treatmenthighlight how an extreme disturbance can impact the tree’s carbon budget.Despite the c. 40% stimulation of photosynthesis in response to CO2 enrichment,this did not translate into carbon that is purely available for growth regardless of whetherone looks at the shoot or stem increment growth records for either of the studied treespecies. In response to elevated CO2, we observed a consistent positive growth responsein Larix evident both in the annual shoot increment record (c. +20-30%; Handa et al.2005, chapters 2&3) and the stem increment record (+41%; when cumulatively integratedover four years and measured relative to four years of pre-treatment measurements;Handa et al. 2006, chapter 3). The increase in radial stem wood growth was the result ofmore latewood production, in particular, the formation of larger tracheids, rather than agreater number of cells. In contrast, both of these lines of evidence (shoot and stemincrement record) showed no positive growth response of Pinus trees, with the exceptionof the very first year of shoot increment data (Hattenschwiler et al. 2002, chapter 5). Our studies underline, yet again, how CO2 effects on plants show strong species specificity(Loehle 1995), and how any meaningful study attempting to address ecosystemresponses, must consider all its key players and account for species diversity (Korner etal. 2005). Defoliation led to a pronounced decrease in annual ring width of both species,marked in particular by less latewood production in the treatment as well as subsequentyear, underlining again the importance of how a biotic interaction within the systemmight completely modify ecosystem responses in a changing global environment(Zvereva & Kozlov 2006).Plants are frequently observed to increase carbon allocation to below-groundsinks and particularly, to accelerate fine root turnover in response to elevated CO2concentration. Our study shows that in this natural system, no change in response toelevated CO2 exposure occurred. There was no difference in total root standing crop afterfour years, in new root production measured over three years and also no effect on rootdecomposition measured over 26 months (Handa et al. 2008, chapter 4). The lack ofpositive growth response below-ground contrasts with the sustained four year abovegroundgrowth response of Larix decidua, but is in line with the lack of positive abovegroundgrowth response of the later successional Pinus uncinata trees and that of some ofthe understory dwarf shrubs (Zumbrunn 2004). Multiple studies have reported positiveroot growth responses to elevated CO2 concentrations, although very few have beenconducted in the field, have exceeded a study duration >1 year or have used mature trees(Norby & Jackson 2000, Tingey et al. 2000). Root quality measurements indicated thatelevated CO2 significantly increased starch concentration, but there was no change in Nconcentration or in dehydrogenase activity. Other studies have also shown higher starchconcentration (Janssens et al. 1998), but also lower N content in roots under elevated CO2(Janssens et al. 1998, Pregitzer et al. 2000, Wan et al. 2004). However, this result iscertainly not ubiquitous (Tingey et al. 2003, King et al. 2005). Finally, our stable isotopedata indicate that only ca. 30% of the new carbon was incorporated into new rootsindicating a rather slow root turnover in this system." @default.
• W1574646622 created "2016-06-24" @default.
• W1574646622 creator A5090380558 @default.
• W1574646622 date "2008-01-01" @default.
• W1574646622 modified "2023-09-27" @default.
• W1574646622 title "Tree and ecosystem responses to four years of in situ CO2 enrichment at the Swiss treeline" @default.
• W1574646622 cites W103899205 @default.
• W1574646622 cites W1501061422 @default.
• W1574646622 cites W1531643369 @default.
• W1574646622 cites W1548802581 @default.
• W1574646622 cites W1559401033 @default.
• W1574646622 cites W1560532690 @default.
• W1574646622 cites W1564371012 @default.
• W1574646622 cites W1601469038 @default.
• W1574646622 cites W1619751255 @default.
• W1574646622 cites W1625260889 @default.
• W1574646622 cites W1630902002 @default.
• W1574646622 cites W1661209811 @default.
• W1574646622 cites W1665688663 @default.
• W1574646622 cites W1669888413 @default.
• W1574646622 cites W17142094 @default.
• W1574646622 cites W1755883143 @default.
• W1574646622 cites W1864647853 @default.
• W1574646622 cites W189964265 @default.
• W1574646622 cites W1903751826 @default.
• W1574646622 cites W1927248456 @default.
• W1574646622 cites W193142372 @default.
• W1574646622 cites W1952939336 @default.
• W1574646622 cites W1963529341 @default.
• W1574646622 cites W1966039340 @default.
• W1574646622 cites W1967466803 @default.
• W1574646622 cites W1967700077 @default.
• W1574646622 cites W1968270907 @default.
• W1574646622 cites W1971550826 @default.
• W1574646622 cites W1971655307 @default.
• W1574646622 cites W1975380304 @default.
• W1574646622 cites W1976229095 @default.
• W1574646622 cites W1976689440 @default.
• W1574646622 cites W1977744997 @default.
• W1574646622 cites W1979280298 @default.
• W1574646622 cites W1979776617 @default.
• W1574646622 cites W1980110132 @default.
• W1574646622 cites W1980317135 @default.
• W1574646622 cites W1980434846 @default.
• W1574646622 cites W1981474468 @default.
• W1574646622 cites W1982520366 @default.
• W1574646622 cites W1982747191 @default.
• W1574646622 cites W1984171908 @default.
• W1574646622 cites W1984412649 @default.
• W1574646622 cites W1984668626 @default.
• W1574646622 cites W1984884511 @default.
• W1574646622 cites W1985168832 @default.
• W1574646622 cites W1986176303 @default.
• W1574646622 cites W1986597875 @default.
• W1574646622 cites W1987223854 @default.
• W1574646622 cites W1989061310 @default.
• W1574646622 cites W1989860257 @default.
• W1574646622 cites W1991664386 @default.
• W1574646622 cites W1992188390 @default.
• W1574646622 cites W1992252468 @default.
• W1574646622 cites W1993317372 @default.
• W1574646622 cites W1994241137 @default.
• W1574646622 cites W1997073161 @default.
• W1574646622 cites W1997742462 @default.
• W1574646622 cites W1998305035 @default.
• W1574646622 cites W1998861947 @default.
• W1574646622 cites W1999078006 @default.
• W1574646622 cites W2000212150 @default.
• W1574646622 cites W2004256739 @default.
• W1574646622 cites W2007169555 @default.
• W1574646622 cites W2008185637 @default.
• W1574646622 cites W2008623756 @default.
• W1574646622 cites W2009332318 @default.
• W1574646622 cites W2010800609 @default.
• W1574646622 cites W2012124708 @default.
• W1574646622 cites W2014145383 @default.
• W1574646622 cites W2015000374 @default.
• W1574646622 cites W2016981567 @default.
• W1574646622 cites W2017050536 @default.
• W1574646622 cites W2017252970 @default.
• W1574646622 cites W2017390318 @default.
• W1574646622 cites W2018106025 @default.
• W1574646622 cites W2018437556 @default.
• W1574646622 cites W2018440025 @default.
• W1574646622 cites W2018757772 @default.
• W1574646622 cites W2019765698 @default.
• W1574646622 cites W2019969363 @default.
• W1574646622 cites W2020507833 @default.
• W1574646622 cites W2021643045 @default.
• W1574646622 cites W2022978549 @default.
• W1574646622 cites W2024033899 @default.
• W1574646622 cites W2025555327 @default.
• W1574646622 cites W2030362769 @default.
• W1574646622 cites W2031113456 @default.
• W1574646622 cites W2034915987 @default.
• W1574646622 cites W2035394351 @default.
• W1574646622 cites W2036516767 @default.
• W1574646622 cites W2038561106 @default.
• W1574646622 cites W2040263482 @default.
• W1574646622 cites W2041564752 @default.

• next