Quantitative ecology

Distribution of tree diameter in a specific stand provides basic information for forest management. Little attention is given to the use of probability distribution functions in characterising the stem diameters of most Nigeria indigenous species. This study used Three-parameters lognormal and Weibull probability distribution functions in characterising the diameter of Nauclea diderrichii plantations within a restricted tropical rainforest of Nigeria for sustainable management. Thirty temporary sample plots of dimensions 20 m × 20 m were randomly laid in three age strata (42, 43 and 46 years). Stem diameters of all living Nauclea diderrichii trees with diameter at breast height ≥10.0 cm in all the sampled plots were enumerated. The performance and suitability result revealed that lognormal distribution gave superior description of the stem diameter for the Nauclea diderrichii species in the study area, with least values of Bias (0.00001), Mean absolute error (0.1214), Mean square error (0.7421), Kolmogorov-Smirnov (0.02781) and Anderson Darling (0.49562) statistics. Hence, three-parameter lognormal using maximum likelihood method was recommended for distributing stem diameter of Nauclea diderrichii in the study area.

La clasificación numérica o análisis de conjuntos, cúmulos o conglomerados (”cluster analysis”) comprende una amplia variedad de técnicas de la estadística multivariada para ordenar entidades en grupos sobre la base de ciertos criterios establecidos. El libro se adentra de manera didáctica en las particularidades metodológicas de la clasificación en los estudios ecológicos, a través de la explicación de sus pasos fundamentales (análisis de datos, medidas de afinidad, métodos de agrupamiento e interpretación de las clasificaciones) y con numerosos ejemplos prácticos.

Validation of risk management tools for genetically modified plants in protected and sensitive areas in Italy" ( MAN-GMP-ITA), progetto LIFE+ NAT/IT/000334. Partner ENEA -Agenzia nazionale per le nuove tecnologie, l'energia e lo sviluppo economico sostenibile, Rotondella (MT); ISPRA -Istituto Superiore per la Ricerca e la Protezione Ambientale, Roma; ALMA MATER STUDIORUM -Università di Bologna, Dipartimento di Scienze e Tecnologie Agroambientali, Bologna; CRA-RPS -Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Centro di Ricerca per lo Studio delle Relazioni tra Pianta e Suolo, Roma; Consorzio In.Bio -Consorzio per la creazione di Incubatori di imprese innovative Biotecnologiche, Roma. Il presente volume è stato ottenuto da una rielaborazione del deliverable dell'Azione di progetto A3 -Report Conclusivo su "Measurement Endpoints, Monitoring and Statistical Methods". Responsabile dell'azione: Università di Bologna. Partner partecipanti: ENEA, ISPRA.

Mendonca VM, Al Jabri MM, Al Ajmi I, Al Muharrami M, Al Areimi M, Al Aghbari H. 2010. Persistent and expanding population outbreaks of the corallivorous starfish Acanthaster planci in the NW Indian Ocean: Are they really a consequence of unsustainable starfish predator removal through overfishing in coral reefs, or a response to a changing environment? Zool Stud 49(1):108-123.

Cited by WIKIPEDIA:
http://en.wikipedia.org/wiki/Crown-of-thorns_starfish#Population_outbreaks 

ABSTRACT: Population outbreaks of the starfish Acanthaster planci have been persisting for at least the past 25 yr on coral reefs in the Gulf of Oman, in the northwestern Indian Ocean. A survey conducted in 2001 showed that the A. planci population on the Dimaniyat Is. was as abundant (around 5 individual (ind.)/transect; equivalent to 100 ind./ha) as that recorded during an outbreak in the early 1980s. Local authorities are controlling starfish populations by culling relatively large adult individuals. These outbreaks cause considerable damage to coral communities, as observed specimens were adult individuals of about 60 cm in total diameter (no juveniles were observed). The situation has persisted for over 2 decades, and has now spread to coral reefs in the Arabian Gulf. Although A. planci population outbreaks were associated in the past with overfishing of starfish predators in coral reef areas, in the present study, we found no connection between this theory and starfish outbreaks, as stomach contents of carnivorous fish specimens likely to prey on this starfish species, caught on coral reefs on the Gulf of Oman, and sold at local fish markets (in Barka, Muscat, and Sur), showed no presence of A. planci in their diets. Therefore, the reason for A. planci population outbreaks could not have been due to overfishing of predator species, but is most likely to have been caused by the frequent input of nutrients, due to frequent upwelling events in the northwestern Indian Ocean, leading to planktonic blooms which thus enhance A. planci recruitment

Large faunal assemblages remain a concern in zooarchaeology. Without sufficiently large assemblages, interpretations about the past
are less secure. The number of potential taxa in an assemblage is related to various factors such as the number of species found in an
ecological zone, economic activities (hunting vs. farming) and taphonomy. In South Africa, no attempt has been made to determine
what constitutes a sufficiently representative assemblage size, yet animal remains are frequently utilised to infer aspects of human
behaviour during the past. We use faunal assemblages analysed using a standardised method, and we plot the number of taxa against
the number of identified specimens (NISP). This way, we are able to determine the asymptote point of a faunal assemblage. Our
initial study suggest that for subsamples, specifically those containing only large mammal remains, the asymptote is reached nearing
1000 NISP, whereas for those assemblages containing a full range of vertebrates and invertebrates, the asymptote is reached when the
NISP nears 2000. The assemblages used are from different ecological zones and vastly different time periods, and each has its own
taphonomic history. As a result, these asymptote points should not be considered as adequate samples for every faunal assemblage in
South Africa. Instead, we advocate that zooarchaeologists analyse the largest possible assemblage to ensure more reliable interpretations
are made from faunal remains. In many instances, only smaller assemblages are available; this is often beyond the control of the
zooarchaeologist. Nevertheless, our data suggest that often, assemblages are adequate in size for archaeological sites as a whole;
however, when comparisons are attempted between layers, occupational phases or spaces at a site, assemblage sizes are often severely
reduced, requiring caution when making inferences about the past.

Mendonca VM, Raffaelli DG, Boyle PR. 2007. Interactions between shorebirds and benthic invertebrates at Culbin Sands lagoon, NE Scotland: Effects of avian predation on their prey community density and structure. Sci Mar 71(3):579-591.

ABSTRACT: In the North Sea, during autumn-winter, intertidal flats often receive a massive influx of migratory shorebirds (wildfowl, waders and seabirds), which utilise the high prey densities that are available. The present study was conducted at Culbin Sands lagoon, NE Scotland, in 1994-1996, to investigate benthic invertebrate standing stock, and the energy flow from benthic invertebrates to shorebirds. Benthic invertebrate standing stock was estimated to be 500 kJ m-2 yr-1, and shorebird consumption efficiency to be 18% of the available standing stock. A series of manipulative field experiments were then conducted to test the effects of shorebirds on benthic invertebrate densities and community structure. Birds were excluded from caged areas (exclosures), and benthic invertebrate densities (total and by class size) in caged and uncaged areas were compared for each season separately. During autumn-winter, especially the gastropod Hydrobia ulvae and larger-sized (>15 mm) clams Macoma balthica were observed to be the most impacted species, being significantly more abundant in birdexclosures than in bird-accessed areas.

Declines in global biodiversity due to land conversion and habitat loss are driving a 'Sixth Mass Extinction' and many countries fall short of meeting even nominal targets for land protection. We explored how such shortfalls in Australia, Brazil and Canada might be addressed by enhancing partnerships between Indigenous communities and other government agencies that recognize and reward the existing contributions of Indigenous-managed lands to global biodiversity conservation, and their potential contribution to meeting international treaty targets. We found that Indigenous-managed lands were slightly more vertebrate species rich than existing protected areas in all three countries, and in Brazil and Canada, that they supported more threatened vertebrate species than existing protected areas or randomly selected non-protected areas. Our results suggest that overall, Indigenous-managed lands and existing protected areas host similar levels of vertebrate biodiversity in Brazil, Canada, and Australia. Partnerships with Indigenous communities that seek to maintain or enhance Indigenous land tenure practices on Indigenous-managed lands may therefore have some potential to ameliorate national and global shortfalls in land protection for biodiversity conservation using a mix of conventional protected areas and Indigenous-managed lands.

The Mediterranean region of Chile is considered a biodiversity hot spot. An increase in temperature and decrease in precipitation, as projected for the end of this century by global circulation models, would likely change the distribution of the sclerophyllous thorny shrubland and woodland. In order to assess those potential impacts, the MAXENT algorithm was used to project potential changes in the distribution of the Mediterranean ecosystem. Ecological niche models were fitted and used to project the potential distribution of these forest ecosystems by the end of the century. Projections were made using data from the PRECIS model for the A2 and B2 climate change scenarios and two strategies of occupancy: free migration and nonmigration. Distribution models of sclerophyllous, woodland and shrubland performed accurately representing current species' distribution. When we assume nonmigration responses under climate change scenarios, results reveal a decrease in the distribution area for all the species. The areas where the highest reduction in a suitable environment was found are located along the coastline, where higher temperature increases have been projected. For native ecosystems from the Andean Range region, such as communities dominated by thorny species, a stable habitat was found, associated with a higher adaptation capability to future climatic projections. Hence, in the future, buffer zones originated by ''topo-climatic'' conditions might play a key role in protecting Central Chile biodiversity.

Mendonca VM, Raffaelli DG, Boyle PR, Hoskins S. 2008. Spatial and temporal characteristics of benthic invertebrate communities at Culbin Sands lagoon, Moray Firth, NE Scotland, and impacts of the disturbance of cockle harvesting. Sci Mar 72(2):265-278.

ABSTRACT: In the present study, Culbin Sands lagoon, a protected site in NE Scotland, was surveyed every 2 to 4 weeks during a three-year period (1994-1996) to study benthic invertebrate communities. Beds of Mytilus edulis covered 18000 m2. 53 macroinfaunal species were identified outside these areas. The most conspicuous were: the lugworm Arenicola marina (mean up to 55 casts m-2); and bivalves Cerastoderma edule (mean up to 158 ind. m-2) and Macoma balthica (mean up to 79 ind. m-2) after settlement. The standing stock ranged from 20 to 32 g AFDW m-2 yr-1 respectively from more exposed to more sheltered areas. Most species showed a clear recruitment peak in autumn, but others (e.g. Capitella capitata, and Spionidae) displayed several peaks in a year. Communities were also compared between the sampling sites before and after an incidental disturbance caused by cockle Cerastoderma edule harvesting, which took place in June 1995. One site showed –0.7% variation in the total standing stock, but +22% for smaller-cockles, as larger filter-feeding cockles were removed therefore enhancing their own larval settlement. Polychaete Spionidae populations also increased after larger cockles were removed. The polychaete Arenicola marina population returned to its normal activities just after the dramatic disturbance of the sediment.

Mendonca VM, Al Saady SM, Al Kiyumi AA, Erzini KA. 2010. Interactions between green turtles (Chelonia mydas) and foxes (Vulpes vulpes arabica, Vulpes rueppellii sabaea, and Vulpes cana) on turtle nesting grounds in the northwestern Indian Ocean: Impacts of the fox community on the behaviour of nesting sea turtles at Ras Al Hadd Turtle Reserve, Oman. Zool Stud 49(4): 437-452.

ABSTRACT: Green turtles Chelonia mydas nest year round at the Ras Al Hadd Nature Reserve, Oman, with a distinct lower-density nesting season from Oct. to May, and a higher-density nesting season from June to Sept. On these beaches, the main predators of turtle eggs and hatchlings are foxes Vulpes spp., wolves Canis lupus arabs, and wild cats Felis spp. and Caracal caracal schmitzi. During 1999-2001, both the nesting behavior of these turtles and the diets of foxes (the main predator on the beaches) were investigated, and we tested whether female turtles were able to avoid/reduce predation pressure on their eggs and hatchlings on the nesting grounds. Elsewhere in the region and globally, foxes are known to feed on rodents, lizards, birds, and insects, but at Ras Al Hadd, their diet is basically composed of sea turtle eggs and hatchlings (comprising about 95% in volume), with smaller contributions from other marine invertebrates (mostly ghost crabs Ocypode spp. and large gastropods), although they also sporadically ingested birds and lizards. The ability to adapt to a diet of sea turtle eggs and hatchlings, on these beaches, is certainly a factor behind the success of this carnivore community in the arid lands of the Arabian Peninsula. Field experiments indicated that nesting sea turtles recognized both natural predators and humans as threats to their offspring, and this was reflected in modifications to their nesting behavior. In relatively undisturbed areas (by both natural predators and humans), sea turtle nest density was significantly higher, and nests were placed further away from the surf ’s edge, in contrast to results from relatively disturbed areas, where turtle nests were closer to the surf ’s edge, thus reducing the distance hatchlings had to travel when they emerge and begin their journey to the sea. Nesting turtles interrupted their nesting cycle if they sensed the presence of people or foxes, returning to the sea without laying a clutch. However, if they had already initiated oviposition when they sensed the presence of people and/or predators, they continued, although they significantly increased efforts to camouflage their nests. Other reasons behind nest site abandonment included sand collapsing events (critical during preparation of the egg chamber) and intraspecific competition for nest sites. These behavioral patterns of sea turtles result from their evolutionary adaptation to nesting on beaches, which surely played a role in their survival, but also highlight the importance of minimizing human disturbance and activities on turtle nesting beaches.

An ever-growing number of IBMs have been developed by modellers, who aim to aid practitioners and inform a range of issues related to conservation, natural resource management, wildlife management and human socio-economic activities. The range of practitioners using IBMs to inform their decision-making processes include statutary authorities with responsibilities in environmental and natural resource management, non-governmental organizations such as conservation charities, and those interested in the sustainable use of natural resources. Thanks to advances in computational power, data availability and ecological theory, increasingly complicated, sophisticated IBMs can be produced. Yet this does not mean that these models will be more useful in informing environmental decision-making. IBMs typically require specialist computational knowledge to build and refine the model, and analyse the model outputs, and so practitioners are unlikely to have the requisite skills to use IBMs directly. Conversely, practitioners may have greater knowledge of the system being modelled, so their input into the modelling process is highly desirable. Thus, it is important that modellers and practitioners collaborate effectively to develop models which can address the key questions that practitioners are interested in. In this paper we highlight the uses of IBMs in environmental decision-making, identify potential obstacles to their successful use, and discuss how such obstacles can be overcome. We aim to help practitioners understand the potential benefits of IBMs, and to help modellers to understand how to develop IBMs which will better aid practitioners and inform environmental management and policy. We refer to a coastal bird IBM case study, from which general lessons can be learned.

"Mendonca VM, Raffaelli DG, Boyle PR, Emes C. 2007. The ecological role of overwintering fish in the food web of the Culbin Sands lagoon ecosystem, NE Scotland: Identifying major trophic links and testing effects of fish Pomatoschistus microps (Pallas) on benthic invertebrates. Sci Mar 71(4):649-660.

ABSTRACT: The Culbin Sands lagoon ecosystem in NE Scotland was studied during a three-year period (1994-1996) to identify the major trophic links from benthic invertebrates to epibenthic predators, and to assess impacts of overwintering fish on their prey communities. Every 2-4 weeks, samples of mobile fauna were collected to study their diets. The major trophic links identified between benthic invertebrates and epibenthic predators were from benthic invertebrates to the shrimp Crangon crangon, and to the common goby Pomatoschistus microps and the plaice Pleuronectes platessa. The energy flow from benthic invertebrates to overwintering fish was estimated at 133 kJ m–2 yr–1. A flow of 10 kJ m–2 yr–1 was also observed from eggs and larval stages of the overwintering shrimp Crangon crangon to the overwintering fish. Nevertheless, manipulative field experiments showed no significant impacts of the most abundant overwintering fish Pomatoschistus microps on prey community densities, despite an overall individual ingestion rate of 89 J day–1.

Mendonca VM, Raffaelli DG, Boyle PR, Emes C. 2009. Trophodynamics in a shallow lagoon off NW Europe (Culbin Sands, Moray Firth): Spatial and temporal variability of epibenthic communities, their diets, and consumption efficiency. Zool Stud 48(2):196-214.

ABSTRACT: Epibenthic communities and their diets, at Culbin Sands (a cold-temperate coastal lagoon in the Moray Firth, northeastern Scotland), were sampled every 2-4 wks for 3 yrs (1994-1996). These communities were more abundant and diverse in warmer months, especially in less-exposed areas of the lagoon. The most common species were the brown shrimp Crangon crangon, the shore crab Carcinus maenas, and teleost fish (sandeel Ammodytes tobianus, sticklebacks Gasterosteus aculeatus and Spinachia spinachia, seascorpion Myoxocephalus scorpius, gobies Pomatoschistus microps and Pomatoschistus minutus, flounder Platichthys flesus, and plaice Pleuronectes platessa). Diets of these epibenthic predators included benthic infauna (especially polychaetes Eteone longa, Pygospio elegans, and Fabricia sabella; oligochaetes Tubificoides benedini; isopods Eurydice pulchra; and bivalves Cerastoderma edule and Macoma balthica), small epibenthic organisms (amphipods especially Bathyporeia pilosa and Gammarus sp., and juvenile crabs Carcinus maenas and shrimp Crangon crangon), and zooplankton (harpacticoids, ostracods mostly Cypris sp., calanoid copepods, mysids Praunus flexuosus, and fish eggs and larvae). Insect larvae (Chironomidae) were also common in the stomach contents of the epibenthic predators. In fact, prey items with higher indices of relative importance for the most abundant predators (brown shrimp, common gobies, and plaice) were insect larvae for shrimp, amphipods Bathyporeia pilosa for shrimp and gobies, harpacticoids for plaice and gobies, and bivalves (larvae and siphons of adult individuals) mostly for plaice. Brown shrimp, common goby, and plaice had daily consumption levels of 1%, 3%, and 2.5% of their own body wet weights, respectively. Energy flows of 150, 68, and 65 kJ m-2 yr-1 were estimated from benthic invertebrates to brown shrimp, common gobies, and plaice, equivalent to consumption efficiencies of 30%, 15%, and 15%, respectively, of the standing stock of benthic invertebrates and small epibenthic species such as amphipods.

The present study was conducted in the Badrinath holy pilgrimage in Western Himalaya. Lichen collected from seven localities (Badrinath, enroute Bhimpul to Vasudhara, Mana, enroute Vasudhara to Mana, Bhimpul, Vasudhara Glacier and enroute Vasudhara to Bhagirathi Glacier). The highest overall IVI (6.64) was recorded for Rhizoplaca chrysoleuca. The maximum number of lichens have been documented in Badrinath locality (139 spp.) while minimum (6) in enroute Vasudhara to Bhagirathi Glacier. The Badrinath has also express maximum 71 site specific species, while the Vasudhara Glacier has only 2 species. The dominance has been computed maximum (0.17) for enroute Vasudhara to Bhagirathi Glacier while, minimum for the Badrinath (0.01). The lowest Simpson Index value (0.83) has been recorded in enroute Vasudhara to Bhagirathi Glacier while the highest (0.99) in Badrinath. The lowest value of Berger-Parker diversity index (0.03), as well as the highest values of Brillouin, Shannon, Menhinick, Margalef and Fisher alpha diversity indices (7.20, 4.78, 8.03, 24.2 and 100.6 respectively) from the Badrinath locality, designates it as a site of highest species diversity. While enroute Vasudhara to Bhagirathi Glacier locality shows the highest value of Berger-Parker diversity index (0.17) as well as the lowest values of Brillouin, Shannon, Menhinick, Margalef and Fisher alpha diversity indices (1.75, 1.79, 0.35, 0.88 and 1.03 respectively). The value of evenness and equitability has been computed maximum (1.00) for enroute Vasudhara to Mana and Vasudhara to Bhagirathi Glacier localities, on the other hand, minimum (0.086 and 0.97 respectively) in the Badrinath.

Changes in climate, food abundance and disturbance from humans threaten the ability of species to successfully use stopover sites and migrate between non-breeding and breeding areas. To devise successful conservation strategies for migratory species we need to be able to predict how such changes will affect both individuals and populations. Such predictions should ideally be process-based, focusing on the mechanisms through which changes alter individual physiological state and behavior. In this study we use a process-based model to evaluate how Black Brant (Branta bernicla nigricans) foraging on common eelgrass (Zostera marina) at a stopover site (Humboldt Bay, USA), may be affected by changes in sea level, food abundance and disturbance. The model is individual-based, with empirically based parameters, and incorporates the immigration of birds into the site, tidal changes in availability of eelgrass, seasonal and depth-related changes in eelgrass biomass, foraging behavior and energetics of the birds, and their mass-dependent decisions to emigrate. The model is validated by comparing predictions to observations across a range of system properties including the time birds spent foraging, probability of birds emigrating, mean stopover duration, peak bird numbers, rates of mass gain and distribution of birds within the site: all 11 predictions were within 35% of the observed value, and 8 within 20%. The model predicted that the eelgrass within the site could potentially support up to five times as many birds as currently use the site. Future predictions indicated that the rate of mass gain and mean stopover duration were relatively insensitive to sea level rise over the next 100 years, primarily because eelgrass habitat could redistribute shoreward into intertidal mudflats within the site to compensate for higher sea levels. In contrast, the rate of mass gain and mean stopover duration were sensitive to changes in total eelgrass biomass and the percentage of time for which birds were disturbed. We discuss the consequences of these predictions for Black Brant conservation. A wide range of migratory species responses are expected in response to environmental change. Process-based models are potential tools to predict such responses and understand the mechanisms which underpin them.

The Mediterranean region of Chile is considered a biodiversity hot spot. An increase in temperature and decrease in precipitation, as projected for the end of this century by global circulation models, would likely change the distribution of the sclerophyllous thorny shrubland and woodland. In order to assess those potential impacts, the MAXENT algorithm was used to project potential changes in the distribution of the Mediterranean ecosystem. Ecological niche models were fitted and used to project the potential distribution of these forest ecosystems by the end of the century. Projections were made using data from the PRECIS model for the A2 and B2 climate change scenarios and two strategies of occupancy: free migration and non-migration. Distribution models of sclerophyllous, woodland and shrubland performed accurately representing current species' distribution. When we assume non-migration responses under climate change scenarios, results reveal a decrease in the distribution area for all the species. The areas where the highest reduction in a suitable environment was found are located along the coastline, where higher temperature increases have been projected. For native ecosystems from the Andean Range region, such as communities dominated by thorny species, a stable habitat was found, associated with a higher adaptation capability to future climatic projections. Hence, in the future, buffer zones originated by ''topo-climatic'' conditions might play a key role in protecting Central Chile biodiversity.

Understanding patterns in plant and herbivorous insect diversity across spatial and temporal scales is fundamental to ecology, but comparative multi-taxonomic studies in tropical seasonally dry forests remain scarce. In 36 sites, distributed over three forest age classes (5-10 y, 10-30 y, >100 y) and three seasonal forest types (dry, intermediate, humid), we sampled plants of different stem diameter classes while caterpillars were sampled across vertically distributed forest layers during three seasons over the year. We recorded 299 plant species and 485 caterpillar morphospecies. For large woody plants, species numbers showed a gradually increasing trend with forest age in the intermediate and humid forest types, while the main portion of explained variation in overall species turnover was accounted for by the forest type × forest age interaction (21.3-23.1% of 44.4-48.7%). Ordinations and multivariate pairwise comparisons suggested a faster but also very distinct successional development of species diversity of large plants in the driest compared with humid and intermediate forest types. In contrast, highest species numbers of small plants in the undergrowth was often found in the 5-10 y-old vegetation across forest types, whereas forest type was the major factor in overall species turnover (contributing 24.2% of 48.7% explained variation). Caterpillar species turnover was most correlated to species turnover of small plants; however, variation in caterpillar species diversity appears to be mostly regulated by seasonal cues, and to a lesser extent by patterns of regional turnover and local diversity of undergrowth plant species.

The present study was conducted in the Badrinath holy pilgrimage in Western Himalaya. Lichen collected from seven localities (Badrinath, enroute Bhimpul to Vasudhara, Mana, enroute Vasudhara to Mana, Bhimpul, Vasudhara Glacier and enroute Vasudhara to Bhagirathi Glacier). The highest overall IVI (6.64) was recorded for Rhizoplaca chrysoleuca. The maximum number of lichens have been documented in Badrinath locality (139 spp.) while minimum (6) in enroute Vasudhara to Bhagirathi Glacier. The Badrinath has also express maximum 71 site specific species, while the Vasudhara Glacier has only 2 species. The dominance has been computed maximum (0.17) for enroute Vasudhara to Bhagirathi Glacier while, minimum for the Badrinath (0.01). The lowest Simpson Index value (0.83) has been recorded in enroute Vasudhara to Bhagirathi Glacier while the highest (0.99) in Badrinath. The lowest value of Berger-Parker diversity index (0.03), as well as the highest values of Brillouin, Shannon, Menhinick, M...

Understanding patterns in plant and herbivorous insect diversity across spatial and temporal scales is fundamental to ecology, but comparative multi-taxonomic studies in tropical seasonally dry forests remain scarce. In 36 sites, distributed over three forest age classes (5-10 y, 10-30 y, >100 y) and three seasonal forest types (dry, intermediate, humid), we sampled plants of different stem diameter classes while caterpillars were sampled across vertically distributed forest layers during three seasons over the year. We recorded 299 plant species and 485 caterpillar morphospecies. For large woody plants, species numbers showed a gradually increasing trend with forest age in the intermediate and humid forest types, while the main portion of explained variation in overall species turnover was accounted for by the forest type × forest age interaction (21.3-23.1% of 44.4-48.7%). Ordinations and multivariate pairwise comparisons suggested a faster but also very distinct successional development of species diversity of large plants in the driest compared with humid and intermediate forest types. In contrast, highest species numbers of small plants in the undergrowth was often found in the 5-10 y-old vegetation across forest types, whereas forest type was the major factor in overall species turnover (contributing 24.2% of 48.7% explained variation). Caterpillar species turnover was most correlated to species turnover of small plants; however, variation in caterpillar species diversity appears to be mostly regulated by seasonal cues, and to a lesser extent by patterns of regional turnover and local diversity of undergrowth plant species.