Seed reserve composition in 19 tree species of a tropical deciduous forest in Mexico and its relationship to seed germination and seedling growth

Patterns of leaf phenological diversity were documented in nine key tree species of a tropical deciduous forest in the Vindhyan region of India. Monthly leaf counts on 160 tagged twigs on ten individuals of each species were made through two annual cycles. Tree species exhibited a gradient of deciduousness (∼leafless duration), ranging from semi-evergreen species (entire population never becoming leafless) to 7-mo-deciduous species. The semi-evergreen species initiated leaf flush (bud break of vegetative bud) earlier around the spring equinox. In all deciduous tree species synchronous leaf-flush initiation, with low inter-annual variability, occurred during the hot dry summer (May–June, day temperature >40 °C), prior to the onset of the rainy season. Based on the quantification of leafless period, leaf-flush duration, and leaf strategy index (leaf-flush rate/leaf-fall rate, proposed in this study) in different species, four plant functional types were recognized: (a) semi-evergreen, spring flushing, showing leaf exchange, with mean leafless period 8 d, leaf-flush duration 6–7 mo and leaf strategy index <0.5 (Shorea robusta); (b) <2-mo-deciduous, summer flushing, leafless period 3–8 wk, leaf-flush duration 5–6 mo, and leaf strategy index >0.5−<0.7 (Anogeissus latifolia, Diospyros melanoxylon and Hardwickia binata); (c) 2–4-mo-deciduous, summer flushing, leafless period 2–3 mo, leaf-flush duration 4–5 mo, and leaf strategy index >0.8−<1.0 (Acacia catechu, Lagerstroemia parviflora and Terminalia tomentosa); and (d) >4-mo-deciduous, summer flushing, leafless period >4–7 mo, leaf-flush duration 3–4 mo, and leaf strategy index 1.0 (Boswellia serrata and Lannea coromandelica). Conspecific trees showed asynchrony with respect to leaf-flush completion, initiation and completion of leaf-fall, and extent of leafless period. Leaf strategy index (indicating rate of resource use and conservation) was strongly related with the leafless period in different species (r=0.82) and can serve as a useful index in leaf phenological studies and classification of plant functional types.

Download Full-text

Studies on effects of seed size on germination and seedling growth of Elaeocarpus and Canarium tree species

INTERNATIONAL JOURNAL OF AGRICULTURAL SCIENCES ◽

10.15740/has/ijas/16.2/270-276 ◽

2020 ◽

Vol 16 (2) ◽

pp. 270-276

Author(s):

Basavaraj L. Tamadaddi ◽

G. Prabhuling

Keyword(s):

Seed Germination ◽

Seed Size ◽

Seedling Growth ◽

Tree Species ◽

Seed Treatment ◽

Growth Parameters ◽

Shoot Length ◽

Medium Size ◽

Dry Matter Accumulation ◽

Collar Diameter

An investigation was undertaken on two medicinally important evergreen tree species of Western Ghats namely, Elaeocarpus munronii and Canarium striuctum to improve seed germination and enhance seedling growth in nursery. The seeds collected from two randomly chosen trees in each species were used for the study. In general seed germination was very poor in both the species. The maximum germination of 4.66 per cent was observed in Elaeocarpus munronii and it was 13.33 per cent in Canarium striuctum. Though big and medium size seeds recorded higher germination per cent than small size seeds in both the species studied, the seed size effect on germination was found to be non-significant. The results of the study revealed that seed size did influence seedling growth in both the species. Seeds of bigger size produced seedlings with higher values of shoot length, root length and collar diameter but their effect on dry matter accumulation was not significant. The effect of seed treatments on seedling growth was not noticed in Elaeocarpus munronii while seed treatment with sulphuric acid in Canarium striuctum showed slight but significant increase in shoot length, however, other growth parameters remained unaffected. The effects of seed size as well as of seed treatment on germination and seedling growth was found to be similar in both the trees species studied.

Download Full-text

Structure and tree diversity patterns at the landscape level in Mexican tropical deciduos forest

Botanical Sciences ◽

10.17129/botsci.1732 ◽

2017 ◽

pp. 43

Author(s):

Elvira Durán ◽

Jorge A. Meave ◽

Emily J. Lott ◽

Gerardo Segura

Keyword(s):

Species Diversity ◽

Tree Species ◽

Dominant Species ◽

Deciduous Forest ◽

Principal Component ◽

Species Group ◽

Average Density ◽

Tropical Deciduous Forest ◽

Tree Species Diversity ◽

Landscape Level

Landscape level variability of structure and tree species diversity was analyzed in a tropical deciduous forest at Chamela, Mexico. Trees with DBH ≥5 cm were sampled in 21 0.24 ha plots (5.04 ha in total) distributed among six different morpho-pedological land units. Average density was 1,385 individuals ha-1, basal area 15.9 m2 ha-1, and canopy height 6.8 m. Trunks with DBH ≤14 cm accounted for 90% of the entire set. A total of 148 species, 102 genera, and 43 families were recorded. Seventy percent of all species were poorly represented (< 10 individuals ha-1). A Principal Component Analysis (PCA) based on structure and diversity variables showed that plots from the same morpho-pedological land unit were not always located close to each other along the two first axes, but a further PCA based on dominant species clearly divided two groups of plots. Although canopy structure and tree species diversity varied continuously across the landscape, -diversity (evaluated through species similarity between plot pairs) and the identities of dominant species exhibited the clearest distinction. The dichotomy between granitic vs. non-granitic lithology was the condition most clearly related with a lower similarity in species composition and the strongest contrast in the dominant species group.

Download Full-text

The Effects of Leaf Extracts of Four Tree Species on Amygdalus pedunculata Seedlings Growth

Frontiers in Plant Science ◽

10.3389/fpls.2020.587579 ◽

2021 ◽

Vol 11 ◽

Author(s):

Xiuqing Wang ◽

Ruiqi Zhang ◽

Jinxin Wang ◽

Long Di ◽

Huaibiao Wang ◽

...

Keyword(s):

Seed Germination ◽

Seedling Growth ◽

Coal Mine ◽

Tree Species ◽

Cell Membrane Permeability ◽

Pinus Tabulaeformis ◽

Allelopathic Effect ◽

Fresh Weight ◽

Leaf Extracts ◽

Fragile Environment

Vegetation reconstruction is an urgent problem in fragile environment like coal mine subsidence areas. Amygdalus pedunculata is an important eco-economic shrub species that promotes wind prevention, sand fixation as well as soil and water conservation. The natural regeneration of pure Amygdalus pedunculata forests is difficult to achieve because of its low seed germination rate and weak seedling growth. A stereo-complex ecosystem could potentially promote the germination and seedling growth of A. pedunculata and establish a steady mixed plantation consisting of trees and shrubs. Here, laboratory and pot experiments were conducted to assess the effect of four tree species on morphological and physiological indexes of A. pedunculata. The laboratory experiment showed that A. pedunculata seed germination and seedling growth from Yuyang County (YC-1) and Shenmu County (SC-6) were higher when plants were treated with the aqueous leaf extracts of Pinus sylvestris, Broussonetia papyrifera, and Pinus tabulaeformis compared with Populus simonii at concentrations of 2.5% (E2.5) and 5% (E5). Furthermore, the donor leaf extract was more sensitive to YC-1 than to SC-6. The pot experiment showed that the E2.5 and E5 treatments with the aqueous leaf extracts on the three tree species had strong promoting effects of seedling length, root length, seedling fresh weight, root fresh weight, and ground diameter for YC-1. The activity of catalase of A. pedunculata seedlings first increased and then decreased, while the activity of peroxidase, superoxide dismutase, roots, and the contents of soluble protein and chlorophyll decreased; the opposite patterns were observed for malondialdehyde, soluble sugar, cell membrane permeability, and proline were the opposite. Synthetical allelopathic effect index values of the leaf extracts of the three species on YC-1 were as follows: P. sylvestris > B. papyrifera > P. tabulaeformis (E2.5 to E20). Therefore, P. sylvestris and B. papyrifera could be used to promote the growth of A. pedunculata seedlings as well as for the construction of mixed plantations in coal mine degradation areas. Generally, this study provides new insight into the creation of stereo-complex ecosystems (P. sylvestris + A. pedunculata and B. papyrifera + A. pedunculata) in arid fragile environment.

Download Full-text

La flora arbórea de Michoacán, México

Botanical Sciences ◽

10.17129/botsci.1721 ◽

2017 ◽

pp. 47 ◽

Cited By ~ 1

Author(s):

Eva M. Cué-Bär ◽

José Luis Villaseñor ◽

Libertad Arredondo-Amezcua ◽

Guadalupe Cornejo-Tenorio ◽

Guillermo Ibarra-Manríquez

Keyword(s):

Tree Species ◽

Deciduous Forest ◽

Coniferous Forest ◽

Tropical Dry Forest ◽

The State ◽

Dry Forest ◽

Tropical Deciduous Forest ◽

Oak Forest ◽

Vegetation Types ◽

Geologic History

Based on the review of floristic and taxonomic literature, as well as on the examination of specimens housed at the herbaria of the Centro Regional del Bajío (IEB) and the Instituto de Biología (MEXU), we recorded 845 species, 352 genera and 100 families of trees for the state of Michoacán, Mexico. The largest numbers of species per family were recorded for Asteraceae (82), Fabaceae (74), Mimosaceae (67), Caesalpiniaceae (39) and Burseraceae (38), while at the genus level Bursera (37), Quercus (35), Lonchocarpus (19), Senna (18), and Acacia (16) are the most speciose. The genus Beiselia (Burseraceae) and 14 species (1.8 %) are strict endemics to the state. A total of 28 families (28%) and 210 genera (60%) are represented in the state only by one tree species each. The most important vegetation types according to their species richness are tropical deciduous forest (593, 70.2%), coniferous forest (336, 39.8%) and oak forest (332, 39.3%). A high proportion (69.9%) of Michoacán’s tree species is located in 2-4 vegetation types; 173 species (21.5%) have been found just in one type, mainly in the tropical dry forest (87 species, 10.3%). The floristic richness of Michoacán is largely explained by its complex geologic history, its rugged physiography, its diverse climate, and its multiple vegetation types, as well as by its location at the confluence of the Holartic and Neotropical floristic kingdoms. Counties and species on which to focus conservation efforts for trees in the state are pinponted.

Download Full-text