scholarly journals Structure and Floristic Composition in a Successional Gradient in a Cloud Forest in Chiapas, Southern Mexico

Author(s):  
Miguel Angel ◽  
Cesar Tejeda-Cruz ◽  
Ruben Martinez-Camilo ◽  
Nayely Martinez-Melendez ◽  
Sergio Lopez ◽  
...  
2017 ◽  
pp. 11
Author(s):  
Mario González-Espinosa ◽  
Neptalí Ramírez-Marcial ◽  
Angélica Camacho-Cruz ◽  
Silvia C. Holz ◽  
José María Rey-Benayas ◽  
...  

Montane forests of southern Mexico have been severely fragmented and their structure and floristic composition have been altered because of traditional agriculture and population growth. In extensive areas of Chiapas, forest restoration is not only an urgent need, but it also represents a viable option for the recovery of products and services that could be used in the future in a sustainable way. Forest restoration should be based upon the understanding of basic ecological processes followed by the design of appropriate practices, and taking into account economic and social issues that may guide an adaptive approach of the action programs. Research, development, and outreach experiences spanning more than a decade lead us to suggest models for some of the ecological, technical, and social issues underlying the recovery, conservation, and rational use of forest resources


2008 ◽  
Vol 24 (4) ◽  
pp. 433-444 ◽  
Author(s):  
R. F. del Castillo ◽  
M. A. Pérez Ríos

AbstractSeed dispersal is the first stage of colonization, and potentially affects recruitment. This process deserves more attention in tropical montane cloud forests (TMCF), since secondary succession is common owing to episodic disturbances. We studied annual seed rain in 10 nearby forest stands, ≈7 to ≈100 y following shifting agriculture, and one primary forest stand in southern Mexico to test the hypothesis that seed rain is limited at the scale of neighbouring fragments and that such limitation differs among species with different dispersal modes and successional origin. Annual seed rain was heterogeneous among forest fragments probably due to the prevalence of local seed dispersal, differences in stand age and the proportion of zoochory, and may help explain the patchy distribution of species observed in TMCF. Seed rain abundance and species diversity per unit trap area increased with the age of the stand. Biotically dispersed seeds increased towards older stands relative to abiotically dispersed seeds. Late-successional seeds were rarer in early successional stands than pioneer seeds in late-successional stands, suggesting that long-distance dispersal is generally more common for pioneer plants. Seed dispersal appears to constrain forest regeneration and to influence fragment species composition as a function of the distance from the source forests.


2007 ◽  
Vol 29 (2) ◽  
pp. 181 ◽  
Author(s):  
L. I. López-Olmedo ◽  
J. A. Meave ◽  
E. A. Pérez-García

The magnitude of the biological differentiation between natural savannas and pastures (anthropogenic grasslands) coexisting in a single landscape, in terms of their floristic composition and community structure, was studied in the Nizanda region, Isthmus of Tehuantepec, Oaxaca State, southern Mexico. Vegetation samples of 15 m2 each were taken at 20 savanna and 11 pasture sites. Cover- and species richness-based diversity and dominance indices were calculated. Geomorphological and edaphic characteristics were also compared. Savannas generally occurred in hill summits with very shallow and stony, discontinuous and acidic soils; contrastingly, pastures were located in piedmonts and floodplains, with more neutral and less stony soils. Savanna sites differed from pasture sites in species richness and Shannon diversity. They did not differ in Simpson dominance index, but the identity of the dominant species was different in each community: Trachypogon spicatus (L.f.) Kuntze in savanna and Megathyrsus maximus (Jacq.) B.K.Simon et S.W.L.Jacobs in pasture. A low species-level similarity (Sørensen Index) was observed between them (8.2%), and genus-level similarity was only slightly higher (27.1%). The magnitude of the biological differentiation in both community floristics and structure between these two grass-dominated communities was larger than anticipated. Current management of savannas as pasture lands may potentially trigger a severe deterioration process involving both the landscape and its plant components.


Geoderma ◽  
2008 ◽  
Vol 144 (3-4) ◽  
pp. 593-612 ◽  
Author(s):  
G. Álvarez Arteaga ◽  
N.E. García Calderón ◽  
P.V. Krasilnikov ◽  
S.N. Sedov ◽  
V.O. Targulian ◽  
...  

Land ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1078
Author(s):  
Tarin Toledo-Aceves ◽  
Manuel R. Guariguata ◽  
Sven Günter ◽  
Luciana Porter-Bolland ◽  
Leticia Merino

Secondary cloud forests (SCFs), those that regenerate naturally following abandonment of human activities in previously deforested land, are of great value as refuges of high species diversity and for their critical role in hydrological regulation. This opinion paper analyzes the main environmental, socio-economic, and regulatory aspects that currently hamper the sustainable use and conservation of SCFs in Mexico for the provision of timber and ecosystem services. The main constraints identified include contradictory norms and policies and the marginalization of smallholders in timber production activities. Developing economic incentives for forest product harvesting and provision of ecosystem services derived from SCFs, while also addressing legal and normative aspects related to their sustainable use, is paramount. Given the high heterogeneity in floristic composition and stand structure of SCFs among localities, technical and social norms for sustainable use should be sufficiently flexible to allow adaptive management approaches. Future research areas should be focused on monitoring the response of SCFs to silvicultural interventions, documenting existing traditional practices as well as conducting socio-economic analyses of timber production and associated ecosystem services. This is essential for developing sound policies and approaches for the sustainable use and long-term management of SCFs in Mexico.


2015 ◽  
Vol 31 (6) ◽  
pp. 499-508 ◽  
Author(s):  
Margoth Acuña-Tarazona ◽  
Tarin Toledo-Aceves ◽  
Alejandro Flores-Palacios ◽  
Vinicio J. Sosa ◽  
M. Luisa Martínez

Abstract:The response of vascular epiphyte communities following natural or human disturbance has been little studied. Over 5 y, we evaluated the post-stripping recolonization of vascular epiphytes in cloud forest. Vascular epiphytes were experimentally removed from branch and trunk plots (1 m in length) on five trees in two secondary cloud forest fragments in southern Mexico. Similarity between colonizer and established communities was compared in each fragment using a further five trees with no stripping. All seedlings were recorded yearly. Non-vascular epiphyte cover was estimated in each plot. The recolonization rate was very high; after 5 y, epiphyte density of the colonizer community (27.4 ± 6.8 individuals per segment) reached similar values to those of the established community (26.7 ± 3.3) in nearby trees. While similarity (composition and abundance) between the colonizer community and established community was high (81%), diversity accumulation curves indicated that the colonizer community presents a lower diversity of epiphytes (5.5 equivalent species) than the established community (11.4). Colonization of xerophytic bromeliads was high, while pteridophytes and orchids presented reduced recovery. The immediately surrounding source of propagules had a strong influence on recolonization. In both the colonizer and established communities, dominance rank was bromeliads > peperomias > pteridophytes. The results show that the recovery capacity of epiphytic vegetation in secondary forest is high, if propagule sources are close by. However, at 5 y after disturbance, it is unclear whether the colonizer community would present the same species composition as the established community or if it would give rise to a different community.


2018 ◽  
Vol 96 (2) ◽  
pp. 200 ◽  
Author(s):  
Ezequiel Hernández-Pérez ◽  
Eloy Solano ◽  
Ramiro Ríos-Gómez

<p class="Standard1"><strong>Background</strong>: The host´s structural characteristics provide diverse microhabitats that influence the distribution patterns of the epiphytes at different vertical zones and among tree species.</p><p class="Standard1"><strong>Hypotheses</strong>: Epiphytic orchids have preference for larger host trees and with non-exfoliating rough bark, while the limiting hosts will be those of smaller size and smooth and exfoliating bark, and there will be fewer individuals in the upper canopy of the host trees because the micro-environmental conditions are more stressful compared to the middle and lower parts of the host trees.</p><p class="Standard1"><strong>Methods</strong>: The host preferences and vertical distribution<strong> </strong>of the epiphytic orchids were analyzed in 20 montane cloud forest fragments. In each fragment, two transects of 2 × 50 m were drawn, and the trees with a diameter at a breast height ≥ 20 cm were recorded. In each tree, basal area was quantified and bark texture was characterized. In each tree and vertical zone, the orchid species present were identified and quantified.</p><p><strong>Results</strong>: Orchid distribution patterns vary between vertical zones and host tree species, and the richness is related to host size and bark texture. The highest species richness and number of epiphytic orchid’s individuals were recorded in host trees with fissured bark and larger size. The distribution of orchids in the host was not homogeneous nor was it related to any particular host species. However, five trees species were considered as host preferred, while five tree species were limiting hosts. The highest richness was recorded in vertical zone II and the lowest in zones I and V.</p><p class="Standard1"><strong>Conclusions</strong>: Larger trees contain greater richness of epiphytic orchids, because they offer better conditions for their establishment, provide a great diversity of microhabitats, greater time and area for epiphytic colonization events. The texture of the bark is a relevant factor in the host preference, and in the hosts with smooth bark, the presence of epiphytic orchids depends on the accumulation of organic matter.</p>


2020 ◽  
Vol 153 (1) ◽  
pp. 12-21
Author(s):  
Derio A. Jiménez-López ◽  
Rubén Martínez-Camilo ◽  
Nayely Martínez-Meléndez ◽  
Michael Kessler

Background and aims – In the tropics, some studies have found that the richness of epiphytic ferns present a peak at mountain mid-elevations. However, it is not well understood how transitions from tropical to subtropical conditions affect this peak, and even less is known about beta diversity of epiphytic ferns. Thus, the objective is to understand the effect of climatic gradients on the variation of local richness of ferns and beta diversity patterns along an elevational gradient in a mountain system in southern Mexico.Methods – We sampled 32 trees, each in four elevational bands (100–2200 m). Alpha diversity patterns were analysed using linear regression models. We used the Morisita index to quantify species turnover between bands. An additive partitioning approach was used to analyse the degree to which individual trees, plots, and bands contributed to total species richness. We evaluated the influence of climatic variables on species composition via linear regression models.Key results – A total of 30 species in five families were recorded. Each family contributed in different magnitude to the elevational richness pattern, with Polypodiaceae dominating due to its richness and presence along the entire transect. Alpha diversity at the three scales (αtree, αplot, αband) increased with elevation and rainfall, and with decreasing temperature. Species turnover was high along the gradient, but was scale-dependent, with βtransect (65–75%) and βband (14%) with the greatest contributing to total diversity. Although the contribution of the individual trees was lower, it increased with elevation. Conclusions – We emphasize the importance of including different scale levels in analyses of diversity along elevational gradients. In the region, cloud forest on the mountain peaks harbours the highest diversity of epiphytic fern communities. Due to a limited extent of this mountain range, the epiphyte ferns are susceptible to the effects of climate change.


1995 ◽  
Vol 11 (4) ◽  
pp. 481-495 ◽  
Author(s):  
Nalini M. Nadkarni ◽  
Teri J. Matelson ◽  
William A. Haber

ABSTRACTThe Monteverde Cloud Forest Reserve protects a variety of primary montane forest communities on volcanic parent materials. We describe the structure and composition of the forest to provide background information for epiphyte and nutrient cycling studies and for comparison with other tropical montane forests. In a 4-ha study plot in leeward cloud forest, density of stems (2062 individuals ha−1 for stems >2 cm dbh, 555 individuals ha−1 for stems > 10cm dbh) and stem basal area (73.8 m2 ha−1 for stems >2 cm, 62.0 m2 ha−1 for stems >10 cm dbh) were high relative to other montane forests. Stems in a subset of the plot (c. 1/3 of the area) were identified and assigned to 47 families, 83 genera and 114 species, which is rich compared with other montane forests. Large stems had a higher spatial variability of structural and floristic characteristics than small stems.


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