Anatomical and blue intensity methods to determine wood density converge in contributing to explain different distributions of three palaeotropical pine species

IAWA Journal ◽  
2021 ◽  
pp. 1-16
Author(s):  
Le T. Ho ◽  
Frank M. Thomas

Abstract Wood density constitutes an integrative trait of water relations and growth. We compared the recently developed blue intensity (BI) method, which has only rarely been applied to tropical conifers, for determining wood density with anatomical analyses in studying the three rarely investigated palaeotropical pine species Pinus kesiya, P. dalatensis and P. krempfii, which co-occur in South-Central Vietnam, but differ in their distribution areas. For species comparisons, we also calculated the hydraulic conductivity of the xylem with the Hagen-Poiseuille equation and the water potential causing 50% loss of hydraulic conductivity () based on the anatomical analyses. We hypothesized (i) that the BI values are correlated with the cell wall fractions, the calculated hydraulic conductivity and the values; and (ii) that the wider occurrence of P. kesiya, which also can grow at drier sites, is reflected by higher wood density, lower hydraulic conductivity, lower (more negative) values and a smaller variation in the wood anatomical features across the years compared to the other two species. In agreement to our hypotheses, the results of the BI and the anatomical method were closely correlated, especially for sapwood, and P. kesiya exhibited features that are related to the growth at drier sites and to a higher tolerance towards drought: higher wood density and cell wall:lumen area ratios of its smaller xylem conduits, lower calculated hydraulic conductivity and more negative values. The BI method is well suitable for determining the wood density in tropical conifers. As a fast and inexpensive method, it may be used for initial screening woody species for their water transport capacity and drought resistance.

PLoS ONE ◽  
2013 ◽  
Vol 8 (3) ◽  
pp. e58205 ◽  
Author(s):  
Chantal M. Morel ◽  
Ngo Duc Thang ◽  
Annette Erhart ◽  
Nguyen Xuan Xa ◽  
Koen Peeters Grietens ◽  
...  

2014 ◽  
Vol 54 (1) ◽  
pp. 76-84 ◽  
Author(s):  
N. G. Emel’yanova ◽  
D. A. Pavlov ◽  
E. D. Pavlov ◽  
Luong Thi Bich Thuan ◽  
Vo Thi Ha

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Francisco M. P. Gonçalves ◽  
Rasmus Revermann ◽  
Amândio L. Gomes ◽  
Marcos P. M. Aidar ◽  
Manfred Finckh ◽  
...  

The study was carried out in the Cusseque area of the Municipality of Chitembo in south-central Angola. Our objectives were to assess the floristic diversity, the species composition, and stand structure of Miombo woodlands during regeneration after shifting cultivation. A total of 40 plots of 1000 m2were surveyed and analyzed, corresponding to mature forests/woodlands and three fallow types of different age. The analyses were based on plot inventories of all trees with DBH ≥ 5 cm. A total of 51 woody species, 38 genera, and 19 families were recorded. The dominant family was Fabaceae, with subfamily Caesalpinioideae being very abundant. Shannon Diversity and Evenness were highest in mature forests and young fallows, while the mature forest stands showed the highest species richness. A Principal Coordinates Analysis (PCoA) showed many species shared between the intermediate fallow types, but only few species were shared with young fallows. Mature forests formed a clearly distinct group. This study shows potential pathways of forest recovery in terms of faster regeneration after agricultural abandonment and, thus, the results presented here can be used in future conservation and management plans in order to reduce the pressure on mature forests.


Afrika Focus ◽  
2020 ◽  
Vol 33 (1) ◽  
Author(s):  
Rabiou Habou ◽  
Moussa Massaoudou ◽  
Tougiani Abasse ◽  
Mahamane Ali ◽  
Mahamane Larwanou ◽  
...  

Les espèces ligneuses jouent un rôle important dans la vie des populations locales. Parmi les espèces couramment utilisées au Niger figurent Balanites aegyptiaca et Ziziphus mauritiana. Ces deux espèces sont exploitées comme sources alimentaires et pour divers produits médicinaux, avec comme conséquence une réduction de leurs peuplements. La présente étude vise à analyser la structure des peuplements et les modes de régénération des deux espèces dans deux secteurs agro-écologiques contrastées de la région de Maradi au centre sud du Niger. Au total, 60 relevés ont été délimités, d’une part dans des formations naturelles dominées par ces espèces, et d’autre part dans les systèmes agrosylvopastoraux des secteurs sahélien et sahélo-soudanien. Dans chaque placette et sur chaque arbre, le diamètre à 1,30 m au rasdu sol , la hauteur totale et deux diamètres perpendiculaires de houppier ont été mesurés. L’inventaire de la régénération a été effectué dans 5 placeaux. La nature de la régénération (drageon, marcotte, semis naturel), la hauteur totale et le nombre de tiges de chaque plantule ont été notés. La densité de B. aegyptiaca ne varie significativement entre sites et entre secteurs. Par contre, la densité de Z. mauritiana varie significativement entre sites et entre secteurs. En effet, le site de Birni Lallé, situé dans le secteur sahélien strict, et le site de Kegil dans le secteur sahélo-soudanien ont les densités les plus élevées de Z. mauritiana avec respectivement 66,4 ± 52,5 et 77,5 ± 61,4 arbres/ha. L’analyse de la distribution des tiges par classe de diamètre montre que pour les deux espèces, les individus jeunes sont bien représentés. Cela suggère une bonne régénération de ces espèces. L’analyse de la densité et nature de régénération montre que les deux espèces se régénèrent essentiellement par drageonnage. En réponse au ramassage des fruits pour diverses utilisations, les espèces B. aegyptiaca et Z. mauritiana ont développé des stratégies alternatives de propagation en zone sahélienne. Cette aptitude à la propagation végétative permet aux deux espèces de s’adapter en zones arides caractérisées par la sécheresse et les hautes températures. MOTS CLÉS : DISTRIBUTION DES ESPÈCES LIGNEUSES, B. AEGYPTIACA, Z. MAURITIANA, MARADI, NIGER, SAHÉLO-SOUDANIEN [83] afrika focus — Volume 33, Nr. 1, 2020 — pp. 83-104 RABIOU HABOU, MOUSSA MASSAOUDOU, TOUGIANI ABASSE, MAHAMANE ALI, MAHAMANE LARWANOU & PATRICK VAN DAMME Wood species play an important role in the life of local communities. Among the species commonly used in Niger, are Balanites aegyptiaca and Ziziphus mauritiana. This species are exploited as food sources and as various medicinal products, with a consequent reduction in their populations. The present study aims to analyze the stand structure and the regeneration modes of the two species in two contrasting agro-ecological sectors of the Maradi region in south central Niger. A total of 60 surveys were delineated in natural formations dominated by these species and in agrosilvopastoral system in the Sahelian and Sahelo-Sudanian zones. On each tree, the diameter at 1.30 m from the ground, the total height and two perpendicular tree crown diameters were measured. The inventory of natural regeneration was carried out in 5 plots delineated in each plot. The mode of reproduction of the regeneration (suckers, marcots, natural seedlings) was recorded as well as the total height and the number of stems of each juvenile were. The density of B. aegyptiaca does not vary significantly between sites and between sectors. The Birni Lallé site, located in the strict Sahelian zone, and the Kegil site in the Sahelo-Sudanese sector stand out in terms of Z. mauritiana density with respectively 66.4 ± 52.5 and 77.5 ± 61.4 trees. /Ha. The analysis of the diameter class structure shows that for both species, young individuals are well represented. This suggests strong regeneration among these species. The analysis of the density and nature of regeneration shows that the two species regenerate mainly by suckering. In response to the collection of fruits for various uses by local populations, B. aegyptiaca and Z. mauritiana have developed alternative propagation strategies in the Sahelian zone. This ability to propagate vegetatively allows these two species to adapt to arid areas characterized by drought and high temperatures. KEY WORDS: DISTRIBUTION OF WOODY SPECIES, B. AEGYPTIACA, Z. MAURITIANA, MARADI, NIGER, SAHELO-SUDANESE


2019 ◽  
Vol 71 (1) ◽  
Author(s):  
Wendy J. Leonard ◽  
O. W. Van Auken

Abstract In the past, grasslands and savannas were common in many areas of south-central Texas, including the San Antonio area. With the advent of European settlers and their livestock, much of this area was converted to agriculture and rangeland. Today, most of San Antonio is developed, but some preservation has occurred. Restored grassland, mechanically cleared of Juniperus ashei (juniper, Ashe juniper) and other woody species in 2013, was examined and compared to adjacent non-cleared woodland. The woodland examined was dominated by Diospyros texana (Texas persimmon) and Juniperus ashei. Richness in the woodland canopy was 15 species. The understory below the canopy had 25 woody species. In the restored grassland area, herbaceous plant cover was 41.8%, woody plant cover 5.8%, bare soil 2.9%, and litter cover 49.5%. Species richness was 71, with 60 herbaceous and 11 woody species (percent cover of each from <0.1–7.1%). The most common species in the restored grassland in descending order were Nassella leucotricha (Texas winter grass), Calyptocarpus vialis (straggler daisy), Carex planostachys (cedar sedge), Sporobolus crypandrus (sand dropseed), D. texana, and Verbesina virginica (frost weed). Several C4 grass species were present with low cover but may increase in abundance over time. Four of the six most common restored grassland species were present below the woodland canopy and 12 woody species were present in the restored grassland as juveniles. Cost of restoration was approximately $38,500 ($7,500 supplies, $31,000 labor).


2013 ◽  
Vol 29 (1) ◽  
pp. 63-80 ◽  
Author(s):  
Mamo Kebede ◽  
Eshetu Yirdaw ◽  
Olavi Luukkanen ◽  
Mulugeta Lemenih

Abstract Floristic diversity and the composition of vascular plants are described for the moist Afromontane forest (MAF) of Wondo Genet, south-central Ethiopia. A total of 75 (20 x 20 m) quadrats were sampled and data on species identity, abundance, elevation, slope and aspect were recorded. Different diversity indices and ordination techniques were used to analyze the data. A total of 240 plant species including seven endemic plant species were found representing 94 families and 210 genera, of which trees constitute 23.8%, shrubs 25%, herbs 35%, lianas 11.3% and ferns 5%. Cluster and indicator species analyses revealed five plant communities described as: Teclea nobilis-Calpurnia aurea, Erythrococca trichogyne-Millettia ferruginea, Croton macrostachyus-Vernonia hochstetteri, Protea gaguedi-Rhus retinorrhoea and Dodonaea angustifolia-Hypericum quartinianum. Elevation (R2=0.48, P<0.001), slope (R2=0.14, P<0.001) and aspect (R2=0.04, P<0.01) correlated significantly and negatively with species richness, whereas only elevation (R2=0.30, P<0.001) and slope (R2=0.13, P<0.001) related significantly and negatively with abundance. Sørensen’s similarity coefficient indicates that the forest of Wondo Genet is similar to moist montane forests of southwestern and southeastern Ethiopia. Given the high diversity, coupled with the existence of endemic species, ecosystem conservation and restoration strategies with further research are warranted.


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