Introduction

The state of Tabasco has been exposed to the processes of economic development, whose results highlight the social impoverishment, ecological deterioration and marginalization. Projects like Plan Chontalpa have caused irreparable destruction of ecosystems in the area, eliminating flora and fauna ^{Murillo (2004)}. Similarly to oil development in Tabasco, the flooded low lands were viewed as an obstacle to economic progress ^{Zavala (1988)}. This has resulted in a loss of about 50% of wetlands due to high rates of deforestation, which coincides with the highest levels of marginalization from the Gulf of Mexico (^{Seingier et al., 2009}; ^{Landgrave and Moreno-Casasola, 2012}).

Mangroves are coastal ecosystems that provide tangible and intangible services to society such as coastal protection, carbon sequestration, biological filters, soil retention; timber, firewood, charcoal; breeding and development of aquatic species of commercial value; nesting, rest, hanger, feeding, shelter and reproduction areas of migratory and resident birds; among others. However, these ecosystems have been anthropogenically altered and modified, where its surface reduction or fragmentation causes disruption of ecological processes, which affects their productivity, their balance, and the provision of human satisfaction.

Due to mangroves are coastal ecosystems that grow in tropical and subtropical latitudes around the world, the impact from climate change will have ecological, economic and social significance on these ecosystems, at structural level and in ecological functions (^{Yañez-Arancibia, 2010}). However, despite their ecological and economic importance, it is still threaten and deforested to promote economic development in the country, coupled to marginalization conditions from coastal communities lead to land use change which in most cases impact in double poverty, environmental and social, due to physic-chemical alteration in soil chemistry. ^{Zaragoza et al. (2005)} reported that mangrove areas are reduced at an annual rate of 2% for the Pacific slope, and 2.8% for the Gulf of Mexico.

NOM-022-SEMARNAT-2003, states that in those areas where degradation or desertification process, or serious ecological imbalances are present, the Ministry of Environment and Natural Resources (SEMARNAT) shall develop and implement ecological restoration programs to recover and restore conditions that favor evolution and continuity of natural processes therein developed (title 2, chapter II, article 78). In this regard, by presidential decree in 2001, the National Forestry Commission (CONAFOR) was instituted as a decentralized body from SEMARNAT thereafter this instance manages and promotes reforestation programs across the country (^{Cervantes et al., 2008}).

^{Gonzalez Maya et al. (2012)} cite that ecological restoration based on reforestation programs has been one of the most applied alternatives in Latin America, although it´s real scope and achievements are unknown. In the specific case of Mexico ^{Céspedes-Flores and Moreno-Sánchez (2010)}, believe that restoration processes are slower to the speed with which natural resources are lost.

To minimize and mitigate the impacts of climate change, it should intensify efforts in restoration-rehabilitation and incorporate them in strategic environmental planning of coastal areas (^{Yáñez-Arancibia et al., 2010}). In this sense, ^{Lewis (2005)} suggests that it is possible to reverse the loss of mangrove forests worldwide through the application of basic principles of ecological restoration, using ecological engineering approaches.

In Tabasco, the National Forestry Commission (CONAFOR) has funded conservation and restoration programs, through the Pro-Arbol program providing support for the implementation of reforestation projects (^{DOF, 2008}). However, there are vulnerable sites to coastal erosion bordering the Gulf of Mexico, where it is urgent to recover mangrove; but the support granted for reforestation do not reflect tangible results or do not meet the goals.

Therefore, and considering that coastal communities are the most vulnerable to the effects of climate change and the measures taken should not be generalizable from one region to another, it is urgent to undertake actions to make more efficient reforestation activities in mangroves from the coast of Tabasco. For this reason, it is necessary to develop a comprehensive diagnosis that allow to define the causes that prevent reforestation programs to be carried out successfully, generating proposals for improvement in its planning and execution. Thus the hypothesis of this study was that the planning and implementation of reforestation programs have weaknesses which limit the recovery of deforested mangrove areas on the coast of Tabasco.

Objective

Analyze the planning and implementation of reforestation programs in mangrove areas from two ejidos, in Cárdenas, Tabasco.

Materials and methods

Study area

The study area is located in the municipality of Cárdenas, Tabasco. In the Ejidos El Alacran located between 18º 21' 0” and 18° 23' 20"north latitude and between 93° 35' 10" and 93º 42' 10"west longitude; and El Golpe located between 18º 18' 20 "and 18º 20' 40" north latitude and between 93° 28' 50"and 93º 31' 50" west longitude; around the La Machona lagoon , which connects to the Gulf of Mexico through an artificial estuary known as Boca de Panteones (Figure 1).

Figure 1 Study area composed by Ejidos El Golpe and el Alacran from the municipality of Cárdenas, Tabasco. 

In the surroundings are located installations and pipelines for oil extraction and driving, where the waste resulting from the mobilization of crude oil has as final destination the coastal lagoon ecosystems Carmen-Machona, Mecoacan, and Tonala River (^{Jacott et al., 2011}). The study area is part of the coastal wetlands of Tabasco, where the predominant vegetation is mangrove associated to estuarine conditions (^{Barba et al., 2006}); the species are Avicennia germinans (black mangrove), Rhizophora mangle (red mangrove), and Laguncularia racemosa (white mangrove); which grow on two soil groups Histosols and Solonchaks (^{Domínguez Domínguez et al., 2011}). The ejido el Alacran has a direct connection to the sea, and is considered an area of high vulnerability due to the extent of coastal erosion, with an estimated coastal retreat of -9 to-10 m year (^{Hernández et al., 2008}). The ejido has 871 inhabitants with 208 houses inhabited; 43.65% of the population aged 15 and over have completed elemental school, and the level of poverty is high (^{CONAPO, 2010}).

Ejido el Golpe experienced an increase in mangrove area, from 1995 to 2008, caused by saltwater intrusion that favored the colonization of mangrove in areas devoted to livestock, as reported in the article from Chapter II; for the same period estimated a loss of 22.6 ha. The ejido has 1187 inhabitants and 335 houses inhabited; 33.10% of the population aged 15 and over have not completed elementary school; and the level of poverty is high (^{CONAPO, 2010}). The main economic activities in the area in order of importance are: fishing, logging of white mangrove, livestock, and to a lesser extent agriculture. This research was conducted from 2011-2012, in which two stages were considered: analysis of planning of the Pro-Arbol Program 2009 from CONAFOR, and the analysis of its implementation.

Results

Discussion

Gathered information allows glimpsing two scenarios; the first refers to the non-strategic program planning, and the second to the stagnation of its implementation at the stage of resource allocation. Such a scenario, invites to thing on the procedure that was conducted to meet the goals. The dissemination of an open call leads to misinterpretation by the population, as it usually when it comes to economic resource there is a demand not because they consider that their land is required to reforest, but because they are aware that they are unclaimed funds and as such they do not have to return them. Also, the selection criteria is very general, and does not consider previous studies that allow to generate a diagnosis of areas to be reforested; since the causes of mangrove deforestation are varied and the degree of damage is manifested in different levels (^{Sol et al., 2002}), it is necessary to count with geographic information that highlights the sites according to the degree of damage and the causes that originated it.

In the study area the self-regeneration of white mangrove benefited 68% of the surface, indicating that the damage was not severe and therefore the site retained the conditions for the ecosystem to recover naturally. Such conditions would have been identified through a previous diagnosis, and therefore scarce resource could have been destined to deforested areas that by themselves would not be possible to regenerate. ^{Gálvez (2002)} proposes five ecological restoration mechanisms: secondary succession, reforestation, introduction of species, species reintroduction, translocation, and biological corridors. In this sense ^{Agraz-Hernández and Flores-Verdugo (2004)} mention that reforestation remains the dominant activity to restore mangrove, and this may be: direct with propagules, nursery seedlings, and the combination of both.

However, for better decision-making in the design of restoration projects, it is necessary to generate scientific information that provides tools to define main goals (^{González-Maya et al., 2012}). ^{Sol et al. (2002)} suggest five priority activities in the restoration process: 1) identification of the area to be restored; 2) definition of the restoration strategy; 3) establishment of plots; 4) maintenance and periodic evaluation; and 5) field data restoration indicators. For a successful restoration of mangroves, ^{Lewis (2006)} proposes six steps: 1) understand the auto-ecology of mangrove species on site; 2) understand the hydrology; 3) evaluate environmental modifications that prevent natural secondary succession; 4) design the restoration program; 5) carry out seeding with propagules, collected seedlings or cultivated; and 6) monitor and reports of success (for 5 years). Unfortunately in the case of the Pro-Arbol program planning and implementation revolves around step 5; i.e. the production of plants in nurseries and transplant.

In the study area the amount allocated was determined according to budget availability (US $94.68 ha^-1); but it is important to note that restoration costs are in function of the goals to be attained, so from here is the need to count with the design of a program to estimate the required financial amount. In this sense, in the area there are already successful experiences through special projects, in which 50 ha of black mangroves were reforested with a cost of US $ 3 945.60 ha^-1, where activities such as sanitation, dredging, soil conservation works, restoration of ridges, support staff training, plants production, transplant, and monitoring have been made (^{Ejido las Coloradas, 2012}).

In Thailand it is estimated that mangrove reforestation amounts to US $ 946 ha^-1 (^{Astralaga, 2006}). In the Philippines when reforestation is made with community support the costs can be relatively low US $ 211 ha^-1 (^{Walton et al., 2006}); however, when considered preliminary and maintenance activities, these can reach US$ 1 156.52 ha^-1 (^{Fernández et al., 2007}). In Vietnam reforestation costs are US $990.96 ha^-1 (^{IFRC, 2011}). The willingness of island countries to invest in reforestation, is because they have found that the loss of mangroves areas places them in vulnerable conditions before the impact of hurricanes, tsunamis, cyclones, etc., which has resulted in higher social and economic costs. In this regard ^{Fernández et al. (2007)} concluded that the benefits of mangrove reforestation projects outweigh its costs.

Faced with the loss of mangrove, the coasts of Mexico will erode easily and would be exposed, defenseless to the severity of hurricanes and tsunamis, storms and rains (^{Ezcurra et al., 2009}). These scenarios are already visible on the coast of Tabasco, where the ejido el Alacran has lost its road infrastructure, housing, schools and productive areas due to the intrusion of sea to the mainland; which has resulted in a migration of the affected population to safer areas, affecting population density, unemployment and the increase of urban poverty. The latter should be one of the conditionings to allocate government spending to reforestation / restoration programs, and in this case to avoid anthropogenic threats that put at risk the ecosystem in pursuit of economic development. ^{Madrid (2011)}, mentions that when public money is invested in strategies to modify deforestation trends in the long run, the benefits are much more durable and social costs will be likely less.

Other determining factors for the success of mangrove reforestation is the socioeconomic status of beneficiaries whose conditions of high marginalization leads them to use their economic resources to meet priority needs, this coupled with the lack of knowledge of program guidelines, followed by commitment made with CONAFOR. Having into account the socioeconomic conditions of the beneficiaries is understood that mangrove reforestation in their land does not represent a priority, as it does not allow them to obtain income such as in the case of agricultural crops that establish more by habit than for profitability, but in which see a way to meet some of their basic needs. In this regard ^{Ramirez et al. (2010)} mention that the biggest problem to restore the mangroves is land availability. Also, in cases where it is accepted to allocate land for reforestation it is important to consider that there is a possibility that at some point that surface can be inherited or sold, because although the reform of article 27 from the Constitution has not reversed the process of land fragmentation (^{García, 2009}), which does not guarantee that the ecosystem can be fully restored, since fragmentation is behind the land use change.

Another important factor to consider is that technicians responsible for monitoring the reforestation process must have specific knowledge of mangrove, and therefore count with proper certification. Similarly, the number of beneficiaries assigned to be assessed by a technician must not exceed its capacity to meet its commitments for assessment; for which should consider assess surface, and time required to move from one place to another; according to the statement by the beneficiaries it is very common its absence in the field, and in some cases besides the payment they received through CONAFOR also charges a fee to the beneficiary; this coupled with beneficiaries not having experience in mangrove reforestation, reduces the interest of fulfilling the commitment made.

In El Salvador was identified that one of the main causes of reforestation failure is that local actors were not involved in the planning process, which should be one of the first steps (^{FIAES, 2011}), just as it happened in this study. Such scenarios make clear that the restoration is not an issue that can be met only by a sector and discipline; restoration is eminently interdisciplinary and multisector (^{Cervantes et al., 2008}).

Conclusions

There are weaknesses in planning and implementing the reforestation program Pro-Arbol, mainly due to:

Absence of scientific criteria to select areas for reforestation.

Lack of a methodological design for interdisciplinary restauration, which include monitoring till a stage that ensures reforestation success.

Lack of community integration during program planning and its willingness to carry out implementation.

The generality of the call promotes the participation of people who have no interest in doing reforestation.