**3. Results**

In general, the lower density of seedlings that emerged from the seed bank samples was observed in old-growth forests, while the highest density in seedlings emerged in agricultural areas (**Figure 1**). Seedling density in old-growth forests had less variability, with numbers varying between 94 and 913 seedlings per m2 (**Table 1**). In the other classes of land use, the density of seeds in the soil was found to be higher and had high variation (**Figure 1** and **Table 1**).

#### **Figure 1.**

*Seedling density (m2 ) emerged from the seed bank in different classes of land use. The vertical bar shows the standard deviation when cited. The datasets used are those described in table 1.*

#### **Figure 2.**

*The proportion of seedlings emerged from seed banks of the ten most abundant families according to different types of land use. A: Old-growth forests, with no evidence of anthropogenic changes in the last 60 years or more; B: Forest fragments with different historical changes; C: Forests with logging of wood species; D: Secondary forests with evidence of natural and anthropogenic changes; E: Agriculture areas.*

**75**

**Figure 3.**

*Ecology of the Seed Bank in the Amazon Rainforest DOI: http://dx.doi.org/10.5772/intechopen.94745*

The type of land use promotes changes in floristic composition (**Figure 2**). Melastomataceae seedlings predominated in all land uses, except for agricultural areas where Rubiaceae seedlings were the most abundant (**Figure 2**). Melastomataceae was represented by the following genera: *Aciotis*, *Adelobotrys*, *Bellucia*, *Clidemia*, *Henriettea*, *Leandra*, *Maieta*, *Miconia,* and *Tococa*. Urticaceae was the second most abundant family in the old-growth forests and the forests with logging of wood species. It was the third most abundant in forest fragments with different historical changes (**Figure 2**). Here, the following genera predominated: *Cecropia*, *Coussapoa,* and *Pourouma*, with only *Cecropia* occurring in agricultural areas and with low density. The families Dilleniaceae (*Davilla*, *Doliocarpus,* and *Tetracera*), Goupiaceae (*Goupia glabra* Aubl.), Moraceae (*Ficus*, *Bagassa*, *Helicostylis,* and *Maquira*), and Araceae (*Philodendron*) were present among the ten most abundant families, but only for old-growth forests (**Figure 2**). Hypericaceae seedlings, as represented by *Vismia* species, were among the ten most abundant families for all types of land use, except for agricultural areas, and, similar to Urticaceae, they occurred at low density (**Figure 2**). Cannabaceae seedlings represented an important component in forest fragments. It was represented by a single species, *Trema micranta* (L.) Blume, with wide distribution, and it serves as an indicator of degraded areas under anthropic use. The Piperaceae family was among the ten most abundant families in the category of intermediate change. It was absent from oldgrowth forests and agricultural areas. Cyperaceae and Poaceae were configured as a common component of altered areas. Poaceae, however, is not among the ten most abundant families for forests with logging of wood species. Solanaceae, as well as Rubiaceae, was present in all forest types; however, the latter had greater abundance in secondary forests and agricultural areas. Asteraceae (*Chromolaena*, *Rolandra*, and *Vernonia)* and Cyperaceae (*Cyperus*, *Rhynchospora*, and *Fimbristyllis*) had greater abundance in agricultural areas (**Figure 2**). Seedlings of Olacaceae (*Heisteria*) were among the ten most abundant families, but only for old-growth forests and forests with logging of wood species (**Figure 2**). Seedlings of Gentianaceae (*Coutoubea* and *Irlbachia*) were among the ten most abundant families, but only for forests with logging of wood species and agricultural areas. Muntingiaceae (*Muntingia*)

*The proportion of seedlings emerged from seed banks divided into life forms according to different types of land use.*

#### *Ecology of the Seed Bank in the Amazon Rainforest DOI: http://dx.doi.org/10.5772/intechopen.94745*

The type of land use promotes changes in floristic composition (**Figure 2**). Melastomataceae seedlings predominated in all land uses, except for agricultural areas where Rubiaceae seedlings were the most abundant (**Figure 2**). Melastomataceae was represented by the following genera: *Aciotis*, *Adelobotrys*, *Bellucia*, *Clidemia*, *Henriettea*, *Leandra*, *Maieta*, *Miconia,* and *Tococa*. Urticaceae was the second most abundant family in the old-growth forests and the forests with logging of wood species. It was the third most abundant in forest fragments with different historical changes (**Figure 2**). Here, the following genera predominated: *Cecropia*, *Coussapoa,* and *Pourouma*, with only *Cecropia* occurring in agricultural areas and with low density. The families Dilleniaceae (*Davilla*, *Doliocarpus,* and *Tetracera*), Goupiaceae (*Goupia glabra* Aubl.), Moraceae (*Ficus*, *Bagassa*, *Helicostylis,* and *Maquira*), and Araceae (*Philodendron*) were present among the ten most abundant families, but only for old-growth forests (**Figure 2**). Hypericaceae seedlings, as represented by *Vismia* species, were among the ten most abundant families for all types of land use, except for agricultural areas, and, similar to Urticaceae, they occurred at low density (**Figure 2**). Cannabaceae seedlings represented an important component in forest fragments. It was represented by a single species, *Trema micranta* (L.) Blume, with wide distribution, and it serves as an indicator of degraded areas under anthropic use. The Piperaceae family was among the ten most abundant families in the category of intermediate change. It was absent from oldgrowth forests and agricultural areas. Cyperaceae and Poaceae were configured as a common component of altered areas. Poaceae, however, is not among the ten most abundant families for forests with logging of wood species. Solanaceae, as well as Rubiaceae, was present in all forest types; however, the latter had greater abundance in secondary forests and agricultural areas. Asteraceae (*Chromolaena*, *Rolandra*, and *Vernonia)* and Cyperaceae (*Cyperus*, *Rhynchospora*, and *Fimbristyllis*) had greater abundance in agricultural areas (**Figure 2**). Seedlings of Olacaceae (*Heisteria*) were among the ten most abundant families, but only for old-growth forests and forests with logging of wood species (**Figure 2**). Seedlings of Gentianaceae (*Coutoubea* and *Irlbachia*) were among the ten most abundant families, but only for forests with logging of wood species and agricultural areas. Muntingiaceae (*Muntingia*)

#### **Figure 3.**

*The proportion of seedlings emerged from seed banks divided into life forms according to different types of land use.*

was configured among the ten most abundant families only for forest fragments, Icacinaceae (*Dendrobangia*) only for forests with logging of wood species and Verbenaceae (*Stachytarpheta*) and Ochnaceae (*Lacunaria*, *Ouratea* and *Sauvagesia*) only for secondary forests. Euphorbiaceae (*Croton*), Phyllanthaceae (*Phyllanthus*) and Molluginaceae (*Mollugo*) were also among the ten most abundant families, but only for agricultural areas (**Figure 2**).

Tree seedlings predominated in all types of land use in the seed bank, except for agricultural areas (**Figure 3**). Herbs increased in frequency according to land use, with a high proportion in the seed bank in agricultural areas. Despite the low proportion of seedlings classified as support-dependent plants (lianas, epiphytes, and hemiepiphytes) they still showed a higher proportion in the old-growth forests. In the seed bank of agricultural areas, a suppression of other life forms was observed (**Figure 3**). In the seed bank of forests with logging of wood species, shrubs decreased, while the proportion of tree seedlings increased.
