Salsola vermiculata is a highly palatable shrub and widely used in rangeland rehabilitation programs, but has short seed longevity. To identify the most cost effective storage method for S. vermiculata, experiments we...Salsola vermiculata is a highly palatable shrub and widely used in rangeland rehabilitation programs, but has short seed longevity. To identify the most cost effective storage method for S. vermiculata, experiments were carried out to test the effects of fruit bracts （wings）, temperature regimes, seed moisture and packaging methods on storage life. Seed samples were removed from storage at monthly intervals for testing and towards the end of the experiments samples were transferred from hermetic to ambient storage conditions and tested for germination. Experiment 1 continued for 1,140 days, Experiment 2 for 720 days. For de-winged seed, high moisture content increased seed longevity, suggesting that desiccation susceptibility is one of the causes of limited longevity in this species. Most longevity regression lines of winged seeds had negative intercepts suggesting increase in germination resulting from gradual dormancy-breaking. Drying and packaging alone increased longevity by 7.6 and 3.8 times in Experiments 1 and 2, respectively. Samples kept at lower temperature and lower moisture treatments survived longer under ambient conditions. Increased longevity by drying and vacuum packaging alone can provide simple, cost effective and environmentally friendly options for rangeland rehabilitation programs.展开更多
A forest carbon （C） sequestration project was conducted to evaluate the economic incentives that would be required by landowners to engage in C trading under different management regimes. Costs associated with joint...A forest carbon （C） sequestration project was conducted to evaluate the economic incentives that would be required by landowners to engage in C trading under different management regimes. Costs associated with joint management for C sequestration and timber would be valuable for establishing sound forest C trading systems. In this study, we calculated the C yield and amortized value of three Wyoming, ponderosa pine stands. The management practices examined were, unmanaged, even-aged （regeneration after clear-cut） and uneven-aged （selectively harvested）. Costs and revenues associated with three stands were converted into 2006 real dollars using the all commodity producer price index to facilitate a comparison among the net revenues of three stands. Net revenues were annualized using a conservative annual interest rate of 4.5%. Our even-aged stand bad the highest annual average C yield of 2.48 Mg·ha^-1·a^-1, whereas, the uneven-aged stand had the lowest C accumulation （1.98Mg·ha^-1·a^-1）. Alternatively, the even-aged stand had the highest amortized net return of S276·ha^-1·a^-1 and the unmanaged stand had the lowest net return of S64·ha^-1·a^-1. On the plots examined, an annual payment of S22 for each additional Mg of C sequestered would encourage a change from uneven aged management to an unmanaged stand that sequesters additional C, in the absence of transactions costs.展开更多
Fossil woods were collected from the Upper Cretaceous to Paleocene beds distributed around Heilong- jang （Amur） River area of China and Russia. A total of 43 specimens were collected from Baishantou, Long- gushan, a...Fossil woods were collected from the Upper Cretaceous to Paleocene beds distributed around Heilong- jang （Amur） River area of China and Russia. A total of 43 specimens were collected from Baishantou, Long- gushan, and Yong＇ancun in Jiayin, China, and 85 specimens from Zeya-Bureya Basin lying southeast of Blagoveshchensk in Russia. Selected specimens were sectioned and studied anatomically. The source deposits of almost all identifiable specimens belong to the Upper Cretaceous （Campanian） Taipinglinchang Formation and the Paleocene Wuyun Formation in China, and the Paleocene Upper Tsagayan Formation in Russia. Al- though the results obtained are still far from complete, the taxonomic composition of the fossil woods show marked stratigraphic differences between the two horizons beyond the K/T boundary in China. There is also a strong similarity in wood flora between the Wuyun Formation of China and the Upper Tsagayan Formation of Russia. All identified specimens from the Taipinglinchang Formation are Xenoxylon latiporosum, This is one of the stratigraphically younger records of Xenoxylon, which is a conifer morphogenus of uncertain affinity most common in the Triassic to Early Cretaceous. Only one specimen with possible derivation from either the Wuyun or the Maastriehtian Furao Formation in China was identified as Taxodioxylon sp. The Wuyun Formation yielded both conifers and dicotyledonous woods. The conifers include Taxodioxylon sequoianum of the Taxodiaceae, and Protopiceoxylon amurense, which is attributable to the extant genera Keteleeria or Nothotsuga of the Pinaeeac, both are at present endemic to China. At least two morphotypes of dicotyledonous woods were recognized, with one identified as el. Hamamelidoxylon , and the other diffuse porous wood is characterized by numerous heterogeneous rays. From the Zeya-Buleya Basin of Russia, Taxodioxylon sequoianum and cf. Hamamelidoxylon sp. were identified from the Upper Tsagayan Formation. The similarity of wood composition in both Wuyun and Upper Tsagayan Formations support lithological as well as biostratigraphic correlations proposed for the two formations.展开更多
文摘Salsola vermiculata is a highly palatable shrub and widely used in rangeland rehabilitation programs, but has short seed longevity. To identify the most cost effective storage method for S. vermiculata, experiments were carried out to test the effects of fruit bracts （wings）, temperature regimes, seed moisture and packaging methods on storage life. Seed samples were removed from storage at monthly intervals for testing and towards the end of the experiments samples were transferred from hermetic to ambient storage conditions and tested for germination. Experiment 1 continued for 1,140 days, Experiment 2 for 720 days. For de-winged seed, high moisture content increased seed longevity, suggesting that desiccation susceptibility is one of the causes of limited longevity in this species. Most longevity regression lines of winged seeds had negative intercepts suggesting increase in germination resulting from gradual dormancy-breaking. Drying and packaging alone increased longevity by 7.6 and 3.8 times in Experiments 1 and 2, respectively. Samples kept at lower temperature and lower moisture treatments survived longer under ambient conditions. Increased longevity by drying and vacuum packaging alone can provide simple, cost effective and environmentally friendly options for rangeland rehabilitation programs.
文摘A forest carbon （C） sequestration project was conducted to evaluate the economic incentives that would be required by landowners to engage in C trading under different management regimes. Costs associated with joint management for C sequestration and timber would be valuable for establishing sound forest C trading systems. In this study, we calculated the C yield and amortized value of three Wyoming, ponderosa pine stands. The management practices examined were, unmanaged, even-aged （regeneration after clear-cut） and uneven-aged （selectively harvested）. Costs and revenues associated with three stands were converted into 2006 real dollars using the all commodity producer price index to facilitate a comparison among the net revenues of three stands. Net revenues were annualized using a conservative annual interest rate of 4.5%. Our even-aged stand bad the highest annual average C yield of 2.48 Mg·ha^-1·a^-1, whereas, the uneven-aged stand had the lowest C accumulation （1.98Mg·ha^-1·a^-1）. Alternatively, the even-aged stand had the highest amortized net return of S276·ha^-1·a^-1 and the unmanaged stand had the lowest net return of S64·ha^-1·a^-1. On the plots examined, an annual payment of S22 for each additional Mg of C sequestered would encourage a change from uneven aged management to an unmanaged stand that sequesters additional C, in the absence of transactions costs.
基金NSFC Project 30220130698 to G. S.the Grant-in-Aid for Scientific Research no.1425507 from the Ministry of Education,Culture,Sports,Science and Technology of Japan to H.N.
文摘Fossil woods were collected from the Upper Cretaceous to Paleocene beds distributed around Heilong- jang （Amur） River area of China and Russia. A total of 43 specimens were collected from Baishantou, Long- gushan, and Yong＇ancun in Jiayin, China, and 85 specimens from Zeya-Bureya Basin lying southeast of Blagoveshchensk in Russia. Selected specimens were sectioned and studied anatomically. The source deposits of almost all identifiable specimens belong to the Upper Cretaceous （Campanian） Taipinglinchang Formation and the Paleocene Wuyun Formation in China, and the Paleocene Upper Tsagayan Formation in Russia. Al- though the results obtained are still far from complete, the taxonomic composition of the fossil woods show marked stratigraphic differences between the two horizons beyond the K/T boundary in China. There is also a strong similarity in wood flora between the Wuyun Formation of China and the Upper Tsagayan Formation of Russia. All identified specimens from the Taipinglinchang Formation are Xenoxylon latiporosum, This is one of the stratigraphically younger records of Xenoxylon, which is a conifer morphogenus of uncertain affinity most common in the Triassic to Early Cretaceous. Only one specimen with possible derivation from either the Wuyun or the Maastriehtian Furao Formation in China was identified as Taxodioxylon sp. The Wuyun Formation yielded both conifers and dicotyledonous woods. The conifers include Taxodioxylon sequoianum of the Taxodiaceae, and Protopiceoxylon amurense, which is attributable to the extant genera Keteleeria or Nothotsuga of the Pinaeeac, both are at present endemic to China. At least two morphotypes of dicotyledonous woods were recognized, with one identified as el. Hamamelidoxylon , and the other diffuse porous wood is characterized by numerous heterogeneous rays. From the Zeya-Buleya Basin of Russia, Taxodioxylon sequoianum and cf. Hamamelidoxylon sp. were identified from the Upper Tsagayan Formation. The similarity of wood composition in both Wuyun and Upper Tsagayan Formations support lithological as well as biostratigraphic correlations proposed for the two formations.
